Theses and Dissertations Collection

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Diversity and temporal fluctuations in abundance of rodents, shrews and their flea- ectoparasites in an extensive agricultural landscape of Mgeta division, Morogoro region, Tanzania
(Sokoine University of Agriculture, 2024-05) Chonde, Constance Chisala
Rodents and shrews play an important role in a variety of ecosystems including crop farming and the keeping of food animals. Increasing cultivation of crops and livestock keeping in Mgeta division, along the western slopes of Uluguru Mountain, is threatening the survival of rodents and shrews, and consequently, changes in the likelihood of these animals in their disease transmission patterns, which involves also their ectoparasites, particularly fleas, due to changes in their abundance and distribution in the ecosystem. This study was conducted from December 2021 to May 2022, and intended to investigate the diversity and temporal fluctuations in abundance of rodents, shrews and their flea- ectoparasites in Mgeta, an area with extensive agriculture in south- east Tanzania. Three habitats (forest, fallow and cultivated lands), each, were selected and defined as low (1,100 - 1,500 m a.s.l) and high (1,600 - 1,900 m a.s.l) elevations and subsequently sampled for rodents, shrews and their flea-ectoparasites. Removal trapping with baited live Sherman®, Harvahart® and locally made traps was carried out. A total of 192 rodents and 15 shrews were captured, and 199 fleas were collected. Identification of the rodents, shrews and fleas was done up to their species levels. Captured rodents included: Rattus rattus (1.45%), Mastomys natalensis (9.66%), Beamys hindei (1.45%), Lophuromys flavopunctatus (21.74%), Lophuromys kilonzoi (2.42%), Praomys delectorum (40.58%), Grammomys ibeanus (8.7%), Graphiurus murinus (1.45%), Mus minutoides (3.38%), Mus musculus (1.45%) and Dasmys spp (0.48%), whereas, the shrew species included: Crocidura olivieri (3.86%) and Crocidura hirta (3.38%). A Total number of 95 (45.89%) rodents and 6 (2.8%) shrews were infested by Dinopsyllus lypusus, Nosopsyllus fasciatus or Ctenopthalmus calceatus. The mean abundance of fleas presented a significant variation among the host species (F (12, 194) = 11.82, P < 0.001), habitats (F (2, 204) = 9.935, P < 0.001) and along the elevation gradient (F (1, 205) = 10.15, P = 0.02). Similarly, the prevalence varied significantly between the hosts (F (12, 194) = 22.44, P < 0.001) and habitats (F (2, 204) = 4.837, P = 0.009) but not with elevation (F (1, 205) = 0.291, P = 0.59). The mean intensity of flea infestation, on the other hand, varied significantly among the hosts (F (12, 194) = 9.257, P < 0.001) and along the elevation gradient (F (1, 205) = 47.91, P < 0.001), but not habitats (F (2, 204) = 0.75, P = 0.474). Furthermore, while rainfall intensity was strongly associated with mean abundance of fleas (r = 0.054, P < 0.05), neither temperature, elevation, nor humidity were correlated with either mean intensity or prevalence of fleas on the hosts. However, rainfall, temperature, and relative humidity had a significant effect on rodent and shrew abundance (P< 0.05). Given the discovery of D. lypusus, which is a well-known vector of the plague pathogen, Yersinia pestis, and a common ectoparasite of M. natalensis and R. rattus. Effective conservation strategies to preserve the remainder forest patches and community awareness programs regarding the existence of potential plague vectors and mitigation measures in the study area as well as avoidance mechanism should be implemented to ensure the health of the entire ecosystem.
Prevalence of parasites in silvery mole rats in Morogoro region, Tanzania
(Sokoine University of Agriculture, 2024-05) Shija, Debora Elias
The silvery mole rat (Heliophobius argenteocinereus) is a subterranean rodent with a wide distributional range throughout Sub- Saharan Africa. They are herbivores feeding on underground organs of a variety of plants. Despite being used as a source of protein by some local communities in Africa, the rats have been reported to host several parasites. However, the status of the parasites infesting/infecting silvery mole rats in Tanzania has not been well studied. Exploring the ectoparasites and endoparasites species diversity in silvery mole rats opens up a fascinating avenue for understanding the intricate relationships between these underground-dwelling mammals and their parasites. It is intriguing to consider the potential threat for transmission of parasitic zoonoses between humans, livestock, and silvery mole rats due to the notable interactions in the environment. Consequently, the key aim of this study is to acquire crucial information about the ectoparasites and endoparasites in silvery mole rats in the Morogoro region, Tanzania. A survey to establish the status of ectoparasites and endoparasites in silvery mole rats was conducted in Mlali (Mlali, Mkuyuni, Mongwe and Kipera villages) and Mji mkuu wards of Mvomero and Morogoro urban districts in Tanzania, from March to June 2023. Silvery mole rats were collected manually using hand hoes excavation from their burrows in agroecological areas. The captured rats were euthanized using Diethyl Ether, ectoparasites were collected from animal fur, blood samples were collected directly from the heart, and GIT contents were collected by flushing the GIT using physiological saline after opening of the abdominal cavity. During postmortem adult worms found inside the tract and around the pelvic, thoracic, and abdominal cavities were collected and preserved in 70% ethanol. The collected ectoparasites were fixed in a series of alcohols, cleared in xylene, and mounted on microscopic slides. A flotation method was adopted for processing gastrointestinal contents, and the recovered adult helminths were processed by using lactophenol mounting techniques for nematodes and aceto-carmine staining techniques for cestodes. For hemoparasites detection, the blood and impression smears from the kidney, liver, and lungs were prepared and stained with Giemsa stain for microscopic examination. Using taxonomic keys, ectoparasites, hemoparasites, and helminths were identified based on their morphological features. The prevalence of ectoparasites, hemoparasites, and gastrointestinal parasites was computed, and a chi-square test was applied to assess the relationship between parasites and animal body parameters, the association with a p ≤ 0.05 was considered significant. One hundred thirty-seven silvery mole rats were collected, adult females 65% (89/137) were the dominant among the collected rats. A total of 1503 ectoparasites were collected, identified, and revealed to two taxa of mite spp which were Androlaelaps spp 93.15% (1400/1503) and Echinolaelaps spp 6.19% (93/1503), and one taxon of tick the Haemaphysalis spp 0.6% (10/1503) with an overall prevalence of 71.5% (98/137), mite species were the most abundant (94.98%). Two species of blood parasites were detected with an overall prevalence of 29.2% (40/137) and identified as Anaplasma spp 25.5% (35/137) and Babesia spp 16.8% (23/137). Three species of gastrointestinal helminth were detected including taxa of cestode and nematode. A taxon of cestode was identified as Hymenolepis diminuta with an overall prevalence of 20.44% (28/137). A total of 385 adult H. diminuta and 1450 cestode EPG were collected from the gastrointestinal tract. Two species of nematodes; Physaloptera spp and Strongyloides spp were revealed with an overall prevalence of 39.42% (54/137), Physaloptera infection was the most prevalent at 37.22% (51/137) and the only adult nematode recovered among the two nematode species. A significant association was shown between blood parasites and adult silvery mole rats (p = 0.004), and between ticks and babesiosis, tick and anaplasmosis with p of 0.001 and 0.01, respectively. The cestode infection had a significant association with both host age and reproductive category (p< 0.05). Adult silvery mole rats had a lower infection risk than sub-adult rats, with an odds ratio of 0.6 (95% CI 0.24-1.87). Female silvery mole rats were at higher risk of being infected with nematode parasites compared to males, with an odds ratio of 1.6 (95% CI 0.78-3.43). The findings of this study indicate that ectoparasites, hemoparasites, and gastrointestinal helminths are prevalent among silvery mole rats in Morogoro region and might be the source of the infection in humans and livestock. Further studies on the epidemiology of the parasites identified and others that were not found in this study at the molecular level for advanced characterization are recommended to explore their zoonotic potential.
Prevalence and antimicrobial resistance profile of foodborne salmonella enterica and escherichia coli from rodents and shrews in Morogoro municipality, Tanzania
(Sokoine University of Agriculture, 2024-05) Uwanyirigira, Marie Chantal
Rodents and shrews were identified as transmitters and carriers of Salmonella enterica, Escherichia coli (E. coli), and their antimicrobial resistant strains; however, few researchers have examined rodents feces infections. Antimicrobial resistance (AMR) is a pressing issue in the field of global public health, impacting both human and animal health. Small mammals such as rodents and shrews excrements constitute a significant reservoir of zoonotic pathogens, including bacteria resistant to antimicrobials. To date, there is a need for more documented research specifically addressing Escherichia coli (E. coli) and Salmonella enterica strains derived from small mammal feces samples collected in Morogoro Municipality. This study aimed to determine the prevalence and antimicrobial resistance profile of Salmonella enterica and E. coli associated with rodents and shrews in five wards selected in Morogoro Municipality, Tanzania, from March to November 2023. Questionnaires were used to assess risk factors of Salmonella enterica and E. coli associated with house rodents and shrews. This study isolated bacteria extracted from fecal samples of rodents and shrews by using a culture test and identified them with biochemical tests. Molecular tests were used to screen out bacteria-targeted. The isolates bacteria were analyzed for AMR using the disc diffusion method for susceptibilities test to the selected antibiotics. Molecular analysis was used to identify the species of bacteria using 16S rRNA and InvA. Polymerase chain reaction (PCR) was used to find resistance genes in each isolate, including Bla TEM, Bla SHV, Bla CTXM, Sul 1, and Sul 2. A total of 148 small mammals were captured, 145 (98%) were rodents and 3(2%) were shrews. These small mammals were captured from domestic, peri-domestic, and marketplaces. Salmonella enterica was detected in 3/148 (2%), and E. coli was found in 54/148 (36.5%) samples. Most rodents infected by E. coli and Salmonella enterica were Mus species, with 16.2% and 1.3% respectively. Regarding habitat, the high prevalence of E. coli was bserved in open markets, at 16.9%, while Salmonella enterica was high inside households, with 1.3%. Regarding the risk factors associated with house rodents and shrews, 83.7% of respondents found rodents feces in uncooked or cooked food, 30.4% found rodents feces in the water storage, 93.2% found food eaten by rodents, whereby 66.9 % of households used food contaminated with feces or eaten by rodents. Twenty-seven percent (27%) of the respondents were diagnosed with Diarrhea, which may be linked with pathogens from rodents and shrews. The AMR on Amoxicillin was observed in shrews at 100%, in Rattus rattus was 89.5%, and Mus spp was 87.5%, while AMR to Ampicillin on Rattus rattus was 74% and in Mus spp was 62.5%. Salmonella Enterica was more resistant than E. coli for Sulphamethoxazole/Trimethoprim, Ciprofloxacin, and ampicillin. E. coli was more resistant to Amoxicillin than Salmonella Enterica. Concerning the genes linked to E. coli and Salmonella enterica, the results showed that Salmonella Enterica harbored more resistance genes (20%) than E. coli (12%). Two (2) isolates, out of 13 contained Sulphonamide-resistant genes as follows: Sul 1 (n=1) of Salmonella enterica and Sul 2 (n=1) of E. coli, both representing 15.4% of the total resistant gene analyzed in this study. β- lactamases (Bla TEM , Bla SHV, Bla CTXM) were found in 7 isolates (53.8%), with Salmonella enterica harboring more resistance genes than E. coli. The results of this study indicated that the public health significance of pathogens in rodents and shrews from the study area requires further investigation because these animals live close to humans and are also able to move from one place to another, which can increase the transmission of pathogens harbored by them to humans or the environment. Also, this research reveals the presence of resistant Escherichia coli and Salmonella enterica in small mammals, which indicate the potential role of rodents and shrews as a reservoir for AMR E. coli and Salmonella enterica that can be transferred to humans.
Hematology and Glinical Chemistry in Goats
(Sokoine University of Agriculture, 1991) Mbassa, Gabriel
The initial objective of this work was to gather as much information on the hematological and clinical chemical reference values for goats. It was desired to present the work in easily readable tables and figures to facilitate comparisons and reference assessments. To achieve this objective it was thought natural, first to review the literature on the factors that affect the reference values and secondly to investigate the trends under the influence of some of the factors. On the second part studies were conducted on growth, environment and metabolic influence on the reference values. This thesis is based on these investigations. Data reported in conventional units were transformed into the International System of Units (SI) to enable comparisons from different sources. Although the contents of the thesis are far from the desired perfection of the objective, it is a pleasure to state that some parts of the original purposes have been accomplished. Credit for this part of the work goes to the Central Laboratory, Department of Clinical Studies, Royal Veterinary and Agricultural University, Frederiksberg and the financial sponsor, the Danish International Development Agency. I am very pleased to express my sincere thanks to Associate Professor Dirch Poulsen, Head of the Central Laboratory. I owe my deep gratitude for his interest in my research on hematological and clinical chemical reference values in goats, his continuous encouragement and allowing me free access to the facilities in the laboratory. I am indebted to Professor Prebcn Willeberg, Department of Animal Science and Animal Health for his fruitful and concentrated knowledge on experimen tal planning and data management via the supporting subject epidemiology. I am also indebted to Associate Pofessor Knud Christensen, Department of Animal Science and Animal Health for advice on statistical analysis of the results. I gratefully acknowledge Mr. Walther Kraul, Central Laboratory for his invaluable knowledge on the theoretical and practical use of computers and softwares in the laboratory. My deep gratitude is extended to Miss Emma Thomsen for her encourage ment, technical help in blood sample collections, careful and skillful work in analysis of the numerous parameters I requested for, which in most cases went beyond normal working hours. I am indebted to Associate Professor Jesper Monrad, Department of Veterinary Microbiology, Mr. Knud Larsen, Ms. Greta Schmedes, Jytte Anderson, Pia Jensen and Ingrid Dam for the offer of goats for blood samples in their herds in Denmark. I extend this gratitude to Dr. D. B. Mpiri, The Commissioner for Livestock Research, Ministry of Agriculture and Livestock Development Tanzania, for granting me permission to perform research at Malya Livestock Research Station, Mwanza, Tanzania. I would like to give my sincere thanks to Professor Sven Gade Christensen, Danida Project Coordinator, Faculty of Veterinary Medicine, Sokoine viUniversity of Agriculture, Morogoro, Drs. J. Msanga, J. Mukangi, M. Yongolo, Mr. Lugola, A. Masanja and other staff of The Veterinary Investigation Center, Mwanza and Malya Livestock Research Station for transport, laboratory facilities and technical assistance. It is impossible to list all my colleagues in the Department of Clinical Studies who assisted me in this project. I express my thanks to them all. I am obliged, however, to mention particularly Associate Professor Jens Ambjerg, Drs. Magishi Mgasa, Asger Lundorff Jensen, Falmer Hansen, Thomas Eriksen and Jens Madsen for their very useful discussions and comments on the manuscripts. I am very grateful to Lis Kjaer Jensen for translation of the thesis abstract into Danish and together with Anne Marie Norregird for secretarial assistance throughout my studies. I am happy to express my profound gratitude to Drs. Kaj Bruhn and Jorgen Henriksen of Research and Information Bureau. As a student of two Universities in a sandwich program, they offered me their sincere and friendly advice on my scholarship and provided solutions to problems that arose in the course of this program. I am also thankful to Mrs Mariane Boesen, the students adviser, Internation al Student Center and Mr. Sdren Clausen, the caretaker of my residential place at the Danida fellowship Center for offering me a very comfortable place that enabled me to concentrate fully on my studies. I am also very pleased to once again acknowledge the continuous support offered to this project by the Danish International Develop ment Agency, Ministry of Foreign Affairs, Copenhagen. Finally I wish to express my deepest gratitude to Anna, Leah, Patrick, Peter and John Mbassa (my family) for allowing me to fulfil my obligations and expectations in Denmark, to gain knowledge for development of Tanzanian people. They have been patient and accepted to endure difficulties due to my absence
Assessment of potential factors for plague transmission in the plague endemic area of Karatu District, Northern Tanzania
(Sokoine University of Agriculture, 2024-05) Jakoniko, Joshua Reuben
Background: Plague, caused by Yersinia pestis, is a severe zoonotic disease with rodents and fleas as primary hosts and vectors. Despite being quiescent in several foci in Tanzania, plague remains a significant public health concern due to its recurring nature. The Karatu district experienced plague outbreaks in 1996 and 1997. Subsequent studies have reported evidence of Yersinia pestis DNA in rodents in this endemic area in 2006 and 2013. Consistent surveillance of the plague pathogen in rodent communities and monitoring rodents and flea abundance is crucial to assess the risk of human plague outbreak and the health of the rodent populations in the vicinity of human habitats. This study aimed to assess potential attributes for plague transmission in Karatu district during the periods of disease quiescence. This study was conducted in Karatu district in January and February, 2022 (wet season) and repeated in July 2022 (dry season) The study aimed to enhance surveillance of plague in plague foci and adjacent non- plague foci - villages to determine the prevalence of plague bacilli in the rodents, and identify the need for enhancing control measures. This work is at the nexus of the One Health approach, as it involves the surveillance of the plague zoonotic pathogen in the small mammals for the purpose of enhancing public health. The results of this study will be useful in informing public health, vector control, and environmental institutions about the potential factors that may underlie the transmission of the plague agent, Y. pestis, in the plague-endemic area of Karatu district, northern Tanzania. Methods: A repeated cross-sectional study was conducted in four selected villages of Karatu district, involving two plague foci villages and two non-plague foci villages, during the wet and dry seasons. A total of 120 Sherman traps were used to capture rodents in farm land habitats, peridomestic areas, bush lands, and forest buffer zones, with an approximate distance of 300 to 500m between habitats. The captured rodents were anaesthetised and identified using a dichotomous key after taking various morphological measurements. Blood samples were collected from the anaesthetised rodents through the supraorbital vein using glass micro capillary tubes. Ectoparasites (fleas) and internal organs (lungs and spleen) were collected and preserved in 70% ethanol and absolute ethanol, respectively. Fleas were processed in the laboratory and identified to genus and species levels using the available dichotomous key. Blood smears were prepared on microscope glass slides and preserved in slide boxes at room temperature. In the laboratory, the blood smears were stained with Wright-Giemsa stain and observed for the presence of Y. pestis coccobacilli under a compound light microscope at ×1000 magnification. The presence of bipolar-stained coccobacilli bacteria triggered suspicion for Y. pestis. The microscopy results were then confirmed using qPCR to detect the presence of the pla gene of Y. pestis DNA, extracted from the rodent lungs and spleens. Results: A total of 291 rodents belonging to nine species were captured in peridomestic areas, farmlands, bushes, and forest buffer zones. Mastomys natalensis was the most abundant species (41.92%), followed by Arvicanthis niloticus (24.05%), Lemniscomys striatus (14.78%), Rattus rattus (8.59%), Lophuromys flavopunctatus (4.47%), Grammomys spp (4.12%), Otomys spp (1.03%), Graphiurus murinus (0.69%), and Praomys delectorum (0.34%). Rodent abundance varied significantly among species and across seasons however, was not statistically significant different between plague and non-plague foci villages or across habitats. The rodent diversity, expressed as Shannon-Wiener diversity index, was slightly higher in plague foci villages compared to non-plague foci villages (0.7 and 0.6, respectively). Peridomestic areas had the highest diversity index (0.92), followed by farmlands (0.65), bush lands (0.64), and forest buffer zones (0.00). Out of the 291 rodent blood smears examined, 34 were suspected positive for Y. pestis coccobacilli, with one sample from M. natalensis confirmed positive for the plasminogen activator (pla) gene of Y. pestis DNA by qPCR. The findings further indicated that 190 fleas belonging to four different species were collected from 73 rodents, belonging to six species. Among the collected fleas, Dinopsyllus lypusus was the most abundant (46.32%), followed by Ctenophthalmus spp (26.84%), Xenopsylla brasiliensis (16.32%), and Xenopsylla cheopis (10.53%). A total of 38.42% fleas were collected from M. natalensis, 22.63% from L. striatus, and 18.42% from R. rattus. The highest flea infestation prevalence was found on R. rattus with preponderance of X. cheopis and X. brasiliensis. The specific flea index of X. cheopis on R. rattus was (1.0 SFI) in plague foci and (<0.5 SFI) in non- plague foci villages. The result of the GLM final model indicated that the flea abundance on rodents was significantly dependent on rodent species, season, habitats, rodent weight, sex, and location. There was a weak positive correlation between rodent weight and flea abundance. Conclusion: Overall, the study suggests a possible enzootic circulation of Y. pestis in sylvatic rodents in the plague foci villages of Karatu district. The high abundance of rodents and fleas, particularly in farmlands and peridomestic areas, increases the potential risk for the transmission of the plague pathogen to the surrounding population and thus poses a threat to public health, especially considering that these habitats serve as crucial sites for human economic activities, interactions, and livelihoods. Therefore, it is of paramount importance to maintain vigilant rodent control to mitigate any risks of repeated plague outbreaks.
Prevalence of parasites, species composition and abundance of rodents and shrews in Ilemela District, Mwanza Region, Tanzania
(Sokoine University of Agriculture, 2024-05) Kiir Deng, Aheir Achuil
Rodents and shrews are extremely diverse in their ecology and lifestyles and can be found in almost every terrestrial habitat. The diversity of rodents and shrews varies with vegetation type, habitat and season. There are tremendous impacts attributed to rodents and shrews which include but not limited to damaging field crops, causing post-harvest losses, contaminating stored food and water supplies. Nevertheless, they are reservoir of different parasites of public health importance and play an important role in the transmission and spreading of zoonotic diseases in Tanzania and worldwide. Generally, this study aimed to determine rodents and shrews species composition and prevalence of parasites, in Ilemela District, Mwanza region, Tanzania. Rodents and shrews were live-trapped using Sherman and modified wire cages from Peridomestic, indoors and agricultural fields and their morphological data were recorded for identification to the genus and species level. Morphological data such as sex, weight, head- body, tail, ear, and hind foot lengths were recorded. They were then anaesthetized with diethyl ether, blood samples were collected aseptically from heart, thin and thick smears were made for haemoparasites identification and their ectoparasites were also collected for identification purposes. The Gastro-Intestinal Tract (GIT) was carefully removed and their contents were evaluated for GIT parasites. A total of 149 small mammals were captured and identified that includes 144 rodents belonging to four species namely Mastomys natalensis 66.4% (99/149), Mus .musculus 21.5% (32/149), Rattus rattus 7.4% (11/149) and Aethomys spp 1.3% (2/149) and the rest 3.4% (4/149) were shrews belonging to Crocidura spp. The overall prevalence of ectoparasites was 56.4% (84/149) and the following ectoparasites were identified, Laelaps echininus 39.6% (59/149), Polyplax spp. 4.0% (6/149), Xenopsylla cheopis 2.7% (4/149) and Heamaphysalis leachi 0.7% (1/149). The highest prevalence of ectoparasites was recorded in M. natalensis at (67.7%). In context to sex, males harbored more ectoparasites 59.0% than females. Additionally, the study also found a prevalence of haemoparasite was 35.5% (53/149) and the identified parasites namely, Anaplasma spp 18.8% (28/149), Trypanosoma lewisi 0.7% (1/149), Plasmodium spp. 1.3% (2/149). There were also two bacteria genus, bipolar coccobacilli2.7% (4/149) and Bacillus spp 3.4% (5/149) identified. Anaplasma spp was found in all of the infested rodent species and its highest prevalence was recorded in M. musculus 34.4% (11/32) followed by M. natalensis 27.3% (27/99). However, T. lewisi was only found in Rattus rattus whereas none of the haemoparasite was identified in Crocidura spp. The relative abundance of the captured rodent’s species were Mastomys natalensis 99 (68.75%), Mus musculus 32 (22.22%), Rattus rattus 11(7.63%) and Aethomys spp 2 (1.38%). Mastomys natalensis was widely distributed in all the habitats and its highest abundance was recorded in agricultural farms (83%, n=82/99). Mus.musculus (96.9%) and all R. rattus (100%) exclusively captured from in-doors, while Aethomys spp 2 (1.3%) were only captured from the Peridomestic habitats. The study found a significant association of the villages) with the captures (p < 0.01). In six of the villages selected for current study, M. natalensis was the most prevalent and abundant species captured. The overall prevalence of GIT parasites was 53.7% (80/149) and the following parasites were recovered, (nematodes 80.5% (91/113), cestodes 14.2% (16/113), trematodes 0.9 (1/113) and protozoan oocysts 4.4% (5/113). The recovered nematode parasites include; Trichuris spp 52.2% (59/113), Angiostrongylus spp 4.4% (5/113), Nippostrongylus spp 6.2% (7/113), Strongyloides spp 13.3% (15/113), Capillaria spp 3.5% (4/113), Physaloptera spp 0.9% (1/113) and Syphacia obvelata 0.9% (1/113). The identified Cestode was Hymenolepis diminuta 14.2% (16/113) while in Trematode, only Echinostoma spp 0.9% (1/113) was identified. Apart from worms also protozoan Oocyst 4.4% (5/113) were identified. Majority of the captured rodents were infected with nematodes 65% (91/113) and the highest prevalence of GIT parasites was recorded in M. natalensis 64.6% (64/99). Trichuris spp was found to be the most prevalent parasite in rodents. Among the identified parasites, Hymenolepis diminuta, Angiostrongylus spp, Capillaria spp and Syphacia obvelata are of public health importance. This study has revealed the presence of parasites of public health and livestock importance in rodents and shrews and we recommend for the control of rodents and shrews as well as screening of human’s population to check for presence of the identified zoonotic parasites reported in rodents and shrews.
Development and rapid assessment of community based health educational package for control of taenia solium cysticercocis/taeniasis in Tanzania
(Sokoine University of Agriculture, 2024-05) Nyangi, Chacha Joseph
aenia solium taeniasis/cysticercosis is a neglected parasitic zoonosis with significant economic and public health impacts worldwide. Food and Agriculture Organization of the United Nations (FAO) and the World Health Organization ranked it first on the global scale of food-borne parasites. Taenia solium cysticercosis/taeniasis (TSCT) impacts is more in developing countries, including Tanzania, where social, economic, and cultural conditions favour its endemicity. Community knowledge is central in successful disease control in endemic areas. For control intervention to be effective and sustainable it should engage the community from planning stage. The study addressed the gap on knowledge, attitude and practices related to the disease, developed and conducted rapid assessment of a community-based health educational package (CHEP) for the prevention and control of TSCT in Tanzania. The study employed a community-based mixed methods approach involving different qualitative and quantitative approaches, using questionnaire for the household survey from 483 selected households, in addition, household infrastructure observations were conducted to the same 483 randomly selected households, Focused Group Discussions (FGD) and Key Informants Interviews (KII) were also conducted in Mbulu, Rungwe, Mbinga and Mpwapwa districts. The information collected led to the formulation of key messages for the development of a health education package, which comprises four components including; a training manual for the training of trainers (TOTs), a booklet with illustrations and instructions on how to perform small doable actions, brochure with key messages and poster with a tapeworm life cycle indicating the areas which can be targeted to interrupt the transmission. The formative research method was used in the development of the package. It is expected that the CHEP will be sustainable as it is development engaged the community in all stages of development. The CHEP developed was assessed in Babati district. This was done to assess the effectiveness of the package towards improvement of community knowledge attitude and practices towards control of TSCT. Qualitative data were analysed using thematic analysis. Descriptive statistics and chi-square test were used to analyse quantitative data including data on knowledge, attitude, and practices. Binary logistic regression was used to examine factors influencing socio demographic factors on knowledge and related practices, both independent and dependent variables were used. Socio demographic factors assessed were sex, age, district/location, education level, age group, main source of income, period of residence in years, and Savings and Credit Cooperative Society. The results revealed good knowledge about porcine cysticercosis, particularly among pig keepers across the districts. Majority of participants (48%) had heard about the pork tapeworm and the knowledge about clinical signs/symptoms and treatment was fair, but the means of transmission and prevention measures were often unknown. The risk perception of the infection with the pork tapeworm was low too and a similar trend is reflected in the attitudes toward the low-risk perception of cysticercosis infection. Hand washing practices was also low, many participants reported not washing their hands before eating or after using the oilet which highlights potential risks for the transmission of human cysticercosis. Almost all participants reported using the toilet always, however, household observations revealed that toilets were either lacking or had no complete walls, with others showing the sign of not being used for some time. Generally, household observations revealed a discrepancy between responses to the questionnaire on one hand and the availability of toilet and handwashing facilities, and the confinement of pigs on the other hand. This highlights the importance of including household observation during data collection. Respondents with tertiary education were more likely to have heard of tapeworm, be aware of T. solium transmission, be aware of T. solium health effects, and be aware of human cysticercosis transmission. Male respondents were more likely to be knowledgeable about porcine cysticercosis transmission. Lack of standardised education materials about the disease might influence the quality of health education in different infected communities. Using the gathered information, the health education package on knowledge, attitude, and practices reported a statistically significant improvement in knowledge regarding the link between epilepsy and cysticercosis and in the practice of washing fruits and vegetables, however, the long-term effect of the health educational package on knowledge, attitude, and practices and the disease parameter need to be evaluated. This study has revealed poor knowledge of T. solium Cysticercosis/Taeniasis with generally better knowledge about its effects on porcine than on human health. The limited overall knowledge, together with negative attitudes and practices may represent an important barrier to TSCT control and elimination efforts. It is therefore recommended to scale up the efforts of knowledge sharing with the general population on transmission, TSCT clinical signs/symptoms, control, treatment, and prevention in Tanzania, preferably adopting one health approach, to improve favourable knowledge, attitude for control and eventual eradication of TSCT. The study shows that socio-demographic factors have a direct influence on knowledge and practices related to TSCT. Education was the most important factor among the others and contributed significantly to the overall models that determined knowledge and practices related to TSCT. It is therefore, recommended that studies that include health education interventions also consider socio-demographic factors. Another area covered by this study was the development and rapid assessment of the health educational package which revealed an improvement in knowledge regarding tapeworm treatment from 61 (81.3%) pre-intervention to 76 (95.0%) post- intervention, while the knowledge regarding condemnation of infected pork increases from 65 (83.3%) pre-intervention to 73 (90.1%) post-intervention. Practices about washing vegetables and fruits significantly improved (P=0.025), while, that of pigs’ confinement increased from 45 (77.6%) pre- intervention to 54 (88.5%) post-intervention. It is recommended that to achieve the maximum impact of the intervention, the educational package should be combined with other existing control strategies as well as other intervention methods such as video, cartoons for school children, and a computer-based health-education tool such as the vicious worm. It is also recommended that the interventions preventing TSCT reinfection, such as improvements in hygiene achieved through health education, are urgently required to augment the effect of other control strategies as part of an integrated approach.
Crop storage practices and occurrence of fungi with public health importance from rodents’ trapped inside and outside the storage facilities in Mbeya, Tanzania
(Sokoine University of Agriculture, 2024-04) Mollel, Anna Peria
Animals play an important role in the dispersal of seeds and fungal spores. Several species that consume fruiting bodies of fungi play a primary role in dispersal networks. Through the rodent-mycorrhizal dispersal relationship, the study was conducted in selected wards of urban and peri-urban areas of Mbeya-Tanzania to discover whether rodents could act as the network for the dispersal of other fungi related to public health. As well as assessment of knowledge, awareness, and practices based on storage conditions, that may influence rodent infestation: implication to fungal contamination in storage facilities. A total of 210 rodents were trapped in and outside the storage facilities in selected wards in Mbeya city of which Rattus rattus (51.0%) was a dominant species, Praomys 40(19.0%), Lophuromys 29(13.8%), Mastomys natalensis 19(9.0%), Mus musculus 9(4.2%), and Lemnicomys spp 4(1.9%). Fresh fecal samples from the rectum were collected. The second form of samples were 77 pellets collected from the ground making a total number of 288 fecal pellets. Both samples were preserved at -20 0C at Mbeya National Research Institute (NIMR) for further laboratory analysis. Colony morphology obtained through Microbiological analysis and identification in selective media. A total number of 6 different fungal isolates were observed and Aspergillus fumigatus was the dominant fungal species from the cultured samples, with a prevalence of 26% (76/288) showing the potential for aspergillosis in humans followed by Aspergillus niger and Fusarium species with a prevalence of 9% (27/288), Aspergillus flavus 3% (10/288) and Aspergillus ochraceus 1% (4/288). Nested PCR confirmed the presence of aflR gene from suspected isolates of Aspergillus flavus, bands observed at 800kb for the first round and 400kb for the second round. Indirect Competitive ELISA performed on 10 maize samples that infected with A. flavus isolates, 10 maize samples free from isolates contamination, and 4 pure isolates of A. flavus. The aim was to check whether the isolates were capable of producing toxins and their respective concentrations (ug/ul) were calculated. To confirm the findings a cross-sectional survey was conducted and a total number of 50 facility storage owners were questioned based on grains storage practices, factors for rodent infestation, facility- building conditions, type of material used for storage of grains, Storage facilities owners’ knowledge based on the effects of rodent infestation and ways to reduce the effects. Poor storage practices, types of storage sacks, facility maintenance and longevity of the facility, and poor knowledge of controlling pests and losses due to rodents and moulds were the major findings. The 74% of respondents indicated that they stored only maize, while 26% stored maize along with other grains such as rice and beans. Among the respondents, 28% agreed that storing maize with other products facilitated rodent infestation, 22% disagreed with this opinion, and the remaining participants were unsure. The 58% of the participants expressed confidence in their understanding of the factors that influence rodent infestation, while 42% did not. Regarding major maintenance of their storage facilities, 38% of the storage keepers performed it annually, while 20% did it whenever they deemed it necessary. In terms of rodenticide application within the storage premises, 54% of the respondents indicated its use.
Metagenomics analysis of pathogens in rodents in selected human-wildlife Interfaces in Tanzania
(Sokoine University of Agriculture, 2024-05) Abel, Agnes
Rodents belongs to the order Rodentia, which comprise the largest proportions of all of the terrestrial mammals in the world. In Africa, rodents occur in 14 families, 89 genera and 290 species, East African region contains 14 families, 62 genera and 161 species of rodents. Over decades, rodents have been reported to harbor more than 60% of emerging zoonotic pathogens including viruses, bacteria and a number of parasites. Several human diseases including the most devastating in the history of mankind Plague‖ have been reported to have originated from rodents. Rodent borne diseases are transmitted either directly (Hantavirus, Lassa fever, Lymphocytic choriomeningitis) or indirectly through consumption of foods and water contaminated with rodent feces and urine (Leptospirosis, tularemia) or through ectoparasites carried by rodents (leishmaniasis, Lyme disease). Risks of human infection is linked to the possibility of contact between rodents, humans and animals, along with the closeness between rodent and human lives. Since there is constant interaction between humans, animals and rodents; it is therefore, essential to understand patterns of pathogen diversity and focusing surveillance in rodents in order to identify zoonotic potential pathogens prior to spill over to humans. Rodents were captured in Kibondo, Kyerwa and Uvinza in 2018. Trapping of rodents was done in peri-domestic areas by using Sherman box and Tomahawk traps added with peanut butter mixed with maize bran as baits. They were anaesthetized by using Isoflurane, and species identification was done by using morphological identification keys. In metagenomics sequencing a total of 116 rodents archived oral- pharyngeal and rectal swabs were subjected to RNA extraction and the products were pooled into twelve pools based on species of rodents, locations and swab types. There were eleven pools of oral- pharyngeal swabs and a single pool of rectal swabs. Pooled samples were sequenced on oxford Nanopore MinIon sequencing platform. This study employed 16S rRNA metagenomics sequencing analysis. Sequences were analyzed by using Kraken 2 classification and Kaiju software. A total of 5263 small mammals were trapped from Kibondo, Uvinza and Kyerwa during the three years of data collection. Majority (87.6%, n=4613) were rodents and 650 (12.4%) were shrews. Among the rodents, rats were the majority (70.0%; n=3683) while mice were 873 (16.6%) and squirrels were only 44 (0.8%). The dominant species in the group of rodents were Mastomys natalensis which constituted 63.6% (n=3346). Among the mice, Arvicanthis spp. were the majority as they constituted 7.1% (n=373) of all small mammals trapped. A total of 13 (0.3%) small mammals identified as rodents their genus was not established. In a metagenomics analysis, 44 bacteria species of public health, veterinary and environmental health importance were identified. They were detected in eight pools, while there was no detection in four pools. A total of 10 (22.7%) bacteria species including H. pylori were detected in the rectal swabs pool and the remaining 34 (77.3%) were distributed among the pools of oral-pharyngeal swabs. A total of 15 potentially pathogenic, zoonotic and bacteria of unknown zoonotic potential including Mycobacterium tuberculosis, Helicobacter pylori, Vibrio cholerae, Vibrio parahaemolyticus, Haemophilus influenzae, Klebsiella pneumonae, Staphylococcus aureus, Streptococcus mutans, Escherichia coli, Chlamydia psittaci, Campylobacter sputorum, Acinetobacter baumannii and Acinetobacter pitti were identified in this study. The findings of this study are in line with several previous studies that have reported a number of rodent species in western Tanzania; also, citing rodents as reservoirs of disease-causing agents; and has the potential to spread and maintain transmission cycles of human and livestock diseases. This study presents the first reports of natural infection of rodents with Helicobacter pylori and Mycobacterium tuberculosis. These findings provide baseline information to inform surveillance systems and the public in general on potential health risks that are associated with interaction between rodents, humans and livestock. Furthermore, it gives insight on the potential of using a unified approach One Health‖ between sectors in order to achieve better health and a safer community. However, since the findings of this study do not explain pathogen transmission from rodents to humansand vice versa, we recommend further studies to characterize them and understand their transmission dynamics.
Merging the gap between formal and informal training: a case study of mobile phone repairers in Morogoro Municipality, Tanzania
(Sokoine University of Agriculture, 2023) Kabelinde Joram
The development of science and technology has led to the emergence of mobile phone technology which has gained tremendous popularity as the ideal device for communication in modern times. In relation to the emergence of mobile phones, there is the need for a new field of profession which ensures mobile phone repair and maintenance. In response to the need, there have emerged a lot of entrepreneurs across the country offering mobile phone repair and maintenance services. Hence, the study aimed to assess the state of mobile phone repairers’ skill development and compare the phone repairers' demands with the coverage of Vocational Education Training Authority (VETA)-Kipawa and Dar es Salaam Institute of Technology (DIT) curricula. The case study design under qualitative approach employed interview, observation and documentary review to gather the data from 15 mobile phone repairers, 20 customers of the repairers and 5 VETA trainers. The findings revealed that most mobile phone repairers joined the industry as a result of both intrinsic and extrinsic motivation. Additionally, the study found that most mobile phone repairers acquired skills through observing experienced mobile phone repairers and short courses organised by VETA. It was discovered that some of the mobile phone repairers lack formal or non-formal trainings relating to mobile phone repair. The researcher reports on the need of the government through training institutions to avail easily accessible and affordable formal and non-formal mobile phone repair trainings. The results also show that the existing curriculum used at VETA to offer trainings to mobile phone repairers does not wholly match their needs. The study based on the findings, it recommends that mobile phone repairers should not only learn informally, especially from more knowledgeable and experienced mobile phone repairers, but also should attend training institutions. It is also recommended that the government should facilitate mobile phone repair training institutions in providing specialized skills relating to mobile phone repair in order to meet the demands of mobile phone repairers.
Phytoconstituents utility in ethiopian kale and african cabbage orphan leafy vegetables and potential cultivation of the vegetables as functional foods
(Sokoine University of Agriculture, 2023) Maina S.W
Various studies have recently highlighted the importance of African leafy vegetables (ALVs), which refer to plants whose leaves are accepted and utilized as vegetables by communities through tradition. Due to their higher concentrations of nutritious and non- nutritive compounds than widely cultivated and consumed "exotic" vegetable species, ALVs constitute an important part of people's diets. Orphan ALVs, such as Cleome gynandra (African cabbage) and Brassica carinata (Ethiopian kale), are indigenous, native species that were introduced centuries ago but are still used locally or regionally, having lots of untapped potential to improve nutritional security. Due to their local benefits, occurrence as wild plants, weeds, or volunteer crops, these vegetables are typically characterized as minor, neglected, underutilized, and/or unimproved; and they are almost entirely ignored by farmers, researchers, crop breeders, and even policymakers. Consumers have recently placed a high value on vegetables as functional foods in their diets, with reports indicating that they are not only nutritionally dense, but also contain high levels of some health-beneficial phytochemicals when compared to commonly consumed staple crops, and that they have a high potential to contribute not only to food security, but also to nutritional security. In this thesis, an extensive study was conducted in order to understand the secondary metabolites present in African cabbage and Ethiopian kale vegetables, their utility in promoting human health, possible strategies to improve the vegetables, and the potential application of these vegetables as functional foods and as a source of natural bioactive compounds in the food and pharmaceutical industries. Firstly, this study involved a systematic review to determine the composition and health beneficial compounds obtainable from leafy vegetables and the possible strategies for improving such compounds during vegetable growth. Then using seeds supplied from a gene bank in Kenya, the Centre for Biodiversity in Kenya Resources Centre for Indigenous Knowledge, National Museums of Kenya (eight accessions for African cabbage and one accession for Ethiopian kale), the vegetables were cultivated in the greenhouse of KIST. Plant materials were collected at different stages and separated into several organs for bioactive component profiling. Target chemicals such as glucosinolates (GLs) and phenolics were detected in the vegetables using chromatographic techniques combined with mass spectrometry, based on their fragmentation patterns and mass to charge ratio. The identified compounds were quantified with commercial pure standards or relative response factors of the compounds using High performance liquid chromatography (HPLC) techniques. Upon identification and quantification of the compounds in the different vegetable parts and accessions, the adaptation of the vegetables for application in a vertical smart farming system was determined by checking the agronomic characteristics/desired traits. Furthermore, the possibility of improving vegetables by accumulating the bioactive secondary metabolites and their associated biological properties was evaluated using elicitors treatment. Different types and concentrations of elicitors and their applicability to vegetables grown in vertical farming system were chosen. In the findings from the review, I obtained crucial data on the major composition of leafy vegetables which include GLs and polyphenols, the type of biological activities associated with these compounds such as anticancer, anti-inflammatory, antioxidant activities as well as the different strategies that can be used to improve vegetables at different stages of growth. For the compositional data, I observed variable components and concentrations of the identified compounds in each vegetable, the accessions under study and the vegetable parts used. During the evaluation of the well adapted vegetable to be used in the vertical farming system, Ethiopian kale vegetables were best suited for this type of farming and the cultivation had positive results in improving not only yield but also the quality of the vegetables and the inherent biological activities attributed to them. This vegetable was the choice for further objectives and analysis in this research and the target development stages were chosen depending on their ability to accumulate the bioactive compounds. Ethiopian kale’s samples extracts were subjected to various chemical and in vitro biological assays including antioxidant and anti-inflammatory potential, chosen depending on the identified compounds and effective activities were attributed to these compounds based on the literature review. The findings on elicitation demonstrate how elicitors could be used as a simple strategy to obtain quality plant functional foods with increased quantities of the health promoting compounds. This study shows the utility of both the edible and non-edible parts of the orphan leafy vegetables. It reduces the gap of unknown compounds in the vegetables and the identification of new compounds and provides a future reference for further studies. The evaluation of potential smart farming techniques to improve both yield and content of essential phytochemicals in the vegetables creates a good opportunity to venture and apply this emerging farming techniques for the production of high-quality functional foods and vegetables with accumulated drug target compounds for use in the pharmaceutical industry. The identification of superior accessions provides potential research targets to be used breeding programs for improving available vegetable varieties while the strategies used in production of quality vegetables are useful in the food industry for the production and processing of functional foods from the orphan leafy vegetables.
Antimicrobial use, prevalence of extended spectrum beta-lactamase producing escherichia coli and economic effects on cattle and poultry in Dar es salaam Tanzania
(SOKOINE UNIVERSITY OF AGRICULTURE, 2023) Azabo R.R
Antimicrobial usage (AMU) in livestock production provides a basis for improving animal health and productivity. However, it is evident that the over-dependence of animal production on antimicrobial agents is one of the major factors driving the emergence of antimicrobial resistance (AMR) in bacteria that can be transmitted via the food chain or environment to humans. This thesis aims to assess antimicrobial use in cattle and poultry production in relation to resistance in Extended Spectrum Beta-Lactamase (ESBL) producing Escherichia coli (E. coli) and also gain insight into economic effects (cost and benefit) of antimicrobial use reduction in animal production inIlala, Kinondoni and Ubungo districts which form part of the Dar es Salaam region, Tanzania with the following objectives.(i) To conduct a systematic review on the methods and metrics used to quantify and assess MU in cattle and poultry production in Sub-Saharan Africa, (ii) To determine the quantity, quality and pattern of antimicrobial use in cattle and poultry production in Dar es Salaam, Tanzania, (iii) To assess antimicrobial consumption in food-producing animals in Dar es Salaam, Tanzania, (iv) To determine the prevalence and antimicrobial resistance pattern of ESBL producing E.coli isolates from cattle and poultry production, and (v) To estimate the economic effects (costs and benefits) of antimicrobial use reduction in cattle and poultry production. In view of these objectives, the findings of this thesis are presented in five scientific papers. Paper 1: A systematic literature review was conducted to provide an overview of methods of measuring AMU and metrics used, reviewing existing data on AMU in cattle and poultry production in order to identify gaps in Sub-Saharan Africa. The study revealed a deficit of studies on estimate of quantity and quality of antimicrobials used in food-producing animals in Sub-Saharan Africa. Paper 2: A cross-sectional study was conducted on 116 farms (51 poultry and 65 small-scale dairy cattle) in Ilala, Kinondoni and Ubungo Districts of Dar-es-Salaam region, Eastern Tanzania from 15th August to 30th September 2019 to investigate the level of antimicrobial use practice, type and quantity (amount) of antimicrobials consumed. The study revealed that 23 (19.8%) of the farms visited had records while 93 (80.2%) relied on recall, 58.6% of the livestock farmers had adequate level of practices (favorable) in accordance to antimicrobial use based on their responses, the most commonly used class of antimicrobials in poultry production were: Fluoroquinolones (25.5%), sulphonamides (21.6%), tetracycline (11.8%) while in the small-scale dairy farms, tetracycline (20.0%), beta-lactams (18.5%), sulphonamides (12.3%) were most commonly used. Quantitatively, in the poultry farms, the frequently used antimicrobial class sulphonamides (46.1%), tetracycline (19%) and Macrolides (14.2%). In the small-scale dairy farms, the use beta-lactams (36.4%), sulphonamides (22.3%), tetracycline (14.3%) were predominant. For Paper 3: a cross-sectional study, using data extraction form to collate antimicrobial use data from sales records (three consecutive years) of five established licensed veterinary pharmaceutical wholesales/outlets which were purposively selected in Ilala, Kinondoni and Ubungo. The study revealed that 178.4 tonnes of antimicrobials (by weight of active ingredients) were consumed during the 3 year study period (2016-2018), with an average of 59.5 ± 3.8 tonnes/year. The commonly sold antimicrobials were tetracycline (44.4%), sulphonamides (20.3%) and aminoglycosides (10.3%). Regarding veterinary antimicrobial use importance to human medicine, 34.4% were critically important antimicrobials; 4.1% were reserve and 51% were watch groups according to AWaRe categorization of WHO. Overall, a mean of 7.44 ± 0.81 mg/PCU (population correction unit) was consumed by food-producing animals during the three-year study period. Paper 4: A cross-sectional study was conducted in 54 of the previously visited farms where a pre-tested questionnaire on antimicrobial (antibiotics) usage was completed. A total of 121 E. coli isolates were obtained from 201 sampled small-scale dairy cattle rectal swabs. Looped rectal swab specimens from Stuart transport medium, were streaked directly onto plain MacConkey agar (Oxoid, Basingstoke, UK) and aerobically incubated at 370C for 24 hours. Presumptive E. coli colonies were Gram stained and then subjected to biochemical tests (Indole test, Methyl red test, Voges-Proskauer test and Citrate Utilisation test; IMViC test) for identification. E. coli strain ATCC 29522 was used as a reference organism. Antimicrobial susceptibility testing (AST) was performed against eight types of antimicrobials: (Tetracycline, (TE) (30 μg), Ampicillin, (AMP) (10 μg), Gentamicin, (CN) (10 μg), Ciprofloxacin,(CIP) (5 μg), Cefotaxime,(CTX) (30 μg), Nalidixic Acid, (NA) (30 μg), Trimethoprim/Sulfamethoxazole, (SXT) (1.25/23.75μg) and Chloramphenicol,(C) (30 μg)). The highest prevalence of AMR was against AMP (96.7%), CTX (95.0%), TE (50.4%) and SXT (42.1%). The 121 isolates of E. coli belong to 41 different phenotypes showing a variation of resistance. The most frequently observed phenotypes were AMP-SXT-CTX with a prevalence of 12.4%, followed by the combination AMP-CTX with 10.7% and TE-AMP-CTX and NA+TE+AMP+CTX with 8.3% each. Fifteen different phenotypes that produce Extended Spectrum Beta-Lactamases (ESBLs) were detected with a prevalence of 42.9% and 74.4% of E.coli isolates exhibited multidrug resistance (MDR). This probably confirms that antimicrobial use is unregulated and thus inappropriate use which led to the emergence and development of resistance. Paper 5: A cross-sectional study was conducted on randomly sampled broiler farms which were in production for one year in Kinondoni and Ubungo Districts in Dar es Salaam region of Tanzania from February to March 2021. A pre-tested questionnaire was used to capture data required to complete the model for the estimation of the economic effects (costs and benefits) on reduction of antimicrobial use. Data collected included: number of chicks bought and dead on the farm (mortality), observed clinical signs; signs of respiratory infections (coughing, wheezing, sneezing and nasal discharge), enteric infection (diarrhea) and lameness (locomotive signs) (morbidity). A Mclnerney model built on biological and economic parameters of disease effects on livestock production was used to analyze the data. The net costs and benefits were estimated within a partial budgeting framework in the model. The results of this study showed that antimicrobial use reduction will have an effect on mortality and morbidity and thus increase the cost of production due to changes in additional management changes (animal health management and technical management). Findings from this thesis recommend that rational AMU should be emphasized by targeting cattle and poultry production in Tanzania in general and Dar es Salaam in particular.
Seroprevalence of leptospira among rodents and shrews in public markets and hospitalized febrile patients in Unguja Island
(Sokoine University of Agriculture, 2023-05) Ally Abdullah Ally
Leptospirosis is a neglected infectious zoonotic disease of public health significance caused by spirochete pathogenic bacteria of the genus Leptospira. This disease occurs mainly in tropical and subtropical countries and affects animals and humans, of which rodents and shrews are considered significant reservoirs of infection. Human might be infected by Leptospira pathogen through a contact mode of transmission, either direct or indirect, with the urine of infected animal’s host or a urine-polluted environment such as water or soil. However, infected humans develop a range of symptoms undifferentiated from other tropical diseases, such as malaria, particularly in regions with high malaria prevalence. A cross-sectional study was carried out between January and April 2022 in Unguja Island (i) to determine the seroprevalence of Leptospira infection among rodents and shrews in public markets and (ii) to determine the seroprevalence of leptospirosis among hospitalized febrile patients. Blood samples were collected from 210 live captured rodents and shrews in the five purposively selected markets including Darajani, Mombasa, Jumbi, Kwerekwe C and Mkokotoni. Likewise, 402 human blood samples were collected from febrile patients who were attended to the selected hospitals namely Mnazi Mmoja referral hospital, Kivunge district hospital and Makunduchi district hospital. The Leptospira antibodies of rodents, shrews and humans were tested against five serovars namely Sokoine, Lora, Pomona, Grippotyphosa and Hebdomadis using the Microscopic Agglutination Test (MAT). The results indicated that out of 210 rodents and shrews captured in public markets, 16 were seropositive for Leptospira serovars. Thus, the overall seroprevalence of Leptospira infection was 7.6% (95% CI =4.4−12.1), with a prevalence of 6.6% (14/210) in rodents and 1.0% (2/210) in shrews. The Leptospira serovars circulating among rodents and shrews antibodies were Sokoine 11 (5.2%), Lora 4 (1.9%), Pomona 2 (1.0%), and Grippotyphosa 1 (0.5%). Rattus rattus were shown to have high seroprevalence of Leptospira infection (4.2%), followed by Rattus norvegicus (1.4%), Mus spp (1.0%) and Crocidura spp (1.0%). Furthermore, out of 402 human sera collected from three hospitals, 31 human samples were seropositive for Leptospira serovars, and thus, the overall seroprevalence of human leptospirosis was 7.7% (95% CI = 5.3−10.8). Females 20 (5.0%) were shown to have high seroprevalence of disease compared to males 11 (2.7%). The major Leptospira serovars circulating in humans were Sokoine 44 (10.9%), Lora 25 (6.2%), Grippotyphosa 20 (5.0%), Pomona 10 (2.5%), and Hebdomadis 9 (2.2%). The findings of this study have indicated that several Leptospira serovars are common to rodents, shrews and humans. Likewise, market features and practices, including a poor drainage system, the presence of stagnant water, unhygienic conditions, and wet soil, favor rodent population and pose a risk of environmental contamination and perpetuation rodent-environment-human infection cycle. This report call for consideration and inclusion of this disease in the differential diagnosis of acute febrile syndromes in humans.
Effects of food insecurity among pastoralist families in the changing climate of Iringa rural District, Tanzania
(Sokoine University of Agriculture, 2014) Mdachi, Mary
Dietary intake measures are useful for assessing nutritional status of an individual. Dietary intake depends on the availability of healthy foods, as well as on resources available to an individual, allowing them to purchase or access foods. This study was carried out in 20 villages in Iringa Rural District, between July and September 2013 to assess effects of food insecurity among pastoralist women and their infants. Interviews were used to gather information on food insecurity and food frequency in pastoralist households. Anthropometric measurements and haemoglobin (Hb) concentrations of the participants were also collected. A total of 200 women and 30 infants were included in the study. The results indicated that majority (75.8%) of women’s diet was of plant origin. Approximately 75% of women had food shortages, defined as having at least one meal per day composed of limited food groups and quantities. All children were given meals mainly composed of carbohydrates (40%) once a day with no consistent pattern of types of foods or feeding times. Data on the nutritional status of children indicated that 6.6% of the Barbaig children experienced wasting while 10% of the Sukuma children were stunted. For women, 28% were underweight, while 7% were obese. Haemoglobin data indicate that 87.5% of children were anaemic while 42% of women were anaemic. It is concluded that most women and children had food insecurity and poor nutritional status which partly would be caused by climate change. It is recommended that nutritional education programs should be introduced in health facilities and in schools so as to improve the knowledge on nutrition. Also education should be given to the heads of households on how to utilize livestock in improving their livelihood/income and strategies to climate change adaptations.
Effects of food insecurity among pastoralist families in the changing climate of Iringa Rural District, Tanzania
(Sokoine University of Agriculture, 2014) Mdachi, Mary
Dietary intake measures are useful for assessing nutritional status of an individual. Dietary intake depends on the availability of healthy foods, as well as on resources available to an individual, allowing them to purchase or access foods. This study was carried out in 20 villages in Iringa Rural District, between July and September 2013 to assess effects of food insecurity among pastoralist women and their infants. Interviews were used to gather information on food insecurity and food frequency in pastoralist households. Anthropometric measurements and haemoglobin (Hb) concentrations of the participants were also collected. A total of 200 women and 30 infants were included in the study. The results indicated that majority (75.8%) of women’s diet was of plant origin. Approximately 75% of women had food shortages, defined as having at least one meal per day composed of limited food groups and quantities. All children were given meals mainly composed of carbohydrates (40%) once a day with no consistent pattern of types of foods or feeding times. Data on the nutritional status of children indicated that 6.6% of the Barbaig children experienced wasting while 10% of the Sukuma children were stunted. For women, 28% were underweight, while 7% were obese. Haemoglobin data indicate that 87.5% of children were anaemic while 42% of women were anaemic. It is concluded that most women and children had food insecurity and poor nutritional status which partly would be caused by climate change. It is recommended that nutritional education programs should be introduced in health facilities and in schools so as to improve the knowledge on nutrition. Also education should be given to the heads of households on how to utilize livestock in improving their livelihood/income and strategies to climate change adaptations.
Prevalence, mean intensity and pathology of ectoparasite infections in nile tilapia (oreochromis niloticus) in aquaculture production systems in Morogoro urban and rural areas, Tanzania
(Sokoine University of Agriculture, 2008) Mtenga, Coletha Mathew
A cross sectional study was carried out between September 2007 to September 2008 in order to investigate the prevalence, mean intensities and pathology of ectoparasite infections on the gills and skin of Nile tilapia (Qreochromis niloticns) in selected ponds in urban and rural areas of Morogoro, Tanzania. Pond area, fish size and water quality were also determined. On-farm oral interviews using structured questionnaire were carried out on each farm involved in the study to establish management practices. Two types of ectoparasite namely: Trichodina species and Monogeneans were identified. Trichodina spp were more prevalent (P < 0.001) than Monogeneans. Gills were the most affected organs than skins with a high number of parasites as well as pathological damage to the tissues (P < 0.001). Main pathological lesions observed on the gills were hyperplasia, sloughing and necrosis of the lamellar epithelium, clubbing and fusion of secondary lamellae. The physico-chemical parameters of water in the ponds and management practices were different from one another in the study area; however, there was no strong correlation between water quality and parasite prevalence and mean intensities of the parasites. Prevalence and mean intensities of parasites in fish varied in different ponds with some ponds having very high prevalence and mean intensity and others with very low. This might be explained by the different management systems based on the knowledge the farmers had on fish husbandry and different weather conditions in the study area. There were significantly higher parasite infections in fish in the urban than in the rural areas (P< 0.05). The overall prevalence in the study area was 68% and on average the mean intensity was 5.3. The ectoparasites seem to pose a threat to the aquaculture industry in Morogoro urban and rural areas as observed in this study. To rescue the situation, educational intervention and further research on tilapia parasitic diseases is needed. Farmers have to be trained on proper husbandry and good management practices of fish farming. There is also a need for the government to promote aquaculture as the country has a great potential for it.
Studies on the effects of trypanosoma congolense infection on the reproductive function of the ram
(University of Glasgow, 1993-12) Mutayoba, Benezeth Mugyabuso
This thesis describes a series of studies carried out in Scottish blackface rams experimentally infected with Trypanosoma congolense stabilates 57/10 and 57/11 (originally imported from ILRAD, Kenya as ILRAD 1180) with the primary aim of determining the effects of infection on the function of the hypothalamo-pituitary-gonadal axis. The studies also investigated the possibility that pyrexia is responsible for inducing gonadal endocrine and exocrine dysfunctions in infected animals. In addition the effect of infection on the function of the hypothalamo-pituitary-adrenal (HPA) axis was assessed in order to determine whether reproductive dysfunction generally seen during trypanosomiasis is related to stress caused by the infection. Chapter I comprises an introduction and a literature review on trypanosome- induced reproductive dysfunctions with emphasis on pyrexia and changes in the HPA axis. Chapter II describes the two experiments carried out in rams infected with T. congolense and the general materials and methods used in these studies. Chapter III describes the effects of infection on semen characteristics and pathology of various reproductive organs such as the testis, cauda epididymis, prostate and pituitary gland. It was found that T. congolense induced a progressive deterioration of semen quality in terms of an increased percentage of abnormal spermatozoa in the ejaculate. Progressive non-inflammatory degenerative changes were observed in the testis and prostate gland. The cauda epididymis showed varying degrees of decreased sperm reserve. Trypanosome-induced pyrexia led to an elevation of scrotal temperature in infected rams, suggesting that the changes in the gonads could have been due to increased testicular temperature. Indeed, similar changes were observed in the semen and gonads of uninfected rams following artificial elevation of testicular temperature by scrotal insulation. The pituitary gland showed changes associated with increased basophilic degranulation in infected rams. Changes in plasma concentrations of reproductive hormones in the same rams are described in Chapter IV. It was observed that soon after the onset of parasitaemia, which occurred within 1-2 weeks of infection, plasma testosterone concentration declined and levels remained low throughout the infection period. This reduction in plasma testosterone concentration was associated with a progressive and marked decline in testosterone pulse amplitude and testosterone secretion after injection of gonadotrophin-releasing hormone (GnRH) was also depressed throughout the infection period. By four weeks after infection, declining plasma testosterone concentration was accompanied by a significant increase in plasma luteinizing hormone (LH) pulse amplitude and increased pituitary responsiveness (LH secretion) to exogenous GnRH. As the infection progressed up to 8 weeks, the plasma LH concentration declined. This could not be associated with some aspects of gonadal steroid feedback as similar LH changes were observed in infected rams which had been castrated. Neither was the decline in plasma LH concentration caused by the inability of the pituitary gland to secrete and release LH as secretion of LH in response to exogenous GnRH was not impaired throughout the infection period. It was therefore concluded that the decline in plasma LH concentration after 8 weeks of infection was possibly induced by a progressive impairment of the ability of the hypothalamus to synthesize and/or release GnRH. Gonadal steroidogenesis in infected rams was investigated in the in vitro experiments described in Chapter V. This work showed that the alteration in plasma testosterone concentration following infection was associated with a decline in Leydig cell steroidogenesis, possibly mediated by increased testicular temperature affecting testosterone biosynthetic enzymes. However, by 4 weeks after infection, reduced plasma testosterone in infected animals was exacerbated by the impaired ability of the testes to release testosterone into the circulation resulting in a significant increase in intratesticular testosterone content. A similar increase was also observed in scrotal- insulated rams and it was therefore suggested that changes in intratesticular testosterone in infected rams at 4 weeks of infection was associated with a trypanosome-induced increase in testicular temperature perhaps through an effect on testicular blood flow. The effects of T. congolense infection on the function of the HPA axis in rams and the relationship between this and the changes in the hypothalamo-pituitary-gonadal axis are described in Chapter VI. The onset of parasitaemia stimulated a significant increase in plasma cortisol concentration which was followed within 3-6 week of infection by a decline in plasma cortisol levels and a reduced ability of the pituitary to secrete adrenocorticotrophin hormone (ACTH) after injection of corticotrophin-releasing hormone (CRH). Thereafter, the activity of the HPA axis was increased in step with the fluctuating parasitaemia. CRH stimulation of the HPA axis had no effect on LH secretion but reduced the plasma concentration of testosterone indicating the possible aggravation of T. congolense-induced reproductive disorders by stress-induced cortisol. The general discussion and conclusions drawn from all the experiments are. presented in Chapter VII. It can be concluded that T. congolense causes a very profound dysfunction of the hypothalamo-pituitary-gonadal axis in rams through actions at various sites. These effects may be partly associated with trypanosome-induced pyrexia and are exacerbated by increased plasma cortisol concentrations resulting from the activation of the HPA axis.
Porcine cysticercosis in Angonia district, North-Western Mozambique: epidemiology and evaluation of the effectiveness and efficiency of oxfendazole treatment
(Sokoine University of Agriculture, 2010) Junior, Alberto Pondja
A research was conducted to investigate the epidemiology of porcine cysticercosis in Angonia district, Mozambique, and to evaluate the effectiveness and efficiency of oxfendazole (OFZ) for the treatment of porcine cysticercosis. Prevalence and risk factors associated with porcine cysticercosis were determined in a cross-sectional survey conducted in 11 randomly selected villages. Out of 661 pigs screened, porcine cysticercosis was diagnosed in 12.7% and 34.9% by lingual examination and Ag-ELISA, respectively. Increasing age (OR = 1.63; 95% CI: 1.13, 2.37) and free-range pig husbandry system (OR = 3.81; 95% CI: 2.08, 7.06) were significant risk factors associated with the disease. The incidence of porcine cysticercosis was determined in a study conducted in 4 endemic villages. A total of 108 piglets were tested repeatedly for porcine cysticercosis (by Ag-ELISA) at 4, 9 and 12 months of age. The incidence rate of porcine cysticercosis increased significantly from 3.8 cases per 100 pig-months in the first period (between 4 and 9 months of age) to 19.3 cases per 100 pig-months in the second period (between 9 and 12 months of age). The effectiveness and efficiency of 30mg/kg dose of OFZ for the treatment of porcine cysticercosis were evaluated in a randomized control trial that involved 216 piglets. Fifty four piglets were treated at 4 months of age (OFZ-T1), other 54 piglets treated at 9 months (OFZ-T2) and matched with 108 controls. Baseline prevalence (by Ag-ELISA) was similar among the study groups. At 12 months of age, infections were found in 66.7% controls, 21.4% OFZ-T1 and 9.1% of the OFZ-T2 pigs. There was a significant risk reduction for cysticercosis if pigs were treated either at 4 months (OR = 0.14; 95% CI: 0.06, 0.34) or 9 months of age (OR = 0.05; 95% CI: 0.01, 0.15). Treating pigs with OFZ resulted in positive incremental net benefits. Porcine cysticercosis is endemic in Angonia district. Oxfendazole treatment is cost-effective, and combined with health education programs would have a significant contribution to the control of Taenia solium transmission. Further studies are needed to fine-tune the use of OFZ into a more practical field control tool for porcine cysticercosis.
Study on congenitally acquired Plasmodium Falciparum infection in neonates in Muheza district, Tanzania
(Sokoine University of Agriculture, 2006) Mwangoka, Grace Wynn
The study aimed to determine if infants diagnosed with malaria parasites in the age below three months acquire the infection congenitally from their mothers through the placenta. Placenta blood, cord blood samples and blood from infants born of mothers diagnosed with placental malaria by blood smear and presented clinical malaria below three months of age were examined by PCR amplification, PCR-RFLP and sequenced. Prevalence of Plasmodium falciparum by PCR in the placenta and cord were 9.2% and 65%, respectively and 18 (19.1%) of infants born from mothers diagnosed with placental malaria developed clinical malaria below three months of age. Placental blood and cord blood sample, and placental blood and blood samples of infants below three months that shared the same band size by PCR and fragments size by PCR-RFLP were considered to be genetically related. Though sequencing results confirm differently that, sharing band size and fragments size between samples does not confirm that the parasites are genetically related. Six pairs (40%) out of 14 pairs of placental blood and cord blood samples that shared band size and fragments size, after sequencing were genetically unrelated while eight pairs (60%) were genetically related which is an indication of transplacental transmission of malaria parasites to the cord. One pair (14.3%) of sequenced placental blood samples and blood samples of infants below three months were genetically related. This showed that the malaria parasite that crossed from the placenta to the infants through the cord caused congenital malaria. Over three-fourths (79.8%) of newborn infants delivered from mothers with placental malaria were below normal gestation age and 14.9% of newborn infants had low birth weights. Some 42.5% of primigravidae were found to be parasitized with P.falciparum in the placental. A higher proportional of infants from primigravid were frequently infected with malaria while infants from multigravid observed to acquire malaria infection early in life. Placental malaria, which leads to cord malaria, observed to significantly decrease (P <0.001) as gravid increases.
Prevalence, risk factors and genetic relatedness among thermophilic campylobacters from humans and chickens using rapd-pcr in Morogoro, Tanzania
(Sokoine University of Agriculture, 2009) Chuma, Idrissa Shomari
jejuni and 5% of C. coli were100% similar. Conclusively, zoonotic thermophilic Campylobacter infections existed between humans and chickens in Morogoro municipality. Besides chickens, the role played by other domestic and wild animals in transmitting thermophilic Campylobacter infections to humans particularly children, should be closely examined. jejuni and 5% of C. coli were

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