Articles, Conference and Workshop Papers Collection

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Self-medication with anti-malarials is a common practice in rural communities of Kilosa district in Tanzania despite the reported decline of malaria
(BioMed Central, 2014) Chipwaza, Beatrice; Mugasa, Joseph P; Mayumana, Iddy; Amuri, Mbaraka; Makungu, Christina; Gwakisa, Paul S
Self-medication has been widely practiced worldwide particularly in developing countries including Tanzania. In sub-Saharan Africa high incidences of malaria have contributed to self-medication with anti-malarial drugs. In recent years, there has been a gain in malaria control, which has led to decreased malaria transmission, morbidity and mortality. Therefore, understanding the patterns of self-medication during this period when most instances of fever are presumed to be due to non-malaria febrile illnesses is important. In this study, self-medication practice was assessed among community members and information on the habit of self-medication was gathered from health workers. Methods: Twelve focus group discussions (FGD) with members of communities and 14 in-depth interviews (IDI) with health workers were conducted in Kilosa district, Tanzania. The transcripts were coded into different categories by MaxQDA software and then analysed through thematic content analysis. Results: The study revealed that self-medication was a common practice among FGD participants. Anti-malarial drugs including sulphadoxine-pyrimethamine and quinine were frequently used by the participants for treatment of fever. Study participants reported that they visited health facilities following failure of self-medication or if there was no significant improvement after self-medication. The common reported reasons for self-medication were shortages of drugs at health facilities, long waiting time at health facilities, long distance to health facilities, inability to pay for health care charges and the freedom to choose the preferred drugs. Conclusion: This study demonstrated that self-medication practice is common among rural communities in the study area. The need for community awareness is emphasized for correct and comprehensive information about drawbacks associated with self-medication practices. Deliberate efforts by the government and other stakeholders to improve health care services, particularly at primary health care facilities will help to reduce self-medication practices.
Productivity of local chickens under village management Conditions
(Kluwer Academic, 2002) Mwalusanya N. A; Katule A. M; Mutayoba S. K; Mtambo, M. M. A; Olsen J. E; Minga U. M
The productivity of local chickens under village management conditions was studied in six villages situated in three climatic zones within Morogoro District in Tanzania. Two villages were picked in each climatic zone (warm and wet, warm and dry, cool and wet) for the study. The data were obtained by actual measurement, qualitative observations and interview of members of the households directly responsible for the care of chickens. In addition, data sheets were given to selected farmers to record the performance of their chickens. The mean £ock size for the three zones was 16.2, with a range of 2 to 58. The overall mean clutch size, egg weight and hatchability were 11.8, 44.1 g and 83.6%, respectively. The overall mean chick survival rate to 10 weeks of age was 59.7%. The mean live weights for cocks and hens were 1948 g and 1348 g, respectively. The mean growth rates to the age of 10 weeks were 4.6 g/day and 5.4 g/day, while those from 10 to 14 weeks of age were 8.4 g/day and 10.2 g/day for female and male birds, respectively. The age at ¢rst lay ranged between 6 and 8 months, and the average hen had three laying cycles per year. Most of the chickens were left to scavenge during the day and were provided with simple housing at night (95.2% of the owners). Only small amounts of supplementary feeds were occasionally given and minimal health care was provided. It was concluded that the low productivity of chickens was partly due to the prevailing poor management practices, in particular the lack of proper health care, poor nutrition and housing.
Partial molecular characterization of peste des petits ruminants virus in goats of Ngorongoro district, Tanzania
(Sokoine University of Agriculture, 2014) MACHA,EMMANUEL SADIKIEL
Livestock sector in the South African Development Community (SADC) accounts for 20 to 40% of agricultural gross domestic products holding high social values of the rural communities in the region of which 60% of the population depend on livestock. However, the sector is hampered by a multitude of economically important diseases including peste des petits ruminants (PPR). The disease is an acute highly contagious viral disease of domestic and wild ruminants caused by PPR virus (PPRV). It was first reported in West Africa in 1940s and confined there for decades. Afterwards, PPR spread to several other parts of the world including Asia and Europe. In Tanzania, PPR was officially reported in 2008 in the northern zone and in 2011 it was reported in the southern zone. The present study was conducted in Ngorongoro District of northern Tanzania to confirm the continued presence of PPRV and to partially characterize the PPRV circulating in northern Tanzania. A total of 28 goat samples (tissues, whole blood and swabs) were collected and analyzed. PPRV was detected in seven goats (25%) in all sample types (blood, tissue and swabs) using reverse transcription polymerase chain reaction (RT-PCR). PPRV nucleotide (N) gene nucleotide sequence analysis clustered PPRV circulating in northern Tanzania into linage HI with the percentage nucleotide identity of 95% to isolates from Ethiopia. Findings from this study indicates that swabs and whole blood are useful clinical samples for screening of PPRV especially in areas where animals may not exhibit clinical signs and carcasses are difficult to find. The continued circulation of PPRV in Ngorongoro District warrants further studies in order to determine whether wild animals serve as reservoirs of PPR.
Farm costs and benefits of antimicrobial use reduction on broiler farms in Dar es Salaam, Tanzania
(Frontiers, 2022-11-15) Azabo, Rogers R.; George, Janeth I.; Mshana, Stephen E.; Matee, Mecky I.; Kimera, Sharadhuli I.
Of all animal derived-food, the demand for poultry meat is the most dynamic. The poultry sector can meet this demand only by introducing intensive production where antimicrobial use is inevitable. Bacterial infection prevention and control is an important factor in intensive livestock production. Antibiotics are an effective and relatively inexpensive means of preventing and controlling infections, thus maintaining animal health and productivity. The aim of this study was to gain insight into the costs and benefits of various scenarios of antimicrobial use reduction at broiler farms in Dar es Salaam, Tanzania. This study focused on the economic impact of an average broiler farm. Costs and benefits for various scenarios of antimicrobial use reduction levels were projected by a partial budget framework using the Mclnerney model. The disease cost of the current situation was US$225. On reduction of antimicrobial use by 20% the avoidable disease cost was US$ 31, by 50% was US$ 83 and by 100% was US$ 147. A reduction in antibiotic use can only be achieved if better alternatives are available to combat disease. In conclusion, the model predicts that reducing antibiotic use increases production costs. Future studies on antimicrobial use reduction’s impact on morbidity and mortality and the efficiency of additional control and other measures of producing poultry meat without high concentrations of antibiotics are necessary.
Antimicrobial use in cattle and poultry production on occurrence of multidrug resistant Escherichia coli. A systematic review with focus on sub-Saharan Africa
(Frontiers, 2022-10-24) Azabo, Rogers; Dulle, Frankwell; Mshana, Stephen E.; Matee, Mecky; Kimera, Sharadhuli
Antimicrobial use in livestock production has been linked to antimicrobial resistance (AMR) worldwide; however, optimization of their use has been considered an important strategy in dealing with it. The aims of this study were as follows: (a) to assess the literature on antimicrobial usage (practices, frequency, class, type) in cattle and poultry production with regard to resistance in Escherichia coli (E. coli) including multidrug resistance (MDR) (b) summarize evidence for quantitative (volumes of active antimicrobial ingredients) and quality (identify and quantify active ingredient) and (c) to identify data gaps. Peer reviewed literature search was conducted by querying two online databases: PubMed and Google scholar from November 15, 2018 to February 2019. The inclusion criteria for eligibility were articles: published in English between 2008 and 2018, including poultry (chicken) or cattle or both, E. coli bacteria of choice, antimicrobial use on farms, quantitative data and quality of antimicrobial used. Microsoft Excel was used for data extraction and Rayyan software for eligibility studies. The search retrieved 1,446 probable articles including those from the reference list of significant papers, of which twenty-four articles remained on full text review with more than a third of the studies being conducted in Nigeria. Farm surveys and antimicrobial sales were identified as the main sources of data and the mean quantities of antimicrobials based on sales data were 23,234, 41,280.87, and 1,538,443 kg of the active ingredient in Nigeria, Zambia and South Africa, respectively. One study from Cameroon determined the quantities of active ingredients based on dose metrics while another study still from Cameroon mentioned the quality of antimicrobials. Tetracyclines, beta-lactams/aminoglycosides and fluoroquinolones were the most common classes of antimicrobials (antibiotics) used. Our review reveals a dearth of information in Sub- Saharan Africa on the quantity and quality of veterinary drugs and yet they play a role in the overall picture of antimicrobial resistance. This finding gives an opportunity in the area of focus for future research as far as resistance and multidrug resistance are concerned in food producing animals.
Assessment of antimicrobial consumption in food animals in Dar es Salaam, Tanzania
(Integrity Research Journals, 2021-10-13) Azabo, Rogers; Matee, Mecky; Kimera, Sharadhuli
Monitoring antimicrobial use in food-producing animals is one of the global strategies to tackle antimicrobial resistance. The purpose of the present study is to generate quantitative information on antimicrobial use pattern in Dar es Salaam, which will be used as an approach for future monitoring and surveillance of antimicrobial quantities consumed in food animals. A 3 years (2016-2018) retrospective survey of antimicrobial usage in food-producing animals in three selected districts of Dar es Salaam city, Eastern Tanzania was conducted. Data on antimicrobial quantities consumed was obtained from five purposively selected licensed veterinary pharmaceutical sales/outlet establishments in the study area, based on keeping detailed sales records for the study period.Data analysis was done using IBM SPSS version20. Animal population data were from FAO-Stat databaseused to extrapolate the quantity consumed in food animals to the entire population during the study period in Tanzania. The antimicrobials were analysed based on class, importance for human medicine and route of administration. The study revealed that 178.4 tonnes of antimicrobials (by weight of active ingredients) were consumed during the 3 years period, with an average of 59.5 ± 3.8 tonnes/year. The commonly consumed antimicrobials were tetracycline (44.4%), sulphonamides (20.3%), aminoglycosides (10.3%) and beta-lactams (7.4%). In relation to veterinary antimicrobial use importance to human medicine, 34.4% were of critically important antimicrobials; 4.1% reserve and 51% watch group according to AWaRe categorization of WHO. Most of the antimicrobials were administered orally. Overall,a mean of 7.44 ± 0.81 mg/PCU (population correction unit) was consumed by food-producing animals during the 3 years period. This finding can help improve monitoring and control of veterinary antimicrobial use in Dar es Salaam in particular and Tanzania in general by preserving the efficacy of antimicrobials for future animal and human generations.
Taenia saginata cysticercosis in cattle in Tanzania
(Sokoine University of Agriculture, 1993) Maeda Godfrey Elikalia
A review on the epidemiology and diagnosis of human taeniasis and bovine cysticercosis with special reference to East Africa is given. All humans are susceptible to the adult tapeworm, T. saginata. Cattle, is the predominant intermediate host, young animals being more susceptible than older ones. Susceptibility of a few wild ruminants makes them potential reservoirs of infection. Characteristics of T. saginata, including a long life span, a high reproductive potential, spontaneous shedding of proglottids from human carriers, occult nature of the cysticerci in cattle, etc, contribute to maintenance of infections. Dispersion and survival of T. saginata eggs are determined by sanitation, personal hygiene, coprophagous animals and weather conditions. Prevalence rates of cysticercosis in cattle reported from various countries depend on local meat hygiene legislations, efficiency of meat inspection, and record keeping in the abattoirs. In this thesis, factors promoting the spread of T. saginata infections in Tanzania were investigated, by interview information from 105 cattle owners, belonging to Masai, Arusha, Iraqw, Gogo and Rangi ethnic groups, from 52 villages in Tanzania. Taeniasis and cysticercosis were reported as common problems among members of the ethnic groups interviewed. Lack of awareness of the source of human tapeworms, scarcity of medicines against taeniasis, habits of consuming raw beef, consumption of uninspected meat, defaecation in the bush, were some of the outstanding factors elucidated. The details of this investigation are discussed and it is concluded that some of the observations need confirmation through further studies in the villages of the ethnic groups concerned. Prevalence rates of taeniasis recorded at Mbulu Hospital were 10% in 1990 and 21% in 1991. In a separate investigation, cysticercosis was detected in 52 (10.5%) out of 496 cattle X xi slaughtered in municipal abattoirs of Arusha, Dodoma, Iringa, Morogoro and Mpwapwa districts in Tanzania during the period between June 1991 and November 1991. The prevalence rates in the individual abattoirs were 16.7% (Arusha), 8% (Dodoma), 9.6% (Iringa), 6.5% (Morogoro) and 7.6% (Mpwapwa). The overall annual prevalence rates of cysticercosis in the Dodoma and Iringa regions were lower than the rates officially recorded in these abattoirs. The results are discussed in relation to sources of infection, endemicity of cysticercosis, efficiency of meat inspection, and records keeping in the abattoirs in the country. In a detailed examination, anatomical distribution of cysticerci of T. saginara (864) was analyzed in zebu cattle at Morogoro abattoir in Tanzania. The cysticerci were found located in the examined tissues preferentially in the following order: heart, M. triceps brachii, tongue, M. psoas and masseter muscles. The liver had relatively high numbers of cysts and is thus considered an important predilection site. Examination of the predilection sites for detecting carcasses positively infected with cysticerci of T. saginara revealed the following efficiency: 80% (heart), 80% (M. triceps brachii), 60% (masseter muscles), 60% (tongue) and 53% (liver). However examination of the heart, M. triceps brachii and the liver together detected all infected carcasses. Most (60%) of the infected carcasses had viable cysticerci. In conclusion, T. saginara taeniasis and cysticercosis are major, but underestimated problems in Tanzania. The diagnostic methods of cysticercosis in cattle and taeniasis in humans all have inherent limitations. But nevertheless, their sensitivity may be significantly be improved and the usual control may be more efficient. The various chapters of the thesis include discussions on ways to improve public control measures and educate consumers and herdsmen.
Antimicrobial resistance pattern of escherichia coli isolates from small scale dairy cattle in Dar es Salaam, Tanzania
(MDPI, 2022-07-21) Azabo Rogers R.; Mshana Stephen E.; Matee Mecky; Kimera Sharadhuli I.
In Tanzania, information on antimicrobial resistance in small-scale dairy cattle is scarce. This cross-sectional study was conducted to determine the different levels and pattern of antimicrobial resistance (AMR), in 121 Escherichia coli isolated from rectal swab of 201 apparently healthy small-scale dairy cattle in Dar es Salaam, Tanzania. Isolation and identification of E. coli were carried out using enrichment media, selective media, and biochemical tests. Antimicrobial susceptibility testing was carried out using the Kirby–Bauer disk diffusion method on Mueller-Hinton agar (Merck), according to the recommendations of Clinical and Laboratory Standards Institute (CLSI). Resistance was tested against ampicillin, gentamicin, chloramphenicol, trimethoprim-sulfamethoxazole, tetracycline, nalidixic acid, ciprofloxacin and cefotaxime. Resistance to almost all antimicrobial agents was observed. The agents to which resistance was demonstrated most frequently were ampicillin (96.7%), cefotaxime (95.0%), tetracycline (50.4%), trimethoprim-sulfamethoxazole (42.1%) and nalidixic acid (33.1%). In this case, 20 extended-spectrum beta-lactamases (ESBLs) producing E. coli were identified. 74.4% (90/121) of the isolates were Multidrug resistant (MDR), ranging from a combination of three to 8 different classes. 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. The high prevalence and wide range of AMR calls for prudent antimicrobial use.
Genetic diversity and risk factors for the transmission of antimicrobial resistance across human, animals and environmental compartments in East Africa: a review
(Springer Nature, 2020-08-06) Katale, Bugwesa Z.; Misinzo, Gerald; Mshana, Stephen E.; Chiyangi, Harriet; Campino, Susana; Clark, Taane G.; Good, Liam; Rweyemamu, Mark M.; Matee, Mecky I.
Background: The emergence and spread of antimicrobial resistance (AMR) present a challenge to disease control in East Africa. Resistance to beta-lactams, which are by far the most used antibiotics worldwide and include the penicillins, cephalosporins, monobactams and carbapenems, is reducing options for effective control of both Gram-positive and Gram-negative bacteria. The World Health Organization, Food and Agricultural Organization and the World Organization for Animal Health have all advocated surveillance of AMR using an integrated One Health approach. Regional consortia also have strengthened collaboration to address the AMR problem through surveillance, training and research in a holistic and multisectoral approach. This review paper contains collective information on risk factors for transmission, clinical relevance and diversity of resistance genes relating to extended-spectrum beta-lactamase-producing (ESBL) and carbapenemase producing Enterobacteriaceae, and Methicillin-resistant Staphylococcus aureus (MRSA) across the human, animal and environmental compartments in East Africa. Main body: The review of the AMR literature (years 2001 to 2019) was performed using search engines such as PubMed, Scopus, Science Direct, Google and Web of Science. The search terms included ‘antimicrobial resistance and human-animal-environment’, ‘antimicrobial resistance, risk factors, genetic diversity, and human animal-environment’ combined with respective countries of East Africa. In general, the risk factors identified were associated with the transmission of AMR. The marked genetic diversity due to multiple sequence types among drug-resistant bacteria and their replicon plasmid types sourced from the animal, human and environment were reported. The main ESBL, MRSA and carbapenem related genes/plasmids were the bla CTX-Ms (45.7%), SCCmec type (27.3%) and IMP types (23.8%), respectively. Conclusion: The high diversity of the AMR genes suggests there may be multiple sources of resistance bacteria, or the possible exchange of strains or a flow of genes amongst different strains due to transfer by mobile genetic elements. Therefore, there should be harmonized One Health guidelines for the use of antibiotics, as well as regulations governing their importation and sale. Moreover, the trend of ESBLs, MRSA and carbapenem resistant (CAR) carriage rates is dynamic and are on rise over time period, posing a public health concern in East Africa. Collaborative surveillance of AMR in partnership with regional and external institutions using an integrated One Health approach is required for expert knowledge and technology transfer to facilitate information sharing for informed decision-making.
Poultry farmers’ information needs and extension advices in Kilosa, Tanzania: evidence from Mobile-based extension, advisory and learning system (meals)
(University of Nebraska - Lincoln, 2018) Msoffe, Grace; Chengula, Augustino; Kipanyula, Maulilio J; Mlozi, Malongo R.S; Sanga, Camilius A
Poultry farmers need different information in order to improve their farming and contribute to the national economy. Information on poultry management is usually obtained from family members, friends, and neighbors with previous experience, extension officers, researchers, Television, radio, web and mobile based agriculture information systems. Promoting utilisation of vetted sources of information is envisaged to support poultry farmers in making informed decisions about management practices. This in turn will result into increased poultry productivity. Objective: Many researches have been done to evaluate various information sources but few have been done to evaluate the mobile based extension, advisory and learning system here referred to “UshauriKilimo”. This study particularly assessed poultry farmers’ information needs and extension advices given through the agro-advisory system among farmers in Kilosa district of Tanzania. The objective was to determine poultry farmers’ information needs submitted through “UshauriKilimo” and resulting advisory responses. Method: ICT based agro-advisory system 'UshauriKilimo' was deployed and used by poutry famrers for more than two years. The data from it were used to assess poultry farmers information needs. Only questions and advisory responses addressing poultry farming were analysed. These data were imported into the Qualitative Data Analysis Software, MAXQDA Plus 12 (Release 12.2.0) where they were coded, counted and analysed. Frequencies of variables were performed during content analysis. Results: More than 340 farmers used “UshauriKilimo” for the period of two years. There were more than 1500 questions and answers which contained 320 questions related to poultry farming. Most of the poultry farmers who used “UshauriKilimo” sought information on health management aspects (diseases transmission, diagnosis, treatment and control); egg production; chicken feeds and feeding; chicken breeds and housing aspects. Information on markets was the least used.
Aedes aegypti abundance, larval indices and risk for dengue virus transmission In Kinondoni district, Tanzania
(BMC, 2022) Ngingo, Baraka L; Mboera, Leonard E. G; Chengula, Augustino; Machelle, Ines; Makange, Mariam R; Msolla, Michael; Mwanyika, Gaspary O; Rugarabamu, Sima; Misinzo, Gerald
Background: Tanzania has experienced periodic dengue outbreaks with increased incidence since 2010. However, there is limited information on vector dynamics and transmission risk in most parts of the country. This study was conducted to determine Aedes mosquito abundance, larval indices and dengue virus infection rate as risk indicators for DENV transmission in Kinondoni district, Dar es Salaam, Tanzania. Methods: A cross-sectional study was conducted in three wards of Kinondoni district in Tanzania between Decem- ber 2019 and January 2020. In each ward, three streets were randomly selected for adult and immature mosquito sampling. The adult mosquitoes were collected using Mosquito Magnet traps, while mosquito larvae and pupae were inspected in water-holding containers in the selected household compounds. The detection of dengue virus (DENV) in female Aedes mosquitoes was done using a one-step reverse transcription–polymerase chain reaction (RT–PCR) method. Results: Of the 1416 adult female mosquitoes collected, Ae. aegypti accounted for 16.8% (n = 238). A total of 333 water-holding containers were inspected and 201 (60.4%) had at least an Aedes larvae or pupae. Water-holding containers supporting the breeding of Aedes larvae and pupae included discarded car tires, flowerpots and small and large plastic containers. The overall House Index, Container Index and Breteau Index were 55.1%, 60.4% and 114.2, respectively. None of the 763 female Aedes mosquitoes tested by RT–PCR was found to be infected with DENV. Conclusion: The presence and abundance Ae. aegypti mosquitoes and the large proportion of water-holding con- tainers infested with the mosquito larvae and pupae put residents of Kinondoni district at high risk of DENV trans- mission. Our findings emphasize the need for continuous mosquito vector surveillance and control to prevent the possibility of future DENV outbreaks in Tanzania.
Poultry ecto-, endo- and haemoparasites in Tanzania: a review
(Austin Publishing Group, 2020) Rukambile, EJ; Chengula, A; Swai, ES; Jongejan, F
Poultry production plays an essential role in food and nutrition security at household level through the provision of eggs and meat and income generation. Ecto-, endo- and haemoparasites occurring in poultry singly or a combination are commonly found in Tanzania and affect poultry sector productivity. At least 27 species of nematodes, one species of trematodes; 13 species of cestodes and seven species of protozoa (only Eimeria spp) reported parasitizing commercial, indigenous chicken, ducks, guinea fowls and pigeons in Tanzania. Several ecto-parasites (fleas, mites, lice, soft and hard ticks) identified and reported in indigenous chickens and pigeons whereas eight species of haemoparasites documented in indigenous chickens, pigeons and guineafowls. Most of the studies conducted in Tanzania skewed toward eastern parts of the country, which makes the use of available reports for determination of poultry parasite profiles and distribution difficult or impossible. This paper reviews the ecto-, endo- and heamoparasite profiles of poultry occurring in Tanzania. This review provides available information and gaps in the occurrence and distribution of the ecto-, endo- and haemoparasites in different types of poultry in Tanzania. The study suggests a broader country survey and frequent surveillances establishing the magnitude of the problem, which is an essential tool in designing control strategies.
Exploring pathogenic and zoonotic bacteria from wild rodents, dogs, and humans of the Ngorongoro district in Tanzania using metagenomics next-generation sequencing
(MDPI, 2023) Issae, Amina Ramadhani; Katakweba, Abdul Selemani; Kicheleri, Rose Peter; Chengula, Augustino Alfred; Van Zwetselaar, Marco; Kasanga, Christopher Jacob
Globally, zoonoses have serious consequences due to their socioeconomic impacts. Ngoron- goro District is home to a diverse range of wildlife and domestic animals, including rodents and dogs, which often coexist in close proximity with humans. The aim of the study was to identify the zoonotic bacteria present in wild rodents, domestic dogs, and humans using metagenomics next-generation sequencing technology. A cross-sectional study was conducted in 2022. This study used both Illumina and Oxford Nanopore sequencing technologies to identify bacteria in 530 blood samples collected from humans (n = 200), wild rodents (n = 230), and dogs (n = 100). Several zoonotic airborne/contagious bacteria, including Mycobacterium spp., Mycoplasma spp., Bordetella spp., and Legionella spp., were detected in wild rodents, domestic dogs, and humans. Arthropod-borne zoonotic bacteria such as Bartonella spp., Borrelia spp., and Rickettsia spp. were detected in all three hosts, while Orientia spp. was found in wild rodents and domestic dogs. Yersinia pestis, Streptobacillus spp. and Anaplasma spp. were found only in wild rodents. Other zoonotic bacteria found shared among wild rodents, domestic dogs, and humans are Leptospira spp., Brucella spp., and Salmonella spp. Generally, wild rodents had the highest prevalence of zoonotic bacterial species when compared to domestic dogs and humans. The detection of zoonotic bacteria in rodents, dogs, and humans supports the hypothesis that infections can spread between animals and humans sharing the same environment.
Genetic diversity of newcastle disease virus involved in the 2021 outbreaks in backyard poultry farms in Tanzania
(MDPI, 2023) Amoia, Charlie F.; Hakizimana, Jean N; Chengula, Augustino A; Rohaim, Mohammed A; Munir, Muhammad; Weger-Lucarelli, James; Misinzo, Gerald
Newcastle disease virus is a significant avian pathogen with the potential to decimate poultry populations all over the world and cause enormous economic losses. Distinct NDV genotypes are currently causing outbreaks worldwide. Due to the high genetic diversity of NDV, virulent strains that may result in a lack of vaccine protection are more likely to emerge and ultimately cause larger epidemics with massive economic losses. Thus, a more comprehensive understanding of the circulating NDV genotypes is critical to reduce Newcastle disease (ND) burden. In this study, NDV strains were isolated and characterized from backyard poultry farms from Tanzania, East Africa in 2021. Reverse-transcription polymerase chain reaction (RT-PCR) based on fusion (F) gene amplification was conducted on 79 cloacal or tracheal swabs collected from chickens during a suspected ND outbreak. Our results revealed that 50 samples out 79 (50/79; 63.3%) were NDV- positive. Sequencing and phylogenetic analyses of the selected NDV isolates showed that 39 isolates belonged to subgenotype VII.2 and only one isolate belonged to subgenotype XIII.1.1. Nucleotide sequences of the NDV F genes from Tanzania were closely related to recent NDV isolates circulating in southern Africa, suggesting that subgenotype VII.2 is the predominant subgenotype throughout Tanzania and southern Africa. Our data confirm the circulation of two NDV subgenotypes in Tanzania, providing important information to design genotype-matched vaccines and to aid ND surveillance. Furthermore, these results highlight the possibility of the spread and emergence of new NDV subgenotypes with the potential of causing future ND epizootics.
Tilapia lake virus does not hemagglutinate avianand piscine erythrocytes and nh 4 cl does not inhibit viral replication in vitro
(MDPI, 2019) Chengula, Augustino Alfred; Mutoloki, Stephen; Evensen, Øystein; Munang’andu, Hetron Mweemba
Tilapia lake virus (TiLV) is a negative-sense single-stranded RNA (-ssRNA) icosahedral virus classified to be the only member in the family Amnoonviridae. Although TiLV segment-1 shares homology with the influenza C virus PB1 and has four conserved motifs similar to influenza A, B, and C polymerases, it is unknown whether there are other properties shared between TiLV and orthomyxovirus. In the present study, we wanted to determine whether TiLV agglutinated avian and piscine erythrocytes, and whether its replication was inhibited by lysosomotropic agents, such as ammonium chloride (NH 4 Cl), as seen for orthomyxoviruses. Our findings showed that influenza virus strain A/Puerto Rico/8 (PR8) was able to hemagglutinate turkey (Meleagris gallopavo), Atlantic salmon (Salmo salar L), and Nile tilapia (Oreochromis niloticus) red blood cells (RBCs), while infectious salmon anemia virus (ISAV) only agglutinated Atlantic salmon, but not turkey or tilapia, RBCs. In contrast to PR8 and ISAV, TiLV did not agglutinate turkey, Atlantic salmon, or tilapia RBCs. qRT-PCR analysis showed that 30 mM NH 4 Cl, a basic lysosomotropic agent, neither inhibited nor enhanced TiLV replication in E-11 cells. There was no difference in viral quantities in the infected cells with or without NH 4 Cl treatment during virus adsorption or at 1, 2, and 3 h post-infection. Given that hemagglutinin proteins that bind RBCs also serve as ligands that bind host cells during virus entry leading to endocytosis in orthomyxoviruses, the data presented here suggest that TiLV may use mechanisms that are different from orthomyxoviruses for entry and replication in host cells. Therefore, future studies should seek to elucidate the mechanisms used by TiLV for entry into host cells and to determine its mode of replication in infected cells.
Porcine circovirus 2 uses heparan sulfate and chondroitin sulfate B glycosaminoglycans as receptors for its attachment to host cells
(Journal of virology, 2006) Misinzo, Gerald; Delputte, Peter L; Meerts, Peter; Lefebvre, David J; Nauwynck, Hans J
Monocyte/macrophage lineage cells are target cells in vivo for porcine circovirus 2 (PCV2) replication. The porcine monocytic cell line 3D4/31 supports PCV2 replication in vitro, and attachment and internalization kinetics of PCV2 have been established in these cells. However, PCV2 receptors remain unknown. Glycosami- noglycans (GAG) are used by several viruses as receptors. The present study examined the role of GAG in attachment and infection of PCV2. Heparin, heparan sulfate (HS), chondroitin sulfate B (CS-B), but not CS-A, and keratan sulfate reduced PCV2 infection when these GAG were incubated with PCV2 prior to and during inoculation of 3D4/31 cells. Enzymatic removal of HS and CS-B prior to PCV2 inoculation of 3D4/31 cells significantly reduced PCV2 infection. Similarly, when PCV2 virus-like particles (VLP) were allowed to bind onto 3D4/31 cells in the presence of heparin and CS-B, attachment was strongly reduced. Titration of field isolates and low- and high-passage laboratory strains of PCV2 in the presence of heparin significantly reduced PCV2 titers, showing that the capacity of PCV2 to bind GAG was not acquired during in vitro cultivation but is an intrinsic feature of wild-type virus. When Chinese hamster ovary (CHO) cells were inoculated with PCV2, relative percentages of PCV2-infected cells were 27% ⴞ 8% for HS-deficient and 12% ⴞ 10% for GAG-deficient cells compared to wild-type cells (100%). Furthermore, it was shown using heparin-Sepharose chromatography that both PCV2 and PCV2 VLP directly interacted with heparin. Together, these results show that HS and CS-B are attachment receptors for PCV2
Historical environmental change in africa drives divergence and admixture of aedes aegypti mosquitoes:aprecursor to successful worldwide colonization?
(John Wiley & Sons Ltd., 2016) Bennett, Kelly louise; Shija, Fortunate; Linton, Yvonne-marie; Misinzo, Gerald; Kaddumukasa, Martha; Djouaka, Rousseau; Anyaele, Okorie; Harris, Angela; Irish, Seth; Hlaing, Thaung; P r a k a s h, A n i l; L u t w a m a, J u l i u s; Walton, Catherine
Increasing globalization has promoted the spread of exotic species, including disease vectors. Understanding the evolutionary processes involved in such colonizations is both of intrinsic biological interest and important to predict and mitigate future dis- ease risks. The Aedes aegypti mosquito is a major vector of dengue, chikungunya and Zika, the worldwide spread of which has been facilitated by Ae. aegypti’s adaption to human-modified environments. Understanding the evolutionary processes involved in this invasion requires characterization of the genetic make-up of the source population (s). The application of approximate Bayesian computation (ABC) to sequence data from four nuclear and one mitochondrial marker revealed that African populations of Ae. aegypti best fit a demographic model of lineage diversification, historical admixture and recent population structuring. As ancestral Ae. aegypti were dependent on forests, this population history is consistent with the effects of forest fragmentation and expansion driven by Pleistocene climatic change. Alternatively, or additionally, histori- cal human movement across the continent may have facilitated their recent spread and mixing. ABC analysis and haplotype networks support earlier inferences of a single out-of-Africa colonization event, while a cline of decreasing genetic diversity indicates that Ae. aegypti moved first from Africa to the Americas and then to Asia. ABC analy- sis was unable to verify this colonization route, possibly because the genetic signal of admixture obscures the true colonization pathway. By increasing genetic diversity and forming novel allelic combinations, divergence and historical admixture within Africa could have provided the adaptive potential needed for the successful worldwide spread of Ae. aegypti.
Human leptospirosis in tanzania:sequencing and phylogenetic analysis confirm that pathogenic leptospira species circulate among agro-pastoralists living in Katavi-Rukwa ecosystem
(BMC, 2016) Muller, Shabani K; Assenga, Justine A; Matemba, Lucas E; Misinzo, Gerald; Kazwala, Rudovick R
Background: Leptospirosis is a neglected zoonotic disease of worldwide public health importance. The disease affects humans, domestic animals and wildlife. However, leptospirosis is challenging in its diagnosis in humans. Culture technique, which is time consuming, is not recommended for clinical diagnosis. For these reasons, serological and molecular techniques remain the test of choice. The major objective of this study was to explore the genetic characteristic of Leptospira species which are prevalent among agro-pastoralists living in Katavi–Rukwa Ecosystem, Tanzania. Methods: A cross-sectional epidemiological study was carried out in the Katavi-Region South-west, Tanzania between August, 2013 and November, 2014. A total of 267 participants were randomly recruited for the study. Microscopic agglutination test (MAT) was used to detect antibody against six Leptospira antigens including local serogroups Icterohaemorrhagiae, Ballum, Grippotyphosa, Sejroe and reference serogroups Hebdomadis, and Australis. Samples with MAT titers ≥ 1:160 were scored as positive, samples with MAT titers ranging from 1:20 to 1:80 were scored as exposed to Leptospira, and absence of agglutination titers was scored as negative. All MAT positive samples, including the low titre samples were subjected to PCR using the respective 16S rRNA primers for the pathogenic and non-pathogenic species. Results: Out of 267 samples tested, 80 (29.9 %) were positive with MAT. The major circulating leptospiral serogroups were Sejroe (15.7 %,), Icterohaemorrhagiae (8.9 %), Grippotyphosa (4.8 %), Hebdomadis (3.37 %), Australis (1.49 %) and Ballum (1.19 %). By using PCR, 33 (15.7 %) out of 210 samples were pathogenic Leptospira while no saprophytic Leptospira spp. was detected. Partial 16S rRNA gene sequences of Leptospira species which were obtained from this study were submitted to GenBank and acquired accession numbers KP313246 and KP313247. Phylogenetic analysis of the nucleotide sequences revealed that species obtained from Katavi-Rukwa ecosystem clustered in the same group with several published pathogenic Leptospira specifically Leptospira interrogans and Leptospira kirschneri. To the best of the authors’ knowledge , this is the first study from Tanzania to confirm pathogenic Leptospira in human subjects using genomic typing technique. Conclusion: These findings provide ultimate evidence of pathogenic Leptospira species circulating among agro-pastoralists living in Katavi-Rukwa Ecosystem suggesting that active disease surveillance should be undertaken in order to achieve greater protection of the agro-pastoral communities in Tanzania.
Climate change influences potential distribution of infected aedes aegypti co-occurrence with dengue epidemics risk areas in Tanzania
(PLOS, 2016) Mweya, Clement N; Kimera, Sharadhuli I; Stanley, Grades; Misinzo, Gerald; Mboera, Leonard E. G
Dengue is the second most important vector-borne disease of humans globally after malaria. Incidence of dengue infections has dramatically increased recently, potentially due to changing climate. Climate projections models predict increases in average annual tem- perature, precipitation and extreme events in the future. The objective of this study was to assess the effect of changing climate on distribution of dengue vectors in relation to epi- demic risk areas in Tanzania.
Ectoparasites of free ranging local chickens in urban and peri-urban areas of Morogoro municipality, Tanzania
(Research Gate, 2022) Materu, Adrian E; Mkhandi, Jastin W
A free range system of poultry production is an important economical investment to most of the poor farmers as a source of income and protein, however it faces several challenges including parasitic diseases such as ectoparasite infestation. A cross-sectional study was undertaken to determine the prevalence of ectoparasites, as well as to assess the possible predisposing risk factors infesting free- ranging local chickens in urban and per urban areas in Morogoro municipality, Tanzania. Samples were randomly taken from 144 chickens and age, sex and management practice status of the study population was simultaneously recorded. An overall 53.5% (77/144) prevalence was recorded in this study and three common taxa of ectoparasites were identified, which are lice, fleas, and mites. The individual ectoparasite prevalence were as follows Menopon gallinae 48.6% (70/144) followed by Cnemidocoptes mutans 16% (23/144), Echidnophaga gallinacean 9.7% (14/144) and Goniodes gigas 5.8% (8/144). Among the potential predisposing factors assessed, age and management practice was found to be statistically significantly associated with ectoparasitic infestation (p< 0.05). However, sex was not found statistically significantly associated with the level of infestation (p> 0.05) . This study reveals that ectoparasites are highly prevalent in free-ranging local chickens in Morogoro Municipality, Tanzania.

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