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Development and evaluation of a novel vaccine storage device for effective vaccination strategy against rabies
(Sokoine University of Agriculture, 2023) Lugelo, Ahmed Kambinda
Canine-mediated human rabies has the highest case fatality rate of any known infectious disease and kills approx. 59,000 people annually, with most deaths being children under 15 years. The vast majority (99%) of these fatalities occur in Africa and Asia, where access to appropriate Post Exposure Prophylaxis (PEP) is limited and where canine vaccination is either inconsistently applied or, commonly, non-existent. Epidemiological studies have shown that rabies has epidemiological features that make elimination a realistic and feasible goal, with success demonstrated by comprehensive mass dog vaccination programmes in the Americas, Western Europe and Japan. In rabies endemic countries, dogs are often vaccinated using annually delivered central point clinics at the village level on an annual basis. For this method to be effective at least 70% of the dog population must be vaccinated to maintain herd immunity between campaigns. However, studies have shown that only a few programmes utilising this approach have attained this level of coverage, highlighting the need for alternative approaches to address this challenge. The current study was carried out to develop an alternative strategy for delivering and maintaining herd immunity over time in low-resource field settings. Through an iterative process of improvement and testing with local communities in northern Tanzania, a passive cooling device “Zeepot” for storage of thermotolerant rabies vaccines was developed at a cost of $11 per unit. The results from a non-inferiority randomised controlled trial showed that the serological response of dogs vaccinated using Nobivac ® Rabies vaccine stored within the Zeepot was not inferior to the response of dogs vaccinated using cold-chain stored vaccine (z = 1.1, df = 313, p-value = 0.25). Indeed, the 28-day post vaccination group geometric mean titre was 1.8 IU/ml and 2.0 IU/ml for dogs vaccinated with vaccines stored under cold-chain versus non-cold-chain respectively. Moreover, the percentage of dogs that seroconverted in each arm was almost identical (85%). There was a positive linear trend between Body Condition Score (O.R. 2.2, 95% CI: 1.1 – 5.1) and seroconversion, suggesting that dogs of poor condition may not respond as expected to vaccination. Our study demonstrated that the potency of Nobivac ® Rabies vaccine is not impacted following storage in Zeepot Clay locally designed Passive Cooling Device. A total of 17,571 dogs were vaccinated in the field study that was conducted to evaluate the effectiveness of the standard delivery method also known as Central Point Vaccination (CPV) and a novel strategy, Decentralized Continuous Vaccination (DCV), 2654 dogs were vaccinated using CPV and 14,917 dogs were vaccinated through three sub-strategies of DCV. At time point 1 (1 month after the initial vaccination campaign), the vaccination coverage achieved by DCV coverage was higher (64.10%; 95CI 62.12 – 66.04) than for CPV (35.86%; 95CI 32.59 – 39.51). Similarly, at time point 2 (11 months after the vaccination campaign) the coverage in DCV (60.67%; 95CI 58.47 – 62.84) remained high while the coverage in pulse vaccination was lower (32.10%; 95CI 28.82-35.57). Overall, > 84% of the respondents were satisfied with the vaccination services they received. DCV has the potential to consistently maintain population level immunity. Overall, this thesis showed that Zeepot Clay has a utility for storing thermotolerant vaccines at sub-ambient temperatures. Moreover, DCV has the potential to consistently maintain population level immunity making it a useful strategy to further investigate for scaling up of mass dog vaccination in East Africa. Together the findings of this work have potential application for rabies elimination programmes, particularly in achieving the global target of zero human deaths by 2030 and potentially for use in other vaccination programmes aiming to reach remote or inaccessible communities.
Reproduction of East-African bats may guide risk mitigation for coronavirus spillover
(BMC, 2020-02-07) Montecino-Latorre, Diego; Goldstein, Tracey; Gilardi, Kirsten; Wolking, David; Van Wormer, Elizabeth; Kazwala, Rudovick; Ssebide, Benard; Nziza, Julius; Sijali, Zikankuba; Cranfield, Michael; PREDICT Consortium; Mazet, Jonna A. K.
Background: Bats provide important ecosystem services; however, current evidence supports that they host several zoonotic viruses, including species of the Coronaviridae family. If bats in close interaction with humans host and shed coronaviruses with zoonotic potential, such as the Severe Acute Respiratory Syndrome virus, spillover may occur. Therefore, strategies aiming to mitigate potential spillover and disease emergence, while supporting the conservation of bats and their important ecological roles are needed. Past research suggests that coronavirus shedding in bats varies seasonally following their reproductive cycle; however, shedding dynamics have been assessed in only a few species, which does not allow for generalization of findings across bat taxa and geographic regions. Methods: To assess the generalizability of coronavirus shedding seasonality, we sampled hundreds of bats belonging to several species with different life history traits across East Africa at different times of the year. We assessed, via Bayesian modeling, the hypothesis that chiropterans, across species and spatial domains, experience seasonal trends in coronavirus shedding as a function of the reproductive cycle. Results: We found that, beyond spatial, taxonomic, and life history differences, coronavirus shedding is more expected when pups are becoming independent from the dam and that juvenile bats are prone to shed these viruses. Conclusions: These findings could guide policy aimed at the prevention of spillover in limited-resource settings, where longitudinal surveillance is not feasible, by identifying high-risk periods for coronavirus shedding. In these periods, contact with bats should be avoided (for example, by impeding or forbidding people access to caves). Our proposed strategy provides an alternative to culling – an ethically questionable practice that may result in higher pathogen levels – and supports the conservation of bats and the delivery of their key ecosystem services.
Factors lowering levels of rabies vaccination: a case of Kibaha town District of Tanzania
(Tanzania Veterinary Journal, 2019) Chikoondo, F. M; Majid, K.S; Muhairwa, A.P; Mpelumbe-Ngeleja, C.A.R
A study was conducted in Kibaha Town Council of Pwani Region of Tanzania to survey the probable factors that negatively affected the anti-rabies vaccinations leading to low percent coverage in some selected wards. The data used in this study were gathered from households keeping dogs and cats and institutions, using a semi-structured questionnaire and interviews. Another set of data was the record of the rabies control programme at the district veterinary office. Analysis of the data was done using SPSS.16, Microsoft Excel 2007 and EpiInfo TM 7. The enquiry instrument centred on three main fields, namely, knowledge of respondents about rabies, responsible dog ownership and their perception of issues pertaining to the conduct of the rabies control programme. The results showed that the last round of vaccination covered dogs for 57% of the sampled households in the selected wards. A huge percentage of the respondents (64%) kept the wrong perception that clinical rabies could be cured. Only 34% of the respondents indicated that they had been taught about rabies in a WHO project area. It was also learnt that there was an outbreak of rabies in the district after 2 years of consecutively vaccinating the dogs in the area. The Chi- square test for linear trends showed very highly significant statistical differences in the progression of numbers of dogs vaccinated over the years (p<0.05; = 0.0000). This study concludes that, lack of sufficient knowledge on rabies and negative attitude towards the control programme were the biggest drawbacks on the vaccination coverage.
Socio-cultural practices related to taenia solium taeniosis and cysticercosis Epidemiology in endemic areas
(TVA, 2020) Kajuna, F.F; Mwang’onde, B.J; Holst, C.; Ngowi, B.; Noll, J; Winkler, A.S.; Ngowi, H.A.
Socio-cultural settings and lifestyles of communities in Taenia solium taeniosis/cysticercosis (TSTC) in endemic areas influence significantly the epidemiology of the disease. This study investigated the community perceptions and practices influencing the occurrence and endemicity of TSTC. A cross- sectional survey focusing on pig-keeping households was carried out in three wards of Iringa District Council as a representative of other TSTC endemic areas. Questionnaire and observation checklists were employed for data collection. Eighty-seven (99%) of the 88 surveyed households had pit latrines, and 84(95%) of the households were found using their latrines. These latrines varied from good to a very good quality according to subjective qualitative scores. About 294 (85%) pigs were enclosed and 52(15%) were free roaming. The results indicated poor adherence to routine pig inspection at sales (50% inspection) and less pork inspection at slaughter (50% uninspected). Furthermore, there were no authorized centres for slaughter and sales. Health Officers and farmers were comfortable with the boiling form and home prepared pork (>90%). Health Officers perceived deep-frying and roasting of pork as inappropriate preparation methods. Generally, the social cultural practices and life style in the study area promoted the endemicity of Taenia solium life cycle. A strategy for surveillance on socio- cultural practices in the community is important during planning for TSTC control. This community needs sustainable health education on TSTC diseases control.
Challenges in the diagnosis of taenia solium cysticercosis and taeniosis in medical and veterinary settings in selected regions of Tanzania: a cross-sectional study
(Hindawi, 2022-06-30) Mlowe, Fredy; Karimuribo, Esron; Mkupasi, Ernatus; Churi, Ayubu; Nyerere, Antony D.; Schmidt, Veronika; Ngowi, Helena; Winkler, Andrea S.; Mlangwa, James
Taenia solium (neuro) cysticercosis/taeniosis (TSCT) is a zoonotic disease complex. There is a perceived inefficient diagnosis of infections by either form, the adult pork tapeworm (taeniosis) and the larval stage of it (cysticercosis), in low-income settings, including Tanzania. This study aimed at identifying potential gaps around TSCT diagnosis and knowledge of primary healthcare providers (officers in charge (OICs) of primary healthcare facilities (PHFs)) and veterinarians (meat inspectors (MIs)) on various aspects of TSCT disease complex and addressing effective disease control in Tanzania. Methodology. A cross-sectional study was conducted between January and April 2020 in Manyara, Dodoma, Ruvuma, Iringa, and Arusha regions in Babati, Mbulu, Kongwa, Mbinga, and Nyasa districts. We interviewed 152 OICs of PHFs and 108 MIs using a structured questionnaire and 33 medical and veterinary officers from level I healthcare facilities and district livestock offices, respectively, from selected study districts to the respective ministerial level using key informant interviews. Results. Quantitative data revealed inadequate microscopic diagnostic facilities (54.6%) and personnel (100%) for taeniosis diagnosis in PHFs (n 152). Approximately 81.2% of MIs compared with only 42.1% of OICs of PHFs scored above average regarding T. solium cysticerci knowledge. Nevertheless, 61.2% of OICs of PHFs compared with only 42.6% of MIs scored above average regarding the adult T. solium tapeworm knowledge. Qualitative data revealed inadequate availability of advanced diagnostic facilities (neuroimaging) and trained personnel for specific diagnosis of TSCT with a focus on neurocysticercosis (NCC) in secondary and tertiary healthcare facilities. Inadequately number of qualified MIs, slaughter slabs, and resource facilitation challenged porcine cysticercosis diagnosis. Conclusion. It is concluded that diagnostic capacity and knowledge of OICs of PHFs and MIs regarding TSCT are insufficient in both medical and veterinary sectors. A One Health approach should be adopted to improve TSCT diagnostic capacity and practitioners’ knowledge in both medical and veterinary sectors.
Incidence estimates of acute Q fever and spotted fever group rickettsioses, Kilimanjaro, Tanzania, from 2007 to 2008 and from 2012 to 2014
(The American Society of Tropical Medicine and Hygiene, 2022) Pisharody, Sruti; Rubach, Matthew P.; Carugati, Manuela; Nicholson, William L.; Perniciaro, Jamie L.; Biggs, Holly M.; Maze, Michael J.; Hertz, Julian T.; Halliday, Jo E. B.; Allan, Kathryn J.; Mmbaga, Blandina T.; Saganda, Wilbrod; Lwezaula, Bingileki F.; Kazwala, Rudovick R.; Cleaveland, Sarah; Maro, Venance P.; Crump, John A.
Q fever and spotted fever group rickettsioses (SFGR) are common causes of severe febrile illness in north- ern Tanzania. Incidence estimates are needed to characterize the disease burden. Using hybrid surveillance—coupling case-finding at two referral hospitals and healthcare utilization data—we estimated the incidences of acute Q fever and SFGR in Moshi, Kilimanjaro, Tanzania, from 2007 to 2008 and from 2012 to 2014. Cases were defined as fever and a four-fold or greater increase in antibody titers of acute and convalescent paired sera according to the indirect immunoflu- orescence assay of Coxiella burnetii phase II antigen for acute Q fever and Rickettsia conorii (2007–2008) or Rickettsia africae (2012–2014) antigens for SFGR. Healthcare utilization data were used to adjust for underascertainment of cases by sentinel surveillance. For 2007 to 2008, among 589 febrile participants, 16 (4.7%) of 344 and 27 (8.8%) of 307 partici- pants with paired serology had Q fever and SFGR, respectively. Adjusted annual incidence estimates of Q fever and SFGR were 80 (uncertainty range, 20–454) and 147 (uncertainty range, 52–645) per 100,000 persons, respectively. For 2012 to 2014, among 1,114 febrile participants, 52 (8.1%) and 57 (8.9%) of 641 participants with paired serology had Q fever and SFGR, respectively. Adjusted annual incidence estimates of Q fever and SFGR were 56 (uncertainty range, 24–163) and 75 (uncertainty range, 34–176) per 100,000 persons, respectively. We found substantial incidences of acute Q fever and SFGR in northern Tanzania during both study periods. To our knowledge, these are the first incidence esti- mates of either disease in sub-Saharan Africa. Our findings suggest that control measures for these infections warrant consideration.
Detection and molecular characterization of canine parvovirus infection in Morogoro and Arusha regions of Tanzania
(Sokoine University of Agriculture, 2021) Uronu, Caroline Eliona
Canine parvovirus emerged as a viral pathogen of dogs in the late 1970s responsible for a severe global panzootic in dogs of all ages, characterized by haemorrhagic enteritis and myocarditis. The virus has evolved rapidly which has led to three antigenic variants: CPV-2a, CPV-2b and CPV-2c, replacing the original antigenic type (CPV-2). There is no information on the CPV -2 variants circulating in Tanzania, despite its worldwide distribution. Despite the canine parvovirus vaccine being one of the cores strategies of control, the virus is still widespread in the canine population. The aim of the present study was to detect canine parvovirus (CPV) from fecal samples of domestic dogs, in Morogoro and Arusha regions of Tanzania. This study was done in both vaccinated and unvaccinated dogs presented to SUA veterinary hospital with gastroenteritis. Rectal swab samples (n = 143) were collected from dogs in Morogoro and Arusha regions in 2020- 2021. Polymerase Chain Reaction (PCR) targeting VP2 gene was used to detect canine parvovirus. Among the 143 samples, 15 were found positive by PCR. Five of the positive PCR products were sequenced. Sequence analysis comparison showed nucleotide identities of 99.53–100% among our CPV-2 isolates. The VP2 gene partial sequences revealed the presence of CPV-2b variant. Phylogenetic analysis of VP2 genes revealed that the CPV-2b variant clustered into two small evolutionary branch and shared the identical branch with two CPV-2b isolates from China and one isolate from South Korea. This study represents the first CPV molecular characterization conducted in Arusha and Morogoro regions of Tanzania.
Integrative taxonomic approach of trypanosomes in the blood of rodents and soricids in Asian countries, with the description of three new species
(Springer, 2018) Mafie, Eliakunda; Saito-Ito, Atsuko; Kasai, Masatoshi; Hatta, Mochammad; Rivera, Pilarita T; Ma, Xiao-Hang; Chen, Eng-Rin; Sato, Hiroshi; Takada, Nobuhiro
Trypanosoma lewisi (Kinetoplastea: Trypanosomatida: Trypanosomatidae) with a cosmopolitan distribution is the type species of the subgenus Herpetosoma, which includes ca. 50 nominal species isolated mainly from rodents. Since members of Herpetosoma in different host species have an almost identical morphology of bloodstream forms, these trypanosomes are referred to as ‘T. lewisi-like’, and the molecular genetic characterization of each species is necessary to verify their taxonomy. In the present study, we collected blood samples from 89 murid rodents of 15 species and 11 soricids of four species in Indonesia, Philippines, Vietnam, Taiwan, and mainland China for the detection of hemoprotozoan infection. T. lewisi and T. lewisi-like trypanosomes were found in the blood smears of 10 murid animals, which included Bandicota indica (two rats), Rattus argentiventer (one rat), and Rattus tiomanicus (two rats) in Indonesia; Rattus rattus (one rat) in the Philippines; and Niviventer confucianus (four rats) in mainland China. Furthermore, large- or medium-sized non-T. lewisi-like trypanosomes were detected in two soricids, Crocidura dracula in Vietnam and Anourosorex yamashinai in Taiwan, respectively. Molecular genetic characterization of the small subunit (SSU) ribosomal RNA gene (rDNA) and glycosomal glyceraldehyde-3-phosphate dehydrogenase (gGAPDH) gene indicated that the trypanosomes from all the murid hosts had identical SSU rDNA or gGAPDH gene nucleotide sequences except for those in N. confucianus in mainland China. These N. confucianus-infecting trypanosomes also showed several unique morphological features such as smaller bodies, anteriorly positioned nuclei, and larger rod-shaped kinetoplasts when compared with T. lewisi trypomastigotes. Trypanosoma (Herpetosoma) niviventerae n. sp. is erected for this new species. Similarly, based on morpho- logical and molecular genetic characterization, Trypanosoma sapaensis n. sp. and Trypanosoma anourosoricis n. sp. are pro- posed for the trypanosomes in C. dracula in Vietnam and A. yamashinai in Taiwan, respectively. More effort directed toward the morphological and molecular genetic characterization of the trypanosomes of rodents and soricids is required to fully understand the real biodiversity of their hemoflagellates.
First record of trypanosoma dionisii of the T. cruzi clade from the Eastern bent-winged bat (miniopterus fuliginosus) in the far East
(Springer, 2018) Mafie, Eliakunda; Rupa, Fatema Hashem; Takano, Ai; Suzuki, Kazuo; Maeda, Ken; Sato, Hiroshi
Chiropteran mammals worldwide harbour trypanosomes (Euglenozoa: Kinetoplastea: Trypanosomatida) of the subgenus ‘Schizotrypanum’ in the classical sense. Latterly, these trypanosomes have been referred to as members of the ‘Trypanosoma cruzi clade’ as their phylogenetic relationships, structure and life cycle conform to T. cruzi, parasitising various terrestrial mammals as well as humans in Latin America. Little is known, however, about the trypanosome species in Asian bats. During a survey on Borrelia spp. in the Eastern bent-winged bat (Miniopterus fuliginosus) living in a cave in Wakayama Prefecture, Japan, incidental proliferation of trypanosomes was detected in two of 94 haemocultures. Squat or slender trypano- somes that proliferated in the cultures were 7.5–20.5 μm in length between both body ends and 1.0–3.8 μm in width with/without free flagella up to 14.5 μm (n = 29). The nucleotide sequences of the small subunit ribosomal RNA gene (SSU rDNA; 2176 bp), large subunit ribosomal RNA gene (1365 bp) and glycosomal glyceraldehyde-3-phosphate dehydrogenase gene (gGAPDH; 843 bp) of the present isolates were characterized to clarify their molecular phylogenetic position in T. cruzi-like trypanosomes. The newly obtained SSU rDNA and gGAPDH nucleotide sequences showed the highest identities with Brazilian and European isolates of Trypanosoma dionisii of the T. cruzi clade, ranging between 99.4 and 99.7% or between 95.6 and 99.3% identities, respectively. Although multiple T. dionisii isolates from the North and South American continents showed the closest molecular genetic relatedness to the present Far East isolates, only short SSU rDNA segments of the former isolates were deposited. Therefore, a definitive conclusion cannot be made until full nucleotide sequencing of at least the American isolates’ SSU rDNA is available. This is the first confirmation of a Far East distribution of T. dionisii, demonstrating a wide geographical distribution of the species in the Eurasian and American continents with a limited nucleotide variation.
Endoparasites of Vietnamese lizards recorded in the last 50 years (1966−2015)
(2016) Thi Tran, Binh; Nguyen, Son Truong; Nguyen, Tao Thien; Van Luc, Pham; Mafie, Eliakunda; Rupa, Fatema Hashem; Sato, Hiroshi
At present, there is a limited knowledge of amphibian and reptile parasites in Vietnam. To date, 45 species of endoparasite in Vietnamese lizards have been recorded. These species consist of 11 cestode, 12 trematode, 18 nematode, one acanthocephalan and three pentastomid species from 10 host species. As Vietnam is one of the global hot spots for herpetofauna diversity (a recent report documented 385 reptiles and 181 amphibians in the country), it appears that only a fraction of the parasites of lizards in this richly biodiverse territory has been recorded. To facilitate the accurate taxonomical identification of parasites and clarify the taxonomic relationship of parasites from Vietnamese lizards with those from Oriental lizards or lizards of other geographical regions, parasites should be characterized both morphologically and phylogenetically.
Genetic diversity of cervid trypanosoma theileri In Honshu sika deer (cervus nippon) in Japan
(Cambridge University Press, 2021) Rosyadi, Imron; Setsuda, Aogu; Eliakunda, Mafie; Takano, Ai; Maeda, Ken; Saito-Ito, Atsuko; Suzuki, Kazuo; Sato, Hiroshi
The taxonomy of ruminant Trypanosoma theileri and its relatives (Kinetoplastida: Trypanosomatidae) is controversial, with recent phylogenetic studies segregating T. theileri in cattle and other ruminants worldwide into two major genetic lineages (the TthI and TthII clades) based on genetic markers. In the present study, T. theileri-like trypanosomes isolated from Honshu sika deer (Cervus nippon) in the western Japan (YMG isolate) were gen- etically characterized using a number of genetic markers. Sika deer trypanosomes of the YMG isolate were genetically different from the Trypanosoma sp. TSD1 isolate previously recorded from Hokkaido sika deer in northern Japan, with the former trypanosome isolate being gen- etically closer to European cervid trypanosomes and the bovine T. theileri TthII lineage. In contrast, the latter isolate exhibited greater relatedness to North American cervid trypano- somes and the bovine T. theileri TthI lineage, although a clear genetic distinction between these was apparent. Furthermore, trypanosomes in Honshu sika deer from the central part of Japan harboured additional genetic diversity and were closer to either TSD1 or YMG iso- lates, while distinct from known T. theileri-related genotypes. Importantly, cervids and wild ruminants worldwide might harbour divergent descendants of a T. theileri ancestor, which exhibit rigid host specificity to either bovines or cervid species.
New host records of monacanthid fish for three kudoa spp. (k. septempunctata, k. thyrsites, and k. shiomitsui) prevalent In the olive flounder (paralichthys olivaceus), with the description Of k. parathyrsites n. sp. from a black scraper (thamnaconus modestus)
(Springer, 2016) Kasai, Akihiro; Li, Ying-Chun; Mafie, Eliakunda; Sato, Hiroshi
Kudoa septempunctata (Myxosporean: Multivalvulida) is known as a cause of foodborne disease associated with consumption of raw flesh of the olive flounder (Paralichthys olivaceus). Knowledge of its life cycle, particu- larly alternate annelid hosts and reservoirs or susceptible fish hosts in natural waters, may facilitate disease control in aqua- culture farms. Our recent survey of myxosporean infection in monacanthid fish in natural waters around Japan revealed in- fection with three kudoid species prevalent in the olive floun- der, i.e., K. septempunctata, Kudoa thyrsites, and Kudoa shiomitsui. Of the 51 black scrapers (Thamnaconus modestus) examined, five fish were infected: two fish with K. septempunctata and three with K. thyrsites. One of the fish infected with K. septempunctata was also infected with a K. thyrsites-like species. One of the 17 threadsail filefish (Stephanolepis cirrhifer) and two of four unicorn leatherjackets (Aluterus monoceros) were parasitized with K. shiomitsui. Three modest filefish (Thamnaconus modestoides) had no kudoid infection. K. septempunctata from a black scraper fished in the Inland Sea of Japan off Yamaguchi had 6–8 (predominantly 7) shell valves/polar cap- sules, whereas K. septempunctata found in another black scraper from the Sea of Japan off Tottori had 5 or 6 (predominantly 6). However, the two isolates displayed iden- tical 18S and 28S ribosomal RNA gene (rDNA) nucleotide sequences, which were also identical to the isolates from the olive flounder. K. thyrsites from the Inland Sea of Japan off Yamaguchi and Sea of Japan off Tottori and K. shiomitsui from the Sea of Japan off Shimane and western Pacific Ocean off Kochi were also morphologically and genetically characterized. They were found to be coincident with the pre- vious reports from olive flounders. Furthermore, the K. thyrsites-like species found in a black scraper from the Inland Sea of Japan off Yamaguchi was morphologically and genetically characterized; a new species, Kudoa parathyrsites n. sp., is erected for this species. The relation- ships of the new species with K. thyrsites and related species as well as those of K. shiomitsui with Kudoa pericardialis and related species parasitizing the pericardium are briefly discussed.
Brief review on atypical human trypanosomiasis of trypanosoma lewisi
(2016) Mafie, Eliakunda; Rupa, Fatema Hashem; Setsuda, Aogu; Saito-Ito, Atsuko; Sato, Hiroshi
Trypanosomes (Kinetoplastea: Trypanosomatida: Trypanosomatidae), particularly salivarian trypanosome species as well as stercorarian Trypanosoma cruzi, are important parasites of humans and other animals that cause often fatal diseases. Stercorarian T. lewisi is known as a rat-specific species of the subgenus Herpetosoma. Rodent trypanosomes cause latent infections, and T. lewisi infection beyond the genus border, e.g. infection in mice, is considered to be virtually impossible. Nevertheless, nine human cases of T. lewisi infection have been reported in recent decades, with an increased incidence (five cases) in the last two decades. In the present review, we summarize the records of atypical human trypanosomiasis ascribed to T. lewisi infection and provide information on the background of disease incidences and possible PCR-based diagnostic approaches.
Morphological and molecular genetic characterization of two Kudoa spp., k. musculoliquefaciens, and k. pleurogrammi n. sp. (myxosporea: multivalvulida), causing myoliquefaction Of commercial marine fish
(Springer, 2016-01) Li, Ying-Chun; Mafie, Eliakunda; Sato, Hiroshi; Kasai, Akihiro
Genetic characterization of myxosporean species, including members of the genus Kudoa, has advanced dramat- ically throughout the last decade. This is in stark contrast to those species described further back in time. Kudoa musculoliquefaciens described from the jellied muscle of swordfish, Xiphias gladius, in the western Pacific Ocean off the Sanriku Coast, northern Japan, is one such species. In the present study, multiple pseudocysts (0.66–1.35 mm average length and 0.06–0.10 mm average width) containing K. musculoliquefaciens spores were collected from three host groups: muscle blocks of swordfish caught in the western Pacific Ocean off the Sanriku Coast, or the northern Indian Ocean, and Indo-Pacific sailfish, Istiophorus platypterus, in the western Pacific Ocean off Kochi, western Japan. Subspherical K. musculoliquefaciens spores, 8.0–10.3 μm in width, 7.3–10.0 μm in thickness, 6.4–7.9 μm in sutural thick- ness, and 5.5–8.1 μm in length, had four subspherical polar capsules, 2.8–4.0 μm in length by 2.2–3.2 μm in width. The kudoid spores found in the different host groups showed mor- phometric variations to some extent but had essentially iden- tical nucleotide sequences of the ribosomal RNA gene (rDNA), closest to those of Kudoa hemiscylli or Kudoa carcharhini recorded from elasmobranchs in the Indo-Pacific Ocean. Another kudoid species, Kudoa pleurogrammi n. sp., was recorded from the jellied and normal muscles of Atka mackerel, Pleurogrammus monopterygius and Pleurogrammus azonus, fished in the northern Pacific Ocean or northern Sea of Japan. Subquadrate spores found in round-ended pseudocysts (1.15–3.85 mm in length and 0.11–0.26 mm in width) in myofibers were 8.2–9.1 μm in width, 7.1–8.2 μm in thickness, 5.4–7.7 μm in sutural thick- ness, and 5.6–6.8 μm in length, with four ovoid polar cap- sules, 2.7–2.9 μm in length by 1.4–2.0 μm in width. Kudoid spores from both jellied and normal muscles or different host fish species had identical 18S or 28S rDNA nucleotide se- quences. Thus, molecular genetic characterization of kudoid species with the potential to induce post-mortem myoliquefaction will facilitate the reliable and specific identi- fication of myxosporeans found in either jellied or normal muscles of important commercial fish
Leveraging sub-national collaboration and influence for improving animal health surveillance and response: a stakeholder mapping in Tanzania
(Frontiers in Veterinary Science, 2021-12-13) George, Janeth; Häsler, Barbara; Komba, Erick V. G.; Sindato, Calvin; Rweyemamu, Mark; Kimera, Sharadhuli I.; Mlangwa, James E. D.
Animal health surveillance plays a vital role in ensuring public health, animal welfare, and sustainable food production by monitoring disease trends, early detecting (new) hazards, facilitating disease control and infection, and providing data for risk analysis. Good stakeholder collaboration across the sector can lead to better communication, better science and decision-making and more effective surveillance and response. An understanding of relevant stakeholders, their interests and their power can facilitate such collaboration. While information on key stakeholders in animal health surveillance is available at the national level in Tanzania, it is missing at the subnational level. The study aimed to explore the existing stakeholders’ collaborations and influences at the subnational level through stakeholder mapping and to determine potential leverage points for improving the national animal health surveillance system. A qualitative design was used, involving consultative workshops with government animal health practitioners in Sumbawanga, Sikonge and Kilombero districts of Tanzania from December 2020 to January 2021. Data were collected using an adapted USAID stakeholder collaboration mapping tool with the following steps: (i) Define the objective (ii) Identify all stakeholders (iii) Take stock of the current relationships (iv) Determine resource-based influence (v) Determine non-resource based influence and (vi) Review and revise the collaboration map. Forty-five stakeholders were identified in all three districts and grouped into four categories: private sector and non-government organizations (n = 16), government (n = 16), community (n = 9) and political leaders (n = 4). Animal health practitioners had a stronger relationship with community stakeholders as compared to other categories. The results also showed that most of the stakeholders have non-resource-based influence compared to resource-based influence. The private sector and non-government organizations have a relatively higher number of resource-based influential stakeholders, while political leaders have more non-resource-based influence. The mapping exercise demonstrated that the system could benefit from community mobilization and sensitization, resource mobilization and expanding the horizon of surveillance data sources. Some of the leverage points include integration of surveillance activities into animal health services, clear operational processes, constant engagement, coordination and incentivization of stakeholders. The diversity in the identified stakeholders across the districts suggests that collaborations are contextual and socially constructed.
Mechanisms and contextual factors affecting the implementation of animal health surveillance in Tanzania: a process evaluation
(Frontiers in Veterinary Science, 2022-01-13) George, Janeth; Häsler, Barbara; Komba, Erick V. G.; Rweyemamu, Mark; Kimera, Sharadhuli I.; Mlangwa, James E. D.
A strong animal health surveillance system is an essential determinant of the health of animal and human population. To ensure its functionality and performance, it needs to be evaluated regularly. Therefore, a process evaluation was conducted in this study to assess animal health surveillance processes, mechanisms and the contextual factors which facilitate or hinder uptake, implementation and sustainability of the system in Tanzania. A mixed-method study design was used to evaluate the national animal health surveillance system guided by a framework for process evaluation of complex interventions developed by Moore and others. The system was assessed against standard guidelines and procedures using the following attributes: fidelity, adherence, exposure, satisfaction, participation rate, recruitment and context. Quantitative and qualitative data were collected using a cross-sectional survey, key informant interviews, document review, site visits and non-participant observation. Data from questionnaires were downloaded, cleaned and analyzed in Microsoft TM Excel. Qualitative data were analyzed following deductive thematic and content analysis methods. Fidelity attribute showed that case identification is mainly based on clinical signs due to limited laboratory services for confirmation. Data collection was not well-coordinated and there were multiple disparate reporting channels. Adherence in terms of the proportion of reports submitted per month was only 61% of the target. District-level animal health officials spent an average of 60% of their weekly time on surveillance-related activities, but only 12% of them were satisfied with the surveillance system. Their dissatisfaction was caused by large area coverage with little to no facilitation, poor communication, and lack of a supporting system. The cost of surveillance data was found to be 1.4 times higher than the annual surveillance budget. The timeliness of the system ranged between 0 and 153 days from the observation date (median = 2 days, mean = 6 days). The study pointed out some deviations in animal health surveillance processes from the standard guidelines and their implication on the system’s performance. The system could be improved by developing a user-friendly unified reporting system, the active involvement of subnational level animal health officials, optimization of data sources and an increase in the horizon of the financing mechanism.
Towards an integrated animal health surveillance system in Tanzania: making better use of existing and potential data sources for early warning surveillance
(BMC Veterinary Research, 2021) George, Janeth; Häsler, Barbara; Komba, Erick; Sindato, Calvin; Rweyemamu, Mark; Mlangwa, James
Background: Effective animal health surveillance systems require reliable, high-quality, and timely data for decision making. In Tanzania, the animal health surveillance system has been relying on a few data sources, which suffer from delays in reporting, underreporting, and high cost of data collection and transmission. The integration of data from multiple sources can enhance early detection and response to animal diseases and facilitate the early control of outbreaks. This study aimed to identify and assess existing and potential data sources for the animal health surveillance system in Tanzania and how they can be better used for early warning surveillance. The study used a mixed-method design to identify and assess data sources. Data were collected through document reviews, internet search, cross-sectional survey, key informant interviews, site visits, and non-participant observation. The assessment was done using pre-defined criteria. Results: A total of 13 data sources were identified and assessed. Most surveillance data came from livestock farmers, slaughter facilities, and livestock markets; while animal dip sites were the least used sources. Commercial farms and veterinary shops, electronic surveillance tools like AfyaData and Event Mobile Application (EMA-i) and information systems such as the Tanzania National Livestock Identification and Traceability System (TANLITS) and Agricultural Routine Data System (ARDS) show potential to generate relevant data for the national animal health surveillance system. The common variables found across most sources were: the name of the place (12/13), animal type/species (12/13), syndromes (10/13) and number of affected animals (8/13). The majority of the sources had good surveillance data contents and were accessible with medium to maximum spatial coverage. However, there was significant variation in terms of data frequency, accuracy and cost. There were limited integration and coordination of data flow from the identified sources with minimum to non-existing automated data entry and transmission. Conclusion: The study demonstrated how the available data sources have great potential for early warning surveillance in Tanzania. Both existing and potential data sources had complementary strengths and weaknesses; a multi-source surveillance system would be best placed to harness these different strengths.
In ovo antiviral potency of the leaf constituents of Tanzanian Toussaintia species against Infectious Bursal Disease Virus and Newcastle Disease Virus
(2014-06) Nyandoro, Stephen S; Msoffe, Peter L.M; Cosam, Joseph C; Nkunya, Mayunga H.H
The chemical constituents of Toussantia orientalis and T. patriciae (Annonaceae) leaf extracts were evaluated for their antiviral activities in ovo against Infectious Bursal Disease Virus (IBDV) and Newcastle Disease Virus (NDV). The nine-day-old embryonated eggs in a set of five were used for testing through the allantoic route inoculation assay for each tested compound and controls. For NDV assay, the allantoic fluids from the specimens were further harvested to determine viral contagion. The tested compounds exhibited potency with varying levels of significance at a screening concentration of 360 μg/ml against the two viral strains. Embryos infected with IBDV survived, grew to normal size with complete organ formation and had mean weights comparable to those of the uninfected ones when treated with the aminocinnamoyl tetraketides 1, 2, and 4, glucosylflavonoid 7 from T. orientalis and ursolic acid derivatives 9 and 10 from T. patriciae demonstrating high efficacy against IBDV. The compounds also exhibited antiviral activity against NDV, showing viral titre reduction ranging from 1:16 - 1:256 in the haemagglutination test, with compound 11 having the lowest titre value (1:16) followed by compound 7 (1:32). The compounds that exhibited significant antiviral efficacy could be considered potential leads for the development of antiviral agents.
Are we prepared for emerging and re-emerging diseases? experience and lessons from epidemics that occurred in Tanzania during the last five decades
(2012-03) Karimuribo, E.D; Mboera, L. E.G; Mbugi, Erasto; Simba, Azma; Kivaria, F. M; Mmbuji, Peter; Rweyemamu, M. M
his paper reviews preparedness for containing and controlling emerging and re-emerging diseases drawing lessons from disease events that occurred in animal and human populations in the last five decades (1961-2011). A comprehensive analysis based on retrieval and analysis of grey and published literature as well as reported cases was carried out to document type and trend of occurrence of emerging and re-emerging infectious diseases in different parts of Tanzania. Overall, the majority of diseases reported in the country were viral in nature followed by bacterial diseases. The trend for the occurrence shows a number of new emerging diseases as well as re-occurrence of old diseases in both animal (domestic and wild) and human populations. In humans, the major disease epidemics reported in the last five decades include cholera, influenza A H1N1, plague and rubella. In animals, the major epidemic diseases reported were Contagious Bovine Pleuropneumonia, Contagious Caprine Pleuropneumonia, Peste des petits ruminants and Giraffe Ear and Skin Diseases. Some epidemics have been reported in both human and animal populations including Rift Valley fever and anthrax. The emergence of the ‘fit-for purpose’ approaches and technologies such as the discipline of One Health, use of participatory epidemiology and disease surveillance and mobile technologies offers opportunity for optimal use of limited resources to improve early detection, diagnosis and response to disease events and consequently reduced impact of such diseases in animal and human populations. ____________________________
Molecular characterization of African swine fever virus from domestic pigs in northern Tanzania during an outbreak in 2013
(Springer Netherlands, 2014-10) Misinzo, Gerald; Kwavi, David E; Sikombe, Christopher D; Makange, Mariam; Peter, Emma; Muhairwa, Amandus P; Madege, Michael J
African swine fever (ASF) is an acute, highly contagious and deadly viral hemorrhagic fever of domestic pigs caused by African swine fever virus (ASFV), a double-stranded DNA virus of the family Asfarviridae. In this study, molecular diagnosis and characterization of outbreak ASFV in northern Tanzania, was performed on spleen, lymph node, kidney, and heart samples collected in June and July 2013 from domestic pigs that died during a hemorrhagic disease outbreak. Confirmatory diagnosis of ASF was performed using polymerase chain reaction (PCR) by partial amplification of B646L gene of ASFV encoding the major capsid protein p72 using PPA1/PPA2 primers. PCR using PPA1/PPA2 primers produced an expected PCR product size, confirming ASF outbreak in northern Tanzania. In addition, nucleotide amplification and sequencing, and phylogenetic reconstruction of the variable 3′-end of the …

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