Browsing by Author "Kazwala, R. R."
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Item Alcelaphine herpesvirus-1 (Malignant Catarrhal Fever Virus) in wildebeest placenta: Genetic variation of ORF50 and A9.5 alleles(PLoS ONE, 2015-05-13) Lankester, F.; Lugelo, A.; Mnyambwa, N.; Ndabigaye, A.; Keyyu, J.; Kazwala, R. R.; Grant, D. M.; Relf, V.; Haig, D. M.; Cleaveland, S.; Russell, G. C.Alcelaphine herpesvirus–1 (AlHV-1), a causative agent of malignant catarrhal fever in cattle, was detected in wildebeest (Connochaetes taurinus) placenta tissue for the first time. Although viral load was low, the finding of viral DNA in over 50%of 94 samples tested lends support to the possibility that placental tissue could play a role in disease transmission and that wildebeest calves are infected in utero. Two viral loci were sequenced to examine variation among virus samples obtained from wildebeest and cattle: the ORF50 gene, encoding the lytic cycle transactivator protein, and the A9.5 gene, encoding a novel polymorphic viral glycoprotein. ORF50 was well conserved with six newly discovered alleles differing at only one or two base positions. In contrast, while only three new A9.5 alleles were discovered, these differed by up to 13% at the nucleotide level and up to 20% at the amino acid level. Structural homology searching performed with the additional A9.5 sequences determined in this study adds power to recent analysis identifying the four-helix bundle cytokine interleukin-4 (IL4) as themajor homologue. The majority of MCF virus samples obtained from Tanzanian cattle and wildebeest encoded A9.5 polypeptides identical to the previously characterized A9.5 allele present in the laboratory maintained AlHV-1 C500 strain. This supports the view that AlHV-1 C500 is suitable for the development of a vaccine for wildebeest-associated MCF.Item Bovine tuberculosis in the lake Victoria zone of Tanzania and its possible consequences for human health in the HIV/AIDS era(Veterinary Research Communications, 1997) Jiwa, S. F. H.; Kazwala, R. R.; Aboud, A. A. O.; Kalaye, A. J.A total of 8190 cattle from 42 well-managed herds in the Lake Victoria zone of Tanzania were tested for bovine tuberculosis by a single comparative intradermal test (SCITT) using avian and bovine puri¢ed protein derivative (PPD) antigens. The prevalence of bovine tuberculosis in this area was found to be 0.2%. There was signi¢cant variation (p50.001) among the herds tested in the four regions in this zone (Kagera, Mara, Mwanza and Shinyanga). The highest prevalence (2.12%) was in a herd of 566 cattle which had recently arrived in Kagera region from Dar-es-Salaam. None of the 915 cattle tested in Shinyanga or of the 254 resident cattle in the Kagera region were positive by SCITT. This area, and particularly the Kagera region, has the highest human morbidity and mortality due to the acquired immunode¢ciency syndrome in Tanzania. Therefore, the presence of bovine tuberculosis in cattle necessitates further investigations on the role of animal-derived tuberculosis in human health.Item Demographics and parasites of African buffalo (Syncerus caffer Sparrman, 1779) in Ruaha National Park, Tanzania(African Journal of Ecology, 2016) Roug, A.; Muse, E. A.; Smith, W. A; Mazet, J. A. K.; Kazwala, R. R.; Harvey, D.; Paul, G.; Meing’ataki, G. O.; Banga, P.; Clifford, D. L.The number of African buffaloes (Syncerus caffer Sparrman, 1779) inhabiting Ruaha National Park, Tanzania, is thought to be declining, but little data exist to determine whether the population is actually in decline. As an initial phase of collecting population data, we conducted demographic surveys, faecal egg counts and gastrointestinal parasite identification in Ruaha’s buffalo herds in September 2011 and 2013. Most herds encountered in the two surveys appeared to be in good health, but with fewer calves in 2013 compared with 2011. The herd-level body condition score was positively associated with the number of calves per 100 cows after adjusting for year, and the lower number of offspring in 2013 could possibly be associated with a below average rainfall in the 2012–2013 rainy season. Mean herd-level egg counts ranged from 83 to 140 and from 28 to 113 eggs per g faeces in 2011 and 2013, respectively. Haemonchus, Nematodirus, Cooperia and Oesophagostomum spp., as well as coccidian oocysts, were detected in the population. Monitoring herd demographics and baseline health parameters over time will provide insight into population performance, increase the understanding of population stressors and contribute to buffalo conservation within Ruaha National Park and other protected areas of Africa.Item Domestic dog demographic structure and dynamics relevant to rabies control planning in urban areas in Africa: The case of Iringa, Tanzania(BMC Veterinary Research, 2012) Gsell, A. S.; Knobel, D. L.; Cleaveland, S.; Kazwala, R. R.; Vounatsou, P.; Zinsstag, J.Background: Mass vaccinations of domestic dogs have been shown to effectively control canine rabies and hence human exposure to rabies. Knowledge of dog population demography is essential for planning effective rabies vaccination programmes; however, such information is still rare for African domestic dog populations, particularly so in urban areas. This study describes the demographic structure and population dynamics of a domestic dog population in an urban Sub-Saharan African setting. In July to November 2005, we conducted a full household-level census and a cross-sectional dog demography survey in four urban wards of Iringa Municipality, Tanzania. The achievable vaccination coverage was assessed by a two-stage vaccination campaign, and the proportion of feral dogs was estimated by a mark-recapture transect study. Results: The estimated size of the domestic dog population in Iringa was six times larger than official town records assumed, however, the proportion of feral dogs was estimated to account for less than 1% of the whole population. An average of 13% of all households owned dogs which equalled a dog:human ratio of 1:14, or 0.31 dogs per household or 334 dogs km-2. Dog female:male ratio was 1:1.4. The average age of the population was 2.2 years, 52% of all individuals were less than one year old. But mortality within the first year was high (72%). Females became fertile at the age of 10 months and reportedly remained fertile up to the age of 11 years. The average number of litters whelped per fertile female per year was 0.6 with an average of 5.5 pups born per litter. The population growth was estimated at 10% y-1. Conclusions: Such high birth and death rates result in a rapid replacement of anti-rabies immunised individuals with susceptible ones. This loss in herd immunity needs to be taken into account in the design of rabies control programmes. The very small proportion of truly feral dogs in the population implies that vaccination campaigns aimed at the owned dog population are sufficient to control rabies in urban Iringa, and the same may be valid in other, comparable urban settings.Item Elucidating the phylodynamics of endemic rabies virus in eastern Africa using whole-genome sequencing(Virus Evolution, 2015) Brunker, K.; Marston, D. A.; Horton, D. L.; Cleaveland, S.; Fooks, A. R.; Kazwala, R. R.; Ngeleja, C.; Lembo, T.; Sambo, M; Mtema, Z. J.; Sikana, L.; Wilkie, G.; Biek, R.; Hampson, K.Many of the pathogens perceived to pose the greatest risk to humans are viral zoonoses, responsible for a range of emerging and endemic infectious diseases. Phylogeography is a useful tool to understand the processes that give rise to spatial patterns and drive dynamics in virus populations. Increasingly, whole-genome information is being used to uncover these patterns, but the limits of phylogenetic resolution that can be achieved with this are unclear. Here, whole-genome variation was used to uncover fine-scale population structure in endemic canine rabies virus circulating in Tanzania. This is the first whole-genome population study of rabies virus and the first comprehensive phylogenetic analysis of rabies virus in East Africa, providing important insights into rabies transmission in an endemic system. In addition, sub-continental scale patterns of population structure were identified using partial gene data and used to determine population structure at larger spatial scales in Africa. While rabies virus has a defined spatial structure at large scales, increasingly frequent levels of admixture were observed at regional and local levels. Discrete phylogeographic analysis revealed long-distance dispersal within Tanzania, which could be attributed to human-mediated movement, and we found evidence of multiple persistent, co-circulating lineages at a very local scale in a single district, despite on-going mass dog vaccination campaigns. This may reflect the wider endemic circulation of these lineages over several decades alongside increased admixture due to humanmediated introductions. These data indicate that successful rabies control in Tanzania could be established at a national level, since most dispersal appears to be restricted within the confines of country borders but some coordination with neighbouring countries may be required to limit transboundary movements. Evidence of complex patterns of rabies circulation within Tanzania necessitates the use of whole-genome sequencing to delineate finer scale population structure that can that can guide interventions, such as the spatial scale and design of dog vaccination campaigns and dog movement controls to achieve and maintain freedom from disease.Item Epidemiology of Brucella infection in the human, livestock and wildlife interface in the Katavi-Rukwa ecosystem, Tanzania(BMC Veterinary Research, 2015) Assenga, J. A.; Matemba, L. E.; Muller, S. K.; Muller, S. K.; Malakalinga, J. J.; Kazwala, R. R.Background: Brucellosis is a zoonosis of public health importance worldwide. In Tanzania, the disease is underreported due to insufficient awareness, inadequate diagnostic protocols, including lack of appropriate reagents for diagnosis. Livestock and wildlife are considered potential sources of infection to humans; however, the role played by these carriers in the epidemiology of the disease in the ecosystems in Tanzania is not fully understood. The objective of this study was to establish the prevalence of anti-Brucella antibodies in humans, wildlife and livestock; and molecular prevalence of Brucella spp in cattle and goats in the Katavi- Rukwa ecosystem. Results: Anti-Brucella antibodies were detected in humans at 0.6 % (95 % CI: 0.1, 2.1 %); cattle at 6.8 % (95 % CI: 5.4, 8.5 %), goats at 1.6 % (95 % CI: 0.4, 4.1 %) and buffaloes at 7.9 % (95 % CI: 1.7, 21.4 %). One of the two sampled lions tested positive. Cattle had a significantly higher prevalence of anti-Brucella antibodies as compared to goats (P < 0.05). A significantly higher seroprevalence was found in female than in male cattle and in adult than in young cattle (P < 0.05). There was an agreement of 95 and 89 % in cattle and goats, respectively, for the Rose Bengal plate Test (RBPT) and Competitive Enzyme Linked Immunosorbent Assay (c-ELISA) in detecting Brucella infection. Eight (3.5 %) out of 231 milk samples tested were positive for Brucella spp on Polymerase Chain Reaction (PCR), and Brucella abortus biovar 1 was detected in cattle milk. However, no Brucella spp were detected in goat milk. Conclusion: This study has shown the presence of anti- Brucella antibodies in humans, livestock, and wildlife in the Katavi- Rukwa ecosystem. Transmission of the infection between wildlife, livestock and humans is likely to continue due to increasing human activities in the human wildlife interface. This information is an important contribution to public health policy development in the human wildlife interface of the Katavi- Rukwa ecosystem.Item Isolation of Mycobacterium bovis from human cases of cervical adenitis in Tanzania: A cause for concern?(The International Journal of Tuberculosis and Lung Disease, 2001-09-28) Kazwala, R. R.; Daborn, C. J.; Sharp, J. M.; Kambarage, D. M.; Jiwa, S. F. H.; Mbembati, N. A.Pastoralist communities in the Northern and Southern zones of Tanzania. DESIGN: Observational study. OBJECTIVES: To determine the involvement of Mycobacterium bovis in tuberculosis cases presenting at tuberculosis (TB) clinics in rural areas in these zones. METHODS: A total of 149 tuberculosis cases identified on the bases of clinical manifestation were sampled. Appropriate specimens were cultured on two Löweinstein Jensen slants with respectively glycerol and pyruvate added. Forty-one isolates were cultured and subjected to biochemical typing. RESULTS: Overall, 31 (70.5%) of the mycobacterialisolates recovered from all forms of tuberculosis were identified as M. tuberculosis, seven (16.0%) were identified as M. bovis, and six (13.6%) were other mycobacterial species. There was a significantly higher isolation rate (P 0.05) of M. bovis among strains recovered from extra-pulmonary (26.8%) than pulmonary tuberculosis samples (4.3%). CONCLUSION: Based on these findings, it is imperative that M. bovis be considered as a pathogen of concern to people living in rural areas of Tanzania. Further work is required to establish a zoonotic link between cattle and the people in these communities who rear them.Item Mobile phones as surveillance tools: Implementing and evaluating a large-scale intersectoral surveillance system for rabies in Tanzania(PLOS Medicine, 2016-04-12) Mtema, Z.; Changalucha, J.; Cleaveland, S.; Elias, M.; Ferguson, M. H.; Halliday, J. E. B.; Haydon, D.T.; Jaswant, G.; Kazwala, R. R.; Killeen, G. F.; Lembo, T; Lushasi, K.; Malishee, A. D.; Mancy, R.; Maziku, M.; Mbunda, E. M.; Mchau, G. J. M.; Murray-Smith, R.; Rysava, K.; Said, K.; Sambo, M.; Shayo, E.; Sikana, L.; Townsend, S. E.; Urassa, H.; Hampson, K.Surveillance is critical to manage preventative health services and control infectious diseases. Integrated surveillance involving public health, veterinary, and environmental sectors is urgently needed to effectively manage zoonoses and vector-borne diseases. However, most surveillance in low-income countries is paper-based, provides negligible timely feedback, is poorly incentivised, and results in delays, limited reporting, inaccurate data, and costly processing. • The potential of mobile technologies for improving health system surveillance has been demonstrated through small-scale pilots, but large-scale evaluations under programmatic implementation remain rare. • An intersectoral mobile-phone–based system was developed and implemented for rabies surveillance across southern Tanzania. Since 2011, the system has facilitated near realtime reporting of animal bites and human and animal vaccine use (almost 30,000 reports) by over 300 frontline health and veterinary workers across a catchment area of 150,000 km2 with >10 million inhabitants, improving data quality, timeliness, and completeness while reducing costs. • The surveillance system infrastructure is a platform that can be further developed to improve services and deliver health interventions; for example, generating automated personalized text messages (SMS) to alert patients to their vaccination schedules improved their compliance with regimens. Other interventions targeting patients and health workers can now be implemented easily. • The system has become an integrated, popular, and valuable tool across sectors, used routinely throughout southern Tanzania to evaluate the impacts of rabies control and prevention activities and to improve their management, directly informed by the experiences of frontline users. • We discuss challenges encountered during development and deployment, how we overcame these, and our recommendations for scaling up mobile-phone–based health (mHealth) interventions in low-income countries.Item Nontuberculous mycobacteria infections in Katavi Rukwa ecosystems(Journal of Agricultural Science and Technology, 2014) Makondo, Z. E.; Kazwala, R. R.; Mwakapuja, R. S.; Malakalinga, J.; Moser, I.; Tanner, M.A study on nontuberculous mycobacteria (NTM) was carried out in wildlife-livestock interface of Katavi Rukwa ecosystem (KRE). 328 livestock tissues and 178 wild animals were cultured, wild animals were sampled opportunistically during professional hunting and game cropping operations in the KRE protected areas. The objective of the study was to generate data on epidemiology of NTM in the wildlife-livestock interface of the KRE. Methods used to identify the NTM were: culture and isolation, polymerase chain reaction, protein heat shock 65 kilodalton (hsp65) and sequencing. Mycobacteria were detected on 25.9% and 11.9% of livestock and wildlife tissue cultures, respectively. The most NTM isolated were M. kansasii (30%), M. gastri (30%), M. fortuitum (1%), M. intracellulare (4%), M. indicus pranii (4%), M. nonchromogenicum (6%) and M. lentiflavum (6%). Other NTM in smaller percentages were M. hibernae, M. engbaekii, M. septicum, M. arupense and M. godii. Due to rise of NTM infection in both human and animals, it is recommended that awareness and laboratory facilities be improved to curb the underreporting especially in TB-endemic countries. For species specific identification, a network of national and regional laboratories is promoted.Item One Health: A concept led by Africa, with global benefits(Veterinary Record, 2015-05-09) Kamani, T. M.; Kazwala, R. R.; Mfinanga, S.; Haydon, D.; Keyyu, J.; Lankester, F.; Buza, J.One Health evolved from the recognition that an interdisciplinary approach is required to understand complex health problems, and that the health of humans and animals are inextricably linked. Through closer cooperation between the human, veterinary and environmental health sectors, added value, in terms of health metrics, cost savings and environmental services is achievable. Although the One Health concept has been recognised for many years, particularly since the seminal work of Calvin Schwabe (Schwabe 1984), many challenges remain in making it operational.Item Pouched rats’ detection of tuberculosis in human sputum: Comparison to culturing and polymerase chain reaction(Tuberculosis Research and Treatment, 2012) Mahoney, A.; Weetjens, B. J.; Cox, C.; Beyene, N.; Reither, K.; Makingi, G.; Jubitana, M.; Kazwala, R. R.; Mfinanga, G. S.; Kahwa, A.; Durgin, A.; Poling, A.Setting. Tanzania. Objective. To compare microscopy as conducted in direct observation of treatment, short course centers to pouched rats as detectors of Mycobacterium tuberculosis. Design. Ten pouched rats were trained to detect tuberculosis in sputum using operant conditioning techniques. The rats evaluated 910 samples previously evaluated by smear microscopy. All samples were also evaluated through culturing and multiplex polymerase chain reaction was performed on culture growths to classify the bacteria. Results. The patientwise sensitivity of microscopy was 58.0%, and the patient-wise specificity was 97.3%. Used as a group of 10 with a cutoff (defined as the number of rat indications to classify a sample as positive for Mycobacterium tuberculosis) of 1, the rats increased new case detection by 46.8% relative to microscopy alone. The average samplewise sensitivity of the individual rats was 68.4% (range 61.1–73.8%), and the mean specificity was 87.3% (range 84.7–90.3%). Conclusion. These results suggest that pouched rats are a valuable adjunct to, and may be a viable substitute for, sputum smear microscopy as a tuberculosis diagnostic in resource-poor countries.Item Prevalence and risk factors for infection of bovine tuberculosis in indigenous cattle in the Serengeti ecosystem, Tanzania(BMC Veterinary Research, 2013) Katale, B. Z.; Mbugi, E. V.; Karimuribo, E. D.; Keyyu, J. D.; Kendall, S.; Kibiki, G. S.; Godfrey-Faussett, P.; Michel, A. L.; Kazwala, R. R.; Helden, P.; Matee, M.Background: Bovine tuberculosis (bTB) is a chronic debilitating disease and is a cause of morbidity and mortality in livestock, wildlife and humans. This study estimated the prevalence and risk factors associated with bovine tuberculosis transmission in indigenous cattle at the human-animal interface in the Serengeti ecosystem of Tanzania. Results: A total of 1,103 indigenous cattle from 32 herds were investigated for the presence of bTB using the Single Intradermal Comparative Tuberculin Test. Epidemiological data on herd structure, management and grazing system were also collected. The apparent individual animal prevalence of tuberculin reactors was 2.4% (95% confidence interval (CI), 1.7 – 3.5%), whereas the true prevalence was 0.6% CI, 0.6 – 0.7% as indicated by a reaction to avian tuberculin purified protein derivatives (PPD) which is more than 4 mm greater than the reaction to avian tuberculin PPD. The results showed that 10.6% (117/1,103) showed non-specific reactions (atypical mycobacterium). The herd prevalence of 50% (16/32) was found. Tuberculin skin test results were found to be significantly associated with age, location, size of the household and animal tested. Of 108 respondents, 70 (64.8%) individuals had not heard about bovine tuberculosis at all. Thirty five percent (38/108) of respondents at least were aware of bTB. About 60% (23/38) of respondents who were aware of bTB had some knowledge on how bTB is spread. Eighty one percent (87/108) of respondents were not aware of the presence of bTB in wildlife. There is regular contact between cattle and wild animals due to sharing of grazing land and water sources, with 99% (107/108) of households grazing cattle in communal pastures. Conclusion: The study has demonstrated a high reported interaction of livestock with wildlife and poor knowledge of most cattle owners concerning bTB and its transmission pathways among people, livestock and wildlife. Although the overall proportion of animals with bTB is relatively low, herd prevalence is 50% and prevalence within herds varied considerably. Thus there is a possibility of cross transmission of bTB at wildlife-livestock interface areas that necessitates use of genetic strain typing methods to characterize them accuratelyItem Tuberculosis in Tanzanian Wildlife(Journal of Wildlife Diseases, 2005) Cleaveland, S.; Mlengeya, T.; Kazwala, R. R.; Michel, A.; Kaare, M. T.; Jones, S. L.; Eblate, E.; Shirima, G. M.; Packer, C.Bovine tuberculosis, caused by Mycobacterium bovis, is a pathogen of growing concern in free-ranging wildlife in Africa, but little is known about the disease in Tanzanian wildlife. Here, we report the infection status of Mycobacterium bovis in a range of wildlife species sampled from protected areas in northern Tanzania. M. bovis was isolated from 11.1% (2/ 18) migratory wildebeest (Connochaetes taurinus) and 11.1% (1/9) topi (Damaliscus lunatus) sampled systematically in 2000 during a meat cropping program in the Serengeti ecosystem, and from one wildebeest and one lesser kudu (Tragelaphus imberbis) killed by sport hunters adjacent to Tarangire National Park. A tuberculosis antibody enzyme immunoassay (EIA) was used to screen serum samples collected from 184 Serengeti lions (Panthera leo) and 19 lions from Ngorongoro Crater sampled between 1985 and 2000. Samples from 212 ungulates collected throughout the protected area network between 1998 and 2001 also were tested by EIA. Serological assays detected antibodies to M. bovis in 4% of Serengeti lions; one positive lion was sampled in 1984. Antibodies were detected in one of 17 (6%) buffalo (Syncerus caffer) in Tarangire and one of 41 (2%) wildebeest in the Serengeti. This study confirms for the first time the presence of bovine tuberculosis in wildlife of northern Tanzania, but further investigation is required to assess the impact on wildlife populations and the role of different wildlife species in maintenance and transmission.