Browsing by Author "Kazwala, R."

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A field vaccine trial in Tanzania demonstrates partial protection against malignant catarrhal fever in cattle
(Elsevier) Lankester, F; Lugelo, A; Ndabigaye, A; Mnyambwa, N; Keyyu, J.; Kazwala, R.; Grant, D; Percival, A.; Deane, D; Haig, D.M.; Cleaveland, S.; Russell, G. C.
A field vaccine trial in Tanzania demonstrates partial protection against malignant catarrhal fever in cattle
(Elsevier, 2016) Lankester, F; Lugelo, A; Ndabigaye, A; Mnyambwa, N; Keyyu, J.; Kazwala, R.; Grant, D; Percival, A.; Deane, D; Haig, D.M.; Cleaveland, S.; Russell, G. C.
Malignant catarrhal fever (MCF) is a fatal lymphoproliferative disease of cattle that, in East Africa, results from transmission of the causative virus, alcelaphine herpesvirus 1 (AlHV-1), from wildebeest. A vaccine field trial involving an attenuated AlHV-1 virus vaccine was performed over two wildebeest calving seasons on the Simanjiro Plain of northern Tanzania. Each of the two phases of the field trial consisted of groups of 50 vaccinated and unvaccinated cattle, which were subsequently exposed to AlHV-1 challenge by herding toward wildebeest. Vaccination resulted in the induction of virus-specific and virus-neutralizing antibodies. Some cattle in the unvaccinated groups also developed virus-specific antibody responses but only after the start of the challenge phase of the trial. PCR of DNA from blood samples detected AlHV-1 infection in both groups of cattle but the frequency of infection was significantly lower in the vaccinated groups. Some infected animals showed clinical signs suggestive of MCF but few animals went on to develop fatal MCF, with similar numbers in vaccinated and unvaccinated groups. This study demonstrated a baseline level of MCF-seropositivity among cattle in northern Tanzania of 1% and showed that AlHV-1 virus-neutralizing antibodies could be induced in Tanzanian zebu shorthorn cross cattle by our attenuated vaccine, a correlate of protection in previous experimental trials. The vaccine reduced infection rates by 56% in cattle exposed to wildebeest but protection from fatal MCF could not be determined due to the low number of fatal cases.
Characterisation of mycobacteria isolated from slaughter cattle in pastoral regions of Uganda
Oloya, J.; Kazwala, R.; Lund, A.; Opuda-Asibo, J; Demelash, B.; Skjerve, E.; Johansen, T. B; Djønne, B.
Characterisation of mycobacteria isolated from slaughter cattle in pastoral regions of Uganda
(2007-10-25) Oloya, J.; Kazwala, R.; Lund, A.; Opuda-Asibo, J; Demelash, B.; Skjerve, E.; Johansen, T. B; Djønne, B.
Bovine tuberculosis is a zoonotic problem in pastoral cattle and communities in Uganda. Tuberculin tests in pastoral cattle had shown a high herd but low animal prevalence, with a high proportion of avian reactors. No work had been done to identify the mycobacterial species involved. The objective of the study was to isolate and characterise Mycobacterial species causing tuberculous lesions in slaughtered animals. Lesioned organs compatible with bovine tuberculosis in slaughtered cattle from pastoral areas in Uganda were collected and cultured to isolate mycobacteria. AccuProbe culture identification kits for the Mycobacterium tuberculosis complex, M. avium complex and M. avium were used to identify the isolates. Spoligotyping and Insertion Sequence (IS) 1311 and IS1245 Restriction Fragment Length Polymorphism analysis (RFLP) were used to further characterise the isolates. Results: Of the 61 lesioned organs and tissues cultured, 19 isolates were identified as M. bovis, 3 as M. avium subsp.hominissuis, 1 as M. intracellulare, 1 as a mixed culture of M. bovis and M. avium sp. and 1 as M. avium sp. and unidentified mycobacteria. Eleven other mycobacteria outside the tuberculosis and avium complex groups were also isolated. Ten new spoligopatterns grouped into three clusters were identified from M. bovis isolates. Two of the three M. avium subsp.hominissuis isolates showed similar patterns on the IS1311 RFLP but all were different on the IS1245 RFLP. Conclusion: The isolation of M. bovis confirms the ongoing infection with spoligotypes unique to Uganda. Isolation of environmental mycobacteria could explain the high avian or non specific tuberculin reactor patterns commonly observed in pastoral cattle and suggests their pathogenic or opportunistic role in the infection of cattle with disseminated bovine tuberculous lesions.
Clinical implication of novel drug resistance-conferring mutations in resistant tuberculosis
(Springer Berlin Heidelberg) Mnyambwa, N. P.; Kim, J.; Ngadaya, E. S.; Kazwala, R.; Petrucka, P.; Mfinanga, S. G.
Comparing methods of assessing dog rabies vaccination coverage in rural and urban communities in Tanzania
(Frontiers in Veterinary Science) Sambo, M.; Johnson, P.; Hotopp, K.; Changalucha, J.; Cleaveland, S.; Kazwala, R.; Lembo, T.; Lugelo, A.; Lushasi, K.; Maziku, M.
In-feed use of heavy metal micronutrients in U.S. Swine production systems and its role in persistence of multidrug-resistant Salmonellae
(ASM News- American Society for Microbiology) Medardus, J. J.; Molla, B. Z.; Nicol, M.; Morrow, W. M.; Rajala-Schultz, P. J.; Kazwala, R.; Gebreyes, W. A.
In-feed use of heavy metal micronutrients in U.S. Swine production systems and its role in persistence of multidrug-resistant Salmonellae
(ASM News- American Society for Microbiology, 2014) Medardus, J. J.; Molla, B. Z.; Nicol, M.; Morrow, W. M.; Rajala-Schultz, P. J.; Kazwala, R.; Gebreyes, W. A.
The study aimed to characterize the role of heavy metal micronutrients in swine feed in emergence of heavy-metal-tolerant and multidrug-resistant Salmonella organisms. We conducted a longitudinal study in 36 swine barns over a 2-year period. The feed and fecal levels of Cu2+ and Zn2+ were measured. Salmonella was isolated at early and late finishing. MICs of copper sulfate and zinc chloride were measured using agar dilution. Antimicrobial susceptibility was tested using the Kirby-Bauer method, and 283 isolates were serotyped. We amplified pcoA and czcD genes that encode Cu2+ and Zn2+ tolerance, respectively. Of the 283 isolates, 113 (48%) showed Cu2+ tolerance at 24 mM and 164 (58%) showed Zn2+ tolerance at 8 mM. In multivariate analysis, serotype and source of isolates were significantly associated with Cu2+ tolerance (P < 0.001). Fecal isolates were more likely to be Cu2+ tolerant than those of feed origin (odds ratio [OR], 27.0; 95% confidence interval [CI], 2.8 to 250; P = 0.0042) or environmental origin (OR, 5.8), implying the significance of gastrointestinal selective pressure. Salmonella enterica serotypes Typhimurium and Heidelberg, highly significant for public health, had higher odds of having >20 mM MICs of Cu2+ than did “other” serotypes. More than 60% of Salmonella isolates with resistance type (R-type) AmStTeKm (32 of 53) carried pcoA; only 5% with R-type AmClStSuTe carried this gene. czcD gene carriage was significantly associated with a higher Zn2+ MIC (P < 0.05). The odds of having a high Zn2+ MIC (≥8 mM) were 14.66 times higher in isolates with R-type AmClStSuTe than in those with R-type AmStTeKm (P < 0.05). The findings demonstrate strong association between heavy metal tolerance and antimicrobial resistance, particularly among Salmonella serotypes important in public health.
Landscape Factors Associated with Livestock Disease Deaths in Idodi and Pawaga Divisions, Tanzania
(Global Livestock Collaborative Research Support Program, University of California) Coppollillo, P.; Clifford, D.; Dickman, A.; Masozera, M.; Kazwala, R.; Erickson, J.; Mazet, J.
Landscape Factors Associated with Livestock Disease Deaths in Idodi and Pawaga Divisions, Tanzania
(Global Livestock Collaborative Research Support Program, University of California, 2009-05) Coppollillo, P.; Clifford, D.; Dickman, A.; Masozera, M.; Kazwala, R.; Erickson, J.; Mazet, J.
In sub-Saharan Africa, livestock deaths due to disease have large impacts on household income and nutrition. As part of the larger Health for Animals and Livelihood Improvement (HALI) project assessing the impact of zoonotic disease and water scarcity on rural livelihoods, the authors examined the association between landscape factors and livestock deaths attributed to disease in pastoralist households living near Ruaha National Park, Tanzania. Preliminary results suggest that households located farther from the center of the village and farther from water sources suffered greater livestock losses due to disease. Livestock disease losses were greater in Pawaga than in Idodi Division, underscoring the importance of localized factors that may influence disease. The presence of wildlife and close proximity to roads were not associated with livestock disease losses. However, that is not to say the perception of disease from wildlife is not important, nor can it be said that interactions in the opposite direction (from livestock to wildlife) are not important. These assessments will require further investigation, which is currently underway. Study data also support the importance of water availability for livestock health and productivity. In conclusion, both local and regional strategies to increase livestock productivity should consider within-village disease variation and ensure that more remote households have access to extension and veterinary services.
Mycobacterium genotypes in pulmonary tuberculosis infections and their detection by trained African giant pouched rats
(Springer Science+Business) Mgode, G. F.; Cohen-Bacrie, S.; Bedotto, M.; Weetjens, B. J.; Cox, C.; Jubitana, M.; Kuipers, D.; Machang’u, R. S.; Kazwala, R.; Mfinanga, S.G.; Kaufmann, S. H. E.; Drancourt, M.
Mycobacterium genotypes in pulmonary tuberculosis infections and their detection by trained African giant pouched rats
(Springer Science+Business, 2015) Mgode, G. F.; Cohen-Bacrie, S.; Bedotto, M.; Weetjens, B. J.; Cox, C.; Jubitana, M.; Kuipers, D.; Machang’u, R. S.; Kazwala, R.; Mfinanga, S.G.; Kaufmann, S. H. E.; Drancourt, M.
Tuberculosis (TB) diagnosis in low-income countries is mainly done by microscopy. Hence, little is known about the diversity of Mycobacterium spp. in TB infections. Different genotypes or lineages of Mycobacte- rium tuberculosis vary in virulence and induce different inflammatory and immune responses. Trained Cricetomys rats show a potential for rapid diagnosis of TB. They detect over 28 % of smear-negative, culture-positive TB. How- ever, it is unknown whether these rats can equally detect sputa from patients infected with different genotypes of M. tuberculosis. A 4-month prospective study on diversity of Mycobacterium spp. was conducted in Dar es Salaam, Tanzania. 252 sputa from 161 subjects were cultured on Lowenstein-Jensen medium and thereafter tested by rats. Mycobacterial isolates were subjected to molecular iden- tification and multispacer sequence typing (MST) to determine species and genotypes. A total of 34 Mycobac- terium spp. isolates consisting of 32 M. tuberculosis, 1 M. avium subsp. hominissuis and 1 M. intracellulare were obtained. MST analyses of 26 M. tuberculosis isolates yielded 10 distinct MST genotypes, including 3 new genotypes with two clusters of related patterns not grouped by geographic areas. Genotype MST-67, shared by one- third of M. tuberculosis isolates, was associated with the Mwananyamala clinic. This study shows that diverse M. tuberculosis genotypes (n = 10) occur in Dar es Salaam and trained rats detect 80 % of the genotypes. Sputa with two M. tuberculosis genotypes (20 %), M. avium homin- issuis and M. intracellulare were not detected. Therefore, rats detect sputa with different M. tuberculosis genotypes and can be used to detect TB in resource-poor countries.
Prevalence of Brucella infection and associated risk factors among children in livestock keeping communities of Morogoro, Tanzania
(East African Journal of Science, Technology and Innovation) Hildegalda, C.; Komba, E.; Kazwala, R.; Mathew, Coletha
Progress towards rabies elimination from Pemba Island, Southern Tanzania.
(Online Journal of Public Health Informatics .) Lushasi, K. S.; Cleaveland, S.; Changalucha, J. J.; Haydon, D.; Kazwala, R.; Lembo, T.; Masoud, M.; Maziku, M.; Mchau, G.; Mtema, Z.; Omar, K.; Maganga, S.; Rysava, K.; Hampson, K.
Progress towards rabies elimination from Pemba Island, Southern Tanzania.
(Online Journal of Public Health Informatics ., 2017) Lushasi, K. S.; Cleaveland, S.; Changalucha, J. J.; Haydon, D.; Kazwala, R.; Lembo, T.; Masoud, M.; Maziku, M.; Mchau, G.; Mtema, Z.; Omar, K.; Maganga, S.; Rysava, K.; Hampson, K.
Using active surveillance approaches to investigate the transmission dynamics of rabies on Pemba Island and across Southern Tanzania, whilst a large-scale dog vaccination program was underway1 , to gain a greater understanding of the dynamics of infection as the disease is driven towards elimination
Quantifying risk factors for human brucellosis in rural northern Tanzania
(PLoS ONE) John, K.; Fitzpatrick, J.; French, N.; Kazwala, R.; Kambarage, D.; Mfinanga, G. S.; MacMillan, A.; Cleaveland, S.
Quantifying risk factors for human brucellosis in rural northern Tanzania
(PLoS ONE, 2010-04-01) John, K.; Fitzpatrick, J.; French, N.; Kazwala, R.; Kambarage, D.; Mfinanga, G. S.; MacMillan, A.; Cleaveland, S.
Background: Brucellosis is a zoonosis of veterinary, public health and economic significance in most developing countries. Human brucellosis is a severely debilitating disease that requires prolonged treatment with a combination of antibiotics. The disease can result in permanent and disabling sequel, and results in considerable medical expenses in addition to loss of income due to loss of working hours. A study was conducted in Northern Tanzania to determine the risk factors for transmission of brucellosis to humans in Tanzania. Methods: This was a matched case-control study. Any patient with a positive result by a competitive ELISA (c-ELISA) test for brucellosis, and presenting to selected hospitals with at least two clinical features suggestive of brucellosis such as headache, recurrent or continuous fever, sweating, joint pain, joint swelling, general body malaise or backache, was defined as a case. For every case in a district, a corresponding control was traced and matched by sex using multistage cluster sampling. Other criteria for inclusion as a control included a negative c-ELISA test result and that the matched individual would present to hospital if falls sick. Results: Multivariable analysis showed that brucellosis was associated with assisted parturition during abortion in cattle, sheep or goat. It was shown that individuals living in close proximity to other households had a higher risk of brucellosis. People who were of Christian religion were found to have a higher risk of brucellosis compared to other religions. The study concludes that assisting an aborting animal, proximity to neighborhoods, and Christianity were associated with brucellosis infection. There was no association between human brucellosis and Human Immunodeficiency Virus (HIV) serostatus. Protecting humans against contact with fluids and tissues during assisted parturition of livestock may be an important means of reducing the risk of transferring brucellosis from livestock to humans. These can be achieved through health education to the communities where brucellosis is common.
Revealing the history of sheep domestication using retrovirus integrations
Chessa, B.; Pereira, F.; Arnaud, F.; Amorim, A.; Goyache, F.; Mainland, I.; Kao, R. R.; Pemberton, J. M.; Beraldi, D.; Stear, M.; Alberti, A.; Pittau, M.; Lannuzzi, L.; Banabazi, M. H.; Kazwala, R.; Zhang, Y. P.; Arranz, J. J.; Ali, B. A.; Wang, Z.; Uzun, M.; Dione, M.; Olsaker, I.; Holm, L. E.; Saarma, U.; Ahmad, S.; Marzanov, N.; Eythorsdottir, E.; Holland, M. J.; Ajmone-Marsan, P.; Bruford, M. W.; Kantanen, J.; Spencer, T. E.; Palmarini, M.
Revealing the history of sheep domestication using retrovirus integrations
(2009-04-24) Chessa, B.; Pereira, F.; Arnaud, F.; Amorim, A.; Goyache, F.; Mainland, I.; Kao, R. R.; Pemberton, J. M.; Beraldi, D.; Stear, M.; Alberti, A.; Pittau, M.; Lannuzzi, L.; Banabazi, M. H.; Kazwala, R.; Zhang, Y. P.; Arranz, J. J.; Ali, B. A.; Wang, Z.; Uzun, M.; Dione, M.; Olsaker, I.; Holm, L. E.; Saarma, U.; Ahmad, S.; Marzanov, N.; Eythorsdottir, E.; Holland, M. J.; Ajmone-Marsan, P.; Bruford, M. W.; Kantanen, J.; Spencer, T. E.; Palmarini, M.
The domestication of livestock represented a crucial step in human history. By using endogenous retroviruses as genetic markers, we found that sheep differentiated on the basis of their “retrotype” and morphological traits, dispersed across Eurasia and Africa via separate migratory episodes. Relicts of the first migrations include the Mouflon, as well as breeds previously recognized as “primitive” on the basis of their morphology, such as the Orkney, Soay and the Nordic short-tailed sheep now confined to the periphery of NW Europe. A later migratory episode, involving sheep with improved production traits, shaped the vast majority of present-day breeds. The ability to differentiate genetically primitive sheep from more modern breeds provides valuable insights into the history of sheep domestication.
Self-reported health effects among short and long-term pesticide sprayers in Arusha, Northern Tanzania: A cross sectional Study
Lyche, J.V.; Manyilizu, W. B.; Mdegela, R. H.; Manyilizu, W. B.; Mdegela, R. H.; Kazwala, R.; Müller, M.; Skjerve, E.