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BACKGROUND: Salmonella Enteritidis and Salmonella Typhimurium are major causes of bloodstream infection and diarrheal disease in East Africa. Sources of human infection, including the role of the meat pathway, are poorly understood. METHODS: We collected cattle, goat, and poultry meat pathway samples from December 2015 through August 2017 in Tanzania and isolated Salmonella using standard methods. Meat pathway isolates were compared with nontyphoidal serovars of Salmonella enterica (NTS) isolated from persons with bloodstream infections and diarrheal disease from 2007 through 2017 from Kenya by core genome multi-locus sequence typing (cgMLST). Isolates were characterized for antimicrobial resistance, virulence genes, and diversity. RESULTS: We isolated NTS from 164 meat pathway samples. Of 172 human NTS isolates, 90 (52.3%) from stool and 82 (47.7%) from blood, 53 (30.8%) were Salmonella Enteritidis sequence type (ST) 11 and 62 (36.0%) were Salmonella Typhimurium ST313. We identified cgMLST clusters within Salmonella Enteritidis ST11, Salmonella Heidelberg ST15, Salmonella Typhimurium ST19, and Salmonella II 42:r:- ST1208 that included both human and meat pathway isolates. Salmonella Typhimurium ST313 was isolated exclusively from human samples. Human and poultry isolates bore more antimicrobial resistance and virulence genes and were less diverse than isolates from other sources. CONCLUSIONS: Our findings suggest that the meat pathway may be an important source of human infection with some clades of Salmonella Enteritidis ST11 in East Africa, but not of human infection by Salmonella Typhimurium ST313. Research is needed to systematically examine the contributions of other types of meat, animal products, produce, water, and the environment to nontyphoidal Salmonella disease in East Africa.
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Salmonella typhimurium , Sepse , Animais , Antibacterianos , Bovinos , Diarreia/epidemiologia , Humanos , Carne , Tipagem de Sequências Multilocus , Salmonella enteritidis/genética , Salmonella typhimurium/genética , TanzâniaRESUMO
BACKGROUND: Sub-optimal performance of the animal health delivery system in rural areas is common in developing countries including Tanzania. However, penetration of mobile phones and availability of good road network and public transport systems offer opportunities for improving the access of rural communities to diagnostic and advisory services from facilities and expertise located in urban areas. A questionnaire survey on possession and use of mobile phones by pastoral and agro-pastoral communities in Kilosa and Gairo districts was carried out between November and December 2015. A total number of 138 livestock keepers from three villages of Chakwale (54), Mvumi (41) and Parakuyo (43) participated in the study. An e-based system was designed and tested to link rural communities with urban diagnostic facilities. RESULTS: It was observed that the average number of phones possessed by individuals interviewed and household families was 1.1 ± 0.26 (1-2) and 3.5 ± 2.23 (1-10), respectively. It was further observed that out of 138 livestock keepers interviewed, 133 (96.4 %) had feature phones while 10 (7.2 %) of them possessed smartphones. Mobile phone is currently used to support livestock production by communicating on animal health in Parakuyo (18, 41.9 %), Mvumi (18, 43.9 %) and Chakwale (14, 25.9 %). Other contributions of mobile phones in livestock and crop agriculture observed in the study area include: exchange of livestock price information, crop price information, communicating on plant health/diseases, livestock extension and advisory services as well as crop farming extension and advisory services. We also designed and tested an e-based SUAVetDiag® system to support timely diagnosis of infectious disease conditions and prompt advice on case management in veterinary underserved areas. CONCLUSIONS: Availability of mobile phones in rural areas, in combination with supporting infrastructure and facilities in urban areas, has potential to stimulate local development and improving delivery of animal health and extension services. It is recommended that more development and refinement of the system should be conducted to ensure that this potential is tapped to revolutionalise delivery of animal health services in rural areas.
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Telefone Celular , Médicos Veterinários , Medicina Veterinária/normas , Criação de Animais Domésticos , Animais , Coleta de Dados , População Rural , Inquéritos e Questionários , TanzâniaRESUMO
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 accurately.
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Tuberculose Bovina/epidemiologia , Animais , Animais Selvagens/microbiologia , Bovinos , Ecossistema , Feminino , Masculino , Prevalência , Fatores de Risco , Inquéritos e Questionários , Tanzânia/epidemiologia , Teste Tuberculínico/veterinária , Tuberculose Bovina/etiologiaRESUMO
Brucellosis is a disease of major socio-economic importance worldwide, particularly in low-income countries. This retrospective study aimed to estimate seroprevalence and risk factors associated with brucellosis in commercial cattle farms in the eastern coast zone of Tanzania (ECZT). A total of 1,052 serum samples collected from 20 commercial farms were subjected to rose bengal plate test (RBPT) and indirect enzyme-linked immunosorbent assay (i-ELISA). Descriptive analysis was employed to determine frequencies and proportions. To establish risk factors, a multivariate logistic regression analysis was carried out using a backward elimination procedure, following a univariate analysis, with 0.1 set as a cut-off point for the selection of putative risk factors. Agreement between RBPT and i-ELISA was determined using a Kappa coefficient (κ). The overall animal-level seroprevalence was 25.9% based on i-ELISA. Logistic regression analysis revealed that odds of infection were significantly higher in females (OR = 1.8, 95% CI: 1.2-2.5, p = 0.002) and in young animals than in adults (OR = 3.6, CI: 2.1-6.2, p < 0.001). In addition, odds of infection were higher during the wet season (OR = 3.4, CI: 3.2-5.2, p < 0.001), in cattle reared in rural farms (OR = 4.8, CI: 2.0-11.5, p < 0.001), in cattle reared in areas, not in contact with wildlife (OR = 2.9, CI: 1.4-2.3, p = 0.004), and in medium-sized farms (OR = 12.5, CI: 6.9-22.9, p < 0.001). These findings confirm that bovine brucellosis was prevalent among commercial cattle farms in the ECZT, posing a serious public health concern to the community living in these settings. The one health approach should be adopted for effective control of brucellosis.
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INTRODUCTION: Brucellosis is a serious community health problem and endemic disease in Tanzania in both humans and animals. Frontline health workers (FHWs) play a vital role in reporting and hence prevent and control brucellosis in rural settings. This study aims to evaluate the effect of awareness training to frontline health workers and use of electronic technology (e- technology) on reporting of brucellosis cases. METHODS: A quasi-experimental design was implemented in two pastoral communities in eastern part of Tanzania with one as control and another as treatment involving 64 FHWs who were purposively selected from May 2020 to December 2020. A total of 32 FHWs from treatment pastoral community were purposively selected for awareness training, rapid diagnosis using Rose Bengal test (RBT) and use of electronic technology (AfyaData app) for brucellosis reporting while nothing was done in control community. Before and after training information about their knowledge, attitude and practices were collected from all participants using a structured questionnaires uploaded in the mobile phone powered by AfyaData application. Blood samples were collected from 141 febrile patients attending the selected facilities in treatment community. Serum obtained from collected blood were analyzed using RBT and Competitive Enzyme Linked Immunosorbent Assay (c-ELISA) for brucellosis screening and confirmatory, respectively. Results from this analysis were reported back to the health facility using AfyaData app. Chi-square was used to analyze categorical variables and t-test and/Anova test was used to assess the effectiveness of the intervention. RESULTS: Results revealed that before the training majority of the participants were ignorant about brucellosis, although they had good attitude towards brucellosis prevention. Participant's awareness, practice and attitude increased significantly (p = 0.003, p = 0.001, p = 0.032) respectively, after the intervention. Total of 17(12.1%) patients were positive on RBT and four (2.8%) were confirmed by c-ELISA. AfyaData app was proven to provide quick reports regarding brucellosis in the study area. CONCLUSION: The training program was effective in increasing the level of knowledge and practice about brucellosis. Electronic based technology (AfyaData app) improved the reporting of brucellosis cases. There is a need for the use of electronic based technology to improve timely management of brucellosis in pastoral communities. Also, continuous training on FHWs regarding the disease is needed to improved their awareness and practices.
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A combination of survival and spatial analyses was applied to a dataset containing cattle mortalities on smallholder dairy farms in two separate regions (Tanga and Iringa) of Tanzania. Cattle mortality data for the year 1998 were collected retrospectively during the period January to April 1999. The objectives of the current study were, firstly, to quantify the hazard of mortality and, secondly, to investigate whether there was a spatial pattern in the variation that was unaccounted for in the hazard of mortality. A Cox regression model with farm as a frailty term was used to quantify the hazard of mortality. Geostatistical techniques were used to explore the first- and second-order spatial distribution of the farm frailty term. A total of 1,790 cattle from 400 randomly sampled smallholder dairy farms were included in the study. The overall mortality incidence rate for the study was 11.8 per 100 animal years (95% CI 10.0-13.8). The hazard of mortality for male cattle was 2.4 (95% CI 1.7-3.4) times higher than that of female cattle. There was evidence of a first-order spatial pattern, i.e., a tendency for farms with higher frailty to aggregate.
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Doenças dos Bovinos/mortalidade , Indústria de Laticínios , Animais , Bovinos , Doenças dos Bovinos/epidemiologia , Feminino , Estimativa de Kaplan-Meier , Masculino , Modelos de Riscos Proporcionais , Análise de Regressão , Estudos Retrospectivos , Fatores de Risco , Fatores Sexuais , Tanzânia/epidemiologiaRESUMO
BACKGROUND: Brucellosis an important zoonotic disease worldwide, which frequently presents as an undifferentiated febrile illness with otherwise varied and non-specific clinical manifestations. Despite its importance, there are few reports on its awareness among frontline health workers. This study aimed at assessing the baseline knowledge, attitude and practice (KAP) related to detection and management of brucellosis among frontline health workers (FHWs) namely; healthcare workers (HWs) and community health workers (CHWs). METHODS: A cross-sectional study was conducted from December 2019 to January 2020 in Kilosa and Chalinze districts of Tanzania. Data on demographic characteristics, knowledge, attitude and practices regarding brucellosis were collected from the study participants using a structured questionnaire. Interviews were conducted with 32 HWs and 32 CHWs who were systematically selected in study districts. Chi square/fisher Exact was used to assess the association between sociodemographic variables and those related to knowledge, attitude and practices. RESULTS: Overall, a total of 30 (93.8%) HWs and nine (28.1%) CHWs from the study districts heard about brucellosis, with (34.4%) of HWs having knowledge about the causative organism. Overall, knowledge showed almost half (46.9%) HWs and (28.1%) CHWs were aware of the symptoms, clinical signs, diagnosis and control regarding brucellosis. Knowledge difference was statistically significant with HWs' age (p = 0.016). Almost half (46.9%) HWs and less than quarter (12.5%) CHWs had good practices regarding brucellosis control. Almost three quarters (71.9%) of HWs and (21.9%) CHWs had positive attitude regarding brucellosis control; overall attitude was statistically significant with CHWs age (p = 0.028) and education level (p = 0.024). Lack of awareness and unavailability of diagnostic tools were the main challenges faced by FHWs in the two districts. CONCLUSION: The majority of participants were not aware of human brucellosis. Moreover, their overall knowledge was inadequate and the common practices were diagnostic tools, and adequate knowledge to manage brucellosis cases. These findings highlight the need to strengthen frontline health workers knowledge, practices and diagnostic capacities related to brucellosis.
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OBJECTIVES: Data on Rift Valley fever virus (RVFV) prevalence in urban settings and pastoral areas of Tanzania are scarce. We performed a cross-sectional study of RVFV seroprevalence and determinants in humans and animals from Ilala, Rufiji, and Sengerema districts of Tanzania. METHODS: Blood samples from the study participants were tested for anti-RVFV immunoglobulin G (IgG) antibodies using an enzyme-linked immunosorbent assay. Logistic regression was used to determine association between exposure risk practices and RVFV seropositivity. RESULTS: The study involved 664 humans, 361 cattle, 394 goats, and 242 sheep. The overall anti-RVFV IgG seroprevalence in humans and animals was 2.1% (95% confidence interval [CI] 0.01-0.04) and 9.5% (n = 95, 95% CI 0.08-0.12), respectively. Seroprevalence in humans in Rufiji, Ilala, and Sengerema was 3.0% (n = 225, 95% CI 0.01-0.06), 1.8% (n = 230, 95% CI-0.005- 0.04), and 1.4% (n = 209, 95% CI 0.01-0.04), respectively (P >0.05). Seroprevalence in animals in Sengerema, Rufiji, and Ilala was 12.1% (n = 40, 95% CI 0.09-0.16), 11.1% (n = 37, 95% CI 0.08-0.15), and 5.4% (n = 18, 95% CI 0.03-0.08), respectively (P = 0.006). Handling of carcasses increased the odds of RVFV seropositivity 12-fold (odds ratio 11.84, 95% CI 1.97-71.16). CONCLUSION: The study confirms previous occurrence of RVFV in multiple species in the study districts. Animal handling practices appear to be essential determinants of seropositivity.
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Febre do Vale de Rift , Vírus da Febre do Vale do Rift , Animais , Anticorpos Antivirais , Bovinos , Estudos Transversais , Ensaio de Imunoadsorção Enzimática , Cabras , Humanos , Imunoglobulina G , Febre do Vale de Rift/epidemiologia , Fatores de Risco , Ruminantes , Estudos Soroepidemiológicos , Ovinos , Tanzânia/epidemiologiaRESUMO
This cross-sectional study was conducted in the Kilosa, Morogoro Urban, Ngorongoro, and Ulanga districts of Tanzania to investigate the practices of community health workers (CHWs) related to disease surveillance functions and to establish their needs and technology capacities. We also established the strength of mobile phone networks and internet connections in the study areas to inform the feasibility of using mobile-based applications in community-based disease surveillance. A total of 135 CHWs from 85 villages participated in the study. Health events captured at the community level were entirely paper-based. CHWs submitted reports to higher-level health authorities mainly on foot (100%), but they also used public transport (65%) and telephone calls (56%). The median number of days between the onset of a suspected disease outbreak at the community level and reporting to a primary healthcare facility was 10 days (interquartile range [IQR] 2-30). The median number of days between submitting a report and receiving a response was 7 days (IQR 2-30). Of the 53 CHWs who reported the most recent health events to a higher-level health authority, 39 (74%) never received feedback. All 85 villages had a reliable mobile phone network and 74 (87%) had a mobile phone internet connection that was strong enough to support data transmission using digital technology. Almost all (n = 132, 98%) of the CHWs owned mobile phones. The practices related to detection and reporting of health events could be improved to enhance early warning disease surveillance. Reliable mobile networks and internet connections and the ownership of mobile phones among CHWs in the study areas present opportunities to strengthen community event-based surveillance using mobile-based solutions.
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Telefone Celular/provisão & distribuição , Agentes Comunitários de Saúde/organização & administração , Monitoramento Epidemiológico , Animais , Agentes Comunitários de Saúde/estatística & dados numéricos , Estudos Transversais , Surtos de Doenças/estatística & dados numéricos , Surtos de Doenças/veterinária , Monitoramento Epidemiológico/veterinária , Feminino , Humanos , Internet/provisão & distribuição , Masculino , TanzâniaRESUMO
Background: Vaccination is considered to be the best approach to control Rift Valley fever (RVF) in animals and consequently in humans. This study assessed the efficacy and safety of the RVF virus (RVFV) Clone 13 vaccine under field conditions. Methodology: A vaccine trial was conducted in sheep (230), goats (230), and cattle (140) in Ngorongoro district, Tanzania. Half of each of the animal species were vaccinated and the other half received the placebo. Animals were clinically monitored and bled before vaccination and at days 15, 30, 60, 180 and 360 (+/- 10) post-vaccination to measure Immunoglobulin M (IgM) and IgG antibody responses to RVFV. Survival analysis was conducted using cox-proportional hazard regression model to measure the time until an event of interest had occurred and to compare the cumulative proportion of events over time. Results: Of 600 animals included in the study, 120 animals were lost during the study, leaving a total of 480 (243 in the vaccinated group and 237 in the control group) for complete follow-up sampling. There was no adverse reaction reported at the injection site of the vaccine/placebo in all animals. Abortions, deaths, or body temperature variations were not associated with vaccination (p > 0.05). By day 15 post-inoculation, the IgG seroconversion in vaccinated goats, cattle and sheep was 27.0% (n = 115), 20.0% (n = 70) and 10.4% (n = 115), respectively. By day 30 post-inoculation, it was 75.0% (n = 113), 74.1% (n = 112) and 57.1% (n = 70) in vaccinated sheep, goats and cattle, respectively. By day 60 post-inoculation, IgG seroconversion in sheep, goats and cattle was 88.1% (n = 109), 84.3% (n = 108) and 64.60% (n = 65), respectively. By day 180, the IgG seroconversion in sheep, goats and cattle was 88.0% (n = 108), 83.8% (n = 105) and 66.1% (n = 62), respectively. By day 360, the IgG seroconversion in sheep, goats and cattle was 87.2% (n = 94), 85.6% (n = 90) and 66.1% (n = 59), respectively. Only five animals from the vaccinated group were RVFV IgM positive, which included four sheep and a goat. Conclusion: RVFV Clone 13 vaccine was well tolerated by sheep, goats, and cattle. The vaccine induced detectable, but variable levels of IgG responses, and of different duration. The vaccine is considered safe, with high immunogenicity in sheep and goats and moderate in cattle.
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We conducted environmental surveillance of antimicrobial resistance (AMR) bacteria in the Msimbazi river basin in Tanzania to determine the occurrence of extended-spectrum ß-lactamase (ESBL)-producing, carbapenem resistant Enterobacteriaceae (CRE) and quinolone resistant Escherichia coli and Klebsiella spp. A total of 213 Enterobacteriaceae isolates were recovered from 219 samples. Out of the recovered isolates, 45.5% (n = 97) were Klebsiella pneumoniae and 29.6% (n = 63) were Escherichia coli. K. pneumoniae isolates were more resistant in effluent (27.9%) compared to the E. coli (26.6%). The E. coli had a higher resistance in river water, sediment and crop soil than the K. pneumoniae (35 versus 25%), respectively. Higher resistance in K. pneumoniae was found in nalidixic acid (54.6%) and ciprofloxacin (33.3%) while the E. coli isolates were highly resistant to ciprofloxacin (39.7%) and trimethoprim/sulfamethoxazole (38%). Resistance increased from 28.3% in Kisarawe, where the river originates, to 59.9% in Jangwani (the middle section) and 66.7% in Upanga West, where the river enters the Indian Ocean. Out of 160 E. coli and K. pneumoniae isolates, 53.2% (n = 85) were resistant to more than three classes of the antibiotic tested, occurrence being higher among ESBL producers, quinolone resistant and carbapenem resistant strains. There is an urgent need to curb environmental contamination with antimicrobial agents in the Msimbazi Basin.
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Enterobacteriáceas Resistentes a Carbapenêmicos , Quinolonas , Antibacterianos/farmacologia , Ecossistema , Escherichia coli , Klebsiella pneumoniae , Testes de Sensibilidade Microbiana , Rios , Tanzânia , beta-LactamasesRESUMO
BACKGROUND: This study was conducted to determine the seroprevalence and risk factors of chikungunya (CHIKV), dengue (DENV), and Zika (ZIKV) viruses in Tanzania. METHODS: The study covered the districts of Buhigwe, Kalambo, Kilindi, Kinondoni, Kondoa, Kyela, Mvomero, and Ukerewe in Tanzania. Blood samples were collected from individuals recruited from households and healthcare facilities. An ELISA was used to screen for immunoglobulin G antibodies against CHIKV, DENV, and ZIKV. RESULTS: A total of 1818 participants (median age 34 years) were recruited. The overall CHIKV, DENV, and ZIKV seroprevalence rates were 28.0%, 16.1%, and 6.8%, respectively. CHIKV prevalence was highest in Buhigwe (46.8%), DENV in Kinondoni (43.8%), and ZIKV in Ukerewe (10.6%) and Mvomero (10.6%). Increasing age and frequent mosquito bites were significantly associated with CHIKV and DENV seropositivity (P < 0.05). Having piped water or the presence of stagnant water around the home (P < 0.01) were associated with higher odds of DENV seropositivity. Fever was significantly associated with increased odds of CHIKV seropositivity (P < 0.001). Visiting mines had higher odds of ZIKV seropositivity (P < 0.05). CONCLUSIONS: These findings indicate that DENV, CHIKV, and ZIKV are circulating in diverse ecological zones of Tanzania. There is a need to strengthen the control of mosquito-borne viral diseases in Tanzania.
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Febre de Chikungunya , Vírus Chikungunya , Vírus da Dengue , Dengue , Infecção por Zika virus , Zika virus , Adulto , Animais , Febre de Chikungunya/epidemiologia , Dengue/epidemiologia , Humanos , Fatores de Risco , Estudos Soroepidemiológicos , Tanzânia/epidemiologia , Infecção por Zika virus/epidemiologiaRESUMO
Brucellosis is a zoonotic disease of importance to both public health and the livestock industry. The disease is likely to be endemic in Tanzania and little is reported on molecular characterization of Brucella species in pastoral settings. This study aimed at characterizing Brucella species (targeting genus Brucella) infecting humans, cattle and goat in Kagera region (Ngara and Karagwe districts) using real-time PCR, PCR amplification of 16S rRNA genes and Sanger sequencing. Brucella spp. were detected in 47 samples (19 sera and 28 milk) out of 125 samples (77 sera, 35 milk and 13 aborted materials) using real-time PCR. All aborted materials (13 samples) were negative to real-time PCR. Out of the 47 real-time PCR positive samples (28 milk and 19 sera), 20 samples (10 milk and 10 sera) showed an expected 16S rRNA gene PCR product. Sequence analysis and blasting confirmed the presence of Brucella spp. in pastoral areas of Kagera region. The Brucella spp. from Kagera were phylogenetically grouped in two clades and three branches all closer to B. melitensis, B. abortus and B. suis from USA, Sudan and Iran. However, they were distinct from other species isolated also in USA, New Zealand, Germany and Egypt. This was expected based on the distance between the geographical regions from which the data (nucleotides sequences from 16S gene sequencing) for the phylogeny reconstruction were obtained. This is the first study to report Brucella species identified using 16S rRNA gene sequencing in East and Central Africa. A livestock vaccination program re-inforced with a high index of Brucella diagnosis is needed to eradicate brucellosis in animals and minimize suffering from Brucella infections in humans in Tanzania.
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Brucella/isolamento & purificação , Brucelose/epidemiologia , Brucelose/veterinária , Doenças dos Bovinos/epidemiologia , Doenças das Cabras/epidemiologia , Feto Abortado/microbiologia , Animais , Brucella/classificação , Brucella/genética , Brucelose/microbiologia , Brucelose Bovina/epidemiologia , Brucelose Bovina/microbiologia , Bovinos , Doenças dos Bovinos/microbiologia , Doenças das Cabras/microbiologia , Cabras , Humanos , Leite/microbiologia , Prevalência , RNA Bacteriano/análise , RNA Ribossômico 16S/análise , Reação em Cadeia da Polimerase em Tempo Real/veterinária , Estudos Soroepidemiológicos , Soro/microbiologia , Tanzânia/epidemiologiaRESUMO
The incidence and potential determinants of tick borne diseases (TBDs) were estimated in a longitudinal study that was conducted in cohorts of youngstock animals of less than 3 years kept in smallholder dairy farms in Tanga region, Tanzania. A combination of serological tests, blood and lymph node smears were used as diagnostic tests for TBDs during the study. A total number of 549 youngstock were followed for a total of 532.2 animal years from August 1999 to July 2001. Overall morbidity and mortality rates (due to all causes) were 8.26 and 12.0 per 100 animals year at risk, respectively. Of the total deaths, 56% were attributed to TBDs (37.5%-East Coast fever (ECF) and 18%-anaplasmosis). Specific morbidity and mortality rates for ECF were estimated to be 3.57 and 4.51 per 100 animals year risk, respectively, and for anaplasmosis 2.21 and 2.25 per 100 animals year risk, respectively. Analysis of survival times to death indicated that calves < 6 months of age and those out on pasture had higher death rates than older calves and those kept under zero-grazing systems (relative risk [RR] 3.80, P = 0.001 for pasture-grazed calves). There was no mortality or morbidity arising specifically from cowdriosis (heartwater) or babesiosis during the whole period of monitoring. The study revealed that most farms were applying under strength acaricide and using acaricides at irregular intervals. It is concluded that TBDs namely ECF and anaplasmosis are important diseases in this farming system and reducing morbidity and mortality in smallholder dairy farms in Tanga region is an achievable goal. Both farmers and extension services should target at risk calves with the provision of both strict tick control and optimal husbandry management practices.
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Doenças dos Bovinos/epidemiologia , Doenças Transmitidas por Carrapatos/veterinária , Distribuição por Idade , Animais , Bovinos , Doenças dos Bovinos/mortalidade , Indústria de Laticínios , Feminino , Estudos Longitudinais , Masculino , Tanzânia/epidemiologia , Doenças Transmitidas por Carrapatos/epidemiologia , Doenças Transmitidas por Carrapatos/mortalidadeRESUMO
BACKGROUND: Zoonoses account for the most commonly reported emerging and re-emerging infectious diseases in Sub-Saharan Africa. However, there is limited knowledge on how pastoral communities perceive zoonoses in relation to their livelihoods, culture and their wider ecology. This study was carried out to explore local knowledge and perceptions on zoonoses among pastoralists in Tanzania. METHODOLOGY AND PRINCIPAL FINDINGS: This study involved pastoralists in Ngorongoro district in northern Tanzania and Kibaha and Bagamoyo districts in eastern Tanzania. Qualitative methods of focus group discussions, participatory epidemiology and interviews were used. A total of 223 people were involved in the study. Among the pastoralists, there was no specific term in their local language that describes zoonosis. Pastoralists from northern Tanzania possessed a higher understanding on the existence of a number of zoonoses than their eastern districts' counterparts. Understanding of zoonoses could be categorized into two broad groups: a local syndromic framework, whereby specific symptoms of a particular illness in humans concurred with symptoms in animals, and the biomedical framework, where a case definition is supported by diagnostic tests. Some pastoralists understand the possibility of some infections that could cross over to humans from animals but harm from these are generally tolerated and are not considered as threats. A number of social and cultural practices aimed at maintaining specific cultural functions including social cohesion and rites of passage involve animal products, which present zoonotic risk. CONCLUSIONS: These findings show how zoonoses are locally understood, and how epidemiology and biomedicine are shaping pastoralists perceptions to zoonoses. Evidence is needed to understand better the true burden and impact of zoonoses in these communities. More studies are needed that seek to clarify the common understanding of zoonoses that could be used to guide effective and locally relevant interventions. Such studies should consider in their approaches the pastoralists' wider social, cultural and economic set up.
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Conhecimentos, Atitudes e Prática em Saúde , Zoonoses/psicologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Feminino , Grupos Focais , Humanos , Masculino , Pessoa de Meia-Idade , Percepção , População Rural , Tanzânia/etnologia , Adulto Jovem , Zoonoses/etnologiaRESUMO
BACKGROUND: More than 90 percent of cattle in Tanzania belong to the indigenous Tanzania Short Horn Zebu (TSZ) population which has been classified into 12 strains based on historical evidence, morphological characteristics, and geographic distribution. However, specific genetic information of each TSZ population has been lacking and has caused difficulties in designing programs such as selection, crossbreeding, breed improvement or conservation. This study was designed to evaluate the genetic structure, assess genetic relationships, and to identify signatures of selection among cattle of Tanzania with the main goal of understanding genetic relationship, variation and uniqueness among them. METHODOLOGY/PRINCIPAL FINDINGS: The Illumina Bos indicus SNP 80K BeadChip was used to genotype genome wide SNPs in 168 DNA samples obtained from three strains of TSZ cattle namely Maasai, Tarime and Sukuma as well as two comparative breeds; Boran and Friesian. Population structure and signatures of selection were examined using principal component analysis (PCA), admixture analysis, pairwise distances (FST), integrated haplotype score (iHS), identical by state (IBS) and runs of homozygosity (ROH). There was a low level of inbreeding (F~0.01) in the TSZ population compared to the Boran and Friesian breeds. The analyses of FST, IBS and admixture identified no considerable differentiation between TSZ trains. Importantly, common ancestry in Boran and TSZ were revealed based on admixture and IBD, implying gene flow between two populations. In addition, Friesian ancestry was found in Boran. A few common significant iHS were detected, which may reflect influence of recent selection in each breed or strain. CONCLUSIONS: Population admixture and selection signatures could be applied to develop conservation plan of TSZ cattle as well as future breeding programs in East African cattle.
Assuntos
Genética Populacional , Genoma , Polimorfismo de Nucleotídeo Único/genética , Seleção Genética , Animais , Cruzamento , Bovinos , Cruzamentos Genéticos , Genótipo , Haplótipos , Homozigoto , Hibridização Genética , TanzâniaRESUMO
BACKGROUND: Despite the long history of Rift Valley fever (RVF) in Tanzania, extent of its suitable habitat in the country remains unclear. In this study we investigated potential effects of temperature, precipitation, elevation, soil type, livestock density, rainfall pattern, proximity to wild animals, protected areas and forest on the habitat suitability for RVF occurrence in Tanzania. MATERIALS AND METHODS: Presence-only records of 193 RVF outbreak locations from 1930 to 2007 together with potential predictor variables were used to model and map the suitable habitats for RVF occurrence using ecological niche modelling. Ground-truthing of the model outputs was conducted by comparing the levels of RVF virus specific antibodies in cattle, sheep and goats sampled from locations in Tanzania that presented different predicted habitat suitability values. PRINCIPAL FINDINGS: Habitat suitability values for RVF occurrence were higher in the northern and central-eastern regions of Tanzania than the rest of the regions in the country. Soil type and precipitation of the wettest quarter contributed equally to habitat suitability (32.4% each), followed by livestock density (25.9%) and rainfall pattern (9.3%). Ground-truthing of model outputs revealed that the odds of an animal being seropositive for RVFV when sampled from areas predicted to be most suitable for RVF occurrence were twice the odds of an animal sampled from areas least suitable for RVF occurrence (95% CI: 1.43, 2.76, p < 0.001). CONCLUSION/SIGNIFICANCE: The regions in the northern and central-eastern Tanzania were more suitable for RVF occurrence than the rest of the regions in the country. The modelled suitable habitat is characterised by impermeable soils, moderate precipitation in the wettest quarter, high livestock density and a bimodal rainfall pattern. The findings of this study should provide guidance for the design of appropriate RVF surveillance, prevention and control strategies which target areas with these characteristics.
RESUMO
The prevalence of mastitis, milk quality and health risks associated with milk consumption were investigated on 96 randomly selected traditional herds in Dodoma rural and Mvomero districts of Tanzania. Mastitis was investigated based on clinical signs, microbiology and California mastitis test (CMT), while milk quality was evaluated using total viable count (TVC)and total coliform count (TCC). Animals were tested for tuberculosis using a single comparative intradermal tuberculin test. The prevalence of subclinical mastitis based on CMT was low (8.3%). The major isolates were Staphylococcus aureus (35.3%), other staphylococci (20.8%), coliforms (27.7%), microcci (5.8%) and streptococci (9.8%). The average TVC of milk in Dodoma rural district (1.0 x 10(7) +/- 3.4 x 10(7)) was significantly higher than that in Mvomero district (8.9 x 10 (5) 3.5 x 10(6)) (p < 0.001) and the proportion of TCC-positive samples in Dodoma (70.7%) were significantly higher (p < 0.001) than that of Mvomero sample(20.8%). Whereas no tuberculin reactor animal was detected in the study animals, atypical mycobacteria were isolated from milk and one sample from Dodoma had Mycobacterium tuberculosis. Knowledge on health risks associated with milk consumption was low (20.8%). It is concluded that lack of awareness on health risks associated with milk consumption amongst rural communities needs to be addressed in order to safeguard their health.
Assuntos
Mastite Bovina/epidemiologia , Leite/microbiologia , Leite/normas , Tuberculose Bovina/epidemiologia , Animais , Bovinos , Feminino , Humanos , Prevalência , Saúde Pública , Tanzânia/epidemiologiaRESUMO
Oxytetracycline is used to treat various diseases in cattle. However, its use may be associated with unacceptable residue levels in food. Oxytetracycline residues in tissues from indigenous cattle were determined in a cross-sectional study conducted in the Kilosa district, Tanzania, between November 2012 and April 2013. A total of 60 tissue samples, including muscle, liver and kidney, were collected from slaughterhouses and butchers and analysed for oxytetracycline using high-performance liquid chromatography. Oxytetracycline residues were found in 71.1% of the samples, of which 68.3% were above acceptable regulatory levels. The mean concentration of oxytetracycline across tissues was 3401.1 µg/kg ± 879.3 µg/kg; concentrations in muscle, liver and kidney were 2604.1 µg/kg ± 703.7 µg/kg, 3434.4 µg/kg ± 606.4 µg/kg and 3533.1 µg/kg ± 803.6 µg/kg, respectively. High levels of oxytetracycline residue in meat from indigenous cattle may pose a health threat to consumers in Kilosa. The findings possibly reflect a general lack of implementation of recommended withdrawal periods, ignorance about drug use and lack of extension services. Strict regulation of the use of antimicrobial drugs in the livestock industry and associated testing of animal-derived food sources prior to marketing are required.
Assuntos
Antibacterianos/análise , Resíduos de Drogas/análise , Carne/análise , Oxitetraciclina/análise , Animais , Bovinos , Cromatografia Líquida de Alta Pressão/veterinária , Estudos Transversais , TanzâniaRESUMO
Rift Valley fever (RVF) is an acute arthropod-borne viral zoonotic disease primarily occurring in Africa. Since RVF-like disease was reported in Tanzania in 1930, outbreaks of the disease have been reported mainly from the eastern ecosystem of the Great Rift Valley. This cross-sectional study was carried out to describe the variation in RVF virus (RVFV) seropositivity in domestic ruminants between selected villages in the eastern and western Rift Valley ecosystems in Tanzania, and identify potential risk factors. Three study villages were purposively selected from each of the two Rift Valley ecosystems. Serum samples from randomly selected domestic ruminants (n = 1,435) were tested for the presence of specific immunoglobulin G (IgG) and M (IgM), using RVF enzyme-linked immunosorbent assay methods. Mixed effects logistic regression modelling was used to investigate the association between potential risk factors and RVFV seropositivity. The overall RVFV seroprevalence (n = 1,435) in domestic ruminants was 25.8% and species specific seroprevalence was 29.7%, 27.7% and 22.0% in sheep (n = 148), cattle (n = 756) and goats (n = 531), respectively. The odds of seropositivity were significantly higher in animals sampled from the villages in the eastern than those in the western Rift Valley ecosystem (OR = 1.88, CI: 1.41, 2.51; p<0.001), in animals sampled from villages with soils of good than those with soils of poor water holding capacity (OR = 1.97; 95% CI: 1.58, 3.02; p< 0.001), and in animals which had been introduced than in animals born within the herd (OR = 5.08, CI: 2.74, 9.44; p< 0.001). Compared with animals aged 1-2 years, those aged 3 and 4-5 years had 3.40 (CI: 2.49, 4.64; p< 0.001) and 3.31 (CI: 2.27, 4.82, p< 0.001) times the odds of seropositivity. The findings confirm exposure to RVFV in all the study villages, but with a higher prevalence in the study villages from the eastern Rift Valley ecosystem.