The epidemiology of brucellosis in animals and humans in Arusha and Manyara regions in Tanzania

The aims of this study were to assess community knowledge, awareness and practices on zoonoses, to gather baseline data on brucellosis in livestock and wildlife, to establish brucellosis seroprevalence in domestic ruminants and humans and risk factors associated with livestock seropositivity, to assess brucellosis dynamics and impact on livestock production and reproduction and to evaluate the performance of the Rose Bengal Plate Test (RBPT) in Tanzania. The results described in this study were carried out through Participatory Rural Appraisal (PRA), cross-sectional and longitudinal studies. In the PRA and cross-sectional studies, rabies, tuberculosis, anthrax and brucellosis were the zoonoses most frequently identified. Cattle were frequently identified as being associated with tuberculosis, anthrax and brucellosis, whereas dogs were frequently identified as being associated with rabies. Small ruminants, pigs, cats and poultry were either infrequently, or not identified as being associated with zoonoses. Recognition of clinical signs of zoonoses in humans was better than in animals. Ingestion of animal products was a route frequently identified as transmitting zoonoses to humans. During the baseline serosurvey, seroprevalences for brucellosis were 6.2% in cattle, 6.5% in small ruminants and 13% in wildlife, respectively. Seropositivity was significantly higher in the pastoral (13.2%), followed by agro-pastoral (5.3%), and lowest in the small holder dairy system (2.3%) (p<O.05). During the cross-sectional serosurvey, the seroprevalence was significantly higher in older animals and large herds (p<O.OOl). Variation in seropositivity between households was higher (1-30%) in the pastoral compared to agro-pastoral (1-14%) households. The model that best explained c-ELISA seropositivity included the feeding of dogs with foetuses and placentae, calving during the wet season, and the fanning system. In humans, 28% of families were seropositive for brucellosis with the highest levels in Ngorongoro district (46%), and lowest in Babati district (0%). Families with seropositive herds were 3.3 times more likely to be seropositive. However, 25% of families were seronegative when their herds were seropositive, and 48% of families were seropositive with seronegative herds. In the longitudinal study, the incidence was 73211,000 cases per animal-years at risk with an estimated survival probability of 0.836. Households with a high seroprevalence at the initial sampling had a high incidence of seroconversion in the subsequent visits. Occurrence of new seropositive cases was significantly higher in the wet season (p< 0.05). Calf serostatus was statistically associated with dam serostatus but no significant difference in growth rate was observed between calves suckled from seropositive and seronegative dams. Brucella melitensis type-1 was isolated from goats' milk following culture. Blood and placenta samples were negative on bacteriological culture. The RBPT was found to have low sensitivity in both field and laboratory settings. Brucellosis infection in livestock is widespread, but poses the greatest risk to human health and livestock production in pastoral systems in Tanzania

Towards an Integrated Mobile Technology on Animal Disease Surveillance Framework in Tanzania: A Systematic Review

Tanzanian Government, through its national audit office in March 2020, reported the prevalence decline of two animal diseases, namely; Foot and Mouth Disease (FMD) and Contagious Bovine Pleuropneumonia (CBPP). Similarly, an increase in three animal diseases, which are African Swine Fever (ASV), Contagious Caprine Pleuropneumonia (CCPP), and Lumpy Skin Disease (LSD). The national audit office mentioned inadequate animal disease surveillance system in the country was among the challenges that hinder diseases control. Therefore, this study reviews the existing animal diseases surveillance systems global and suggests measures to enhance animal diseases surveillance systems in Tanzania. This review focuses on the possibility of sharing surveillance data among livestock stakeholders (including livestock keepers) in Tanzania, considering available resources such as animal diseases existing prediction models and mobile-based surveillance systems. Also, the availability of mobile technologies such as Short Message Service (SMS), Unstructured Supplementary Service Data (USSD) and automatic voice calls (Robocalls). Reviews synthesize the previous studies to explore strengths, opportunities, weaknesses and challenges for better future interventions through proper and timely information sharing. This study selected 46 records from the 147 identified for review. The selected records include 24 from bibliographic databases, 14 from full-text journals and other non-bibliographic databases, and 8 from the open search on websitesinfo:eu-repo/semantics/publishedVersio

Diagnosis Challenges and Control Strategies of Transboundary Diseases Presenting with Respiratory Signs in Small Ruminants in Developing Countries: Emphasis on Contagious Caprine Pleuropneumonia and Peste Des Petits Ruminants

This research article was published in the International Journal of TROPICAL DISEASE & Health Volume 41 [Issue 22], 2020Aims: To review the diagnosis challenges and control strategies of the diseases presenting with respiratory signs. The emphasis being more on two transboundary animal diseases of small ruminants; contagious caprine pleuropneumonia (CCPP) and peste des petits ruminants (PPR). Clinical signs and postmortem lesions associated with the two diseases were also explicated. Study Design: Review. Place and Duration of Study: Department of Global Health, School of Life Science and Bio-Engineering (LiSBE), Nelson Mandela African Institution of Science and Technology (NM-AIST) from December 2017 to June 2020. Methodology: A comprehensive review was carried out following Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. A total of 506 articles, handbooks, Master’s and PhD thesis and conference proceedings were collected and after removal of the duplicates 80.6% (424/526) passed the first stage. Of the remaining search materials, (n=291) were removed including handbooks, master’s and PhD thesis which did not originate from the developing countries, 31.4% (133/424) passed the second. Of the articles that passed the second stage, (n=85) were removed from the study, these included all articles that did not involve field diagnosis such as review papers and those not originating from the developing countries, 36.1% (48/133) passed the third stage. In the fourth stage, (n=5) articles which reported on retrospective cases and archived samples were removed and 43 articles were reviewed. Results: Out of the 526 documents retrieved, 43 were eligible for review as they met all criteria for inclusion. Control strategies were recommended in 44.2% (19/43) of the articles of which most of them 63.2%, 12/19) recommended vaccination as a control strategy. Most of the articles reported definitive diagnosis reached following laboratory involvement as majority of them involved outbreak investigation or research works which is not the case in routine diagnosis. The major clinical signs mentioned in the review articles including fever 60.9% (14/23), oculonasal discharge 87.0% (20/23), respiratory distress 82.6% (19/23), erosive stomatitis 43.5% (10/23), diarrhea 56.5% (13/23) and coughing 30.4% (7/23) have been discussed relating to the definitive diagnosis reached in reporting articles. On the other hand, postmortem lesions including lung consolidation 38.1% (8/21), intestinal hemorrhage 38.1% (8/21), lung congestion 28.6% (6/21), serofibrinous pleurisy 28.6% (6/21), pneumonic lungs 23.8% (5/21) and unilateral lung inflammation 14.3% (3/21), have been discussed in relation to the definitive diagnosis reached. Conclusion: Despite the similarities in clinical signs and postmortem lesions associated with diseases presenting with respiratory signs, definitive diagnosis of CCPP was reached in cases that involved clinical signs and postmortem lesions confined in the respiratory system whereas, PPR was more diagnosed in cases that presented with clinical signs and postmortem lesions associating the digestive system. However, presence of respiratory signs in the cases the diagnosed PPR may implicate presence of unidentified secondary bacterial infections. Vaccinations being the most advocated approach of control, require a broader look to make sure that polyvalent vaccines are available against the four common diseases. Also, use of treatment to reduce the effect of secondary infecting bacteria may be of help. Furthermore, for effective outcomes of the control strategies, collaborative efforts among countries at risk should be advocated

Prevalence of brucellosis in the human, livestock and wildlife interface areas of Serengeti National Park, Tanzania.

This research article published by AOSIS, 2016Between 2005 and 2006, a cross-sectional survey was carried out in domestic ruminants in agropastoral communities of Serengeti district, Tanzania to determine the seroprevalence of brucellosis in domestic-wildlife interface villages. Both the Rose Bengal Plate Test (RBPT) and Competitive Enzyme Linked-immunosorbent Assay (c-ELISA) were used to analyse 82 human and 413 livestock sera from four randomly selected villages located along game reserve areas of Serengeti National Park. Although both cattle (288) and small ruminants (125) were screened, seropositivity was detected only in cattle. The overall seroprevalence based on c-ELISA as a confirmatory test was 5.6%. In cattle both age and sex were not statistically associated with brucellosis seropositivity (P = 0.63; 95% CI = 0.03, 0.8 and 0.33; 95% CI = 0.6, 3.7, respectively). Overall herd level seropositivity was 46.7% (n = 7), ranging from 25% to 66.7% (n = 4-10). Each village had at least one brucellosis seropositive herd. None of the 82 humans tested with both RBPT and c-ELISA were seropositive. Detecting Brucella infection in cattle in such areas warrants further investigation to establish the circulating strains for eventual appropriate control interventions in domestic animals

Epidemiology of leptospirosis in Tanzania:: A review of the current status, serogroup diversity and reservoirs

BACKGROUND: Tanzania is among the tropical countries of Sub-Saharan Africa with the environmental conditions favorable for transmission of Leptospira. Leptospirosis is a neglected zoonotic disease, and although there are several published reports from Tanzania, the epidemiology, genetic diversity of Leptospira and its host range are poorly understood. METHODS: We conducted a comprehensive review of human and animal leptospirosis within the 26 regions of the Tanzanian mainland. Literature searches for the review were conducted in PubMed and Google Scholar. We further manually identified studies from reference lists among retrieved studies from the preliminary search. RESULTS: We identified thirty-four studies describing leptospirosis in humans (n = 16), animals (n = 14) and in both (n = 4). The number of studies varied significantly across regions. Most of the studies were conducted in Morogoro (n = 16) followed by Kilimanjaro (n = 9) and Tanga (n = 5). There were a range of study designs with cross-sectional prevalence studies (n = 18), studies on leptospirosis in febrile patients (n = 13), a case control study in cattle (n = 1) and studies identifying novel serovars (n = 2). The most utilized diagnostic tool was the microscopic agglutination test (MAT) which detected antibodies to 17 Leptospira serogroups in humans and animals. The Leptospira serogroups with the most diverse hosts were Icterohaemorrhagiae (n = 11), Grippotyphosa (n = 10), Sejroe (n = 10), Pomona (n = 9) and Ballum (n = 8). The reported prevalence of Leptospira antibodies in humans ranged from 0.3–29.9% and risk factors were associated with occupational animal contact. Many potential reservoir hosts were identified with the most common being rodents and cattle. CONCLUSION: Leptospirosis is prevalent in humans and animals in Tanzania, although there is regional and host variation in the reports. Many regions do not have information about the disease in either humans or their animal reservoirs. More studies are required to understand human leptospirosis determinants and the role of livestock in leptospirosis transmission to humans for the development of appropriate control strategies

Influence of fluoride on the prevalence of diabetes mellitus in selected fluoride endemic areas of Tanzania

This research article published by International Journal of Biosciences, 2019Diabetes Mellitus prevalence in developing countries and globally is on the increase due to various factors and its association with excessive fluoride contamination is not much elucidated. This study aims to determine fluoride levels in serum along with capillary fasting blood sugar levels of individuals in selected area of Ngarenanyuki ward (fluoride endemic) in Arusha region, located at the slopes of volcanic mount Meru, which is connected to East African Great Rift Valley System. A cross sectional survey was conducted to assess fluoride levels in human sera (Measured by minitype Ion-Selective Electrode) and capillary fasting blood sugar levels (Measured by Automatic glucometer) in the community, after overnight fasting and to look for its relationship. The survey was conducted whereby, 50 individuals, aged 25 years old and above volunteered and consented for fluoride levels in serum determination along with capillary fasting blood sugar test. The 32 participants enrolled were females while18 were males. The mean age of the study participants was 48.7 (13.4) years. The median (range) fasting blood sugar was 4.8 (3.0 – 14.7) mmol/l and fluoride levels in serum was 0.0543 (0.0324 – 0.2200) mg/l. The correlation between the levels of fluoride in serum and fasting blood sugar was (Pearson`s correlation coefficient (r) = - 0.0632 and p < 0.663). There was no significant correlation between fluoride levels in serum and fasting blood sugar levels. The findings indicate that fluoride levels in serum does not influence the increase of fasting blood sugar levels. Further work to include other confounders is therefore recommended in order to understand broadly the influence of fluoride in hyperglycemia

Enhancing livestock vaccination decision-making through rapid diagnostic testing

No abstract available

Risk factors associated with Mycoplasma capricolum subspecies capripneumoniae and morbillivirus infection in small ruminants in Tanzania.

This research article published by Springer Nature Switzerland AG., 2019Mortality of domestic small ruminants caused by contagious caprine pleuropneumonia (CCPP) and Peste des petits ruminants (PPR) is frequently reported in Tanzania. A cross-sectional survey was conducted between June, 2016 and July, 2017 to identify risk factors for small ruminants exposure to Mycoplasma capricolum subsp. capripneumoniae (M. capripneumoniae), the causative agent of CCPP, and small ruminant morbillivirus (SRMV), the causative agent of PPR. Antibody detection was done using competitive enzyme-linked immunosorbent assays (cELISA); similarly, a semi-structured questionnaire was administered in flocks where serum samples were collected. Individual seropositivity for M. capripneumoniae was 6.5% (n = 676) and 4.2% (n = 285) in goats and sheep respectively, whereas SRMV was 28.6% in goats (n = 676) and 31.9% in sheep (n = 285). Multivariable analysis indicated that mixing of flocks was a risk factor for exposure to M. capripneumoniae (χ = 3.9, df = 1, p = 0.05) and SRMV (χ = 6.3, df = 1, p = 0.01) in goats. Age was a protective factor for SRMV seropositivity in both goats (χ = 7.4, df = 1, p = 0.006) and sheep (χ = 10.2, df = 1, p = 0.006). SRMV seropositivity in goats was also influenced by grazing in contact with wild animals (χ = 5.9, df = 1, p = 0.02) and taking animals to the animal markets (χ = 8.2, df = 1, p = 0.004). M. capripneumoniae and SRMV are influenced by several risk factors and their control needs concerted efforts between stakeholders, which may include community involvement in mandatory vaccination and animals' movement control

Integrating serological and genetic data to quantify cross-species transmission: brucellosis as a case study

Epidemiological data are often fragmented, partial, and/or ambiguous and unable to yield the desired level of understanding of infectious disease dynamics to adequately inform control measures. Here, we show how the information contained in widely available serology data can be enhanced by integration with less common type-specific data, to improve the understanding of the transmission dynamics of complex multi-species pathogens and host communities. Using brucellosis in Northern Tanzania as a case-study, we developed a latent process model based on serology data obtained from the field, to reconstruct Brucella transmission dynamics. We were able to identify sheep and goats as a more likely source of human and animal infection than cattle; however, the highly cross-reactive nature of Brucella spp. meant that it was not possible to determine which Brucella species (B. abortus or B. melitensis) is responsible for human infection. We extended our model to integrate simulated serology and typing data, and show that although serology alone can identify the host source of human infection under certain restrictive conditions, the integration of even small amounts (5%) of typing data can improve understanding of complex epidemiological dynamics. We show that data integration will often be essential when more than one pathogen is present and when the distinction between exposed and infectious individuals is not clear from serology data. With increasing epidemiological complexity, serology data become less informative. However, we show how this weakness can be mitigated by integrating such data with typing data, thereby enhancing the inference from these data and improving understanding of the underlying dynamics