Rift Valley fever potential mosquito vectors and their infection status in Ngorongoro District in northern Tanzania

Background: Rift Valley fever (RVF) is a mosquito-borne viral zoonotic disease. Rift Valley fever virus (RVFV) has been isolated from more than 40 species of mosquitoes from eight genera. This study was conducted to determine the abundance of potential mosquito vectors and their RVFV infection status in Ngorongoro District of northern Tanzania.Methods: Adult mosquitoes were collected outdoors using the CDC light traps baited with carbon dioxide in five randomly selected villages namely, Meshili, Malambo, Osinoni, Endulen and Nainokanoka. The study was carried out towards the end of rainy season in May 2013. The traps were set in proximity to potential breeding sites and cattle kraals. The collected mosquitoes were identified to genus and species using morphological keys. They were tested for RVFV RNA  using  real time reverse transcription-polymerase chain reaction (rRT-PCR).Results: A total of 2,094 adult mosquitoes belonging to three genera and nine species were collected. Most of them (87.5%) were collected in Meshili, followed by Malambo (8.2%) and Osinoni (4%) villages. No single mosquito was collected in Nainokanoka or Endulen. The nine species collected were Culex pipiens complex, Cx. antennatus, Cx. tigripes, Cx. annulioris, Cx. cinereus, Anopheles arabiensis, An. squamosus, An. pharoensis and Mansonia uniformis. No RVFV RNA was detected in the mosquito specimens.Conclusion: Various RVFV potential mosquito species were collected from the study villages. These mosquito vectors were heterogeneously distributed in the district suggesting a variation in RVF transmission risk in the study area

Isolation and identification of Listeria species along the milk value chain in one region of Tanzania

Milk is an important source of nutrients in the diet. However, due to its nutritional nature it also serves as an ideal medium for growth and development of various microorganisms under suitable conditions. It is a staple food, which is linked to zoonotic pathogens. This study was carried out in two districts (one region namely Tanga) of Tanzania to evaluate the awareness of farmers on milk contamination and to estimate microbial load along the milk value chain. In total 114 respondents were visited to conducted interviews on awareness as well as strategies for solving the problem of milk contamination. Subsequently milk samples were aseptically collected from each of the 114 respondents for laboratory analyses using the standard ISO procedures for food microbial analyses in particular the horizontal methods. We have showed that there are poor hygienic practices by the majority of actors along the milk value chain in Tanga region. Concerning microbial level, our results revealed that above 90 percent of all samples collected showed total plate count (TPC) above standard acceptable in the Eastern Africa countries (EAC) of 2.0x105 CFU/ml. It was also shown that there was more contamination in milk samples obtained from the household farms compared to those which were collected from the milk suppliers and in the extensive farming system than in the intensive system (P < 0.05). Moreover, three Listeria species namely L. innocua, L. ivanovii and L. monocytogenes were identified. L. monocytogenes were isolated and identified as the common contaminants in milk along the value chain in the study region

A One Health Evaluation of the Southern African Centre for Infectious Disease Surveillance

Rooted in the recognition that emerging infectious diseases occur at the interface of human, animal, and ecosystem health, the Southern African Centre for Infectious Disease Surveillance (SACIDS) initiative aims to promote a trans-sectoral approach to address better infectious disease risk management in five countries of the Southern African Development Community. Nine years after SACIDS’ inception, this study aimed to evaluate the program by applying a One Health (OH) evaluation framework developed by the Network for Evaluation of One Health (NEOH). The evaluation included a description of the context and the initiative, illustration of the theory of change, identification of outputs and outcomes, and assessment of the One Healthness. The latter is the sum of characteristics that defines an integrated approach and includes OH thinking, OH planning, OH working, sharing infrastructure, learning infrastructure, and systemic organization. The protocols made available by NEOH were used to develop data collection protocols and identify the study design. The framework relies on a mixed methods approach by combining a descriptive and qualitative assessment with a semi-quantitative evaluation (scoring). Data for the analysis were gathered during a document review, in group and individual interviews and in an online survey. Operational aspects (i.e., OH thinking, planning, and working) were found to be balanced overall with the highest score in the planning dimension, whereas the infrastructure (learning infrastructure, systemic organization, and sharing infrastructure) was high for the first two dimensions, but low for sharing. The OH index calculated was 0.359, and the OH ratio calculated was 1.495. The program was praised for its great innovative energy in a difficult landscape dominated by poor infrastructure and its ability to create awareness for OH and enthuse people for the concept; training of people and networking. Shortcomings were identified regarding the balance of contributions, funds and activities across member countries in the South, lack of data sharing, unequal allocation of resources, top-down management structures, and limited horizontal collaboration. Despite these challenges, SACIDS is perceived to be an effective agent in tackling infectious diseases in an integrated manner

Occurrence of Eimeria species parasites on small-scale commercial chicken farms in Africa and indication of economic profitability.

Small-scale commercial poultry production is emerging as an important form of livestock production in Africa, providing sources of income and animal protein to many poor households, yet the occurrence and impact of coccidiosis on this relatively new production system remains unknown. The primary objective of this study was to examine Eimeria parasite occurrence on small-scale commercial poultry farms in Ghana, Tanzania and Zambia. Additionally, farm economic viability was measured by calculating the farm gross margin and enterprise budget. Using these economic measures as global assessments of farm productivity, encompassing the diversity present in regional husbandry systems with a measure of fundamental local relevance, we investigated the detection of specific Eimeria species as indicators of farm profitability. Faecal samples and data on production parameters were collected from small-scale (less than 2,000 birds per batch) intensive broiler and layer farms in peri-urban Ghana, Tanzania and Zambia. All seven Eimeria species recognised to infect the chicken were detected in each country. Furthermore, two of the three genetic variants (operational taxonomic units) identified previously in Australia have been described outside of Australia for the first time. Detection of the most pathogenic Eimeria species associated with decreased farm profitability and may be considered as an indicator of likely farm performance. While a causal link remains to be demonstrated, the presence of highly pathogenic enteric parasites may pose a threat to profitable, sustainable small-scale poultry enterprises in Africa

Are we prepared for emerging and re-emerging diseases? Experience and lessons from epidemics occurred in Tanzania during the last five decades

This paper reviews preparedness for containing and controlling emerging and re-emerging diseases drawing lessons from disease events that occurred in animal and human populations in the last five decades (1961-2011). A comprehensive analysis based on retrieval and analysis of grey and published literature as well as reported cases was carried out to document type and trend of occurrence of emerging and re-emerging infectious diseases in different parts of Tanzania. Overall, the majority of diseases reported in the country were viral in nature followed by bacterial diseases. The trend for the occurrence shows a number of new emerging diseases as well as re-occurrence of old diseases in both animal (domestic and wild) and human populations. In humans, the major disease epidemics reported in the last five decades include cholera, influenza A H1N1, plague and rubella. In animals, the major epidemic diseases reported were Contagious Bovine Pleuropneumonia, Contagious Caprine Pleuropneumonia, Peste des petits ruminants and Giraffe Ear and Skin Diseases. Some epidemics have been reported in both human and animal populations including Rift Valley fever and anthrax.&nbsp; The emergence of the &lsquo;fit-for purpose&rsquo; approaches and technologies such as the discipline of One Health, use of participatory epidemiology and disease surveillance and mobile technologies offers opportunity for optimal use of limited resources to improve early detection, diagnosis and response to disease events and consequently reduced impact of such diseases in animal and human populations

Spatial and Temporal Pattern of Rift Valley Fever Outbreaks in Tanzania; 1930 to 2007

Rift Valley fever (RVF)-like disease was first reported in Tanzania more than eight decades ago and the last large outbreak of the disease occurred in 2006–07. This study investigates the spatial and temporal pattern of RVF outbreaks in Tanzania over the past 80 years in order to guide prevention and control strategies. A retrospective study was carried out based on disease reporting data from Tanzania at district or village level. The data were sourced from the Ministries responsible for livestock and human health, Tanzania Meteorological Agency and research institutions involved in RVF surveillance and diagnosis. The spatial distribution of outbreaks was mapped using ArcGIS 10. The space-time permutation model was applied to identify clusters of cases, and a multivariable logistic regression model was used to identify risk factors associated with the occurrence of outbreaks in the district. RVF outbreaks were reported between December and June in 1930, 1947, 1957, 1960, 1963, 1968, 1977– 79, 1989, 1997–98 and 2006–07 in 39.2% of the districts in Tanzania. There was statistically significant spatio-temporal clustering of outbreaks. RVF occurrence was associated with the eastern Rift Valley ecosystem (OR = 6.14, CI: 1.96, 19.28), total amount of rainfall of .405.4 mm (OR = 12.36, CI: 3.06, 49.88), soil texture (clay [OR = 8.76, CI: 2.52, 30.50], and loam [OR = 8.79, CI: 2.04, 37.82]). RVF outbreaks were found to be distributed heterogeneously and transmission dynamics appeared to vary between areas. The sequence of outbreak waves, continuously cover more parts of the country. Whenever infection has been introduced into an area, it is likely to be involved in future outbreaks. The cases were more likely to be reported from the eastern Rift Valley than from the western Rift Valley ecosystem and from areas with clay and loam rather than sandy soil texture

Detection of peste des petits ruminants and concurrent secondary diseases in sheep and goats in Ngorongoro district, Tanzania

Small ruminants play an important role in the livelihoods of resource-constrained communities. This study was initiated because of a massive outbreak of a respiratory disease in sheep and goats in Loliondo area in Ngorongoro district of Arusha region in Tanzania in 2016. During flock examination, a total of 240 serum samples and 61 nasal swabs were collected. Antibodies to small ruminant morbillivirus, causative agent of peste des petits ruminants (PPR), were detected from sera using a competitive enzymelinked immunosorbent assay. A multiplex reverse transcription real-time polymerase chain reaction assay was used to detect four pathogens: small ruminant morbillivirus, Mycoplasma capricolum subspecies capripneumoniae, Pasteurella multocida, and Capripoxvirus from the nasal swabs. Overall seroprevalence of PPR was 74.6%, with all four pathogens detected from nasal swabs. Co-infections of small ruminant morbillivirus and Mycoplasma capricolum subspecies capripneumoniae, small ruminant morbillivirus and Capripoxvirus, small ruminant morbillivirus and Pasteurella multocida, and Mycoplasma capricolum subspecies capripneumoniae and Capripoxvirus were also detected. Presence of PPR and the other diseases in this study provided insight into the severity of the outbreak in sheep and goats in Ngorongoro district. Thus, laboratory confirmation is critical for prompt and appropriate interventions to be made for control of diseases in sheep and goats with similar clinical signs. The findings also call for research into development of combined vaccines targeting common diseases of small ruminants in Tanzania

Food safety risk assessment in beef in Arusha municipality, Tanzania

BACKGROUND: Thermophilic Campylobacter is one of the most important pathogen causing food borne illness in the world. In Tanzania, the risks of campylobacteriosis had not been studied yet and the risks especially from informally marketed foods are in a great need for assessment. A study on risk assessment for Thermophilic Campylobacter infection through consumption of ready to eat beef in Arusha was therefore carried out from January to March 2010. METHODS: A total of 160 samples were collected from beef carcasses (swabs) in butcher (n=73) and roast beef (nyama choma in Swahili language) (n=45; one gram pieces) and skewer beef (mishikaki) (n=42, one gram pieces) sold in beer bars. All the samples were served for isolation of thermophilic Campylobacter spp. The number of customers per hour was recorded in nine nyama choma and nine mishikaki centres for seven consecutive days. A risk model for assessing risk of campylobacteriosis due to the consumption of ready-to-eat beef was developed in @Risk (Palisade) and these data were fed into it. Dose-Response relationship was modeled using reported variables in literatures. Immunity against thermophilic Campylobacter for adults was modeled using the diarrhoeal data in a hospital reported in a separate study. Monte Carlo simulation was run for 10,000 iterations and sensitivity analysis was run for 63 simulations in 1000 iterations. RESULTS: The overall contamination rate of ready-to-eat beef with thermophilic Campylobacter was 24%. The probability of consuming contaminated meat with thermophilic Campylobacter at nyama choma pubs was 15.5% and at mishikaki shops was 34.7%. The total amount of beef sold at nyama choma pubs in Arusha municipality per day was 3,595 kg (90% CI: 1,745-6,173) and that sold as mishikaki per day was 165 kg (90% CI: 57-328). The probability that a naturally immunized person develops illness when he/she ingests enough dose of thermophilic Campylobacter causing illness to a susceptible person was 13.1% by point estimate. Risk characterization showed that the incidence rate of campylobacteriosis in Arusha per day was estimated as 6.43 people (90%CI:3.4-10.4) per 1000 people. Sensitivity analysis found that the most sensitive risk input was initial population of Campylobacter in ready-to-eat beef which we did not study in the present study. SUMMARY: Contamination of carcasses with Campylobacter spp has indicated the need of applying good hygienic standards at all levels from farm to table in order to ensure food wholesomeness and safety in beef. Public education programmes, consumer awareness and training of food handlers on general food hygiene are recommended to reduce potential health risks to the public. Additional studies on the concentration of Campylobacter in different stages of value chain especially on the surfaces of ready-to-eat beef is required to update the present study for the more reliable risk characterization