Disease status and risk factors for Peste Des Petits ruminants along Tanzania-Burundi and Democratic Republic of Congo border

Masters DissertationAn epidemiological study was carried out between September 2011 and February 2012 to determine the disease status of Peste des Petits ruminants (PPR) in western Kigoma region bordering Burundi and Democratic Republic of Congo (DRC). The study aimed at establishing the seroprevalence of PPR and identifying risk factors associated with the disease in three districts (Kasulu, Kibondo and Kigoma rural) of Kigoma region. The study also assessed the presence or absence of clinical cases in the study area. A total of 35 sheep and 415 goats were sampled, 150 animals from each districts. Serological analysis employed monoclonal antibody based competitive Enzyme Linked Immunosorbent Assay (cELISA). A questionnaire survey was used to collect information on potential factors associated with the seroprevalence of the disease. In-depth interview of farmers with PPR seropositives and suspected cases was also conducted. The overall seroprevalence established was 5.1% (95% CI: 3.30%-7.70%). Stratification of the seroprevalence by district indicated that Kibondo had the highest seroprevalence (2.0%) followed by Kasulu (1.8%) and Kigoma rural (1.3%). Factors that had an impact on PPR spread includes communal grazing (p=0.01) and introduction of new animal in the flock (p=0.005). The potential risk factor associated with PPR seroprevalence and clinical cases was introducing new animal(s) in the flock from other locations in the study area (p=0.0054). To the best of my knowledge, this is the first study which has reported the prevalence of PPR in western region of Tanzania. As the study area borders neighbouring countries of Burundi and DRC, concerted efforts are required to jointly control the disease with the ultimate aim of eradicating it from the region

Epidemiological study of Rift Valley fever virus in Kigoma, Tanzania

Rift Valley fever virus (RVFV) is an acute, zoonotic viral disease caused by a  Phlebovirus, which belongs to the Bunyaviridae family. Among livestock, outbreaks of the disease are economically devastating. They are often characterised by large, sweeping abortion storms and have significant mortality in adult livestock. The aim of the current study was to investigate RVFV infection in the Kigoma region, which is nestled under the hills of the western arm of the Great Rift Valley on the edge of Lake Tanganyika, Tanzania. A region-wide serosurvey was conducted on non-vaccinated small ruminants (sheep and goats, n = 411). Sera samples were tested for the presence of anti-RVFV antibodies and viral antigen, using commercial enzyme-linked immunosorbent assay and reverse transcriptase polymerase chain reaction, respectively. The overall past infections were detected in 22 of the 411 animals, 5.4% (Confidence Interval (CI) 95% = 3.5% – 8.1%). The Kigoma rural area recorded the higher seroprevalence of 12.0% (CI 95% = 7.3% – 18.3%; p 0.05) and the Kasulu district at 0.8% (CI 95% = 0.0% – 4.2%; p > 0.05). The prevalence was 12.5% and 4.7% for sheep and goats, respectively. Reverse transcriptase polymerase chain reaction results indicated that only eight samples were found to be positive (n = 63). This study has confirmed, for the first time, the presence of the RVFV in the Kigoma region four years after the 2007 epizootic in Tanzania. The study further suggests that the virus activity exists during the inter-epizootic period, even in regions with no history of RVFV