Seroprevalence of CCPP, FMDV, BTV and BVDV among small ruminants in Tanzania : A minor field study with focus on differential diagnoses of peste des petits ruminants virus

Abstract: This degree project has been performed as a Minor Field Study (MFS) in Tanzania, investigating the seroprevalence in goats and sheep of three diseases causing similar signs as peste des petits ruminants virus (PPRV): foot and mouth disease (FMD), bluetongue (BT) and contagious caprine pleuropneumonia (CCPP), as well as bovine viral diarrhoea (BVD) and border disease (BDV) which is believed to affect an outbreak of PPR due to immunosuppression. Sheep and goats play a key role in national food and nutritional security, income security and livelihood resilience in the least economically developed countries across the world and because of the complicated epidemiology and socio-economic impact of these diseases it is of great interest to further evaluate the prevalence of PPRV and its differential diagnosis. In this study blood samples were collected from 483 goats and sheep. Samples from a previous MFS done in 2014 were also analysed. The sampled animals came from three different regions in south-eastern Tanzania and the seroprevalence of FMD, BT, CCPP and BVDV was investigated by tracing antibodies in serum by competitive ELISA. The seroprevalence differed highly between the diseases. BTV had the highest seroprevalence with a total seroprevalence of 67.0%, while BVDV had the lowest with a total seroprevalence of 2.9%. The total seroprevalence of FMD was 26,5% and CCPP 19.0%. The results in this study show that FMDV, BTV, BVDV and CCPP are serologically present in southern Tanzania. These diseases are likely circulating and endemic in the area but the importance of the different diseases varies because of the differing levels of severity and consequences for farmers. FMD and CCPP are relevant differential diagnoses to PPR and should be taken into consideration when working to prevent, and in longer term, eradicate PPRV. The risk of mistaking PPR for BT and vice versa appears to be very low at the moment considering these diseases do not appear to cause similar clinical signs as PPR in Tanzanian sheep and goats.