Transboundary caprine diseases in Zambia : A study on seroepidemiology and associated risk factors for peste des petits ruminants, foot and mouth disease and contagious caprine pleuropneumonia

Abstract: Peste des petits ruminants (PPR), contagious caprine pleuropneumonia (CCPP), and foot and mouth disease (FMD) are highly contagious that can rapidly spread throughout a country. Due to the many health effects, and potentially high mortality, they have an extensive impact on the production system. In Zambia, most livestock are kept by small-scale farmers. The poverty level is high, and many rely on their animals both for generating food and income and suffer directly if their animals were to fall ill or die. Also, on a national level, major costs arise because of e.g. campaigns for surveillance and vaccination. For low- and middle-income countries, controlling and if possible eradicating diseases like PPR, CCPP, and FMD are of vital importance. FMD is considered endemic in Zambia with reoccurring outbreaks. The previous research in Zambia has focused on FMD in cattle and to a lesser extent on smaller ruminants such as goats. Regarding PPR, seropositive animals have previously been found, but no cases with clinical disease have been confirmed. No published research has been conducted in Zambia regarding CCPP. Since both PPR and CCPP have been confirmed in neighboring countries, there is a significant risk of these diseases being either introduced or already circulating in Zambia undetected. Further research on these diseases in goats is therefore motivated. In this study, goats were sampled in the Southern province in the districts of Monze and Mazabuka, as well as the Central Province in the district of Chibombo. In total, 482 serum samples were collected from 120 households. The samples were analyzed for serology using competitive ELISA. Internal factors such as gender, age and origin were noted for each animal. Each household was interviewed using a questionnaire to collect information on the management routines, for example, questions regarding grazing, contact with other animals, trade, signs of disease, medical treatment, and household conformation. Statistical analysis was conducted to correlate factors to the serological status of the animal and household. The total, apparent seroprevalence for FMD was 18% (confidence interval (CI) 95% 15; 22) and for CCPP 4.2 (Cl 95% 2.7; 6.3). The seroprevalence of PPR awaits confirmation before publication. Contact with wild ruminants was found as a risk factor for PPR (p-value=0.014). Herds with less than 15 goats had increased risk for PPR seropositivity compared to larger herds (p-value=0.042). Nasal discharge within the last 12 months increased the risk for FMD seropositivity (p=0.043). As a conclusion, to find goats seropositive for the sampled diseases is important, since previous knowledge of the diseases in Zambia is limited. These are serious diseases, both for the animals and their owners, and likely cause major socioeconomic consequences. Therefore, the result motivates effort to further understand the role of the diseases in Zambia and form effective control programs.