Transmission dynamics of foot and mouth disease in selected outbreak areas of northwest Ethiopia

Foot and mouth disease (FMD) is a highly contagious and economically important disease of cloven-hoofed animals, which is endemic in Ethiopia. An outbreak follow-up study was undertaken to quantify the transmission parameters of FMD in the crop–livestock mixed (CLM) system and commercial dairy farms in selected areas of northwest Ethiopia. The transmission parameters were quantified using a generalised linear model (GLM) based on a susceptible–infectious–recovered (SIR) epidemic model. The per day average transmission rate between animals was 0.26 (95% CI 0.22–0.32) and 0.33 (95% CI 0.21–0.57) in the CLM system and in the commercial dairy farms, respectively. The average basic reproduction ratio of FMD was 1.68 (95% CI 1.42–2.07) in the CLM system and 1.98 (95% CI 1.26–3.42) in the commercial dairy farms. The medium per day transmission rate and moderate basic reproduction ratio observed in this study indicated that a vaccination coverage needed to stop transmission of the disease in these populations might not be very high.