World epidemiological meta-analyses of peste des petits ruminants (1997-2017)

Estimating the occurrence and distribution of infection and identification of risk factors remain key components in understanding the epizootiology and monitoring of peste des petits ruminants (PPR). This study was performed from 1997 to 2017, and included details of flocks with emergent infections, within-flock prevalence and risk association between PPR incidence and various flock management factors worldwide. In assessing the impact of PPR on livestock, outbreak incidence per country was used as an effective indicator of the intensity of the infection process. To decode the spatial and temporal dynamics of PPR outbreaks and clarify their relationship with geographical factors, systematic review and logistic regression analyses were conducted. The impact of climatic and socio-economic conditions on PPR was moderate and high, respectively. In the PPR risk analysis, infected PPR zones were 1.68 times more likely to spread the infection to goat farms than to sheep farms (relative risk: 1.69; odds ratio: 3.26). Moreover, during PPR occurrence, goats are more susceptible to infection than sheep. Through a regression model of outbreaks, a value of 960.67 outbreaks was calculated as the expected mean in 2018. The polynomial regression of PPR cases was followed by extrapolation (medium-sized smoothing of the three following points) to define the expected value in 2018. The probability of PPR could be effectively reduced by coordinating the work in disadvantaged countries with low-income farmers, and disease control must be prioritised to support alleviation of poverty, which has a negative impact on livestock production.