Spatio-temporal analysis of peste des petits ruminants outbreaks in PR China (2013-2018): Updates based on the newest data.

Abstract

Peste des petits ruminants (PPR) is a highly contagious disease of small ruminants. The purpose of this study was to investigate the epidemic characteristics of PPR outbreaks in the People's Republic of China (PR China) from 2013 to 2018. A total of 41,876 PPR outbreaks were recorded in small ruminant populations in PR China during that period. Data from February to June 2018 were used to study new developments in the PPR epidemic in PR China. Spatio-temporal clusters and temporal distribution patterns were studied based on PPR notifications. We also used multiple logistic regression to examine the contribution of anthropogenic, climatic and topographic factors to PPR outbreaks. Distance to the nearest road (OR=1.007 [95% CI: 1.001-1.014]), price of mutton (OR=1.904 [95% CI: 1.358-2.668]) and mean monthly temperature in July (OR 1.156=[95% CI: 1.110-1.204]) showed positive effects on PPR outbreaks. Negative effects were observed for number of large-scale farms (OR=0.962 [95% CI: 0.940-0.985]). We also found that observed patterns of seasonality were characterized by peaks in April of 2014. Spatio-temporal clusters occurred in Yunnan, Jiangsu, Anhui, Heilongjiang province and Chongqing municipality. Hunan province reported PPR occurrences every year from 2014 to June 2018. Yunnan, Jiangsu and Anhui province have 56, 33 and 30 epidemic locations, respectively. PPR infections were first reported as the cause of death for 19 wild bharals in Qinghai province in 2018. All of this suggests that domestic trading of sheep and goats may be closely related to the spread of PPR. Prophylactic immunization in suspected animal populations or areas is recommended for the control of PPR and wild small ruminants should be monitored. Results presented here provide improved knowledge about PPR dynamics in PR China, which could be helpful in designing more effective prevention strategies.