Epidemiological characteristics and spatiotemporal patterns of scrub typhus in Yunnan Province from 2006 to 2017

Scrub typhus is an acute infectious disease in humans. A temporal, spatial and epidemiologic study was conducted to understand the characteristics of scrub typhus in Yunnan, to assist public health prevention and control measures. Based on the data on all cases reported in Yunnan during 2006-2017, we characterized the epidemiological features. Spatio-temporal patterns and Q-type cluster method were adopted to analyze the incidence of scrub typhus in Yunnan. In total, 27,838 scrub typhus cases were reported in Yunnan during 2006-2017. Of these, 49.53% (13,787) were male and 50.47% (14,051) were female (P > 0.05). Most patients were farmers (71.70%) (P < 0.05) and children aged 0-5 years (13.16%) (P < 0.01), which accounted for 84.86% of the total cases. An almost 20-fold increase in the number of patients was observed in 2017 (6,337 cases) compared to 2006 (307 cases). Baoshan and Lincang had the most cases accounting for 41.94%, while Diqing had the lowest incidence (only 3 cases). Sixteen municipalities infected were classified into three groups numbered in sequence. The incidence of scrub typhus in Yunnan is high and the annual incidence increased noticeably over time. Our results also indicate that surveillance and public education need to be focused on Baoshan, Lincang and Dehong.