Climate factors driven typhus group rickettsiosis incidence dynamics in Xishuangbanna Dai autonomous prefecture of Yunnan province in China, 2005\u20132017

Yuan Gao,Xueshuang Wang,Haixia Wu,Qiyong Liu,Ning Zhao,Fengxia Meng,Xiaobo Liu,Wanwan Sun,Yanlin Niu,Yujuan Yue,Jun Wang,Keke Liu

doi:10.1186/s12940-019-0558-3

Abstract

BackgroundTyphus group rickettsiosis (TGR), which is a neglected vector-borne infectious disease, including epidemic typhus and endemic typhus. We explored the lag effects and nonlinear association between meteorological factors and TGR incidence in Xishuangbanna Dai autonomous prefecture from 2005 to 2017, China.MethodsA Poisson regression with a distributed lag nonlinear model (DLNM) was utilized to analyze TGR cases data and the contemporaneous meteorological data.ResultsA J-shaped nonlinear association between weekly mean temperature and TGR incidence was found. The cumulative exposure to weekly mean temperature indicated that the RR increased with the increment of temperature. Taking the median value as the reference, lower temperatures could decrease the risk of TGR incidence, while higher temperatures could increase the risk of TGR incidence and last for 21 weeks. We also found a reversed U-shaped nonlinear association between weekly mean precipitation and TGR incidence. Precipitation between 5 mm and 13 mm could increase the risk of TGR incidence. Taking the median value as the reference, no precipitation and lower precipitation could decrease the risk of TGR incidence, while higher precipitation could increase the risk of TGR incidence and last for 18 weeks.ConclusionsThe prevention and control measures of TGR should be implemented according to climatic conditions by the local government and health departments in order to improve the efficiency.

Highlights

Typhus group rickettsiosis (TGR), which is a neglected vector-borne infectious disease, including epidemic typhus and endemic typhus
According to our previous study, we found that TGR was sensitive to the climate, and most cases occurred from May to October
We had evaluated the interaction of each variable in one generalized additive model, the results showed that TGR cases were best predicted as positive smooth functions in the weekly mean temperature and mean cumulative precipitation

Summary

Introduction

Typhus group rickettsiosis (TGR), which is a neglected vector-borne infectious disease, including epidemic typhus and endemic typhus. Typhus group rickettsiosis, which is a neglected vectorborne infectious disease, including epidemic typhus and endemic typhus, is caused by Rickettsia prowazekii and Rickettsia typhi, respectively [1]. Epidemic typhus or louse-borne typhus, is usually transmitted through the human body louse [2]. Endemic typhus or murine or flea-borne typhus, is usually transmitted by fleas. There are only a few regions still monitor murine typhus, such as Texas, Hawaii, California and Taiwan [7, 11]. Murine typhus poses a threat to the health of travelers, and travel destinations primarily locate in Southeast Asia, Africa and America [12]

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Conclusion