Mapping the distributions of blood-sucking mites and mite-borne agents in China: a modeling study

Abstract

Background Emerging mite-borne pathogens and associated disease burdens in recent decades are raising serious public health concerns, yet their distributions and ecology remain under-investigated. We aim to describe the geographical distributions of blood-sucking mites and mite-borne agents and to assess their ecological niches in China. Methods We mapped 549 species of blood-sucking mites belonging to 100 genera at the county level and eight mite-associated agents detected from 36 species of blood-sucking mites in China during 1978–2020. Impacts of climatic and environmental factors on the ecology of 21 predominant vector mites and a leading pathogen, Orientia tsutsugamushi, were assessed using boosted regression tree (BRT) models, and model-predicted risks were mapped. We also estimated the model-predicted number, area and population size of affected counties for each of the 21 mite species in China. Results Laelaps echidninus is the leading mite species that potentially affects 744 million people, followed by La. jettmari (517 million) and Eulaelaps stabularis (452 million). Leptotrombidium scutellare is the mite species harboring the highest variety of mite-borne agents including four Rickettsia species and two viruses, followed by Eu. stabularis (2 agents), L. palpale (2) and La. echidninus (2). The top two agents that parasitize the largest number of mite species are O. tsutsugamushi (28 species) and hantavirus (8). Mammalian richness, annual mean temperature and precipitation of the driest quarter jointly determine the ecology of the mites, forming four clusters of major mite species with distinct geographic distributions. High-risk areas of O. tsutsugamushi are mainly distributed in southern and eastern coastal provinces where 71.5 million people live. Conclusions Ecological niches of major mite species and mite-borne pathogens are much more extensive than what have been observed, necessitating expansion of current filed surveillance. Graphic Abstract

A potential tool for predicting epidemic trends and outbreaks of scrub typhus based on Internet search big data analysis in Yunnan Province, China

“…China is an important epidemic area included in the “tsutsugamushi triangle” region. In particular, the southern part of the country, located in the tropical or subtropical zone with a hot and humid climate and broad lush vegetation, bears a great burden of scrub typhus disease as the conserved area of Orientia tsutsugamushi ( 6 ). Typically, hundreds of thousands of cases are reported each month in each province in this area, not to mention the undocumented, underdiagnosed, and misdiagnosed cases, causing a major concern to public health.…”

“…Yunnan Province, located in the southwest of China, is one of the provinces that report the highest prevalence of blood-sucking mites, mite-borne agents, and scrub typhus cases in China ( 6 ). In the present study, to predict the epidemic trends and outbreak of scrub typhus, a novel prediction model based on the BSI and prevalence data from January 2012 to December 2020 in Yunnan Province was established and evaluated.…”