High genetic diversity in hard ticks from a China-Myanmar border county.

BACKGROUND: Many tick species have great morphological similarity and are thus grouped into species complexes. Molecular methods are therefore useful in the classification and identification of ticks. However, little is known about the genetic diversity of hard ticks in China, especially at the subspecies level. Tengchong is one of the epidemic foci of tick-borne diseases in China, but the tick species inhabiting the local area are still unknown. METHODS: Eighteen villages in Tengchong County, China, were selected for sampling carried out from September to October 2014. Infesting hard ticks were removed from the body surface of domestic animals and questing ticks were collected from grazing fields. After morphological identification, molecular characteristics of each tick species were analyzed based on both 16S rRNA and cytochrome c oxidase subunit 1 (cox1) gene fragments. RESULTS: Six tick species were identified based on morphology: Rhipicephalus microplus, R. haemaphysaloides, Ixodes ovatus, Haemaphysalis longicornis, H. shimoga and H. kitaokai. Phylogenetic analysis using the cox1 gene revealed that R. microplus ticks from the present study belong to clade C. For tick samples of both R. haemaphysaloides and I. ovatus, three phylogenetic groups were recognized, and the intergroup genetic distances exceeded the usual tick species boundaries. Haemaphysalis longicornis ticks were clustered into two separate clades based on the cox1 gene. For ticks from both H. shimoga and H. kitaokai, two phylogenetic groups were recognized based on the phylogenetic analysis of the 16S rRNA gene, and the intergroup genetic distances also exceeded the known boundaries for closely related tick species. CONCLUSIONS: According to molecular analyses, new species or subspecies closely related to R. haemaphysaloides, I. ovatus, H. shimoga and H. kitaokai probably exist in the China-Myanmar border Tengchong County, or these ticks form species complexes with highly divergent mitochondrial lineages. Morphological comparisons are warranted to further confirm the taxonomic status of these tick species.

[Investigation of tick bites in outpatients with fever from health care facilities in Tengchong County].

OBJECTIVE: To study the prevalence of tick bites and relative factors of outpatients with fever from health care facilities in Tengchong County. METHODS: From July to August, 2014, the outpatients with fever in five health care facilities namely Tengchong Center for Disease Control and Prevention, Hehua Health Center, Jietou Health Center, Qushi Health Center and Xinhua Health Center were investigated by questionnaires. The factors related to tick bites were explored with the univariate analysis and multiple regression models. RESULTS: Totally 884 effect questionnaires were acquired. Among the 884 participants, 85 (9.6%) had experienced tick bites. The frequency of tick bites was associated with locations, gender, age group, ownership of cattle, working at foreign country, firewood cutting and lumbering in the forest (all P < 0.05). The multiple regression revealed that the male and people raising cattle, working at foreign country, engaging in firewood cutting and lumbering in the forest had a more risk for tick bites. CONCLUSIONS: Tick bites are common in the residents of Tengchong County. The risk of being bitten varies in different populations. The local health departments should promote health education in the high-risk population to reduce the risk of infecting tick-borne diseases.

Investigation of tick bites in outpatients with fever from health care facilities in Tengchong County / 中国血吸虫病防治杂志

Objective To study the prevalence of tick bites and relative factors of outpatients with fever from health care fa?cilities in Tengchong County. Methods From July to August,2014,the outpatients with fever in five health care facilities namely Tengchong Center for Disease Control and Prevention,Hehua Health Center,Jietou Health Center,Qushi Health Cen?ter and Xinhua Health Center were investigated by questionnaires. The factors related to tick bites were explored with the univari?ate analysis and multiple regression models. Results Totally 884 effect questionnaires were acquired. Among the 884 partici?pants,85(9.6%)had experienced tick bites. The frequency of tick bites was associated with locations,gender,age group,own?ership of cattle,working at foreign country,firewood cutting and lumbering in the forest(all P<0.05). The multiple regression revealed that the male and people raising cattle,working at foreign country,engaging in firewood cutting and lumbering in the forest had a more risk for tick bites. Conclusions Tick bites are common in the residents of Tengchong County. The risk of be?ing bitten varies in different populations. The local health departments should promote health education in the high?risk popula?tion to reduce the risk of infecting tick?borne diseases.