Coinfection of Severe Fever with Thrombocytopenia Syndrome Virus and Coxiella burnetii in Haemaphysalis longicornis in subtropical region, South Korea.

배경: Severe fever with thrombocytopenia syndrome virus (SFTSV) is transmitted through tick bites. Q fever is transmitted by inhaling contaminated aerosols, contacting an infected animal, and consuming contaminated dairy products. Ticks are considered a potential Coxiella burnetii vector. This study aimed to analyze SFTSV and C. burnetii infection rates in ticks in rural areas on Jeju Island, South Korea, monthly from 2016 to 2019. 방법: Free ticks were collected from the natural environment, and SFTSV RNA was extracted from the collected ticks. Ribosomal RNA gene sequencing was used to identify Coxiella species, and phylogenetic analyses were conducted. 결과: From the 3,187 ticks collected during the study period, the most common species was Haemaphysalis longicornis (n=3,139; 98.4%), followed by Haemaphysalis flava (n=48; 1.6%). Tick number gradually increased from April, peaked in August (12.4%), and was lowest in March. Of all collected ticks, 2,597 (81.3%) were nymphs; the remaining ticks were adults (18.6%) and larvae (0.1%). SFTSV-infected ticks comprised 390/3,187 (12.2%) of all ticks. The SFTSV-infected ticks were lowest in November–December and increased from January. SFTSV-infected ticks were mostly identified in the adult stage during June–August. Of the SFTSV-infected ticks, C. burnetii co-infection was seen in H. longicornis (4.9%), with the highest infection rate in January, followed by December and November. 결론: Coxiella burnetii-infected ticks were mainly identified in the nymph stage. This region is at high SFTSV risk and potential Q fever endemic. This study provides important information on SFTSV and Q fever risk to humans, according to Korean tick developmental stage. [ABSTRACT FROM AUTHOR]