We investigated population densities of mosquitoes in Gyeongbuk region from March to November, 2017 and pathogens were detected from the mosquitoes. Mosquito populations were investigated at 3 sites in downtown and 1 site in cowshed in Andong, 3 sites in Yeongdeok downtown and 3 sites near migratory birds habitat in Sangju by collecting trap. Total collected female mosquitoes were 7 genus, 13 species, 9,892 individuals and relatively dominant ratios are Aedes vexans (40%), Ae. albopictus (20%), Culex pipiens (16%). Flavivirus were monitored in 9,125 collected mosquitoes by real-time PCR and no target flavivirus causing infectious diseases were detected in Gyeongbuk area in 2017.
Trombiculid mites are known to be the vector of scrub typhus by transmitting rickettsial pathogen, Orientia tsutsugamushi, to human. In this study, we tried to establish a monitoring system for trombiculid mites using chigger mite collecting traps instead of the conventional rodent-capture method. For selection of collecting points, 10 environmental points were chosen from three regions (Taean, Jinan and Chungju) and two field collections were performed in spring (March-May) and autumn (October-November) seasons from 2013 to 2014. Among 10 environmental points, waterway (37.9%), grass field (28.0%), rice field and field near mountain side (11.4%) and reservoir/wet field (7.3%) showed high collecting rates and they should be included for the representative collecting points for surveillance using chigger mite collecting trap. In order to test the possibility that the dried chigger mites from collecting trap can be used for detection of O. tsutsugamushi, we pooled 30, 10 and 5 chigger mites separately and performed the nested PCR. The infection of O. tsutsugamushi was successfully detected from 5 chigger mites pooling sample. This study shows that chigger mite collecting trap could be an alternative method for monitoring system of scrub typhus vectors.