title: Detection of Orientia tsutsugamushi, the causative agent of scrub typhus, in a novel mite species, Eushoengastia koreaensis, in Korea.
abstract: To identify potential vector species of scrub typhus in the Republic of Korea (ROK), chigger mites were harvested from wild rodents captured at nine localities in October 2005. The bodies of the chigger mites were individually punctured with a fine pin, squeezed out internal contents, and examined for Orientia tsutsugamushi DNA by nested polymerase chain reaction. The exoskeleton of associated chiggers was mounted on glass slides with polyvinylalcohol (PVA) medium for identification. Among 830 individuals belonging to 4 genera and 14 species, O. tsutsugamushi was detected from 22 chiggers of six species, with an overall infection rate of 2.7%. The infection rate was highest for Leptotrombidium palpale (5.3%), followed by Neotrombicula japonica (4.3%), Leptotrombidium scutellare (3.7%), Leptotrombidium orientale (3.6%), Eushoengastia koreaensis (1.9%), and Leptotrombidium pallidum (1.5%). This study first reported O. tsutsugamushi infection from N. japonica and E. koreaensis larvae in the ROK. The population densities of L. pallidum (33.4 chiggers/rodent), historically confirmed as a primary vector of scrub typhus in the ROK, were high, whereas its infection rate was relatively low (1.5%). However, E. koreaensis was only collected from 154 individuals at seven collection sites and its infection rate was demonstrated relatively high (mean 1.9%). Additional studies are needed to determine the role of vector species in the epidemiology of scrub typhus.
authors: Division of Medical Entomology, Korea Centers for Disease Control and Prevention, Seoul, Korea.
authors: Hee Il
authors: HI
authors: Lee
authors: Soo Kyoung
authors: SK
authors: Shim
authors: Bong Gu
authors: BG
authors: Song
authors: Eun Na
authors: EN
authors: Choi
authors: Kyu Jam
authors: KJ
authors: Hwang
authors: Mi Yeoun
authors: MY
authors: Park
authors: Chan
authors: C
authors: Park
authors: E-Hyun
authors: EH
authors: Shin
mesh_terms: D000818:Animals; D001096:Arachnid Vectors / Q000382:microbiology*; D004269:DNA, Bacterial / Q000235:genetics; D051189:Murinae / Q000469:parasitology; D012285:Orientia tsutsugamushi / Q000235:genetics / Q000302:isolation & purification*; D016133:Polymerase Chain Reaction; D011156:Population Density; D056910:Republic of Korea / Q000453:epidemiology; D012376:Rodent Diseases / Q000453:epidemiology / Q000469:parasitology*; D012377:Rodentia; D012612:Scrub Typhus / Q000453:epidemiology / Q000382:microbiology* / Q000517:prevention & control / Q000635:transmission; D017422:Sequence Analysis, DNA; D014323:Trombiculiasis / Q000453:epidemiology / Q000469:parasitology / Q000662:veterinary*; D014324:Trombiculidae / Q000382:microbiology*
chemical_list: D004269:DNA, Bacterial