title: The Diversity and Geographical Structure of Orientia tsutsugamushi Strains from Scrub Typhus Patients in Laos.
abstract: Orientia tsutsugamushi is the causative agent of scrub typhus, a disease transmitted by Leptotrombidium mites which is responsible for a severe and under-reported public health burden throughout Southeast Asia. Here we use multilocus sequence typing (MLST) to characterize 74 clinical isolates from three geographic locations in the Lao PDR (Laos), and compare them with isolates described from Udon Thani, northeast Thailand. The data confirm high levels of diversity and recombination within the natural O. tsutsugamushi population, and a rate of mixed infection of ~8%. We compared the relationships and geographical structuring of the strains and populations using allele based approaches (eBURST), phylogenetic approaches, and by calculating F-statistics (FST). These analyses all point towards low levels of population differentiation between isolates from Vientiane and Udon Thani, cities which straddle the Mekong River which defines the Lao/Thai border, but with a very distinct population in Salavan, southern Laos. These data highlight how land use, as well as the movement of hosts and vectors, may impact on the epidemiology of zoonotic infections.
authors: Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit, Microbiology Laboratory, Mahosot Hospital, Vientiane, Laos PDR.
authors: Rattanaphone
authors: R
authors: Phetsouvanh
authors: Department of Molecular Tropical Medicine and Genetics, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
authors: Piengchan
authors: P
authors: Sonthayanon
authors: Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
authors: Sasithon
authors: S
authors: Pukrittayakamee
authors: Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine & Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, United Kingdom.
authors: Daniel H
authors: DH
authors: Paris
authors: Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit, Microbiology Laboratory, Mahosot Hospital, Vientiane, Laos PDR.
authors: Paul N
authors: PN
authors: Newton
authors: Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom.
authors: Edward J
authors: EJ
authors: Feil
authors: Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine & Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, United Kingdom.
authors: Nicholas P J
authors: NP
authors: Day
mesh_terms: D000818:Animals; D014644:Genetic Variation; D006801:Humans; D007812:Laos / Q000453:epidemiology; D008969:Molecular Sequence Data; D058885:Multilocus Sequence Typing; D012285:Orientia tsutsugamushi / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification*; D010802:Phylogeny; D011446:Prospective Studies; D012612:Scrub Typhus / Q000453:epidemiology / Q000382:microbiology*; D013785:Thailand / Q000453:epidemiology