Prevalence and associated risk factors of Leishmania infection among immunocompetent hosts, a community-based study in Chiang Rai, Thailand.

• Published in: PLOS Neglected Tropical Diseases
• Main Authors: Pamornsri Sriwongpan, Supalert Nedsuwan, Jidapa Manomat, Sakarn Charoensakulchai, Kittiphat Lacharojana, Jamnong Sankwan, Natheeporn Kobpungton, Taweesak Sriwongpun, Saovanee Leelayoova, Mathirut Mungthin, Suradej Siripattanapipong, Toon Ruang-Areerate, Tawee Naaglor, Theethach Eamchotchawalit, Phunlerd Piyaraj
• Format: Article in Journal/Newspaper
• Language: English
• Published: Public Library of Science (PLoS) 2021
• Subjects: Arctic medicine. Tropical medicine; RC955-962; Public aspects of medicine; RA1-1270; Arctic; Chiang
• Online Access: https://doi.org/10.1371/journal.pntd.0009545; https://doaj.org/article/2bdeb760f46a4f2482d8f141e7fa6356

Background Leishmaniasis is an emerging infectious disease reported in the north and south of Thailand of which patients with HIV/AIDS are a high risk group for acquiring the infection. A lack of information regarding prevalence, and the risk association of Leishmania infection among asymptomatic immunocompetent hosts needs further investigation. Information on potential vectors and animal reservoirs in the affected areas is also important to control disease transmission. Methods An outbreak investigation and a cross-sectional study were conducted following one index case of cutaneous leishmaniasis (CL) caused by L. martiniquensis in an immunocompetent male patient reported in August 2015, Chiang Rai Province, Thailand. From September to November 2015, a total of 392 participants at two study areas who were related to the index case, 130 students at a semi-boarding vocational school and 262 hill tribe villagers in the patient's hometown, were recruited in this study. The nested internal transcribed spacer 1-PCR (ITS1-PCR) was performed to detect Leishmania DNA in buffy coat, and nucleotide sequencing was used to identify species. Antibody screening in plasma was performed using the Direct Agglutination Test (DAT), and associated risk factors were analyzed using a standardized questionnaire. Captured sandflies within the study areas were identified and detected for Leishmania DNA using nested ITS1-PCR. Moreover, the animal reservoirs in the study areas were also explored for Leishmania infection. Results Of 392 participants, 28 (7.1%) were positive for Leishmania infection of which 1 (4.8%) was L. martiniquensis, 12 (57.1%) were L. orientalis and 8 (38.1%) were Leishmania spp. Of 28, 15 (53.6%) were DAT positive. None showed any symptoms of CL or visceral leishmaniasis. Risk factors were associated with being female (adjusted odds ratio, AOR 2.52, 95%CI 1.01-6.26), increasing age (AOR 1.05, 95%CI 1.02-1.08), having an animal enclosure in a housing area (AOR 3.04, 95%CI 1.13-8.22), being exposed to termite mounds ...