Gene amplification of Plasmodium vivax multidrug resistance 1 gene in Thailand, Laos, and Myanmar

Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; The Royal Institute, Grand Palace, Bangkok, Thailand; Southwest Foundation for Biomedical Research (SFBR), San Antonio, Texas, USA; Mahosot Hospital Wellcome Trust-Mahosot-Oxford Tropical Medicine Research Collaboration Vientiane, Lao PDR; Shoklo Malaria Research Unit, Mae Sot, Tak, Thailand; Centre for Clinical Vaccinology and Tropical Medicine, Churchill Hospital, Oxford, UK

^* To whom correspondence should be addressed. Email: noi{at}tropmedres.ac.

	Abstract

Plasmodium vivax mdr1 gene amplification, quantified by real time PCR, was significantly more common on the western Thailand border (6 of 66 samples), where mefloquine pressure has been intense, than elsewhere in Southeast Asia (3 of 149; p=0.02). Five coding mutations in pvmdr1, independent of gene amplification, were found also.