title: Using Respondent Driven Sampling to Identify Malaria Risks and Occupational Networks among Migrant Workers in Ranong, Thailand.
abstract: BACKGROUND
  Ranong Province in southern Thailand is one of the primary entry points for migrants entering Thailand from Myanmar, and borders Kawthaung Township in Myanmar where artemisinin resistance in malaria parasites has been detected. Areas of high population movement could increase the risk of spread of artemisinin resistance in this region and beyond.
  
  
  METHODS
  A respondent-driven sampling (RDS) methodology was used to compare migrant populations coming from Myanmar in urban (Site 1) vs. rural (Site 2) settings in Ranong, Thailand. The RDS methodology collected information on knowledge, attitudes, and practices for malaria, travel and occupational histories, as well as social network size and structure. Individuals enrolled were screened for malaria by microscopy, Real Time-PCR, and serology.
  
  
  RESULTS
  A total of 619 participants were recruited in Ranong City and 623 participants in Kraburi, a rural sub-district. By PCR, a total of 14 (1.1%) samples were positive (2 P. falciparum in Site 1; 10 P. vivax, 1 Pf, and 1 P. malariae in Site 2). PCR analysis demonstrated an overall weighted prevalence of 0.5% (95% CI, 0-1.3%) in the urban site and 1.0% (95% CI, 0.5-1.7%) in the rural site for all parasite species. PCR positivity did not correlate with serological positivity; however, as expected there was a strong association between antibody prevalence and both age and exposure. Access to long-lasting insecticidal treated nets remains low despite relatively high reported traditional net use among these populations.
  
  
  CONCLUSIONS
  The low malaria prevalence, relatively smaller networks among migrants in rural settings, and limited frequency of travel to and from other areas of malaria transmission in Myanmar, suggest that the risk for the spread of artemisinin resistance from this area may be limited in these networks currently but may have implications for regional malaria elimination efforts.
authors.affiliation: Bureau of Vector Borne Diseases, Department of Disease Control, Ministry of Public Health, Nonathaburi, Thailand.
authors.forename: Piyaporn
authors.initials: P
authors.lastname: Wangroongsarb
authors.affiliation: U.S. President's Malaria Initiative, Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America.|Global Health Group, University of California San Francisco, California, United States of America.
authors.forename: Jimee
authors.initials: J
authors.lastname: Hwang
authors.affiliation: Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America.
authors.forename: Julie
authors.initials: J
authors.lastname: Thwing
authors.affiliation: Thailand MOPH-US CDC Collaboration, Nonathaburi, Thailand.
authors.forename: Samart
authors.initials: S
authors.lastname: Karuchit
authors.affiliation: Ranong Provincial Health Office, Ministry of Public Health, Ranong, Thailand.
authors.forename: Suthon
authors.initials: S
authors.lastname: Kumpetch
authors.affiliation: Department of Infectious & Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom.
authors.forename: Alison
authors.initials: A
authors.lastname: Rand
authors.affiliation: Department of Infectious & Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom.
authors.forename: Chris
authors.initials: C
authors.lastname: Drakeley
authors.affiliation: Thailand MOPH-US CDC Collaboration, Nonathaburi, Thailand.
authors.forename: John R
authors.initials: JR
authors.lastname: MacArthur
authors.affiliation: Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America.
authors.forename: S Patrick
authors.initials: SP
authors.lastname: Kachur
authors.affiliation: Bureau of Vector Borne Diseases, Department of Disease Control, Ministry of Public Health, Nonathaburi, Thailand.
authors.forename: Wichai
authors.initials: W
authors.lastname: Satimai
authors.affiliation: Malaria Consortium, London, United Kingdom.
authors.forename: Sylvia
authors.initials: S
authors.lastname: Meek
authors.affiliation: U.S. President's Malaria Initiative, USAID/RDMA, Bangkok, Thailand.
authors.forename: David M
authors.initials: DM
authors.lastname: Sintasath
mesh_terms: D000328:Adult; D000368:Aged; D000962:Antimalarials / Q000494:pharmacology / Q000627:therapeutic use; D037621:Artemisinins / Q000494:pharmacology / Q000627:therapeutic use; D004351:Drug Resistance; D005260:Female; D015438:Health Behavior; D007722:Health Knowledge, Attitudes, Practice; D006801:Humans; D008288:Malaria / Q000188:drug therapy / Q000453:epidemiology* / Q000635:transmission*; D008297:Male; D008875:Middle Aged; D016273:Occupational Exposure / Q000009:adverse effects*; D018570:Risk Assessment / Q000379:methods*; D011795:Surveys and Questionnaires; D013785:Thailand / Q000453:epidemiology; D014171:Transients and Migrants / Q000706:statistics & numerical data*; D055815:Young Adult
chemical_list: D000962:Antimalarials; D037621:Artemisinins; C031327:artemisinin