Malaria infection and life-style factors among hilltribes along the Thai-Myanmar border area, northern Thailand.

A cross sectional study was conducted between January, 2001 and June, 2002 to determine the life-style factors associated with malaria infection among hilltribes in the Chiang Rai Province, Mae Fah Luang district located along the Thai-Myanmar border, northern Thailand. The data collected were a thick blood film examination and a face-to-face interview using a local language interviewer at a mobile clinic or a home visit. The chi-square test, odds ratio, 95% confidence interval and multiple logistic regression were used as data analysis. P. vivax (61.3%) was detected more than P falciparum (38.2%). Parasitic infection was seen in 45.8% of a total of 417 blood examinations. The study area was in a valley covered with forests and small streams, which was ideal for a malaria epidemic. The communities were distributed along different ethnic groups. There were 12 ethnic groups, dominated by the Muser, Eko, and Akha tribes (60-70%). The risk factors included living or working in the forest, accompanying their family during movement through the forest, age < or =14 years (40.9%), poor knowledge of how to protect against malaria (75-80%), and unavailability of protection against malaria via long sleeved clothes, topical repellents, and insecticide treated nets (use and carry), which resulted in an increased exposure to malaria and risk for malaria infection.