A cross-sectional study was conducted from January, 2001 to June, 2002 among some migrant populations, living in malaria endemic areas along the Thai-Myanmar border, in the Mae Fah Luang and Mae Sai districts, Chiang Rai Province, Northern Thailand using blood exams and face-to-face interviews as
the research methods. This study focused on the knowledge and practice of primary malaria prevention, aimed at identifying the association between behavioral factors in migrant populations and malaria infection. P. vivax (51.8%) was detected more often than P. falciparum (47.7%). The proportion of malaria infections was 45.4% of the total of 421 blood examinations. The working age group (15-44 yr) and males were the majority of the study subjects. Two age groups (0-14 and 15-34 yr) and visiting or staying in the forest 14 days prior to the blood exam were significant risk factors. The ethnic group of Thai-Yai and hilltribe was a significant protective factor (p < 0.05) compared to the Myanmar people. A poor knowledge of primary malaria prevention (63-68%), the presence of international migration, poverty, lack of malaria prevention resources, namely bednets (not using or taking them) and not using a smoky fire were factors which led to failure in primary prevention and control of malaria infections. Residence-workplace-living style in the forest need more consideration to serve the common failure of effective primary prevention.

Keywords: Behavioral factors, Malaria Infection, Migrant Population