Results: Laboratory diagnosis revealed 6.2% total positive rate. As compared to microscopy (26.7%), SnM-PCR
was more sensitive (93.3%) for malaria. Plasmodium falciparum was predominant than P. vivax (53% : 40%,
respectively). The majority of positive cases were from Myanmar workers who had low parasitaemia and without
symptoms. The highest prevalence (13.7%) was found among migrant workers from Kanchanaburi province in
western Thailand.