Background & objective: A cross-sectional study was conducted to determine the prevalence of Plasmodium infections among migrant workers in Thailand. Methods: A total of 241 migrants at Kanchanaburi, Pathumthani and Nakornpathom provinces of Thailand were recruited in our surveillance. Blood samples were examined for human malaria parasites by using microscopy and semi-nested multiplex PCR (SnM-PCR). 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. Conclusion: These findings indicate risk of malaria transmission from migrant workers. Malaria surveillance should be included in the health-screening program for migrants in Thailand to manage this health risk.

Migrant workers Thailand Semi-nested multiplex PCR Malaria

Plasmodium ovale blood sampling Plasmodium ovale malaria Multiplex Polymerase Chain Reaction mass screening Thailand human sex difference controlled study Malaria Asymptomatic Diseases intermethod comparison Cross-Sectional Studies migrant worker cross-sectional study Humans male female Myanmar Plasmodium polymerase chain reaction prevalence Article disease transmission Parasitemia Plasmodium vivax Malaria, Vivax major clinical study Malaria, Falciparum microscopy malaria falciparum Plasmodium vivax malaria Plasmodium falciparum Plasmodium malariae Plasmodium malariae infection Transients and Migrants health hazard health survey