Lymphatic filariasis caused by Brugia malayi in an endemic area of Narathiwat Province, southern of Thailand.

Lymphatic filariasis caused by Brugia malayi is highly prevalent in Narathiwat province of Thailand. The World Health Organization has aimed to eliminate the disease globally by the year 2020. To achieve the goal, assessment of the real disease situation should be integrated as part of the control program. The preliminary data for long-term study of the disease situation in this endemic area is necessary for the elimination program of lymphatic filariasis. By using the conventional microscopic method, the microfilarial rate of B. malayi in an endemic area of Narathiwat province was 1.38 per cent. The microfilarial densities ranged from 17 microfilariae/ml to 1,250 microfilariae/ml median = 50. The highest prevalence was found in the age group > 45-60 (4.69%). The lowest microfilarial rate was in the age group < or = 15 (0.37%). The infection in males was about three fold the number in females. A PCR-based method was employed to detect a B. malayi-specific Hha I repetitive DNA sequence with high specificity and sensitivity. The PCR assay will be useful in assisting the elimination program of lymphatic filariasis in control and monitoring the disease in Thailand.