Detection of bancroftian filariasis in human blood samples from Sorsogon province, the Philippines by polymerase chain reaction

The polymerase chain reaction (PCR) was used for diagnosing Wuchereria banc rofti infection in a small village in the province of Sorsogon, the Philipp ines. Of 54 night-time blood samples collected, 4 (7.4%) were found to be m icrofilaremic as determined by combined direct blood film examination and m embrane filtration of blood followed by blood film examination. However, ut ilization of the SspI PCR assay to detect repeated W. bancrofti DNA sequenc es in human blood doubled the number of microfilaremic individuals to 8 (13 .0%). The results of this survey suggest that utilization of diagnostic too ls based on microscopy could underestimate the true prevalence of W. bancro fti in the Philippines.