Comparison of Microscopic to PCR for Detecting Microfilaria in 21 Lymphatic Filariasis Patients Treated with Diethylcarbamazine

Abstract

Background: Lymphatic filariasis (LF) marked by the World Health Organization (WHO) as one of seventeen Neglected Tropical Disease (NTD) which can be eliminated. Giemsa-stained blood smear remained as the standard method to detect microfilariae, albeit this method has many weaknesses. The PCR method has long been proposed to replace it, but PCR is seldom used in a routine examination. Objective: This study aimed to examine the sensitivity and specificity of standard examination compared to PCR in post-therapy subjects. Methods: As many as 21 subjects, who had received Diethylcarbamazine (DEC) for 10 days, were enrolled in the study. The capillary blood sample was taken 6 months after the therapy. Half of the blood samples was examined using Giemsa –stained blood smear, and the other half using the PCR. Results: From 6 positive samples, the PCR only confirmed 4 of them. The sensitivity of the blood smear was 100% and the specificity was 88%. Conclusion: The Giemsa-stained capillary blood smear has a better sensitivity and specificity compared to the PCR. Thus, it remains the gold standard to check microfilaria in routine field examination. A PCR can be used as an alternative.