Detection of Entamoeba histolytica DNA from liver abscess aspirate using polymerase chain reaction (PCR): a diagnostic tool for amoebic liver abscess.

Amoebic liver abscess is common in Bangladesh. It is usually diagnosed by suggestive clinical features, ultrasound findings and positive serology. However, none of these are definitive and the picture overlaps with pyogenic liver abscess. It is critical to differentiate amoebic liver abscess from pyogenic liver abscess as the treatment are different. This study was designed to evaluate the feasibility of using polymerase chain reaction (PCR) for detection of Entamoeba histolytica (E.histolytica) DNA in liver abscess pus for confirmatory diagnosis of amoebic liver abscess. This study was carried out in the department of Hepatology, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh. Thirty patients of amoebic liver abscess were included in this study. PCR was done to detect E.histolytica DNA in liver abscess aspirate of all patients by real time PCR method, using oligonucleotide primer containing small-subunit rRNA gene of E.histolytica. Real time PCR detected E.histolytica in liver abscess aspirate in 29 cases out of 30 cases and the sensitivity was 97% (p<0.001). This study also showed that antigen detection by ELISA in liver abscess aspirate was positive in 12 cases only and sensitivity was 40%. The study indicates that detection of E.histolytica by PCR is more sensitive than amoebic antigen detection and PCR assay can be successfully used to confirm the diagnosis of amoebic liver abscess.