Genital infection caused by Entamoeba histolytica confirmed by polymerase chain reaction analyses

Abstract

Entamoeba histolytica is estimated to infect approximately 1% of the global population. In Japan, the prevalence of amebic dysentery has been increasing, with more than 800 patients newly diagnosed annually. However, genital infection with E. histolytica is uncommon even in endemic areas. We present a case of vaginitis caused by E. histolytica. A 50-year-old Japanese woman without history of overseas travel presented to a nearby clinic with increased vaginal discharge. She had hemorrhagic erosion at the uterine cervix with yellowish vaginal discharge, and was referred to our hospital for exclusion of malignancy. Cervical cytology revealed periodic acid-Schiff-positive protozoa not aggregating around squamous cells, and thus amebic vaginitis was suspected. We performed polymerase chain reaction (PCR) analyses and identified E. histolytica. The vaginitis was treated with metronidazole, and the disappearance of amebic protozoa was confirmed by cytology and PCR. Therefore, it may be important to obtain early diagnosis by cervical cytology and PCR.

Practical Guidance for Clinical Microbiology Laboratories: Laboratory Diagnosis of Parasites from the Gastrointestinal Tract

“…E. histolytica may cause hepatic amoebic abscesses and, rarely, pleuropulmonary disease, in addition to ulceration in the colon (227). Other sites of extraintestinal infections have been reported, but they are significantly less common (228). PCR has been used as a test complementary to serology for the diagnosis of amoebic hepatic liver abscess, since the stool is often free of amoebae during this phase of disease, and amoebae may be difficult to visualize and differentiate from histiocytes in the direct examination of aspirated abscess contents (229).…”