Molecular Prevalence of Entamoeba Species among Diarrheal Patients in Eastern Kenya

Abstract

Data on the epidemiology of Entamoeba infections in Eastern part of Kenya is scanty. Diagnostic tests in use have limited capacity to differentiate common infecting species. The performance of Polymerase Chain Reaction (PCR) to differentiate between pathogenic Entamoeba histolytica and two nonpathogenic species E. dispar and E. moshkovskii is largely undetermined. Therefore, this study sought to determine the prevalence and associated factors for Entamoeba infections and evaluate the performance of PCR to differentiate Entamoeba complex species among diarrheal patient in Eastern region of Kenya. Stool samples were obtained from 400 patients attending Meru Teaching and Referral Hospital (MTRH) presenting with diarrhea. Samples were processed by direct wet mount using normal saline and iodine stain for microscopic examination. Entamoeba species differentiation was done using PCR targeting the 16S rRNA gene. A total of 33 (8.3%) samples had Entamoeba cysts/trophozoites by microscopy while 29 (7.3%) were identified as E. histolytica by PCR. Entamoeba infections was most common among adults 23 (5.8%) and in females 20(5%). The sensitivity of microscopy was 29/29 (100%; 95% CI 88.1% - 100%) with a specificity 367/371 (98.9%; 95% CI 97.3 % - 99.7%). In multivariate analysis, factors that independently influenced Entamoeba infection included sources of drinking water, use of toilet with water, regular use of soap or sanitizer, having diarrhea that persists for two weeks and stool consistency. Entamoeba infection was found to be responsible for most diarrhea condition especially among children. Patients hygienic and sanitation characteristics contributes significantly to Entamoeba infection. The performance of microscopy to detect Entamoeba infection is comparable to those of PCR except for the lack of species differentiation. Molecular species differentiation will improve disease diagnosis, control and management. Continuous monitoring of patient presenting with diarrhea for Entamoeba infection would improve treatment outcomes.