title: Different clinical outcomes of Entamoeba histolytica in Malaysia: does genetic diversity exist?
abstract: The present study was conducted to investigate the clinical outcomes of Entamoeba histolytica infection in symptomatic and asymptomatic Orang Asli (aborigine) communities in Malaysia. Examination was performed on 500 stool samples obtained from Orang Asli communities in 3 different states using formalin-ether concentration, trichrome staining, and single-round PCR techniques. Out of 500 stool samples, single infection of E. histolytica, Entamoeba dispar, and Entamoeba moshkovskii was identified in 3.2%, 13.4%, and 1%, respectively. In addition, 10 samples had mixed infections with E. histolytica and E. dispar. Six samples containing E. dispar were also positive for E. moshkovskii, and only 2 samples had E. histolytica in association with E. dispar and E. moshkovskii. Seventeen E. histolytica-positive samples were from symptomatic subjects, whereas the remaining 11 samples came from asymptomatic subjects. These findings suggest a predominant distribution of pathogenic potential of E. histolytica strains in this community. Therefore, further studies on genotyping of E. histolytica is required, to find out association between E. histolytica genotype and the outcome of the infection.
authors.affiliation: Department of Parasitology & Medical Entomology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, Kuala Lumpur, Malaysia.
authors.forename: Tengku Shahrul
authors.initials: TS
authors.lastname: Anuar
authors.forename: Hesham M
authors.initials: HM
authors.lastname: Al-Mekhlafi
authors.forename: Mohamed Kamel
authors.initials: MK
authors.lastname: Abdul Ghani
authors.forename: Siti Nor
authors.initials: SN
authors.lastname: Azreen
authors.forename: Fatmah Md
authors.initials: FM
authors.lastname: Salleh
authors.forename: Nuraffini
authors.initials: N
authors.lastname: Ghazali
authors.forename: Mekadina
authors.initials: M
authors.lastname: Bernadus
authors.forename: Norhayati
authors.initials: N
authors.lastname: Moktar
mesh_terms: D000293:Adolescent; D000328:Adult; D058070:Asymptomatic Diseases; D002648:Child; D002675:Child, Preschool; D060085:Coinfection / Q000469:parasitology / Q000473:pathology; D004747:Entamoeba / Q000145:classification* / Q000302:isolation & purification / Q000472:pathogenicity*; D004749:Entamoebiasis / Q000469:parasitology / Q000473:pathology*; D005243:Feces / Q000469:parasitology; D005260:Female; D014644:Genetic Variation; D006801:Humans; D008296:Malaysia; D008297:Male; D008875:Middle Aged; D016896:Treatment Outcome
keywords: Entamoeba histolytica; Malaysia; asymptomatic; clinical outcome; genetic diversity; symptomatic