Entamoeba histolytica and amoebic liver abscess in northern Sri Lanka: a public health problem

Abstract

Entamoeba histolytica (E. histolytica) is a facultative protozoan parasite implicated in amoebic liver abscesses (ALA), the most common extraintestinal manifestation of this infection. E. histolytica is endemic to subtropical and tropical countries and has been a major public health concern in northern Sri Lanka (SLK) for the last three decades. This has been attributed to a multitude of factors such as poor sanitation, hygiene, male sex, middle age, overcrowding, unsanitary practices in the production of indigenous alcoholic beverages, and alcohol consumption. Additionally, while rates of E. histolytica have declined substantially throughout the rest of the island, largely due to better infrastructure, it remains pervasive in the northern peninsula, which is generally less developed. Infection arises primarily from fecal-oral transmission through the consumption of contaminated drinking water containing cysts. Upon ingestion, cysts multiply into trophozoites and colonize the host colonic mucosa using lectin and cysteine proteases as virulence factors, leading to host invasion. Symptoms occur along a spectrum, from asymptomatology, to pyrexia, abdominal cramping, and amoebic dysentery. Colonization of the colon results in the formation of distinct flask-shaped ulcers along the epithelium, and eventual penetration of the lamina propria via the production of matrix metalloproteinases. ALA then develops through trophozoite migration via the mesenteric hepatic portal circulation, where microabscesses coalesce to form a single, large right-lobe abscess, commonly on the posterior aspect. The progression of infection to invasive disease is contingent on the unique interplay between host and pathogen factors, such as the strength of host-immunity to overcome infection and inherent pathogenicity of the Entamoeba species. As a preventable illness, E. histolytica complications such as ALA impose a significant burden on the healthcare system. This mini-review highlights epidemiological trends, risk factors, diagnostic modalities, treatment approaches, and opportunities for prevention of E. histolytica-induced ALA, to help address this endemic problem on the island of SLK.

“A Divine Infection”: A Systematic Review on the Roles of Religious Communities During the Early Stage of COVID-19

“…Twenty-six studies reported on the mitigating role of religion during the early stage of COVID-19 (Ahmed & Memish, 2020 ; Al-Rousan & Al-Najjar, 2020 ; Ali & Alharbi, 2020 ; Atique & Itumalla, 2020 ; Crubézy & Telmon, 2020 ; Ebrahim & Memish, 2020a , 2020b ; Escher, 2020 ; Frei-Landau, 2020 ; Gautret et al, 2020 ; Ha, 2020 ; Hong & Handal, 2020 ; Iqbal et al, 2020 ; Kim et al, 2020 ; McCloskey, et al, 2020a , 2020b ; Memish et al, 2020 ; Muurlink & Taylor-Robinson, 2020 ; Quadri, 2020 ; Tarimo & Wu, 2020 ; Waitzberg et al, 2020 ; Weinberger-Litman et al, 2020 ; Wildman et al, 2020 ; Wong et al, 2020 ; Yezli & Khan, 2020a , 2020b ) (Appendix 3 ).…”

“…Findings on policy recommendations for religious groups to combat COVID-19 are summarized in Table 1 . A total of 26 articles provided recommendations on controlling and managing COVID-19 (Ahmed & Memish, 2020 ; Al-Rousan & Al-Najjar, 2020 ; Atique & Itumalla, 2020 ; Chirico & Nucera, 2020 ; Crubézy & Telmon, 2020 ; Ebrahim & Memish, 2020a , 2020b ; Escher, 2020 ; Gautret et al, 2020 ; Greene et al, 2020 ; Ha, 2020 ; Hashmi et al, 2020 ; Hong & Handal, 2020 ; Iqbal et al, 2020 ; Jaja et al, 2020 ; Kang, 2020 ; Koenig, 2020b ; Mat et al, 2020 ; McCloskey, et al, 2020b ; Memish et al, 2020 ; Quadri, 2020 ; Tarimo & Wu, 2020 ; Thompkins et al, 2020 ; Wong et al, 2020 ; Yezli & Khan, 2020a , 2020b ).…”

A Comparative Analysis of Microscopy, Coproantigen Serology, and Nested Multiplex PCR in the Laboratory Diagnosis of Entamoeba histolytica Infection

“…Similar findings were also noted by Tharmaratnam et al and Kantor et al in their study. 4,11 From the very old days, the laboratory diagnosis of E. histolytica has always been based on direct microscopic examination of stool samples showing distinct protozoan morphology. 12 Currently, however, usage of the direct microscopy-based identification techniques to differentiate among protozoa with similar morphological features like E. coli, E. moshkovskii, E. dispar, and E. hartmanni is seemingly unreliable.…”

Acute fulminant necrotizing amebic colitis in a pediatric patient: a rare complication of amebiasis with high mortality—a case report

“…Another study identified 346 molecular and immunologically confirmed patients with amebic liver abscess, all seen at the Teaching Hospital, Jaffna, within 3 years [ 14 ]. A more recent study identified E. histolytica as a public health problem in northern Sri Lanka, owing to poor sanitation and poor hygienic practices [ 15 ].…”