Polymorphism and virulence factors in the pathogenesis of amoebiasis

Amoebiasis is one of the world's most prevalent infectious diseases of developing world. E. histolytica and E. dispar are two morphologically identical but genetically distinct species. Infection with E. histolytica may be symptomatic and asymptomatic. E. dispar is non-pathogenic. Both innate and acquired immune responses limit amoebic infection while different strains of E. histolytica and its virulence have been described and virulence factors of E. histolytica such as cysteine proteinases; Gal/GalNAc-inhibitable lectin and ameobapore are known to be involved in E.histolytica pathogenesis. Proteolytic enzymes and cysteine proteases facilitate tissue invasion while Gal/GalNAc-inhibitable lectin aids adherence and amoebapores are involved in lysis of target cells. Three new strains of E. histolytica (Rahman; HK-9; and 200: NIH) have been described as well as the previously known strain (HM 1 IMSS). This review highlights the newly described strains and virulent factors involved in the pathogenesis of E. histolytica

Amoebone colique: difficultes diagnostiques a propos d'un cas

Amoeboma is an inflammatory mass of the colon. It is uncommon with most cases occurring in Latin America and South Africa. When amoeboma is the presenting symptom of amoebiasis; it poses the problem of differential diagnosis of colon cancer. This report describes the case of a 60-year-old patient who presented a painful mass in the left hypochondrium. Radiologic and endoscopic examinations depicted a ring-like stenosis of the transverse colon in association with a mesenteric reaction. The presumptive diagnosis was colon cancer and the patient was referred to the National Oncology Institute for surgical treatment. Histological examination of the surgical specimen after segmental colectomy confirmed diagnosis of intestinal amoeboma. The patient was treated medically using metronidazole. Since intestinal amoebiasis is common in our country; amoeboma must be considered as a rare but potential diagnosis in patients presenting masses of the colon. Differentialdiagnosis of carcinoma is necessary to avoid the risks associated with unnecessary surgery

Entamoeba Histolytica Infection Among Patients at Wonji-Shoa Sugar Estate Hospital; Ethiopia

Background and objective: Infection by Entamoeba histolytica is cosmopolitan but is more prevalent and causes serious public health and socioeconomic problems in developing countries of the tropics and subtropics. The objective of this study was to determine the magnitude of amoebiasis among inpatients and outpatients of Wonji-Shoa Sugar Estate hospital; Ethiopia. Patients and methods: The study subjects were inpatients and outpatients of Wonji-Shoa Sugar Estate Hospital in Ethiopia. The study covered a a follow-up period of almost 17 years; from 1987 to 2003. Faecal specimens from the patients were microscopically examined by the direct smear method. Results: The annual prevalence; which ranged from 12 to 32 showed an increasing trend from year 1987 to 2003. The monthly prevalence of infection among patients (both trophozoites and cysts combined) analyzed for 8 months in 1992 ranged from17 in 1999 to 43 in 2002; with higher rates occurring in the months of December to May and July to September in some years. Analysis by amoebic stages showed that 35 of the patients passed trophozoites in their faeces while only 6 passed cystic stage. Conclusions: In the Wonji-Shoa Sugar Estate which is one of the major agroindustrial sites; amoebiasis tends to increase from year to year perhaps due to deterioration of water supply and sanitation as well as overcrowding

Amibiase colique maligne aspects epidmiologiques et cliniques et therapeutiques : a propos de 10 cas colliges dans le service de Chirurgie Generale Digesive et Endocrinienne du CHU de treichvillle

Objectif : Elaborer une strategie diagnostique; therapeutique et surtout prophylactique de l'amibiase colique maligne adequate et adaptee a nos conditions d'exercice et visant a baisser considerablement le taux de mortalite de cette affection. Methode : Etude retrospective realisee sur une periode de 14 ans entre 1987 et 2001 avec pour support les dossiers complets de malades ayant presente cette pathologie au service de chirurgie generale; digestive et endocrinienne du CHU Treichville. L'analyse a porte sur les aspects epidemiologiques; cliniques et therapeutiques. Resultats : 10 patients (6 hommes et 4 femmes) ages de 4 a 63 ans; age moyen 39;5 ans; Sexe ratio H-F= 1;5; 8 patients (80 pour cent) se sont presentes dans un tableau peritonite; 1patient (10 pour cent) dans un tableau de syndrome occlusif; 1 patient (10 pour cent) dans un tableau de d'hemoperitoine. Il a ete effectue : 5 colectomies dont 2 totales et 3 hemicolectomies et 5 ileostomies (dont 3 de sagesse). Sur ces 10 patients; on a deplore 8 deces (soit 80 pour cent). Cette mortalite en general postoperatoire; est dominee par le choc septique dans 50 pour cent des cas et le choc toxi-infectieux dans 37;5 pour cent des cas. CONCLUSION : L'amibiase colique maligne reste une pathologie grave mais peu frequente dans le monde; et meme en Afrique. Devant les lesions preperforatives ou presphaceliques; l'ileostomie de sagesse est l'intervention de choix .Devant les lesions de gangrene; de sphacele et de necrose intense; la colectomie plus ou moins etendue s'impose. L'amelioration de son pronostic passe par un diagnostic precoce et une reanimation 'intense et energique et surtout une bonne prophylaxie de l'amibiase