title: Is Entamoeba histolytica in homosexual men a pathogen?
abstract: Entamoeba histolytica (EH) in homosexual men is generally considered to be pathogenic. To test this hypothesis, the generally accepted features of invasion (haematophagous trophozoites in faeces; high-titre serum antibody; moderate to severe acute inflammatory change; and presence of EH in the mucosa on rectal biopsy) and the zymodeme pattern of cultured trophozoites were assessed in twenty-three EH excretors and eleven control homosexual men. No trophozoites or antibody to EH were found in either group. When other pathogens were excluded, no patient in either group had severe, acute histopathological proctitis. Moderately severe change was seen in 38% of EH excretors and 18% of controls (not significant). All the zymodemes were non-pathogenic. Successful eradication of EH did not result in even a trend towards normalisation of the moderate inflammatory histopathology. There are, therefore, no data here to suggest that EH is a pathogen in homosexual men.
authors.forename: D
authors.initials: D
authors.lastname: Goldmeier
authors.forename: P G
authors.initials: PG
authors.lastname: Sargeaunt
authors.forename: A B
authors.initials: AB
authors.lastname: Price
authors.forename: P E
authors.initials: PE
authors.lastname: Munday
authors.forename: O
authors.initials: O
authors.lastname: Billington
authors.forename: I
authors.initials: I
authors.lastname: Dixon
authors.forename: P
authors.initials: P
authors.lastname: Borriello
authors.forename: J M
authors.initials: JM
authors.lastname: Carder
authors.forename: A
authors.initials: A
authors.lastname: Shaw
authors.forename: J
authors.initials: J
authors.lastname: Hilton
mesh_terms: D000328:Adult; D000368:Aged; D002986:Clinical Trials as Topic; D004311:Double-Blind Method; D004748:Entamoeba histolytica / Q000472:pathogenicity*; D004749:Entamoebiasis / Q000188:drug therapy; D005243:Feces / Q000469:parasitology; D005500:Follow-Up Studies; D006716:Homosexuality; D006801:Humans; D008131:London; D008297:Male; D008795:Metronidazole / Q000627:therapeutic use; D008828:Microbiological Techniques; D008875:Middle Aged; D011897:Random Allocation; D012007:Rectum / Q000469:parasitology
chemical_list: D008795:Metronidazole