title: Increased risk for Entamoeba histolytica infection and invasive amebiasis in HIV seropositive men who have sex with men in Taiwan.
abstract: BACKGROUND
  Incidence of Entamoeba histolytica infection and clinical manifestations and treatment response of invasive amebiasis (IA) in HIV-infected patients have rarely been investigated before.
  
  
  RESULTS
  At the National Taiwan University Hospital, medical records of HIV-infected patients who received a diagnosis of IA between 1994 and 2005 were reviewed. The incidence of amebiasis was investigated in serial blood and stool samples from 670 and 264 HIV-infected patients, respectively, using serological and specific amebic antigen assays. DNA extracted from stool samples containing E. histolytica were analyzed by PCR, sequenced, and compared. Sixty-four (5.8%) of 1,109 HIV-infected patients had 67 episodes of IA, and 89.1% of them were men having sex with men (MSM). The CD4 count at diagnosis of IA was significantly higher than that of the whole cohort (215 cells/microL vs. 96 cells/microL). Forty episodes (59.7%) were liver abscesses, 52 (77.6%) colitis, and 25 (37.3%) both liver abscesses and colitis. Fever resolved after 3.5 days of metronidazole therapy (range, 1-11 days). None of the patients died. The incidence of E. histolytica infection in MSM was higher than that in other risk groups assessed by serological assays (1.99 per 100 person-years [PY] vs. 0 per 100 PY; p<0.0001) and amebic antigen assays (3.16 per 100 PY vs. 0.68 per 100 PY; p = 0.12). In multiple logistic regression analysis, only MSM was significantly associated with acquisition of E. histolytica infection (adjusted odds ratio, 14.809; p = 0.01). Clustering of E. histolytica isolates by sequencing analyses from geographically-unrelated patients suggested person-to-person transmission.
  
  
  CONCLUSIONS
  HIV-infected MSM were at significantly higher risk of amebiasis than patients from other risk groups. Despite immunosuppression, amebic liver abscesses and colitis responded favorably to treatment.
authors.affiliation: Department of Internal Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: Chien-Ching
authors.initials: CC
authors.lastname: Hung
authors.forename: Dar-Der
authors.initials: DD
authors.lastname: Ji
authors.forename: Hsin-Yun
authors.initials: HY
authors.lastname: Sun
authors.forename: Ya-Tien
authors.initials: YT
authors.lastname: Lee
authors.forename: Shui-Yuan
authors.initials: SY
authors.lastname: Hsu
authors.forename: Sui-Yuan
authors.initials: SY
authors.lastname: Chang
authors.forename: Cheng-Hsin
authors.initials: CH
authors.lastname: Wu
authors.forename: Yun-Hsien
authors.initials: YH
authors.lastname: Chan
authors.forename: Chin-Fu
authors.initials: CF
authors.lastname: Hsiao
authors.forename: Wen-Chun
authors.initials: WC
authors.lastname: Liu
authors.forename: Robert
authors.initials: R
authors.lastname: Colebunders
mesh_terms: D000293:Adolescent; D000328:Adult; D000913:Antibodies, Protozoan / Q000097:blood; D016054:DNA, Protozoan / Q000235:genetics; D004198:Disease Susceptibility; D004748:Entamoeba histolytica / Q000235:genetics / Q000302:isolation & purification / Q000502:physiology*; D004749:Entamoebiasis / Q000097:blood / Q000453:epidemiology* / Q000469:parasitology; D005260:Female; D005500:Follow-Up Studies; D015658:HIV Infections / Q000150:complications* / Q000453:epidemiology; D018451:Homosexuality, Male; D006801:Humans; D015994:Incidence; D007422:Intestines / Q000469:parasitology; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors; D013624:Taiwan / Q000453:epidemiology; D055815:Young Adult
chemical_list: D000913:Antibodies, Protozoan; D016054:DNA, Protozoan