Increased risk for Entamoeba histolytica infection and invasive amebiasis in HIV seropositive men who have sex with men in Taiwan.
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.
Hung
Chien-Ching
CC
Department of Internal Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan.
Ji
Dar-Der
DD
Sun
Hsin-Yun
HY
Lee
Ya-Tien
YT
Hsu
Shui-Yuan
SY
Chang
Sui-Yuan
SY
Wu
Cheng-Hsin
CH
Chan
Yun-Hsien
YH
Hsiao
Chin-Fu
CF
Liu
Wen-Chun
WC
Colebunders
Robert
R
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
D000913:Antibodies, Protozoan; D016054:DNA, Protozoan