Among HIV-negative patients, age <50 years, male sex, history of HBV infection, and history of syphilis were risk factors for amebic colitis (Table 2).
The prevalence of patients with amebic colitis was 0.
Multivariate analysis indicated that risk factors for amebic colitis in this study were male sex, age <50 years, and histories of syphilis and HIV infection.
The reason male sex was a risk factor might be related to specific sexual preference (8,10-15) because 52 male patients with amebic colitis often had contact with MSM (n = 35) or female CSWs (n = 8).
The present study included many patients with HIV infection or history of syphilis, which supports the hypothesis that these factors increase the risk for amebic colitis.
Under existing conditions, the reason for HIV infection representing a risk factor for amebic colitis is considered the preference for oral-anal sex as a common risk factor for both infectious conditions.
We compared prevalence and risk factors between amebic colitis patients with and without HIV infection.
Third, the number of patients with amebic colitis was small; thus, the statistical power of the study might have been low.
In conclusion, although this study was conducted at 1 center and involved retrospective analysis of a relatively small number of cases of amebic infection, the results suggest that the number of amebic colitis patients with or without HIV infection is tending to increase in Japan.
Describe yearly change in prevalence of amebic colitis, based on a Japanese study of persons who underwent endoscopy