Amebic colitis and other forms of amoeba parasites are second only to malaria in terms of protozoa-associated mortality.
The combined prevalence of amebic colitis and amebic liver abscess is estimated at 40 to 50 million cases annually worldwide, resulting in 40,000 to100,000 deaths every year.
However, the reasons amebiasis is increasing and the actual prevalence of amebic colitis in daily clinical practice have not been fully clarified.
To address these issues, we clarified annual changes in prevalence and risk factors for amebic colitis among persons who had undergone endoscopy.
Amebic colitis was suspected on the basis of endoscopic findings, such as erythema, edematous mucosa, erosions, white exudates, and ulcers (Figure 1) (22,23).
When amebic colitis was diagnosed, the physician asked the patient directly for information about the route of amebic infection.
To determine risk factors for amebic colitis, we estimated the odds ratio (OR) between amebic colitis and clinical factors including age, sex, sexual preference, and history of STDs.
In HIV-positive patients, the relationship between prevalence of amebic colitis and CD4 cell counts in 4 categories was evaluated by using the [chi square] test for linear trends.