Amebiasis Deaths in the United States

We read with great interest the article published by Gunther and others that describes the amebiasis-related mortality among United States residents from 1990 to 2007. Of 134 amebiasis deaths during the study period, human immunodeficiency virus (HIV) infection was a co-existing condition in 14 (10.4%), which was statistically significantly more common than in the control, non-amebiasis group with a matched odds ratio of 7.7 (95% confidence interval, 3.16–18.77). Although more studies are warranted to identify the causes of the higher association between HIV infection and amebiasis deaths in the United States, the findings of several previous studies between the 1980s and 2000s concluded infection with Entamoeba histolytica that is pathogenic was rare in men who have sex with men (MSM). Regardless of HIV serostatus, this may hinder health care providers from considering invasive amebiasis high in the list of differential diagnosis when HIV-infected patients present with symptoms of amebic colitis or abscesses that are difficult to be differentiated from other competing causes of colitis or liver abscess. Although the spectrum of amebiasis is similar between HIV-infected patients and the general population, the amebiasis-related mortality rate is low in developed countries where HIV-infected MSM have long been recognized as a high risk group for amebiasis. In the two largest case series of invasive amebiasis in HIVinfected men in Taiwan and Japan, Hung and others and Watanabe and others retrospectively reviewed 67 and 170 cases of invasive amebiasis, respectively, and the amebiasisrelated mortality rate was 0% and 1.2%, respectively, despite a high percentage of amebic abscess and complications. Recent studies that report cases of invasive amebiasis in MSM and bisexuals in other developed countries and a higher frequency of amebiasis, detected by specific antigen assays for E. histolytica and serologies, in both developed and developing countries should raise concerns and warrant reevaluation of amebiasis in patients with HIV infection, especially in MSM.