What is the global prevalence of amebiasis?

Updated: Jul 19, 2019
  • Author: Vinod K Dhawan, MD, FACP, FRCPC, FIDSA; Chief Editor: Michael Stuart Bronze, MD  more...
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Worldwide, approximately 50 million cases of invasive E histolytica disease occur each year, resulting in as many as 100,000 deaths. This represents the tip of the iceberg because only 10%-20% of infected individuals become symptomatic. [23, 24, 25] The incidence of amebiasis is higher in developing countries. [26] Amebiasis is the second leading cause of death due to parasitic diseases, killing about 40,000-100,000 people per year globally. [27]

Earlier estimates of E histolytica infection, based on examination of stool for ova and parasites, are inaccurate, because this test cannot differentiate E histolytica from E dispar and E moshkovskii. In developing countries, the prevalence of E histolytica, as determined by enzyme-linked immunosorbent assay (ELISA) or polymerase chain reaction (PCR) assay of stool from asymptomatic persons, ranges from 1% to 21%. On the basis of current techniques, it is estimated that 500 million people with Entamoeba infection are colonized by E dispar. [17]

The prevalence of Entamoeba infection is as high as 50% in areas of Central and South America, Africa, and Asia. [28] E histolytica seroprevalence studies in Mexico revealed that more than 8% of the population were positive. [29] In endemic areas, as many as 25% of patients may be carrying antibodies to E histolytica as a result of prior infections, which may be largely asymptomatic. The prevalence of asymptomatic E histolytica infections seem to be region-dependent; in Brazil, for example, it may be as high as 11%.

In Egypt, 38% of individuals presenting with acute diarrhea to an outpatient clinic were found to have amebic colitis. [4] A study in Bangladesh indicated that preschool children experienced 0.09 episodes of E histolytica -associated diarrhea and 0.03 episodes of amebic dysentery each year. In Hue City, Vietnam, the annual incidence of amebic liver abscess was reported to be 21 cases per 100,000 inhabitants. [30]

An epidemiologic study in Mexico City reported that 9% of the population was infected with E histolytica in the 5-year to 10-year period preceding the study. Various factors, such as poor education, poverty, overcrowding, contaminated water supply, and unsanitary conditions, contributed to fecal-oral transmission.

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