Short report: Amebiasis-related mortality among United States residents, 1990-2007.

Despite the endemic nature of Entamoeba histolytica infection in the United States there is a lack of data on amebiasis-related mortality. We analyzed national death certificate data from 1990 to 2007 to assess the occurrence of amebiasis-related deaths and determine demographic and regional associations. A total of 134 deaths were identified. Mortality rates were highest in males, Hispanics, Asian/Pacific Islanders, and persons 75 years of age and older. An association with human immunodeficiency virus infection was also observed. A declining trend of amebiasis deaths was noted over the 18-year study period. Over 40% of fatal amebiasis cases occurred in residents of California and Texas. United States-born persons accounted for the majority of amebiasis deaths; however, all of the fatalities in Asian/Pacific Islanders and 60% of the deaths in Hispanics were in foreign-born individuals. Although uncommon, amebiasis-related deaths routinely occur in the United States.

Public health and clinical importance of amoebiasis in Malaysia: a review.

Entamoeba histolytica, the causative agent of human amoebiasis remains a significant cause of morbidity and mortality in developing countries and is responsible for up to 100,000 deaths worldwide each year. Entamoeba dispar, morphologically indistinguishable from E. histolytica is more common in humans in many parts of the world. Similarly Entamoeba moshkovskii, which was long considered to be a free-living amoeba is also morphologically identical to E. histolytica and E. dispar, and is highly prevalent in some E. histolytica endemic countries. Humans are the host of infection and there would not appear to be other meaningful animal reservoirs of E. histolytica. Entamoeba. histolytica can be present in sewage and contaminated water. The infection is mainly transmitted via ingestion of water or food contaminated by faeces containing E. histolytica cysts. Clinical features of amoebiasis range from asymptomatic colonization to amoebic dysentery and invasive extraintestinal amoebiasis, which is manifested most commonly in the form of abscesses in liver and lungs. The epidemiology of amoebiasis has dramatically changed since the separation of E. histolytica and E. dispar species and the worldwide prevalence of these species has not been estimated until recently. Morever, E. moshkovskii, another morphologically indistinguishable human parasitic Entamoeba was not mentioned or considered as a contributor to the prevalence figures in endemic areas. Amoebiasis is still a major health problem especially in aboriginal settlements and amongst people living in remote area in Malaysia. However, until now there is only one data currently available to indicate the true prevalence and incidence of E. histolytica and E. dispar. Further studies are needed to determine the burden of E. histolytica, E. dispar and E. moshkovskii infections in Malaysia. In the present review, we briefly summarize all methods use in diagnosing Entamoeba species, ranging from microscopic identification to molecular detection such as culture and isoenzyme analysis, antibody detection tests, antigen detection tests, immunochromatographic assays, conventional PCR, real-time PCR and loop-mediated isothermal amplification (LAMP).

The immunopathogenesis of Entamoeba histolytica.

Amebiasis is the disease caused by the enteric dwelling protozoan parasite Entamoeba histolytica. The WHO considers amebiasis as one of the major health problems in developing countries; it is surpassed by only malaria and schistosomiasis for death caused by parasitic infection. E. histolytica primarily lives in the colon as a harmless commensal, but is capable of causing devastating dysentery, colitis and liver abscess. What triggers the switch to a pathogenic phenotype and the onset of disease is unknown. We are becoming increasingly aware of the complexity of the host-parasite interaction. During chronic stages of amebiasis, the host develops an immune response that is incapable of eliminating tissue resident parasites, while the parasite actively immunosuppresses the host. However, most individuals with symptomatic infections succumb only to an episode of dysentery. Why most halt invasion and a minority progress to chronic disease remains poorly understood. This review presents a current understanding of the immune processes that shape the outcome of E. histolytica infections during its different stages.

Amoebic cases at autopsy and factors that might have contributed to death at Ibadan.

Twenty-one cases of amoebiasis seen at autopsy at the University College Hospital, Ibadan, over a 10-year period are reviewed. They constituted 0.59 percent of 3,556 autopsies performed during this period. Delay in seeking medical advice and in diagnosis and commencement of appropriate therapy were some of the factors contributing to the mortality in 16 (76pc) cases. Furthermore, Chronic renal failure, Cirrhosis, Lymphoma, Pregnancy and Sickle cell disease were also contributory factors to mortality in 7 (33pc) cases. With the progressive deterioration of the economics of Nigeria, urban migration and the increasing size of urban slums with crowded unhygienic conditions, the spread of this infection may accelerate and so result in greater mortality in the future.

Problems in recognition and diagnosis of amebiasis: estimation of the global magnitude of morbidity and mortality.

Major problems with a wide array of imperfect tests for diagnosis of amebiasis severely limit the understanding of its magnitude and epidemiology. A greater hindrance is the varied, inconsistent application of existing methods in different areas of the world. The best estimates suggest that probably 480 million people were infected with Entamoeba histolytica and 36 million developed disabling colitis or extraintestinal abscesses in 1981. At least 40 thousand deaths are attributable to amebiasis, and on a global scale, amebiasis likely ranks third among parasitic causes of death, behind only malaria and schistosomiasis. Much remains to be learned of its frequency of occurrence and epidemiology as needed improved diagnostic tools are developed.