アメーバ赤痢の多様な病態を規定する外的・内的要因について

抄録

Amebic dysentery, caused by the protozoan Entamoeba histolytica, is a serious intestinal parasitic disease associated with a high mortality, second only to that associated with malaria among parasitic infections globally. This disease is marked by severe intestinal symptoms, including bloody diarrhea, which can lead to fatal dehydration, particularly in young children in under-resourced areas. Japan has reported a rise in the number of cases of amebic dysentery, partly due to transmission via sexual contact, changing the traditional perception that amoebiasis is a travel-related infection. Despite its inclusion in mandatory infectious disease reporting, the level of awareness among medical practitioners and limitations of the diagnostic methods available remain challenges, and fatalities are still reported. This paper reviews the diverse pathogenetic mechanisms, including internal (pathogen-related) and external (microbiota-related) pathogenic factors, that contribute to disease progression and persistence of E. histolytica. The cyst-trophozoite lifecycle is described, alongside modes of transmission and resistance mechanisms that enable the parasite to survive passage through the gastric environment and establish itself in the colon. In addition, recent insights into the complex interactions between E. histolytica and the gut microbiota have revealed a modulation of the pathogenesis, suggesting that alterations in the microbiota composition can have an impact on the response of the parasite to oxidative stress. Further research into the relationship between E. histolytica and gut microbiota could pave the way for innovative therapeutic strategies, offering potential advancements in infection control and sustained prevention efforts.