温帯気候国における暖地性寄生虫の侵入

Long-term changes in weather conditions on Earth have a significant impact on the world around us. These include not only increasingly extreme weather events such as droughts and heatwaves. These effects can be felt throughout the natural environment, influencing the spread of parasites and the diseases they transmit. Climate change can alter the range and life cycles of parasites, and accelerate and lengthen the activity period of vectors. Four species are described in this manuscript: Balamuthia mandrillaris, Naegleria fowleri, Trypanosoma cruzi and Strongyloides stercoralis. Balamuthia mandrillaris is a species of an opportunistic cyst-forming free-living amoeba. The main habitat is moist soil and freshwater reservoirs. It could be pathogenic to humans. The amoeba consumes cutaneous tissue and excretes enzymes leading to an immune response of the host. Naegleria fowleri is a free-living amoeba that might cause primary amoebic meningoencephalitis (PAM) whose mortality rate reaches as much as 98%. Trophozoites enter the body through the nasal cavity while underwater. Most often cases of PAM include immunocompetent children and young adults. Trypanosoma cruzi is a flagellate protozoan with life cycle between hematophagous insects of the Triatominae subfamily and various mammal species including human. Trypanosoma cruzi causes the Chagas disease (American trypanosomiasis). Strongyloidiasis, caused by the parasite Strongyloides stercoralis, is a neglected tropical disease (NTD). Infection starts when the host walks barefoot on soil contaminated with filariform larvae that penetrate the skin. Immunosuppression in infected patients can lead to hiperinfection and death.