noun
parasitic disease; vermination
Medical term for diseases caused by parasites. 'Vermination' is a rarer, more technical synonym.
海外旅行では寄生虫症に注意が必要です。
When traveling abroad, you need to be careful about parasitic diseases.
寄生虫 means 'parasite' (the organism itself), while 寄生虫症 refers to the disease caused by parasites.
Compound of 寄生虫 (parasite) + 症 (disease, condition).