弓形蟲感染症簡介

Toxoplasmosis

弓形蟲普遍存在世界大多數地區。它可以感染大部分溫血動物。貓科動物是弓形蟲的最終宿主。人類感染經由下列三種方式之一：食入未煮熟已遭弓形蟲組織囊腫感染的動物肉類；食入受貓糞污染的水或泥土中弓形蟲卵囊；或經由先天性胎盤傳遞（從在懷孕期間感染弓形蟲的母親傳遞給胎兒）。免疫力正常的入感染弓形蟲通常沒有症狀。但有少數患者出現急性感染表現出淋巴結腫大，倦怠，衰弱，中度發燒（38-38.5°C），甚至眼部疾病。然而，免疫功能低下的人感染弓形蟲如果沒有治療將可能引起致命腦炎。每年通報到台灣疾管局的弓形蟲病病例個案數，根據Wallace在1976年對台灣弓形蟲感染的血清學調查來看，被嚴重低估了。我們希望這篇文章可以提醒所有醫師記住這個非罕見疾病。

Toxoplasma gondii, a protozoan that is widespread in most areas of the world, infects most of the warm-blooded animals. The cat species is the final host of T. gondii. Humans acquire T. gondii infection through one of the following 3 routes: ingestion of T. gondii tissue cysts present in the undercooked meat of infected animals; ingestion of oocysts present in the water, exposure to soil contaminated with infected cat feces; or congenital transplacental transmission (from mothers who become infected during pregnancy and pass the infection to the fetus). Immunocompetent people with T. gondii infection are usually asymptomatic. However, few patients with acute infection develop swollen lymph nodes, malaise, weakness, moderate fever (38-38.5 °C ) , and even ocular disease. Immunocompromised people infected with T. gondii develop fatal encephalitis if left untreated. The annual number of toxoplasmosis cases reported in the Centre for Disease Control (CDC) in Taiwan are severely underestimated according to Wallace’s serological evaluation (1969). We hope that this article on toxoplasmosis will enable all physicians to be aware of the existence of this common disease.