Extra-intestinal and long term consequences of Giardia duodenalis infections
摘要
Giardiasis is the most common waterborne parasitic infection of the human intestine worldwide.The etiological agent,Giardia duodenalis(syn.G.intestinalis,G.lamblia),is a flagellated,binucleated protozoan parasite which infects a wide array of mammalian hosts.Human giardiasis is a true cosmopolitan pathogen,with highest prevalence in developing countries.Giardiasis can present with a broad range of clinical manifestations from asymptomatic,to acute or chronic diarrheal disease associated with abdominal pain and nausea.Most infections are self-limiting,although re-infection and chronic infection can occur.Recent evidence indicating that Giardia may cause chronic post-infectious gastrointestinal complications have made it a topic of intense research.The causes of the post-infectious clinical manifestations due to Giardia,even after complete elimination of the parasite,remain obscure.This review offers a state-of-the-art discussion on the long-term consequences of Giardia infections,from extra-intestinal manifestations,growth and cognitive deficiencies,to post-infectious irritable bowel syndrome.The discussion also sheds light on some of the novel mechanisms recently implicated in the production of these postinfectious manifestations.