<unk>  is a common enteric infectio caused by Giardia lamblia, a flagellated protozoan parasite. It is a worldwide infection that is common in settings of poor sanitation.<unk>  may be classified based on the duration of clinical manifestations into either acute (2-4 weeks) or chronic (more than 4 weeks). Common risk factors in the development of<unk>  include recent history of hiking and camping, immunosuppression, young age (especially < 5 years of age), exposure to infected individuals, drinking unsafe water, recent sexual history with unprotected anal or oral-anal contact, and recent travel to developing countries.<unk>  usually transmitted via the fecal-oral route through personal contact and contaminated water and food.  Following transmission of Giardia, patients may remain asymptomatic for 1-3 weeks. Early symptoms typically include acute, profuse, watery diarrhea, bloating, and abdominal cramping, which are usually self-limited. If left untreated,<unk>  may persist in a small proportion of patients and subsequently results in chronic<unk> , which typically manifests with chronic diarrhea, anorexia, weight loss, malaise, and failure to thrive. Complications may be related to either severe dehydration (e.g. acute kidney injury), malabsorption (e.g. vitamin B12 deficiency), post-infectious diseases (e.g. reactive arthritis, chronic fatigue syndrome), or rarely, spread of Giardia to extraluminal sites (e.g. involvement of the gallbladder, pancreas, or eyes). The prognosis is generally excellent. Recurrence of the disease is particularly common among children even with optimal treatment. The diagnosis of<unk>  requires the detection of Giardia parasites in at least 1 out of 3 stool samples upon ova and parasite examination. Multiple stool collections (i.e., three stool specimens collected on separate days) should be performed for ova and parasite examination (O & P) to increase test sensitivity since Giardia cysts are excreted intermittently (detects approximately 80% of cases). Patients diagnosed with<unk>  require antimicrobial therapy. Medical therapy for<unk>  includes either metronidazole, albendazole or quinacrine. Furazolidone or nitazoxanide may be used in pediatric patients. Patients must be monitored for the persistence of symptoms following adequate therapy (suggestive of treatment failure) or the re-development of symptoms (recurrence). There is no vaccine against<unk> . Prophylaxis against<unk>  is not recommended. Hygiene practices (such as hand washing, drinking safe water) may help reduce the risk of Giardia transmission.
Giardiasis
Cryptosporidiosis
Enterobiasis
Cyclosporiasis
Eosinophilic gastroenteritis
Dientamoebiasis
Opisthorchiasis
Amoebiasis