Topic overview

Start with the big picture

Illness ranges from self-limited diarrhea to prolonged, severe disease, particularly in people with advanced immunosuppression. Common features include watery diarrhea, abdominal cramps, nausea, fever, and weight loss; dehydration and electrolyte loss may complicate illness. Diagnosis commonly relies on stool PCR or antigen testing, with microscopy as another option and repeat sampling sometimes useful. Care includes rehydration and, in selected patients, antiparasitic treatment; in people with HIV, optimizing antiretroviral therapy is central. Prevention focuses on safer water and food practices, hand hygiene, and limiting transmission around swimming. The full lesson places these decisions in context, including risk groups, complications, special populations, and public-health considerations.