giardiaasiin

Giardiasis, also known as Giardia lamblia infection, is a diarrheal illness caused by the flagellated protozoan Giardia lamblia (also called Giardia intestinalis or Giardia duodenalis). The parasite colonizes the upper small intestine and can cause a range of symptoms from none to severe.

Transmission occurs by ingesting cysts in contaminated water, food, or through the fecal-oral route. Cysts can persist in the environment, and outbreaks are common in places with poor sanitation, among hikers using untreated water, and in institutions with close contact among individuals. Zoonotic transmission from animals to humans is possible, and asymptomatic carriers can contribute to spread.

Symptoms, when present, typically begin days to weeks after exposure and may include diarrhea (sometimes greasy or fatty), abdominal cramps, bloating, nausea, and weight loss. Some people, especially children, may experience fatigue or dehydration. Many infections are asymptomatic or result in mild, self-limited illness, but chronic infection can contribute to malnutrition and growth disturbances in children.

Diagnosis relies on laboratory testing of stool samples. Stool microscopy for Giardia, stool antigen tests, and molecular methods such as PCR are used; multiple samples may be required for detection. Endoscopy is rarely necessary.

Treatment involves prescription antiparasitic medications, with commonly used options including metronidazole, tinidazole, or nitazoxanide. Adequate hydration and electrolyte replacement are important. Infected individuals should avoid spreading the parasite during treatment and practice good hygiene.

Prevention focuses on safe drinking water, water treatment and filtration, thorough handwashing, food safety, and proper sanitation to reduce transmission.