Official website of the Johns Hopkins Antibiotic (ABX), HIV, Diabetes, and Psychiatry Guides, powered by Unbound Medicine. Johns Hopkins Guide App for iOS, iPhone, iPad, and Android included. Explore these free sample topics:
-- The first section of this topic is shown below --
- Giardia lamblia (syn. G. duodenalis or G. intestinalis)
- Life cycle forms are: 1) highly infectious cysts; and 2) disease-causing trophozoites.
- Following excystation, trophozoites multiply and colonize the upper small intestine.
- Trophozoites with flat ventral surface adhere to brush border of enterocytes and cause malabsorption.
- Transmitted by contaminated water, food, person-to-person, and fecal-oral contact.
- Surface water is easily contaminated by cysts shed from mammalian hosts such as beaver, sheep, cattle, dogs, or cats.
- Highly contagious, low infective dose of 10 cysts.
- Occurs worldwide, specifically in settings of day care centers, over-crowded areas with poor sanitation, and outdoor recreation or swimming pools.