County of Los Angeles
Department of Public Health
Acute Communicable Disease Control
313 N. Figueroa Street, #212
Los Angeles, CA 90012
Phone: (213) 240-7941
Fax: (213) 482-4856
Giardiasis is an intestinal infection caused by the zoonotic protozoan parasite
Giardia intestinalis (previously G. lamblia). Giardia cysts shed in animal or human
feces may contaminate food or drinking water or be transferred on hands or fomites;
recreational waters such as lakes and pools may also serve as vehicles of transmission.
Incubation can range from 3–25 days or longer, but the median incubation time is 7–10
days. While usually asymptomatic, symptoms can include sulfurous burps, chronic
diarrhea, frequent loose and pale greasy stools, bloating, cramps, fatigue, and
weight loss. Complications are rare, but may include malabsorption of fats and
fatsoluble vitamins. Children in day care represent a reservoir of disease in developed
countries. There is no vaccine.
Public Health has made reasonable efforts to provide accurate translation. However, no computerized translation is perfect and is not intended to replace traditional translation methods. If questions arise concerning the accuracy of the information, please refer to the English edition of the website, which is the official version.