Giardia Duodenalis Ashley Tharayil

Domain-- Eukarya Single or multi cellular organisms Have nuclei and sub divisions inside cell

Kingdom--Protista Most are one cell

Phylum--Protozoa Chiefly motile heterotrophic

Class--Sacromastigophora “mastigo”— “whip or flagella” “phor”– “carry or bear”

Order--Diplomonadida “Di” “Diplo”– “two” Bilaterally symmetrical Two nuclei

Have six or eight flagella Family--Hexamitidae “Hexa”— “six” Have six or eight flagella

Giardia duodenalis Domain--Eukarya Kingdom- Protista Phylum- Protozoa Class: Sarcomastigophora Order: Diplomonadida Family: Hexamitidae Genus: Giardia Species: duodenale

Introduction Commonly transmitted through impure water sources Gives rise to serious diarrhea “Giardiosis” Also, called “back packers diarrhea” and “beaver fever”

Hosts Early experiments suggested narrow host range… Then in 1970, cross transmission between Russian workers and dogs.. Now,known to naturally infect—humans, cats, dogs, beaver, coyote and cattle and can experimentally infect a number of species of rodents and other mammals.

Morphology I. General description: Two nuclei Flagellated protozoa II. Adult parasite— “Trophozoite” “feeding stage” measures about 18 um long X 5 -10 um wide. It has6- 8 flagella and the ventral side is modified as a sucking disk

Morphology.. contin III. Cyst Stage Inactive stage The cysts average about 13 µm in length, are oval, and also contain two nuclei like the trophozoites.  

Life Cycle Cysts released through feces Infection occurs by the ingestion of cysts in contaminated water, food, or by the fecal-oral route In the small intestine, excystation releases trophozoites (each cyst produces two trophozoites) Trophozoites multiply by binary fission Encystation occurs as the parasites transit toward the colon. 

Where is it found? Anywhere with poor water sanitation All over the world.. Particularly in regions w/ warm climates Estimate 7% of North America is infested The most common flagellate of the human digestive tract. Most common waterborne illness in United States  (100,000 to 1 million infections annually)  

Aspen spring, Colorado Old sewer pipes leaked sewage into a well serving one part of the town. At least 25 people suffered from Giardiosis.

Symptoms.. Onset.. etc Onset delayed 5-25 days after exposure Diarrhea illness persists 1-3 weeks Abdominal pain and cramping Belching Weight loss * Sometimes infections don’t show any symptoms

Diagnosis Observing symptoms Finding motile trophozoites in a fresh fecal smear Finding cysts in feces by concentration technique

Drugs Quinacrine – recommended by CDC, but bad for kids Metronidazole – most popular worldwide, but mildly carcinogenic. Furazolidone – more child-friendly drug

Epidemiology and Control Personal health Treatment of drinking water to remove/kill cysts Avoid contaminated water Sanitary procedures to avoid contact w/ cysts Surveillance and treatment of companion animals in household

Epidemiology and Control Public Health Sewage treatment Adequate treating of drinking water Surveillance and treatment of food handlers

The End.. Marquardt, William, Richard Demaree, and Robert Grieve. Parasitology Vector Biology. 2nd ed. San Diego, California: ACADEMIC PRESS, 2000. Garcia, Lynne. Diagnostic Medical Parasitiology . 4th. Washington D.C.: ASM, 2001.

"Giardiasis. " CDC. September 17, 2004 <http://www. cdc Giardiasis. Iowa State University center of Veteniary medicine. May 1,2005 <http://www.cfsph.iastate.edu/Factsheets/pdfs/giardiasis.pdf> http://64.233.187.104/search?q=cache:-9if_PJimqAJ:www.idready.org/webcast/spr05_materials/zoonotic_infections/2005-02-22/Parasites_Mycotics_Dunne.ppt+Duodenalis,+Giardia+powerpoint&hl=en&gl=us&ct=clnk&cd=5