1. Giardia duodenalis or lamblia
By Kamran Ahmed

2. Introduction Unicellular, eukaryotic, protozoan flagellate
Transmitted by fecal-oral route
Lives in small intestine
Symptoms include diarrhea, nausea, abdominal cramps, and weight loss

3. Discovery
1681 – Anton van Leeuwenhoek first observed trophozoites in his own diarrheal stools.
1859 – Vilem Dusan Lambl did more extensive research and parasite came to be named after him.
Scientific community did not realize that Giardia was cause of diarrhea outbreaks until the 1970’s when it started appearing in southern California. Until that time, they had thought Giardia was a harmless inhabitant of the intestines.

4. Opening section of Leeuwenhoek’s letter describing discovery of Giardia. This is letter No. 66 in the Leeuwenhoek archive of the Royal Society of London addressed to Robert Hooke dated November 4, 1681.
Vilem Dusan Lambl
Anton van Leeuwenhoek

5. Spreading Giardia Drinking from mountain streams on hikes
Spread Giardia Stop spread of Giardia
Drinking from mountain streams on hikes
Not washing hands
Swimming in contaminated lakes or rivers
Contaminating other streams with canteens
Day cares
Worldwide problem
Boiling water
Washing hands
Using Giardia water filters

6. Movements or Migrations that Increase Prevalence
Wars (P.O.W. Camps)
Traveling to undeveloped countries (Traveler’s Diarrhea)

7. Infrastructure Wastewater irrigation Free-roaming cattle
Wells exposed to run-off

8. Health Care Response
Treatment – metronidazole (oral pill taken for 5-10 days)
Side-effects – nausea, dizziness, headache
Mostly endemic in unsanitary areas

9. Anthropogenic Effects
Sewer systems decrease prevalence
Keeping animals away from sources of drinking water reduces water contamination – urbanization or better ranching techniques.