ALLIE CONWAY

Giardia lamblia

History of Giardia

Commonly known as: Beaver Fever, Traveler’s Diarrhea or Giardiasis.

In 1681 Antoine van Leeuwenhoek discovered Giardia while examining his own stools.

In the 1970s there was increased awareness of the disease when many visitors of the Soviet Union returned with symptoms of Giardia.

A little Giardia fun fact tidbit!

Giardia is the most common non bacterial cause of diarrhea in the United States!

What would it be like if YOU had Giardia? (including outward symptoms and incubation period)

You are jogging on a beautiful creek-side trail, when you get so thirsty, you decide to dip your hand in the cool, clear water and take a sip. (Source of infection: unfiltered, not chlorinated water)

A little more than a week later you start getting abdominal cramps and have the chills. You have explosive diarrhea, extremely foul gas, and bloating, along with nausea and vomiting. Thankfully you live alone and haven’t had to come in contact with anyone else, so you haven’t infected anyone. (Incubation period: 9-15 days)

This stage lasts for 3 or 4 days, so you decide to go to the doctor. The doctor decides to take at least 3 non consecutive stool samples from you to do an Ova and Parasite (O+P) exam. A skilled technician will examine the stool for Giardia cysts.

After they identify the Giardia in your stool, the doctor prescribes you with Tinidazole, which you have to take 3 times a day for 5-7 days.

Giardia lamblia is a protozoa

This protozoa starts out as a cyst. Once it enters your stomach it turns into a trophozoite with 2 distinct nuclei and 4 pairs of flagella.

As a cyst it is approximately 7-10 um in length and as a trophozoite it is about 12-15 um in length.

The trophozoites colonizes in the small intestine, attaching to the mucosa using ventral sucking discs.

They multiply by longitudinal binary fission

As the Giardia trophozoite moves toward the colon, it returns to cyst form and is passed in the feces.

Description of Giardia

Life Cycle of Giardia lamblia

-FLAGELLA (4 PAIRS ON THE TROPHOZOITE)

--ABILITY TO CHANGE FROM CYST TO TROPHOZOITE

--HOOKS ONTO SMALL INTESTINE BY USE OF

SUCKERS

Virulence Factors

Pathophysiology

The intestinal mucosa may be damaged by the trophozoite itself because it disrupts the epithelial brush border during attachment.

 Release of toxic substances from the trophozoite could cause damage to the intestinal epithelium.

Absorptive activities may also be blocked due to the trophozoites covering the mucosa of the intestine.

Transmission Vectors

Fecal-oral routeContaminated

waterContaminated

foodInfected people

Anyone who is infected that you come in contact with.

Able to be transmitted from animals to humans

Mode of transmission + possible vectors

Diagnostic Processes

Ova and parasite or O+P test, this is the test in which the carriers stool is examined for cysts.

Giardia antigen tests, which can detect an infection even without cysts present in the stool.

The string test: a gel capsule is swallowed and one end of a string is taped to the inside of the patients cheek, the rest of the string is inside the capsule. Once the capsule is dissolve (4-6 hrs later), the string is removed and microscopically examined for trophozoites.

Prevention Treatment

Practice thorough hand washing

Do not drink untreated water

Drink bottled water in foreign areas

Avoid raw fruits and vegetables when traveling

Avoid contact with the feces of infected people

Metronidazole

Tinidazole

Nitazoxanide

Methods of Prevention + Treatment

Number of Cases in Oregon

Why is it important to study Giardia?

Giardia is an important disease to study because it causes such intense symptoms and it is fairly common. It needs to be studied because it is a virulent protozoa and could become resistant to chlorinated treated water. People may think that they do not have Giardia because their symptoms are similar to many other diseases, like food poisoning. It needs to be treated otherwise you will keep it in your system for a long time!

Giardia lamblia in cyst form (Visual aid 1)

This is the form that Giardia takes when it enters and exits its host.

As a cyst, it travels into the body of the host and forms into a trophozoite triggered by stomach acid and bile salts.

Trophozoite form of Giardia. (Visual aid 2)

Giardia looks like it has a face in its body. The “eyes” are its two nuclei and its arms and legs are the 4 pairs of flagella.

References

Giardiasis . (n.d.). Retrieved from http://www.giardiasis.org/Index.aspx

-Found and used information about treatment, photos, diagnosis, physical characteristics and pathophysiology.

• Giardiasis . (n.d.). Retrieved from http://public.health.oregon.gov/DiseasesConditions/CommunicableDisease/DiseaseSurveillanceData/AnnualReports/arpt2011/Documents/2011_giardia.pdf

-Used for the number of cases in Oregon

• Giardia infection. (n.d.). Retrieved from http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001333/

-Used information about symptoms, photos, and transmission

Giardia. (n.d.). Retrieved from http://en.wikipedia.org/wiki/Giardia

- Used for pictures and information about history and factoids.