Gardiasis presentation
description
Transcript of Gardiasis presentation
GARDIASISPRESENTED TO :
DR SHAKIRA SADIQ GILLPRESENTED BY :
Abdul Wajid 2012-mphil- 2180department epidemiology and
public health
Contents
Introduction and etiology Epidemiology transmission Who is at Risk? Signs & symptoms Incubation period Life cycle Diagnosis Differential diagnosis Treatment Prevention
Introduction and etiology Giardiasis is a diarrheal illness caused by Giardia intestinalis (also
known as Giardia lamblia)
The parasite is passed in the stool of an infected person or animal (both cysts & trophozoites)
The motile ,vegetative tropozpite is 10-20µm long and 8-15µm wide.
The parasite is protected by an outer shell that allows it to survive outside the body and in the environment for long periods of time
During the past 2 decades, one of the most common causes of waterborne disease (drinking and recreational) in humans in the United States
Very contagious
Epidemiology Giardiasis is a global disease.
It infects nearly 2% of adults and 6% to 8% of children in developed countries worldwide.
Nearly 33% of people in developing countries have had giardiasis.
In the United States, Giardia infection is the most common intestinal parasitic disease affecting humans
G. intestinalis has high prevalence rates particularly among young children in third world countries.
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In tropical areas , about 50-80% of people are carriers.
The variable occurrence in distinct groups of the population is apparently related to certain nutritional conditions.
Latin america is about 200 million, with some 500,000 new infections per year.
In humans,giardiasis is one of the the most common intestinal parasitoses in western industrialized countries.
Geographical distribution of Giardia
Worldwide.
More prevalent in warmer climates and in
young age animals and humans.
Infection occurs mostly in areas of low
sanitation standards and all the day care centers.
Who is at risk?EveryonePersons at increased risk include:
child care workerschildren who attend day care centers international travelershikers, campers, swimmerspeople drinking or accidentally swallowing
untreated water
Symptoms Symptoms include
diarrhea loose or watery stool foul-smelling stool stomach cramps upset stomach weight loss dehydration
Some may be asymptomatic
Giardiasis
Host examples Humans Cats, dogs Cows, lamb Beavers, deer
Manifest in 7-10 days Lasts 2- 6 weeks Symptoms
Severe diarrhea Abdominal cramps Bloating Flatulence Nausea Vomiting
May lead to Weight loss Dehydration
Common Chronicvs.
• More severe condition
• Lasts 2 months - years
• Symptoms– Increased gas– Dehydration– Burping– Loose stools– Slowed growth
Incubation Period & Duration
Incubation period Symptoms generally begin 1-2 weeks after
being infected
Duration Healthy persons, symptoms may last 2-6 weeks
Transmission Giardiasis is passed via the face- oral route.
Primary routes are personal contact and contaminated water and food.
people who have contact with individuals already infected.
It is a particular danger to people hiking or backpacking in wilderness areas worldwide, especially if they have no immediate access to medical supplies.
Transmission and Life cycle of Giardia
Life Cycle (Pectoral representation)
Life cycle Cysts are resistant forms and are responsible for
transmission of giardiasis. Both cysts and trophozoites can be found in the feaces (diagnostic stages) .
The cysts are hardy and can survive several months in cold water. Infection occurs by the ingestion of cysts in contaminated water, food, or by the fecal-oral route (hands or fomites) .
In the small intestine, excystation releases trophozoites (each cyst produces two trophozoites) .
o Trophozoites multiply by longitudinal binary fission, remaining in the lumen of the proximal small bowel where they can be free or attached to the mucosa by a ventral sucking disk
o Encystation occurs as the parasites transit toward the colon. The cyst is the stage found most commonly in no diarrheal feces .
o Because the cysts are infectious when passed in the stool or shortly afterward, person-to-person transmission is possible. While animals are infected with Giardia, their importance as a reservoir is unclear.
Zoonotic Aspects of Giardia
Giardia lamblia which parasitize humans belong to either of two genotypes, A or B,
These two genotypes also were found in cysts from fecal samples of animal origin such as dogs, cats, some farm animals and wild animals.
In addition, trophozoites recovered from cysts obtained from environmental samples belonged to these two genotypes as well, suggesting that the G. lamblia genotypes A and B are widespread and possibly zoonotic.
Diagnosis
Fecal immunoassays that are more sensitive and specific should be used.
Rapid immune-chromatographic cartridge assays also are available but should not take the place of routine ova and parasite examination.
PCR (e.g.,polymerase chain reaction) can be used to identify the subtypes of Giardia.
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• Giardia should be identified 50 to 70% of the time after one stool, and 90% identification after three stools
• Biopsy tissue/duodenal aspirate stained by trichrome or Giemsa stain.
• Enzyme immunoassay and fluorescent-anitbody monoclonal antigen detection systems
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Giardia is also suspected to be zoonotic communicable between humans and other animals.
Major reservoir hosts include Dogs
Cats
horses
humans
cattle and birds
DIFFERENTIAL DIAGNOSISGiardiasis must be differentiated from:
Bacterial diarrhoea, Amoebic diarrhoea, Salmonellosis Viral gastroenteritis.
Giardia – Zoonotic transmission?
Treatment
Several prescription drugs are available metronidazoleTinidazoleNitazoxanide.
Alternatives to these medications include paromomycin, quinacrine, and furazolidone.
Young children & pregnant women may be more susceptible Drink plenty of fluids while ill
PreventionPractice good hygiene
Wash hands properly with soap and waterafter using the toilet before handling or eating food after every diaper change
Protect others by not swimming if experiencing diarrhea
Continued… Avoid food that might be contaminated
Wash and/or peel all raw vegetables and fruits before eating
Use uncontaminated water to wash all food that is to be eaten raw
Avoid eating uncooked foods when traveling in countries with minimal water treatment and sanitation systems
Refrences http://www.cdc.gov/parasites/giardia/gen_info/index.html http://ideas.health.vic.gov.au/diseases/Giardiasis-
facts.asp http://www.stanford.edu/class/humbio103/
ParaSites2006/Giardiasis/epidemiology.htm http://www.uptodate.com/contents/epidemiology-clinical-
manifestations-and-diagnosis-of-giardiasis