giardiasis

Giardiasis

Giardia Enteritis
Lambliasis
Beaver Fever

Giardia

Giardia lamblia is a flagellated protozoan that infects the duodenum and small intestine.
range from asymptomatic colonization to acute or chronic diarrhea and malabsorption.
more prevalent in children

Parasite Stages

Two stages of the parasite: cyst and trophozoite
Center for Food Security and Public Health, Iowa State University, 2013

EPIDEMIOLOGY

usually occurs sporadically
major reservoir for spread :water contaminated with Giardia cysts
Giardia cysts are relatively resistant to chlorination and to ultraviolet light irradiation
Boiling is effective for inactivating cysts.
Person-to-person spread also occurs .
Human milk contains glycoconjugates and secretory IgA antibodies that may provide protection to nursing infants.

Morbidity and Mortality: Humans

Populations affected
Children
Travelers
Swimmers
Prevalence in developed countries
2% of adults
6-8% of children
Up to 15% in developing countries
Center for Food Security and Public Health, Iowa State University, 2013

Morbidity and Mortality: Humans

Naïve populations
Morbidity rate up to 20%
Infections often resolve spontaneously
Illness usually lasts for 1-2 weeks

Center for Food Security and Public Health, Iowa State University, 2013

Disease in Humans
Chronic infections reported
May last months to years
Immunodeficient and immunocompetent individuals
May contribute to decreased lifespan in immunodeficient individuals
• -May lead to malabsorption syndromes, vitamin deficiencies, severe weight loss, and debilitation

Center for Food Security and Public Health, Iowa State University, 2013

Geographic Distribution

Giardia intestinalis
Occurs worldwide
Most common in warm climates
Center for Food Security and Public Health, Iowa State University, 2013


Transmission
Cysts
Direct transmission
Fomites
Contaminated water and/or food
Ingested cysts release trophozoites
Trophozoites multiply and encyst in intestines
Excreted in feces

Center for Food Security and Public Health, Iowa State University, 2013

CLINICAL MANIFESTATIONS
incubation period :1–2 wk
clinical manifestations :asymptomatic . acute infectious diarrhea, chronic diarrhea with failure to thrive and abdominal pain or cramping.
Symptomatic infections occur more frequently in children than in adults.
Most symptomatic patients : acute diarrhea. low-grade fever, nausea, and anorexia;
intermittent or more protracted course characterized by diarrhea, abdominal distention and cramps, bloating, malaise, flatulence, nausea, anorexia, and weight loss develops

CLINICAL MANIFESTATIONS

stools may be profuse and watery and later become greasy and foul smelling
Stools do not contain blood, mucus, or fecal leukocytes
Varying degrees of malabsorption may occur.


Abnormal stool patterns may alternate with periods of constipation and normal bowel movements.
Malabsorption of sugars, fats, and fat-soluble vitamins has been well documented and may be responsible for substantial weight loss.
Giardiasis has been associated with growth stunting and repeated Giardia infections with a decrease in cognitive function in children in endemic areas.

Giardiasis should be considered in young children in child care or in any person who has had contact with an index case or a history of recent travel to an endemic area who has persistent diarrhea, intermittent diarrhea and constipation, malabsorption, crampy abdominal pain and bloating, failure to thrive, or weight loss

TREATMENT

should receive therapy :
acute diarrhea
failure to thrive
exhibit malabsorption

Treatment

Anti-protozoal drugs
Metronidazole
Tinidazole
Ornidazole
Chronic cases
May be resistant
Prolonged therapy may be necessary
Center for Food Security and Public Health, Iowa State University, 2013


PREVENTION
Handwashing
purify public water supplies adequately include chlorination and filtration.
Travelers to endemic areas are advised to avoid uncooked foods that might have been grown, washed, or prepared with water that was potentially contaminated.
Purification of drinking water can be achieved by a filter or by brisk boiling of water for at least 1 min