COMPENDIUM ON FUNCTIONAL MEDICINE - Flipbook - Page 262
● Primary route: Ingestion of Giardia cysts in contaminated
water
● Secondary routes:
○ Unwashed produce irrigated with contaminated water
○ Person-to-person contact in daycare centers and
households
○ Recreational water exposure (swimming pools, lakes,
rivers)
○ Rare transmission from pets, particularly dogs
Clinical Significance: Causes giardiasis, characterized by diarrhea,
abdominal cramping, nausea, and malabsorption.
Unique Features: Forms resistant cysts that can survive chlorination
and environmental exposure for months.
Cryptosporidium parvum
Prevalence: Responsible for approximately 748,000 cases annually
in the United States [7].
Transmission Mechanisms:
● Primary route: Ingestion of Cryptosporidium oocysts from
contaminated water sources
● Secondary routes:
○ Recreational water facilities (extremely
chlorine-resistant)
○ Person-to-person contact in healthcare and childcare
settings
○ Contact with infected livestock, particularly calves
○ Consumption of contaminated raw produce
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