Strongyloidea, Rhabditoidea, Trichuroidea Flashcards
Ancylostoma caninum
Deep buccal capsule, 3 pairs of teeth, larvae can develop under 2 days, can infect by ingestion of infective larvae, percutaneously, transmammary, or leak back. PPP can be as short as 2 weeks. Canlead to anemia or edema.
What happens when the larvae are ingested for A. caninum?
They undergo somatic migration until arrested in the tissues or mucosal migration until they are adults in the small intestine. They could also undergo tracheal migration until they are adults in the small intestine. When they are adults they shed eggs as morulas in the feces. It takes a week until the eggs hatch and become infective in the environment.
What happens in percutaneous infection for A. caninum?
They penetrate the skin from the environment, undergo somatic migration or tracheal migration until they are adults.
What happens in transmammary infection for A. caninum?
The larvae start from encysted in the tissues. They are then reactivated and shed in the milk which the pups ingest.
What happens in leak back for A. caninum?
The larvae start from encysted in the tissues. They are reactivated and go to the intestine where they mature. The leak back happens in stress, during pregnancy, prolonged boarding, or greyhounds.
Ancylostoma tubaeforme
Cats. Infective third stage larvae can infect via oral or skin penetration. Rodents can be PH and no transp/transm or leak back. Can lead to anemis and edema.
Uncinaria stenocephala
Oral route with mucosal migration. No prenatal or transmammary. Graze on villi. Mildly pathogenic.
How to treat Ancylostoma?
Anthelmintics, check in a month for reinfection.
Can you reduce A. spp infection by transp/m?
Yes, fenbendazole or ivermectin. Non FDA aproved
How do you control A. spp?
Sodium borate, Clorox, remove feces daily
Is A. caninum and braziliense zoonotic? How?
Yes, Cutaneous Larval Migrans. Penetrate skin and migrate through tissues. Caninum has papular and pustular infections, braziliense has serpentine pruritic tracts. Occurs in SE or Gulf Coast.
What are other effects of A. spp on humans?
Eosinophilic enteritis, poorly adapted to human hosts.
Strongyloides stercoralis
Intestinal threadworm, unique because have free living and parasitic ones. Parasitic males don’t exist. Females reproduce by mitotic parthenogenesis. Live in small intestine. Larvated eggs hatch before leaving animal!!
What happens to the S. stercoralis larvae once it is in the feces?
Can molt to become free living or molt to become infective filariform larva. The infective ones penetrate skin or oral mucosa from soil and migrate to the lungs, go through the bronchial tree until get to the pharynx, and are swallowed.
What is unique about the larvae in S. stercoralis?
Can become infective in the small intestine and cause autoinfection. Favoured if dog is on corticosteroids or neonatal. Recognized by genital primordium.
