L 67 Trichinosis and Larva Migrans Flashcards Preview

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Flashcards in L 67 Trichinosis and Larva Migrans Deck (23):

Official word for roundworm



How do you get infected with trichinellosis?

Ingest the eggs or larvae from the environment that mature to adults in the intestines
Ingest raw/undercooked meat with encysted larvae (adult and encysted larvae in same host)
Pig, horse, bear, moose, boar, other mammals


How do you get infected with cutaneous or visceral larva migrans?

Visceral larva migrans: eggs or larvae ingested
Cutaneous larva migrans: larvae penetrate the skin


Infective agent of Trichinellosis

Trichinella spiralis


Where in the body do Trichinella worms go?

We eat muscle from an infected animal and the larvae mature in small intestine. Females give birth and the larvae migrate to the most active muscles in the body and encyst intracellularly where they are viable for months to years.


Clinical manifestations of Trichinellosis

Intestinal phase: nausea, diarrhea, vomiting, abdominal pain; symptoms usually abate 2-5 weeks later

Systemic phase: myalgia, facial swelling, eosinophilia, F/C, weakness, headache, cough, subungual splinter hemorrhages; heavy infections may damage the heart (life threatening), CNS, lungs, kidneys


Trichinellosis diagnosis

Myalgia, periorbital edema, eosinophilia, Hx eating pork, bear, etc.
Serological tests 3-5 weeks into infection
Muscle biopsy definitive but not required


Trichinellosis treatment

DOC: albendazole or mebendazole
Corticosteroids manage inflammation


Trichinellosis control

Careful control of pig farming techniques, meat inspection, keep mice and rats at bay
Cook well pork and other meats
Freezing will only kill in pork meat but not in bear or other meat
Salting/smoking/drying doesn't work


Larva Migrans primary hosts

These are a zoonotic infection, prefer GI of dogs, cats, and others
Humans are accidental hosts, rarely do they make it into our guts and rearely do they mature to adults


Visceral Larva Migrans infection

Ingestion of the Eggs from the soil
Ingestion of encysted larva from undercooked liver or meat


Cutaneous Larva Migrans

Soil-dwelling larvae penetrate human skin


Causative agents of Visceral Larva Migrans

Toxocara canis and T. cati


Who tends to get infected by visceral Larva Migrans?

Kids who play in soil
The eggs get into the soil from the feces of dogs and cats and other animals, eggs viable 3-4 weeks later. Prefers warm, moist, soil


VLM manifestations

Most infections are asymptomatic
14% of people are infected, but only 100 sever cases per year
Symptoms occur from the damage caused by the migrating larva and the host eosinophilic response
Invades mostly LIVER, LUNGS, but also heart, brain, and muscle
Fever, anorexia, weight loss, cough, wheezing, rashes, H/S-megally
Ocular Larva Migrans (OLM): in retina of the eye causing irreversible vision loss


Visceral Larva Migrans diagnosis

Clinical presentation, Hx, labs
Confirm with serology
Look in eye for OLM


Visceral Larva Migrans Treatment

DOC: albendazole or mebendazole


Visceral Larva Migrans prevention

Avoid undercooked meat or liver
Wash hands
Deworm pets
Dispose of pet feces in timely manner
Don't eat dirt


Cutaneous Larva Migrans also known as?

Creeping eruption


Cutaneous Larva Migrans causative agents

Ancylostoma braziliense
A. caninum
(types of hookworms)


Cutaneous Larva Migrans more commonly found where, and who?

southeastern US
Travelers, beachgoers, kids, those who frequently contact the soil


Cutaneous Larva Migrans manifestation

Signs from the inflammatory reaction along the track of the migrating larvae
Pruritic, red papules, elevated, serpiginous, reddish-brown lesions
Usually resolve in 2-8 wks without therapy


CLM treatment and prevention

DOC: ivermectin or albendazole
Antihistamines for the pruritis

Prevent contamination of environment similar to VLM
Wear shoes, avoid contacting the soil especially in tropical environments