Tissue Invasive Nematodes Flashcards Preview

Final Multisystems Microbiology > Tissue Invasive Nematodes > Flashcards

Flashcards in Tissue Invasive Nematodes Deck (39)
Loading flashcards...

How do we get Trichinella Spiralis?

Undercooked meat will give us this intestinal nematode


Discuss the pathology and symptoms of Trichinella Spiralis

Sx: fever, vomiting, muscle pain/myalgia , abdominal cramps, periorbital edema, myocarditis, encephalitis, pneumonia

Path: larvae ingested → mature in intestine→ larvae shed into blood stream → deposit in striated muscle as new cysts (also in brain and heart)


Discuss the lab values and how we diagnose Trichinella Spiralis

Labs: Eosinophilia
Dx: muscle biopsy (often insensitive); serology


Treatment for Trichinella Spiralis?

Tx:Albendazole (disrupts microtubules)


Discuss the pathology of Strongyloides stercoralis

intestinal nematode: (hookworm)
foot (skin)-- blood --lungs -- gi-- feces
eggs laid in intestinal wall repenetrate and enter blood stream
intestinal nematode: (hookworm)
foot (skin)-- blood --lungs -- gi-- feces
eggs laid in intestinal wall repenetrate and enter blood stream


How does Strongyloides present?

sx: diarrhea, bloating


Discuss the diagnosis and treatment for strongyloides

dx: larvae in stool
tx: Albendazole , ivermectin; steroids contraindicated


Pathology and presentation of Enterobius vermicularis

intestinal nematode: (pinworm)
ingestion of pinworm eggs, by hands, food, or water
sx: itching in the anal area where eggs are lain


How to diagnose and treat enterobius vermicularis

dz: eggs on scotch-tape test
tx: Albendazole


What the hell is Angiostrongylius cantonensis? Where do we get it from?

tissue trematode: (rat lungworm)

most common cause of eosinophilic meningitis worldwide

source: ingesting infected snails or slugs, prawns or crabs (paratenic hosts), or (snail) contaminated vegetables

Found in SE Asia and Caribean


Discuss the pathology and presentation of Angiostrongylius cantonensis

In rats, adults develop in 2-3 weeks and migrate from brain surface to pulmonary arteries through venous system
In humans, adults develop and cause meningitis 1-2 weeks post infection


How do we diagnose and treat Angiostringylius cantonensis?

Dx: CSF eosinophilia + meningitis + exposure history

Tx: corticosteroids may help


Three presentation types of Filariasis

threadlike worms coming out of skin

Lymphatic filariasis (Wuchereria bancrofti and Brugia malayi)can be asymptomatic or cause lymphangitis ( acute filarial lymphangitis is inflammatory nodule with descending lymphangitis due to adult worms. Can cause dermatolymphngioadenitis (acute dermatolymphangioadenitis is ascending bacterial cellulits /lymphangitis). Can also cause lymphatic obstruction (lymphedema, elephantiasis, hydrocele)

pulmonary eosinophilia which manifests as paroxysmal nocturnal asthma, pulmonary infiltrates


Discuss source and labs we see for filariasis in general

abs: blood eosinophilia, IgE elevation, and/ or filarial antibody titers
Source: spread by black flies (Simulium type) and mosquitoes.


Treatment of Filariasis

Tx: elevation, hygiene, foot care, cutaneous fungal infections/ bacterial infections


Discuss the source and location for Wuchereria

source: mosquito
lavae introduced to skin -- invades lymphatics-- blood
location: found in tropics


Discuss the disease progression of Wucheria bancrofti

Dz: Chronic Lymphatic filariasis → elephantiasis; also cough from filariasis in lungs
granulomas obstruct the lymphatic system → lymphedema


How do we diagnose and treat Wucheria bancrofti?

Dx: see microfilariae in nightime blood smear, or detection of antigen, or adult worm (biopsy or U/S)
tx: diethylcarbamazine (DEC)


Discuss the source and pathogenesis of onchocerca volvulus

source: blackfly
location: Africa, Americas
larvae introduced to skin-- adults mate in subcutaneous fat layer of the skin-- microfila enter lymph and blood -- accumulate in skin and eye


Sympoms for onchocerca volvulus

dz: Subcutaneous filariasis and river blindness
sx: nodules under the skin, hyper/hypopigmented spots, severe itching, hanging groin, and blindness (begins as punctate keratitis)


Discuss the diagnosis and treatment for onchocerca volvulus

dx: microfilariae on microscopy of skin punch biopsy, serology, nodulectomy
tx: ivermectin


Discuss Loaloa

“african eyeworm”
Vector: deer fly
host: human only (no reservoir)
blood borne microfilariae
adult worms live in subcutaneous tissue
found in Africa


Symptoms for Loa loa

Sx: may be asymptomatic, non-specific (fatigue, urticaria, arthralgia, myalgia)
subcutaneous angioedematous swelling (calabar swelling), eyeworm (does not cause blindness)


Diagnosis and treatment for Loa loa

Dx: ID adult worm in conjunctiva, microfilaria seen in noon blood smear, or clinical picture + antifilarial antibodies


What causes heartworm?

Dirofilaria Immitis (Heartworm)


What type of bug is Toxocariasis and how do we get it?

tissue nematodes
Humans acquire infection by ingestion of eggs in dog/cat feces. Larvae hatch in intestine and travel to liver, spleen, lungs, brain, and/ or eye


Symptoms of Toxocriasis

Sx: visceral larva migrans in 2-5 y.o.: fever, eosinophilia, hepatomegaly, wheezing, pneumonia, splenomegaly
10-15 y.o.: ocular larva migrans- retinal lesions that appear as solid tumors near macula (can cause blindness)


Diagnosing and treating Toxocariasis

Dx: clinical picture + serology
Tx: self-limited or albendazole for acute


Typical clinical vignette for Toxocariasis

kid in sandbox with dogs


Source and pathogenesis for Anisalkis simplex

tissue nematodes
source: ingestion of raw or undercooked seafood (worldwide but many cases in Japan and Spain)
Inhabits stomach of final host. The parasite will bury head in gastric mucosa causing intra-abdominal abscess. Worm eventually dies.