Tissue invasive nematodes II Flashcards
Threadlike, tissue-invasive roundworms transmitted by insect vectors?
Filariae
Lymphatic filarial infections transmitted by mosquitos
Wuchereria bancrofti
Brugia malayi
Nematode infection transmitted by Chrysops (deer) flies
Loa Loa (eyeworm)
Adult worms live in tissue nodules and are transmitted by blackflies
Onchocerca volvulus (river blindness)
Treatment of both lymphatic filariasis and loa loa
DEC
Drugs to avoid in eye worm infections with high microfiliaria blood levels
DEC and Ivermectin
Treatment for Onchocerciasis
Ivermectin
Filarial infection with no known non-human reservoir
Wuchereria bancrofti
Range of lymphatic filariasis
W. Bancrofti tropics worldwide
B. spp. Asia
4 Clinical manifestations of Lymphatic filariasis
Asymptomatic microfilaremia
Lymphangitis
Lymphatic obstruction
Tropical pulmonary eosinophilia
What is unique about filarial lymphangitis?
Retrograde
What causes paroxysmal nocturnal asthma, pulmonary infiltrates, peripheral eosinophilia, elevated serum IgE, and high filarial antibody titers?
Tropical pulmonary eosinophilia
When do blood levels of lymphatic microfilariae peak?
Midnight
coincides with mosquito biting activity
Methods of definitively diagnosing lymphatic filariasis
ID microfilariae in nighttime blood
Detect circulating W. bancrofti antigen
ID adult worm by biopsy or US
Edema and lymphatic drainage problems necessitates aggressive topical treatment in lymphatic filariasis to prevent what?
bacterial skin infections
Where is onchocerciasis volvulus endemic?
Along rivers in equatorial Africa and central America
Adult worms dwell in subcutaneous nodules for 10-15 years
Onchocercaisis volvulus
Clinical manifestations of Onchocerciasis infection?
Skin-nodules, pruritis, rash, depigmentation
Eye-keratitis, chorioretinitis
Hanging groin, elephantiasis
What are the two methods of diagnosing Onchocerciasis?
Serology (anti-filiarial or oncho. specific)
Parasitologic (skin snips or nodulectomy)
What is the mechanism of action of Ivermectin?
paralyses worms by opening ion-gated Cl- channels
What drugs must be used together to eradicate an Onchocerca infection?
Ivermectin -kills microfilariae
Doxycycline -kills Wolbachia brachtig
Calabar swellings suggest infection with what?
Loa loa
Where are adult loa worms found?
Subcutaneous tissue
When should you look for microfilariae in blood to diagnose eye worm?
Noon
correlated to Deer fly activity
If a patient with loa loa fails DEC what is the back up?
Albendazole
What’s the most common cause of eosinophilic meningitis?
Angiostrongylus cantonensis
rat lungworm
What state has the highest incidence of Angiostrongylus infections?
Hawaii
Symptoms of Angiostrongylus infection?
Headache Paresthesias Stiff neck Photophobia rare: fever
Findings of eosinophilia, leukocytosis, increase in muscle enzymes and IgE, and a muscle biopsy showing L1 Larvae
Trichinellosis
What causes visual and ocular larva migraines in 2-5 year olds and 10-15 year olds, respectively?
Toxocara canis and catis
Worm that buries into gastric mucosa causing pain and an allergic reaction?
Anisakis simplex