export_sst and muscle parasites and arthropods Flashcards
Three clinical presentations of leishmaniasis
Cutaneous
Mucocutaneous
Visceral
Cutaneous leishmaniasis organisms
L. major
L. tropica
L. mexicana
Cutaneous leishmaniasis presentation
Raised, dry, crusted lesions
Self-limited
Mucocutaneous leishmaniasis organisms
L. braziliensis
Mucocutaneous leishmaniasis presentation
Initially as a typical cutaneous lesion
Months/years later ulceration occurs
Onchocerca volvulus vector
Black fly
Onchocerca volvulus disease
River blindness
Onchocerca volvulus features
Filarial nematodes
Microfilariae
River blindness symptoms
Migrating and dying microfilariae induce an intense “itching” reaction
Sclerosing keratitis and blindness
Treat river blindness
Ivermectin
Mansonella spp. features
Filarial nematode
Mansonella spp. vector
Infected midge
Mansonella spp. symptoms
Most are asymptomatic
Can cause itching, edema, and joint pain
Mansonella spp. diagnosis
Observing microfilaria on blood smears
Dracunculus medinensis features
Largest tissue dwelling nematode
Dracunculus medinensis life cycle
Ingestion of infected water
Larvae penetrate intestine and travel to subcutaneous tissue
Females cause a blister, lay eggs, and release microfilariae into water
Dracunculus medinensis disease
Dracunculosis
Diagnose dracunculosis
Symptoms
“Wash out” microfilariae from ulcer
Treat dracunculosis
Wind worm out on stick
Slowly; if you break the worm, you will elicit an anaphylactic reaction
Cutaneous larval migrans causative agent
Ancylostoma (hookworms) that normally infect dogs or cats
Ancylostoma organisms that cause cutaneous larval migrans
A. braziliense
A. canium
Cutaneous larval migrans symptoms
Intense inflammatory reaction from larval secretions
Scabies causative agent
Sarcoptes scabiei
Sarcoptes scabiei features
Small, roundish, eight-legged arthropods
Scabies symptoms
Superficial dermatitis
Itching, starting at hands then progress to arms, trunk, etc.
Raised, cutaneous tracts where mites have burrowed
Scabies hyperinfection
Thousands of mites
Results in Norwegian (crusted) scabies
Crusted lesions on hands, feet, and body
Diagnose scabies
Observing adult mites at end of burrows
Treat scabies
Topical formulations to resolve infection
Treat all household members
Meticulous cleaning of clothing and linens
Lice disease
Pediculosis
Lice features
Obligate, blood-feeding (sucking) ectoparasites
Wingless, six-legged, flattened insects
Lice organisms
Pediculus humanus - body louse
Pediculus capitis - head louse
Phthirus pubis - crab louse
Head lice features
Attached to hair on head
Spreads easily
Bites localized behind ears and back of neck
Body lice features
Usually found clothing
Will move to body for a blood meal, then back to clothing
Crab lice features
Spreads via sexual contact
Inhabit the hairs of the pubic and perianal region
Nits
Eggs laid by female lice, attached to hair shafts
Diagnose lice
Identification of lice or eggs in hair or seams of garments
Treat lice
Dusts, shampoos, lotions, and creams available
Retreat a second time
Linens should be cleaned thoroughly
Myiasis causative agent
Dermatobia hominis (human botfly)
Myiasis transmission
Botfly lays eggs on mosquito
Mosquito bites you and transmits eggs into subQ
Trichinosis causative agents
Trichinella spiralis
Trichinosis disease
Infection in muscle
Trichinosis transmission
Undercooked pork, etc.
Ingestion of eggs, larvae migrate to muscle, encysts (“nurse-cell”)
Trichinosis symptoms
Early phase - intestinal problems (diarrhea, abdominal pain)
Migration phase - fever, chills, eosinophilia, muscle pain
Diagnose trichinosis
Difficult to observe
Presence of eosinophilia, elevated muscle enzyme levels, dietary history
Loiasis causative agent
Loa loa
Loiasis disease
Eye worm
Lung fluke causative agent
Paragonimus westermani
Lung fluke transmission
Ingestion of fresh water crabs or crayfish
Lung fluke symptoms
Blood-tinged sputum
Fibrotic cyst wall forms, lung abscesses can occur
“Rusty sputum”
