Tissue Nematodes Flashcards
Tissue Nematodes
1) Trichinellosis
2) Lymphatic Filariasis
3) Onchocerciasis
4) Loiasis
5) Dracunculiasis
Trichinellosis worm and cause
Trichinella spiralis
Uncooked pork, bear, walrus and seal.
Trich life cycle
Ingest meat, larvae penetrate epitelial lining of small intestine and undergo 4 molts and become sexually mature adults.
They bang, newborn larvae pass through lymphatic system enter blood cystem and become encysted in striated muscle
Trich Clinical course
Biphasic:
1) intestinal phase- GI sx
2) systemic phase- 1 wk after ix, facial/periorbital edema, myalgias, fever
Trich dx
Muscle biopsy (usually due to painful myalgias), serology
Trich tx
steroids, anthelminthic drug
Human Filariases
1) lymphatic filariasis
2) onchocerciasis (river blindness)
3) loiasis (african eye worm disease)
4) Dracunculiasis (guinea worm ix)
LF causative agent
1) Wuchereria bancrofti (90% of cases)
2) Brugia malayi; Brugia timori in SE Asia
LF transmission and most infected
1) mosquito transmitted
2) chilren aquire disease early and are affected for life
LF Life cycle
Mosquito bites you, larvae enter wound, matures in lymphatics. If new microfilariae are in blood, they must get taken up by a new mosquito to enter adult phase again
LF Clinical sx
1) asymptomatic to irreversible lymphedema
2) Early: acute lymphangitis and lympadenitis, esp in young
3) TROPICAL PULMONARY EOSINOPHILIA esp in young men
4) over time: lymphadema and elephantitis of lower extremities, breast, genitalia as well as HYDROCELE and scrotal elephantitis
LF dx
Clinical suspicion ( individual in endemic region >10yo with lyphedema
or Mircrofilariae on thick blood smear- COLLECT AT NIGHT as they have nocturnal peroidicity
** w. bancrofti ICT rapid blood antigen test
or Serology shows cross reactivity with other helminths
OR U/Z of lymph nodes- aldult worm nests- Filaria dance sign
LF TX
not attempted in endemic area, but if a traveler comes back you can try repeated/prolonged tx
LF management
1) Interrupt transmission, by single dose, once yearly 2 drug regimen for 4-6 years that kills microfillarie and stuns adult worm from reproducing
2) control morbidity, releive suffering
Onchocerciasis life cycle
Transmitted by fly through skin. Not found in blood, won’t catch in a blood smear, stays in tissues/eyes
Oncho sx
Pruritis, dermatitis
onchocercomata on bony nodules (subcutaneous nodules that you can extract the worm from)
lymphadenopathy
OCULAR lesions ( sclerosing keratitis) that can progress to blindess— thus the name River Blindness
Oncho dx
Skin snips for micro visualization of micorfil, or palpable nodules
Oncho tx
Ivermectin, single dose, every 6-12 months til asymptomatic
-tx has eliminated a great deal of oncho
Loa Loa Life Cycle
“African Eye Worm”-
1) transmitted by a fly
2) micro into sub-cutaneous tissue (similar to oncho), but also gets into bloodstream (similar to LF)
Loa Loa Clinical sx
conjunctivae, CALABAR swellings ( migratory episodes of angiodema due to adult worms), microfilariae- found in the blood during the day
Loa Loa dx
Micro in blood during the day, eosinophilia, calabar swellings, and adult worms SEEN in the eye, ACK!
Loa Loa tx
DEC or Ivermectin
surgical removal of adult worms if accessibel
Drancunculiasis fun name and worm
Fiery red serpent of the Israelites/ Guinea worm infection
Dracunculus medinensis
Dranc life cycle
gets in a COPEPOD (da fuq?) and then that’s ingested, released in small intestines, penetrates sub-q layer of abdominal wall and migrates to lower extremities
