T2 - Micro - Parasites 10 - Hydatids And Filarial Infections

Front 1

Hydatid disease - what organism should we think of?

Back 1

this is a tapeworm, though a smaller one - worst is Echinococcus granulosus

Front 2

life cycle of echinococcus granulosus?

Back 2

depends on dogs and herbivores.

definitive host = dog (carnivore) - dog poops out lots of eggs. sheep/cattle/goats eat eggs, get worm infection out in their muscles/intestinal tract.

animals slaughtered, fed to dogs, continue life cycle.

humans here are INCIDENTAL HOSTS (recall that for the earlier tape worms, the taenia species, that humans are a necessary/definitive host).

alternate cycle - dogs lick ass, give humans eggs when they get close to owners. humans = incidental, dead end hosts.

Front 3

pathology associated with hydatid disease?

Back 3

the echinococcus granulosus eggs hatch in people, run around and set up big cysts all over the body.

likely in liver and lung.

disease from the mass effect of the cysts, and take YEARS to get big (kids infected, symptoms later in life). Many people never show symptoms.

cysts are full of PROTOSCOLICES, which when ruptured, can travel around and set up cysts all over the body.

also the fluid inside is highly allergenic.

so disease from poorly walled off cysts (like in the lung), allergic reactions, and mass effects.

Front 4

diagnosis and treatment?

Back 4

imaging may help see cysts. Serology if the cysts are leaking - if they're intact, unlikely to have antibodies as the cysts are very non-antigenic.

treatment:
SURGICAL - though not favored due to risk of rupture. Pre=treat with injecting drugs first.

PAIR technique - inject/suck dry.

Albendazole

avoid by keeping dogs de-wormed.

Front 5

Filiariasis - what do the various organisms/progressions have in common? what are the 3 big diseases?

Back 5

these are nematodes transferred by a vector of some kind. there are generally two forms of the organisms - an ADULT stage and a larval MICROFILARIAL stage (and we definitely need to know, for each disease, where each of the life stages live).

the 3 diseases are:
LYMPHATIC FILIARIASIS
ONCHOCERCERCIASIS
LOIASIS.

Front 6

lymphatic filiariasis - what is our causitve agent and major disease? Life cycle? make sure to mention where ADULTS and MICROFILARIA live.

time of day effects?

Back 6

worried about Bancroftian filiariasis, caused by Wucheria bancrforti.

adults live in LYMPH NODES
microfilaria live in BLOOD.

adults coiled up in lymph nodes crank out the little MF's, which circulate in the blood (highest concentration AT NIGHT because the mosquito is the vector).

MF's get taken up by mosquito, they molt up to L3, then get re-injected into people. Move up to lymph nodes, wait a few months, crank out more MF's.

Front 7

Lymphatic filiariasis - how is disease caused and what's caused?

Back 7

this is elephantiasis.

several diseases possible - Filarial Adenolymphangitis - this is RETROGRADE lymphangitis (red streaks going DOWN arm) = ADL.


LYMPHEDEDMIA (LE) - adults screw up lymphatic return, get swelling. Need long-term exposure for this one. through this, get Hydrocele (big sack), dermatolymphangioandentis (bacterial infection of swollen are), elephantiasis.


CHYLURIA - if pelvic nodes blocked, drain chyle into renal pelvis/ureters, pee out all your cholesterol/complement/proteins.

Tropical Pulmonary Eosinophelia (nocturnal wheezing, eospinphelia, fever, weight loss)

Front 8

how do you diagnose lymphatic filiariasis?

Back 8

see the MF in the blood (night sample!)

ANTIGEN test, not antibody- actual antigen, which is good because it demonstrates active infection.
"dancing sign" - ultrasound on junk, see dancing worms.

Front 9

treatment for lymphatic filiariasis?

Back 9

DEC - di ethyl carbamazine (DEC) - also, albendazole/ivermectin.

NOTE - doxycycline can be good beacsuse it kills Wolbachia, a bateria in the worm that it seems to need.

Front 10

Onchocerciasis - what's the disease and vector? where do the adults and infants live?

Back 10

onchocerciasis causes RIVER BLINDNESS and is transmitted by BLACK FLIES.

in contrast to the lymphatic filiarisis (where the adults live in LN's and MF live in blood), for onchocerciasis, caused by onchocerca volvus, the adults live in NODES (not lymph nodes, but physical nodes over bones) and the kids live in the subcutaneous tissues/dermis.

Front 11

life cycle of onchocerciasis?

Back 11

adults in hard nodes over bones, usually. release microfileria into the subcutaneous tissue/dermis.

these migrate around, get taken up by the BLACKFLIES, where they mature and become infectious larvae, ready to invade another host. Larvae invade and become nodules, make MF's, etc.

Front 12

signs and symptoms of onchocerciasis?

Back 12

MF's in the subcutaneous tissue cause serious SKIN AND EYE PROBLEMS;

loose elasticity, pigmentation, become fibrotic, "lizard skin" or "leopard skin"

cause suicidal-level ITCHING = puritis. KERATITIS, then blindness (RIVER BLINDNESS) - see in mostly old folks.

see lymphadenopathy = groove sign or HANGING GROIN.

so, river blindness = itching, skin changes, hanging groin. adults are in random nodes, babies are in the subcutaneous areas.

invades

Front 13

diagnosis of onchocerciasis? what complication does this make you think of?

Back 13

SKIN SNIPS - pull off skin, examine under scope, see worms crawl out.

"mazzotti reaction" - they're very susceptible to DEC (di-ethyl-carbamazine) - if you put a little DEC on skin, it'll kill the worms underneath, they'll illicit an immune response, you see hypersensitivity reaction (like PPD).

remember not to give DEC systemically - huge immune response and death.

Front 14

treatment of onchocericacosis?

Back 14

don't use DEC systemically!

use ivermectin - this only kill the microfilaria, which is a good thing. so repeat.

Front 15

what's the last filarial disease?

Back 15

Loiasis = eyeworm = loa loa. Remember that this has a big preference for visiting peace corps volunteers.

Front 16

life cycle of loiasis? vector? time of day?

Back 16

here, ADULTS IN SKIN
MF in the BLOOD. Here, the adults cause disease. In onchocerciasis, the MF cause disease. In lymphatic filiariasis (elephantitis), the adults cause disease.

deer fly is the vector.

adults sit in subcutaneous tissue, release MF's which float around in the blood, get taken up by deer flies, mature into infectious larvae, get deposited in fly bites.

can take 1-4 years to mature and make MF's.


SHOW UP DURING THE DAY - the MF's know the deer flies are day-biters (opposite to elephantiasis)

Front 17

pathology of loaisis?

Back 17

see big eye worms.

also calabar swellings - look like tracks where worm was.

possible nephropathy and brain problem/heart problems, very rare.

eye problems rare.

people from not around them parts get more calabar swellings, more allergic reactions, high eosinophelia.

Front 18

diagnosis of loa loa?

Back 18

DAYTIME blood smear looking for the MF's. Locals may still be negative for this. Some serology available. Carabal swellings.

Front 19

treatment of loa loa?

Back 19

treat with DEC (remember not to use with river blindness!).

use corticosteroids just in case there are more worms than you think.

sometimes has to be repeated. ivermectin/albendazole also can be used.

peace corps volunteers take prophylactic DEC.