Zoonotic helminths + extras

Question 1

What is meant by zoonotic helminth

Answer 1

Humans are dead end hosts

Question 2

What causes visceral larva migrans? What human helminth is it the same as? Life cycle ? Sx

Answer 2

Toxocara canis/cati [or Baylisascariasis]
-type of Ascaris
Dogs pass eggs in faeces
Human ingests - > larva hatch in bowel
Migrate mostly to LIVER then die
-Occasionally to eye / spleen / other places

Get Hepatosplenomegaly (tiny granuloma where ascaris dies) and Eosinophilia
+/- Retinal granuloma [ocularlarva migrans]

Question 3

Toxocara canis/cati rx? Prevent ?

Answer 3

Larvae will die over a few weeks
[Maybe DEC]
Steroids for ocular disease

Lids on sandboxes
Deworm puppies - can be infected by mother though placenta

Question 4

Ix Toxocara canis/cati

Answer 4

NO eggs in stool as worms in the wrong host and die - likey clinical with eosinophilia and hepatomegaly

Question 5

Baylisascaris procynois from? Features? Dx?

Answer 5

Racoons
Larvae migrate though CNS -> eosinophilic meningitis and common ocular involvement
[REALLY BAD - basically eat through brain]

Brain imaging often lags clinical disease
Basically everyone who gets this dies

[Baylifts take bins where racoons live]

Question 6

Baylisascariasis procynois from? Features? Dx?

Answer 6

Racoons
Larvae migrate though CNS -> eosinophilic meningitis and common ocular involvement
[REALLY BAD - basically eat through brain]

Brain imaging often lags clinical disease
[Can get serology in some labs]

Basically, everyone who gets this dies
No proven Rx - people give albendazole
[BUT albendazole does not really work against Larva of any helminth]

Question 7

Cutaneous lava migrans caused by? Main issue? Rx?

Answer 7

Dog/cat ancylostoma
Eg Ancylostoma Braziliense
Bacterial superinfection

Single dose Albendazole / ivermectin

Question 8

goes to dinner at a well-known sushi bar. 4 hrs later develops the worst abdominal pain ever experienced

Answer 8

Anisakis larva

‘Ani sak that’s sore’

[Pseudoterranova decipiens]

Question 9

Anisakis from? Rx? prevent?

Answer 9

Raw seafood
Endoscope removal of nematode or may need surgical resection of eosinophilic granuloma

Need to freeze for 4 hours
Experienced chefs can identify larva

Question 10

insidious onset of an intractable bitemporal headache
Development of meningismus and a 6th nerve palsy
CSF eosinophilic meningitis
Seafood Market=

Answer 10

Angiostrongyliasis (eosinophilic
meningitis)
Angiostrongylus cantonensis

Question 11

Angiostrongyliasis from ? Features? Imaging? Dx? Species?

Answer 11

Rat lungworm lays eggs -> faeces
[then the number of intermediate hosts including slugs/snails which can contaminate greens]

Eosinophilic meningitis
MRI - generalised meningeal thickening
PCR for Dx

Angiostrongylus cantonensis

Question 12

Angiostrongyliasis classic vector

Answer 12

Giant African land snails

Question 13

Angiostrongyliasis Rx?

Answer 13

CSF taps
Steroids
[Antihelminths mostly contraindicarted as if larva die in brain -> inflammation (some use with high dose steroids)]

Question 14

Gnathostomiasis from? Intermediate host?

Answer 14

Cats [garfield]
Fish intermediate host (sushi)

Question 15

Gnathostomiasis features? Main complication? Rx?

Answer 15

Woms have spines on -> when migrating cause haemorrhagic tracts [creeping eruption]
-Track like necrosis with haemorrhage along nematode tract

Key issue is cerebral haemorrhage if migrates through CNS

Cook food
Ivermectin / albendazole

Question 16

Cerebral haemorrhage which worm?

Answer 16

Gnathostomiasis

gnathostomiasis spinigerum

Question 17

Open lung resection of pulmonary nodule - worm discovered = ? From?

Answer 17

Dirofilariasis
Dogs - lives in R ventricle of heart
- This is what dogs get de wormed for “heartworm’

[Causes necrotic lesion in lungs]

dirofilaria immitis

Question 18

42 hunter from US. complaining of
migratory transient swellings on his face and has one which crawls through eye ?
Rx?

Answer 18

Dirofilaria
Surgical
[occasionally DEC/Albendazole]

Question 19

Which Dirofilaria in lungs

Answer 19

dirofilaria immitis

(It ‘imitates’ TB symptoms)

Question 20

Capillariasis From? resevoir ? Key issue? rx?

Answer 20

Raw fish
Birds

Capillaria philippinensis

Profuse watery diarrhoea + eosinophilia
Massive malabsorbtion

Albendazole - at least 3 weeks

Question 21

Raw fish in Hx then profuse watery diarrhoea Egg

Answer 21

Capillaria philippinensis

Question 22

Where is most guinea worm now

Answer 22

Dogs - remain a reservoir especially in Chad

Chad, Ethiopia, Mali, South Sudan and Angola, with most cases in Chad and Ethiopia

Question 23

Trichinella spiralis where do larvae migrate to? clinical features? Name a complication? Dx? Rx?

Answer 23

Muscles - form cysts + inflammation
Then infects the next host that eats the dead host
[Usually pig]

Affects many animals eg horse, bear, hunted animals

Eosinophilia - usually very high
Can get myocarditis - the heart is a muscle dumb ass
Periorbital oedema

Serology for Dx
Albendazole

Question 24

Which zoonic helminth from muscle meat

Answer 24

Trichinella spiralis

Question 25

Cause of guinnae worm infection? geography

Answer 25

Dracunculus medinensis. Ingesting contaminated water. Copepods in the water. Blisters on legs. Now confined to africa and thought to become the second disease eradicated after small pox

Question 26

Guinae worm life cycle? Vector?

Answer 26

Limb exposed to freshwater containing their host - cyclops (copepod "water flea") Human consumes flea Penetrate gut wall and develop in sub cut tissue -Grow 50-100cm over 3 months and have millions of larvae After approx 1 year secrete enzymes which allow worm to leave via the skin and release 'white cloud of larvae' when in water and re infect flea

Question 27

Guinae worm presentation? dx?

Answer 27

-Get burning pain from worm trying to emerge from skin -> makes people put affected area in water to cool -May also get allergic Sx due to worm emerging and also forms a blister -Common to get an abscess where this happens Dx usually clinical - especially if see white cloud of larvae released from female worm in water

Question 28

Guinae worm (Dracunculiasis) rx?

Answer 28

Medical therapy usually doesn't work -surgical and delicate removal of the worm [sometimes gently pulled out over several days]

Question 29

What causes the main disability in Dracunculiasis?

Answer 29

Ulceration / abscess formation / secondary infection

Question 30

Dracunculiasis control?

Answer 30

Safe drinking water protected from people bathing Guinea worm host cyclops flea can be filtered out even by just straining drinking water through a cloth [now eliminated from Asia - down from 50M infections to only 150 annually worldwide]

Question 31

5F travelled to SE Asia for 2 mo 3 wk after return, onset of fever, abdominal pain, diarrhoea, and an urticarial rash.

Answer 31

Toxocara - visceral larva migrans

Question 32

Sparganosis life cycle and eg species

Answer 32

Spirometra mansoni