Zoonotic Nematodes

Question 1

Causes of eosinophilia meningitis

Answer 1

Baylisascariasis
Gnathostomiasis
Angiostrongyliasis

Question 2

Visceral larva migrans
Cause
Mode of acquisition

Answer 2

Toxocara canis or cati

Ingestion of toxocara eggs contaminated with dog or cat faeces

Question 3

Visceral larva migrans clinical features

Answer 3

Asymptomatic Eosinophilia
Migration of larva causes abdominal pain, resp symptoms and fever Hepatomegaly
Retinal granuloma - uveitis or retinitis

Question 4

Diagnosis and treatment of visceral larva migrans

Answer 4

Biopsy and identification of larva in infected tissues
Serology- not well standardised
DEC
Steroids for ocular disease
No evidence albendazole will help as larva

Question 5

Baylisascariasis
Etiologic agent
Mode of acquisition

Answer 5

Baylisascaris Procyonis
Soil hands or fomites contaminated with raccoon faeces containing embryo eggs

Question 6

Baylisascaris
Clinical manifestations
Pathology and diagnosis

Answer 6

Migration of larva into tissues mostly in CNS
Eosinophilic meningoencephalitis
Ocular involvement common
No asymptomatic cases yet described
CSF eosinophilia, large CNS tracks
Diagnosis by finding larva in infected tissues
Treatment- no survivors usually occurs in very young children in temperate climates

Question 7

Cutaneous larva migrans
Etiology

Answer 7

Dog/cat hookworm trapped in skin
Cannot cut out as larva is ahead of the track
Treat with ivermectin or albendazole

Question 8

Anisakis

Answer 8

Larva invades gastric mucosa
Anisakis simplex more species
Source undercooked infected fish or shellfish
Definitive host dolphins
Clinical manifestations abdominal pain nausea diarrhoea or vomiting
Can get eosinophilia
Diagnosis visualisation of larva
Treatment worm removal - anti helminths don’t work

Question 9

Angiostrongyliasis
Clinical features

Answer 9

Migrate to CNS
Bitemporal headache
Meningismus
6th nerve palsy

Can get CSF eosinophilia
Get leptomeningitis

Question 10

Angiostrongyliasis (rat lungworm)

Epidemiology
Source

Answer 10

Thailand
Taiwan
South Pacific
Source
Ingestion of immature larva in intermediate hosts:snails,slugs,shrimp,frog or vegetables contaminated with slugs

Question 11

Angiostrongyliasis

Answer 11

Steroids main treatment antihelminthics generally CI

Question 12

Gnathostomiasis
Etiology
Clinical

Answer 12

Gnathostoma spinigerum
CNS - eosinophilic meningitis, intracerebral haemorrhage
Gnathostoma binucleatum
Cutaneous- bruising haemorrhage in skin fast moving

Question 13

Gnathostomiasis
Epidemiology

Answer 13

Thailand and Japan some other Asian countries and Australia emerging in Latin America
Get from eating fish or amphibians

Question 14

Solitary pulmonary nodule containing a larva

Answer 14

Dirofilariasis

Natural host dog right ventricle

Question 15

Dirofilaria

Answer 15

Transmitted by flies L3 larva

No treatment
Can remove surgically

Question 16

Hunter from south Alabama migratory transient swellings on face
Diagnosis

Answer 16

Dirofilaria tenuis
Subcutaneous
Raccoon host

Question 17

Migratory swellings across the eye

Answer 17

Mosquito or fly vectors
D. Tenuis differential for loa loa would cross react on serology so epidemiology important

Question 18

Dirofilaria repens

Answer 18

Emerging
Host cats
Subcutaneous
Can get in eye
Happens in Europe and china
Transmitted by mosquitos

Question 19

Capillaria

Answer 19

C. Philippines is

Massive diarrhoea and weight loss
Can auto infect
Source is raw fish
Lab diagnosis eggs in stool
Found in Philippines and Thailand sporadic in Egypt, Korea Taiwan,India Japan
Treat with high dose albendazole

Question 20

Trichinella spiralis

Answer 20

Cosmopolitan
Source eating undercooked pork, boar,horse and bear
Adults live in human small
Bowel and larva migrate to muscles
Get inflammation myalgia and raised CK
Can cause myocarditis