Toxocara species

Question 1

_____disease from stray dogs and cats

Answer 1

zoonotic

Question 2

Larvae causes the disease:

• Toxocara____: dog roundworm

• Toxocara____: cat roundworm

Answer 2

canis

cati

Question 3

Life cycle is completed in_____

Answer 3

dogs or cats

Question 4

Female dogs

•_____ eggs may be reactivated and infects their puppies ->__________ transmission

Answer 4

Encysted

transplacental or transmammary

Question 5

Epidemiology

• Common among_____ than adults
• Tendency to play in soil
• Exhibit geophagia or soil eating

• Common in places where dogs and cats are not dewormed

Answer 5

children

Question 6

Biology

• Accidental Host:

Answer 6

Humans

Question 7

Paratenic Host:

Answer 7

• Rabbits and small mammals

Question 8

Definitive Hosts:

Answer 8

Dogs or cats

Question 9

Infective Stage:

Answer 9

• Humans
• Embryonated ova
• Encysted larvae in small mammals like rabbit

Question 10

Diagnostic Stage:

Answer 10

• Larvae encysted in tissues

Question 11

• Shed unembryonated ova

Answer 11

Dogs and Cats

Question 12

External environment

• Undergo_____ -> infective (ova containing L3)

Answer 12

embryonation

Question 13

Embryonated Ova

1. Ingested by the_____
2. Ingested by____

Answer 13

definitve hosts (dogs/cats)

paratenic host

Question 14

Host?

• Infective ova hatch to larva -> penetrate the gut wall

Answer 14

Definitive Host

Question 15

Young dogs:

Answer 15

larvae undergo lung migration

Question 16

Older:

Answer 16

larval encystment in tissues is more common

Question 17

Female Old Dogs:

Answer 17

encysted larvae reactivated during pregnancy

Question 18

Transplacental and transmammary

Answer 18

(T canis)

Question 19

Transmammary > Transplacental

Answer 19

(T cati)

Question 20

Habitat:

Answer 20

small intestine (usual young dogs)

Question 21

• Major source of environmental egg contamination

Answer 21

Young dogs

Question 22

2._______ Hosts - like rabbits

• Ingest embryonated ova (generally Toxocara canis)

• hatch to larvae and encyst in various tissues

Answer 22

Paratenic

Question 23

What host?

• Ingestion of embryonated ova, or infected paratenic host (Food-borne) -> L3 penetrate intestinal wall

• -> liver, heart, lungs, brain, muscle, eyes

Answer 23

Humans as accidental host

Question 24

Pathogenesis and Clinical Manifestations

• Migration of the larvae and death in different organs -> intense inflammatory response as eosinophilic granuloma

Answer 24

Visceral Larva Migrans (VLM)

Question 25

Pathogenesis • Solitary mass -> seizures, encephalitis, optic neuritis, eosinophilic meningitis

Answer 25

CNS: Neurological Toxocariasis

Question 26

: pneumonia, respiratory failure : hepatomegaly, necrosis : Loeffler endomyocarditis

Answer 26

Lungs Liver Heart

Question 27

Pathogenesis and Clinical Manifestations • Common among children 5-10 years old: unilateral visual impairment and strabismus • Retinal Invasion: most serious consequence

Answer 27

Ocular Larva Migrans (OLM)

Question 28

Pathogenesis and Clinical Manifestations • Less specific syndrome or may be asymptomatic

Answer 28

Covert Toxocariasis (CoTOX)

Question 29

Diagnosis • Definitive:________ • Other Tests(2)

Answer 29

Tissue Biopsy demonstrating larva • ELISA test for IgG • PCR

Question 30

has no role in the diagnosis of human toxocariasis

Answer 30

Stool exam to demonstrate eggs

Question 31

Treatment • Most patients recover without therapy • If therapy is warranted: •____ or _____PLUS ____ • For those with CNS, cardiac, or lung complications

Answer 31

Albendazole or Mebendazole PLUS anti-inflammatory drug (Steroids)

Question 32

Treatment is more difficult for_______ -> prevent progressive damage to the eye

Answer 32

Ocular Toxocariasis

Question 33

Prevention and Control

Answer 33

• Control and capture of stray dogs and cats • Cleaning up feces from soil and pavements • Closing of potentially contaminated areas to animals and children • Gardens should be fenced to prevent fecal contamination by dogs and cats • Vegetables gathered from possible contaminated gardens should be washed thoroughly. • Avoidance of consumption of raw or undercooked meat of potentially infected animal. • Hand washing at all times.

Question 34

Prevention and Control • Strategic antihelminthic treatment of dogs and cats • Puppies: start____ weeks of age, repeated every 2 weeks until 12 weeks age • Adult: treated every__ months • Female: after each____ cycle

Answer 34

2-3 6 estrus

Question 35

Ingested by paratenic host

Answer 35

L3 larvae in tissue

Question 36

Adults in (habitat) of definitive host

Answer 36

small intestine

Question 37

Unembryonated egg is embryonated in the _____

Answer 37

External environment

Question 38

Paratenic host ingests _____

Answer 38

Third stage larvae

Question 39

Humans ingests _____ from environment/ paratenic host

Answer 39

Third stage larvae