Lecture 21 - Echinococcus, Screwworm, Tick Paralysis

What are other names for Echinococcus?

- Hydatidosis
- Hydatid cyst disease

Scientific name for Echinococcus

Echinococcus spp.

E. granulosa

Species involved with Echinococcus

- Canids
- Sheep
- Cattle
- Goats
- Pigs
- Foxes
- Coyotes
- Rodents
- Humans

Geographic distribution of Echinococcus

Worldwide

Clinical signs of Cystic Echinococcus

- Pain
- Vomiting
- Fever
- Urticaria
- Eosinophilia
- Anaphylactic shock

Clinical signs of Alveolar Echinococcus

- Abdominal pain
- Biliary obstruction
- Liver failure

Morbidity/mortality of Echinococcus

- CE: 5-10% morbidity, <2% mortality
- AE: 50-75% mortality

Diagnostic tests for Echinococcus

- Diagnostic imaging
- Serology

How is Echinococcus transmitted?

Ingestion of eggs

How is Echinococcus treated?

- Surgery
- Chemotherapy
- Drainage
- Albendazole

How is Echinococcus prevented?

Deworming

what is the incubation period of Echinococcus?

can be years

Scientific name for Screwworm

Cochliomyia hominivorax

Species involved with Screwworm

Mammals

Geographic distribution of Screwworm

Southern US, Western hemisphere, South America, Caribbean

Clinical signs of Screwworm

- Discomfort
- Lethargic
- Anorexic
- Decreased milk production
- Seclusion
- Death

Morbidity/mortality of Screwworm

Mortality in fawns varies from 20-80%

Diagnostic tests for Screwworm

- Samples of eggs/larvae/flies
- Identification

How is Screwworm transmitted?

Flies lay eggs in open wounds

How is Screwworm treated?

- Remove larvae
- Clean wound
- Pesticide
- Organophosphate

How is Screwworm controlled?

Eradication

Is Screwworm reportable?

YES

How do newborn foals get infected with Screwworm?

Umbilicus is infected

Species involved with Tick Paralysis

- Humans
- Cattle
- Sheep
- Dogs
- Fowl
- Birds
etc.

Geographic distribution of Tick Paralysis

- Eastern Australia
- North America
- Africa
- Argentina

Clinical signs of Tick Paralysis

- Ataxia -> paralysis
- Weakness
- Change in bark
- Fatigue
- Muscle pain
- Laryngeal paresis
- Bronchoconstriction
- Nausea

Morbidity/mortality of Tick Paralysis

Untreated: 10-12% mortality
Treated: 5% mortality

Diagnostic tests for Tick Paralysis

- Evidence of recent tick attachment
- Abnormalities on lab work

How is Tick Paralysis transmitted?

Tick saliva

How is Tick Paralysis treated?

- Removal of tick
- Antitoxin if severe

How is Tick Paralysis controlled?

- Check for ticks!
- Tick repellent

What disease does Tick Paralysis look like?

Guillain-Barre syndrome

Is Tick Paralysis zoonotic?

no

What causes the clinical signs in Tick Paralysis

Neurotoxins from the tick

Are tick-borne diseases on the rise in the US?

Yes