Zoonoses and food-borne diseases Flashcards
What should you do if you suspect and anthrax case?
Peripheral blood smear and stain with new methylene blue.
Notify the government and send sample to state lab.
What are the three forms of anthrax in humans?
How dangerous is it for humans?
Cutaneous - black ulcerative, not painful
Pulmonary
Gastrointestinal
More severe when untreated, can kill.
What steps should you take to control and prevent an anthrax outbreak? (6)
Notify gov Movement control PPE Bury deep in pit with lining. Vx Pest control (can pick up spores and translocate).
How is leptospirosis spread?
For the less common routes, what climate do these mostly occur?
Rodent urine or water most common. Other animals can carry different serovars like pigs, cattle and dogs. These other routes are more common in tropical areas.
What are the 3 serovars of leptosporidia that are unique to Australia?
Arborea
Australis
Topaz
What is the pathophysiology and the 2 types of infection for Lepto in humans?
Endothelial damage, can be icteric or anicteric.
Has two phases:
Bacteraemic - neuro and gastro signs
Immune or complicated - renal adn pulmonary issues.
How do you control and prevent spread of lepto? (5)
Vx with specific serovar (humans and livestock)
control sylvanic reservoirs (rats, feral pigs)
Treat water
Education
PPE
How can humans contract Psittacosis?
Inhalation of small particals from bird (faeces, dander, nasal secretions).
What are some human clinical signs of psittacosis?
Flu-like that progresses into pneumonia and pneumonitis.
If the bacteria localises into liver, heart of CNS then you will see respective CSx.
How do humans most commonly contract Bartonella?
Cat scratch.
Why does Bartonella seem to have a higher prevalence in shelters?
Cats fight more Have more fleas (vector) Live in higher density Dirtier environment Usually young cats (who are more susceptible).
What are the CSx of Bartonella in humans?
Painful and chronic lymphadentitis Fever Rash \+/- GIT signs Sequalae --> neuro
What is coxiella burnetii more commonly known as?
Q fever
What makes coxiella burnetii more of a concern in public heath?
Pleomorphic quality so can become more spore like and survive harsh environments (UV, temp, disinfectants and drying).
Can travel far distances in wind.
How can humans be infected by coxiella burnetii? (transmission pathways)
Any ruminant fluids (esp. amniotic fluids) Ixodes tick sp. Dog and cat secretions Aerosol and dust Clothing.
What are the CSx of Q-fever?
How can the disease progress if chronic?
Severe flu-like headache retro-ocular pain fever penumonitis. Chronic --> endocarditis or hepatic complications.
What are the best control and prevention strategies for coxiella burnetii?
PPE
Workplace design, operation design to reduce exposure and transmission
Vx
How is tuberculosis spread between people?
Fomites and oronasal material.
What diseases does Mycobacteria Bovis (M. Bovis) cause in cattle?
Tuberculosis
How was M. bovis eradicated in Aus?
Test and cull, injected with unactive bacterial cell wall, if saw swelling later –> cull.
What are some other diseases caused by mycobacteria?
non-tubercular mycobacteria (NTM)
M. avium ssp. paratuberculosis (MAP)
How does tuberculosis spread to humans from cattle?
Unpasturised milk (MAP survives pasturisation) Contaminated water
What human GIT disease is MAP associated with?
Crohn’s disease.
What are hosts of most concern in Aus for carrying ans spreading Brucellosis?
Cattle and feral pigs
What are human CSx of brucellosis?
What are some complications if it is chronic?
fever, septicaemia, fatigue, arthralgia, insomnia.
Chronic –> spondylosis, endocarditis or orchitis
What techniques were taken to eradicate brucella abortus? (Cattle)
Volunteer testing to identify infected and carriers
Vx to reduce prevalence
BTEC (gov organisation) of test and cull + surveillance of milk and meat.
What are some tips to control Brucella suis? (6)
Control feral pigs Educate pig hunters Don't take dogs, Vx dogs PPE Don't touch/let dog eat pig repro tissues Report incidences.
What are some zoonotic parasites that are carried by dogs?
Hook worm - ancylostoma caninum
Round worm - Toxocara canis and strongyloides stercoralis
How do humans contract hookworms and round worms from dogs? (three different parasites in total)
Eggs excreted from dogs in faeces
A. caninum –> cutaneous penetration
S. stercoralis –> cutaneous penetration
T. canis –> ingestion.
What are the health conditions associated with A. caninum in humans?
Itchy feet
Cutaneous larval migrans
Enosinophilic enteritis (pre-adult/non-patent worm at ileocolic junction)
How do you treat people who are infected with A. caninum?
Albendazole/Ivermectin +/- AM
Mechanical removal
What are the clinical signs of S. stercoralis in humans?
Cutaneous larval migrans
GIT signs including malabsorption
Respiratory form tracheal migration
Hyper-infection syndrome –> death.
Describe how hyper-infection syndrome develops?
Build-up of adults in SI, many auto-infection of larvae, which then migrate into other intestinal sites. This results in septicaemia, bronchopneumonia, hepatitis.
Can be fatal.
How do you treat hosts of S. stercoralis? When will it be impossible to completely uninfect?
Tx = ivermectin moxidectin.
When auto-infected migrating larvae develop the antihelmithics will never reach them.
What makes it difficult to control Toxocara canis in the environment?
Highly resistant, can survive years.
What are the clinical manifestations that occur in humans with Toxocara canis?
Occular larval migrans
Visceral larval migrans
Takes a years for these clinical signs to appear (1-8 yrs or more)
What are some general methods to decrease dog and cat zoonotic parasite spread? (7)
- Hygiene
- Remove dog faeces so eggs don’t hatch in to larvae
- Regular de-worming
- Control feral dog population
- Don’t lie on dog beaches
- Shoes
- Education