Zoonoses Flashcards
Definition of a Zoonoses
Infections that are naturally transmitted between vertebrate animals and humans
4 diseases that are commonly mistaken for zoonoses
- Malaria
- Schistosomiasis (snail fever)
- Oncoceriasis (river blindness)
- Elephantiasis (lymphatic filariasis)
What is Anthroponosis
Reverse of zoonose, in that humans infect animals
4 examples of Anthroponosis
- Influenza (virus affecting birds and pigs)
- Strep throat (bacteria affecting dogs)
- Leishmaniasis (parasite affecting dogs)
- Chytridiomycosis (fungus affecting amphibians)
5 bacterial zoonoses
- Salmonella
- Campylobacter
- Anthrax
- Leptospirosis
- Brucella
5 viral zoonoses
- Rabies
- Avian Influenza
- Ebola Virus
- West Nile Fever
- Crimean-congo Haemorrhagic Fever (CCHF)
3 parasitic zoonoses
- Toxoplasmosis
- Visceral Larva Migrans (toxocara)
- Cysticercosis
2 fungal zoonoses
- Dermatophytoses
- Sporotrichosis
4 common zoonoses in the UK
- Salmonella
- Campylobacter
- Toxoplasma
- Ringworm/dermatophytosis
4 uncommon zoonoses in the UK
- Anthrax
- Rabies
- Bubonic Plague
- Acute Brucellosis
What virus causes Rabies and how it transmitted
- Lyssavirus
- Bite from infected animal (97% from dogs)
Incubation period of Rabies
2wks to several months
What does Rabies to the body
- Travels to brain via peripheral nerves
- Causes an acute Encephalitis
Malaise, headache & fever
Progressing to mania, lethargy & coma
Over production of saliva & tears
Unable to swallow & hydrophobia
Death by Respiratory fever
How to diagnose Rabies
- PCR of saliva or CSF
- Often confirmed post mortem on brain biopsy
Diagnosis is difficult
Management of Rabies
- Immediately after bite give post-exposure prophylaxis
Human rabies immunoglobulin (HRIG)
Infiltrated round the bite (if possible)
+4 doses of rabies vaccine over 14 days
What is Brucellosis
- Occupational hazard of farmers, vets and slaughter house workers
- Organisms are excreted in milk, placenta and aborted foetus
- Acute brucellosis may begin with mild flu-like symptoms or symptoms such as:
Fever
Abdominal pain
Back pain
Chills
Excessive sweating
Fatigue
If you suspect Brucellosis what must you do to prevent spread
Inform the laboratory of your suspicion as there’s a risk of spread in the lab.
How is Brucella categorised
Small, gram negative coccobacilli
Incubation of Brucella
5-30 days (up to 6 months)
4 stages of symptoms
- Acute (now very rare in Scotland)
- Subacute
- Chronic
- Subclinical (commonest)
Describe the Acute presentation of Brucellosis
- Last 1-3 weeks
- High, undulant, fever
- Weakness, headaches
- Drenching sweats
- Splenomegaly
Describe the subacute presentation of Brucellosis
- Lasts over 1 month
- Fever and joint pains (knee, hip, back SI joints)
Describe the chronic presentation of Brucellosis
- Lasts for months or years
- Flu-like symptoms
- Malaise
- Depression
- Chronic arthritis
- Endocarditis
- Splenomegaly
Describe the subclinical presentation of Brucellosis
- Most common form
- 50% of exposed have positive serology
Treatment for Brucellosis
- Long acting Doxycycline for 2-3 months
- Rifampicin or Intramuscular Gentamycin for first week(s)
- Add Cotrimoxazole for 2 weeks in CNS disease
Symptoms of Leptospirosis
Flu like symptoms, then jaundice and renal failure
Treatment for Leptospirosis
Penicillin ASAP
What is Toxoplasmosis
- Caused by Toxoplasma Gondii
- Usually asymptomatic
- Can get flu-like symptoms, such as:
high temperature (fever)
aching muscles
tiredness
feeling sick
sore throat
swollen glands - Pneumonia
- Symptoms normally resolve on their own within ~6 weeks
Diagnosis of Toxoplasmosis
- IgM antibodies, indicates acute infection
- Toxoplasma dye test, +ve within 1 month and remains +ve for the rest of your life.
Treatment for Toxoplasmosis
- Most don’t require treatment
- Sulphonamide and Pyrimethamine
- Occasionally Tetracycline
