Zoonoses Flashcards
What are zoonoses?
Infections that can spread from animals to humans, with the animal being the source of the infection.
Infections that depend on the human host for part of their life cycle such as malaria and schistosomiasis are not classified as zoonoses
What are anthroponoses?
Infections where humans infect animals
What are the features of monkeypox?
Endemic in central and west Africa
Characterised by a vesicular rash
What are the features of rabies?
Spread from the bite of an infected animal (usually dogs)
Incubation period in humans varies from two weeks to several months
Can spread to the brain and cause an acute encephalitis
What are the symptoms of a rabies encephalitis?
Malaise, headache & fever Progression to mania, lethargy & coma Over production of saliva & tears Unable to swallow & ‘hydrophobia’ Death by respiratory failure
How is rabies diagnosed?
PCR of saliva or CSF most useful tests
Diagnosis often confirmed post mortem
How is rabies treated?
Always fatal if untreated
Post-exposure prophylaxis given ASAP following bite by infiltrating human rabies immunoglobulin (HRIG) around the bite
Prophylaxis followed by four doses of rabies vaccine given over fourteen days
How is brucellosis transmitted?
Infectious product excreted in milk, placenta and aborted fetus Humans most commonly infected by: -Milking infected animals -During parturition (birthing) -Handling carcasses of infected animals -Consuming unpasteurized dairy products
What are the characteristics of the brucellosis bacteria?
Gram negative coccobacilli
Incubation period of 5-30 days but can be up to 6 months
What are the characteristics of the acute brucellosis presentation?
Lasts 1-3 weeks High, undulant fever Weakness Headaches Drenching sweats Splenomegaly
What are the characteristics of the sub-acute brucellosis presentation?
Lasts over one month
Fever
Joint pain (knee, hip, back sacroiliac joints)
What are the characteristics of the chronic brucellosis presentation?
Lasts for months or years Flu-like symptoms Malaise Depression Chronic arthritis Endocarditis Epididymo-orchitis Rarely meningism Splenomegaly
What are the characteristics of the subclinical brucellosis presentation?
Most common presentation
50% have positive serology
How is brucellosis treated?
Long acting doxycycline for 2-3 months
Additional rifampicin and IM gentamicin for first few weeks
Cotrimoxazole added for 2 weeks if CNS disease present
What are the characteristics of leptospirosis icterohaemorrhagia?
Common in fish working populations
Symptoms start as flu-like before developing jaundice and renal failure