Zoonoses Flashcards
What is rabies?
Viral infection transmitted from bite of infected animal, mainly dogs
What is the incubation period of rabies?
2 weeks to several months
How does rabies spread in the body?
Travels to brain via peripheral nerves and causes acute encepgalitis
How is rabies diagnosed?
PCR of saliva or CSF
Often confirmed post mortem on brain biopsy
What is the treatment of rabies?
Post exposure prophylaxis- human rabies immunoglobulin around bite, 4 doses of rabies vaccine over 14 days
What is brucellosis?
Small gram negative coccobacilli
What is the incubation period of brucellosis?
Usually 5-30 days, but up to 6 months
Where is the brucellosis organism excreted into?
Milk
Placenta
Aborted foetus
How is brucellosis passed from animals to people?
Milking infected animals
Parturition
Handling carcasses of death animals
Consumption of unpasteurised dairy products
What are the 3 species of brucellosis?
Melitensis
Suis
Abortus
What is brucellosis melitenis?
Most virulent form, host animals are goats, sheep and camels
Occurs in Med, South America, China, India and Middle East
What is brucellosis suis?
Host animals are pigs
Occurs in North and South America, and SE Asia
What is brucellosis abortus?
Least virulent form
Host animals- cattle and buffalo
Seen worldwide
What are the phases of brucellosis?
Acute= 1-3 weeks
Subacute= >1 month
Chronic= months to years
Subclinical
What are the signs and symptoms of acute brucellosis?
Hugh undulant fever
Weakness, headaches, drenching sweats
Splenomegaly
What are the signs and symptoms of subacute brucellosis?
Fever and joint pain
What are the signs and symptoms of chronic brucellosis?
Flu like Malaise Depression Chronic arthritis, endocarditis, epididymo-orchitis, splenomegaly Rarely meningism
What is the treatment of brucellosis?
Long acting doxycycline for 2-3 months and rifampicin or IM gentamicin for a few weeks
If CNS disease, add co-trimoxazole
What is the most common form of leptospirosis?
L hardijo from cattle
How does leptospirosis spread to humans?
Penetrate unabridged skin or mucous membranes and cause systemic illness
Either via direct or indirect contact
What is the incubation period of leptospirosis?
2-30 days, normally 10-14
What are the signs and symptoms of leptospirosis?
Fever Meningism Myalgia Headaches Abdo pain
What are the signs and symptoms of severe leptospirosis?
Weil’s disease- jaundice, AKI, bleeding
Pulmonary haemorrhage
What sign doesn’t occur in leptospirosis where L. hardijo is the infective organism?
Jaundice
How is leptospirosis diagnosed?
ELISA serology
PCR
Culture
When should leptospirosis be considered?
Cattle farmers
Exposure to water or rates
How long does leptospirosis culture take?
at least 1 week
What is the early treatment of leptospirosis>
Doxycycline for mild
IV penicillin for severe
What is the overall treatment for leptospirosis?
Doxycycline or IV penicillin
Prompt dialysis
Mechanical ventilation
What is the organism associated with Lyme disease?
Borrelia burgdorferi
What are the possible signs and symptoms of Lyme’s?
Erythema migrant Acrodermatitis chronic atroficans (ACA) Lymphocytoma Neuroborreliosis Carditis and heart block Arthritis
When des erythema migrans develop in Lyme’s?
3-90 days after bite, normally 7-30
What is ACA?
Bluish-red discolouration occurring on extensor surfaces of distal extremities
Peripheral neuropathy
What causes ACA?
B. afzeii
What is lymphocytoma?
Bluish solitary nodule, usually on earlobe or areola
More common in children
What is neuroborreliosis?
Triad of facial nerve palsy, radicular pain, lymphocytic meningitis
Symptoms 2-6 weeks after bite
How is Lyme’s diagnosed?
Clinical diagnosis- neuro symptoms consistent and other causes excluded
What diagnostic tests can be done for Lyme’s?
CSF pleocytosis
Paired blood and CSF serology
What is the treatment of Lyme’s?
Oral doxycycline or ampicillin, or IV ceftriaxone
Treat for 21 days, or 28 if ACA or arthritis
