zoonoses Flashcards
what are zoonoses ?
infections that pass between living animals and human
what are examples of anthroponosis ?
influenza
strep throat - dogs
leishmaniasis - dogs
chytridiomycosis - fungus affects amphibians
what are common zoonoses in the UK ?
salmonella campylobacter toxoplasma psittacosis - chlyamydophila psittaci Q-fever - coxiella burnetti ringworm/dermatophytosis
how long is the incubation period for rabies ?
2 weeks to several months
what is the progression and what are the symptoms of rabies ?
travels to brain via peripheral nerves and causes an acute encephalitis
malaise, fever, headache progress to mania, lethargy, coma overproduction of saliva and tears unable to swallow and hydrophobia death by respiratory failure
how is rabies diagnosed ?
PCR or saliva or CSF
often confirmed post mortem on brain biopsy
how do you treat rabies ?
post exposure prophylaxis (human rabies immunoglobulin) HRIG immediately
+4 doses of rabies vaccine over 14 days
infiltrated round bite if possible
what is brucellosis ?
brucella - small, gram -ve coccobacilli
used to be occupational hazard of farmers, vets, slaughterhouse workers
how is brucellosis spread ?
organisms excreted in milk, placenta and aborted foetus
during milking infected animals
during parturition
handling carcasses f infected animals
consumption of unpasteurised dairy products
what are the 3 species of brucellosis ?
melitensis - goats, sheep, camels
suis - pigs
abortus - cattle
what is the incubation period of brucellosis ?
5-30 days
up to 6 months
what is the acute and subacute presentation of brucellosis ?
high undulant fever weakness headaches sweats splenomegaly
subacute lasts over 1 month
fever and joint pain
what is the chronic presentation of brucellosis ?
lasts months/years flu-like symptoms malaise depression chronic arthritis endocarditis epididymis-orchitis meningitis and splenomegaly
how do you treat brucellosis ?
long acting doxycycline 2-3 months
+ rifampicin OR IM gentamicin for first weeks
add cotrimoxazole for 2 weeks in CNS disease
relapse occurs due to intracellular organism
chronic hard to treat
what is leptospirosis
caused by spirochaetes L. hardjo from cattle is commonest
penetrate abraded skin and mucous membranes
11% dairy workers have positive serology
how do you get infected with leptospirosis ?
direct contact with animal
contact with water contaminated with urine
incubation 2-30 days
how does leptospirosis present ?
undifferentiated fever
myalgia
headaches
abdo pain
sever disease 5-15%
Weil’s disease - jaundice AKI, bleeding
pulmonary haemorrhage
how do you diagnose leptospirosis ?
microscopic agglutination test (MAT) paired sera - not great
ELISA serology
PCR ?
culture - takes one week
how do you treat leptospirosis ?
treat early doxycycline for mild disease IV penicillin for severe prompt dialysis mechanical ventilation
what is the causative organism for Lyme disease ?
borrelia burgdorferi
transmitted by ticks from deer - ixodes ricinus
what are clinical signs of Lyme disease ?
erythema migrans - bullseye rash, 3-90 days
acrodermatitis chronic atroficans - distal extensor surface, blue-red discolouration progressive + peripheral neuropathy
lymphocytoma - blue solitary painless nodule, earlobe/areola, kids
neuroborreliosis - triad facial nerve palsy, radicular pain and lymphocytic meningitis , onset 2-6 weeks after
how do you diagnose lymes disease ?
EM is a clinical diagnosis
high serology titres
how do you treat Lyme disease ?
oral doxycycline or IV ceftriaxone
treat for 21 days
