Zoonoses Flashcards
What is the definition of zoonoses?
Diseases and infections that can be transferred from vertebrate animals to humans
How can zoonoses be transmitted?
- Scratches/bites
- Contaminated soil or litter
- Food stuffs
How can zoonoses be classified? Give examples of each
Wild animals: UK
- Campylobacter
- Salmonella
Companion animals: UK
- Bartonella
- Toxoplasmosis
- Ringworm
- Psitticosis
Wild animals: Tropical
- Brucella
- Coxiella
- Rabies
- VHF
Companion animals: Tropical
- Rabies
- Tick-bites
- Spirilum minus
Describe campylobacter
It is usually found in poultry/cattle and in contaminated food.
Presentations:
- Diarrhoea
- Cramps
One should investigate with a stool culture and treat supportively.
Describe salmonella
It is usually found in poultry; there are over 200 types but only 2 affect humans (typhi, paratyphi) and is transmitted through contaminated foods.
Describe bartonella
Usually found in cats (kittens) and transmitted through catch scratches.
Catch Scratch Disease:
- Macular and may be pustular
- Investigated with serology
- Treated with erythromycin or doxycycline
If the patient is immunocompromised, they may develop bacilliary angiomatosis. Treatment is the same with added rifampicin.
Describe toxoplasmosis
Usually found in cats and transmitted by faecal contamination.
Presentation:
- Fever
- Seizures
- Neuropathy
Investigated with serology and possible CT. Treated with spiramycin.
Describe viral haemorrhagic fever
This is caused by 4 viruses:
- Lassa
- Ebola
- Marburg
- Congo-Crimean
Describe brucellosis
This is gram negative bacilli which is transmitted through inhalation or consumption of contaminated foods. It can also be caught from laboratory tests.
Presentations:
- Fever
- Malaise
- Rigors
- Myalgia
- Tiredness
Signs:
- Arthritis, orchitis, lymphadenopathy, splenomegaly, hepatomegaly
Investigations:
- Serology
- LABEL SAMPLE
Treatment:
- Tetracycline/doxycycline with streptomycin (4-6 weeks)
Describe rabies
Caused by rhabdovirus which affects warm-blooded animals (dogs, bats). The infection migrates to the CNS and can cause fatal encephalitis. It can take years for this to develop.
Investigations:
- Serology
Treatment:
- If asymptomatic - vaccine or IgG
- Symptomatic - lol will die
Describe the plague
Caused by Yersinia pestis and is transmitted by fleas. Still seen in some areas of north America. It is diagnosed on PCR.
Bubonic: flea bites human, swollen lymph nodes
Pneumonic: epidemics, man-to-man spread
Treatment: streptomycin, doxycycline, gentamicin, chloramphenicol
Describe leptospirosis
This is excreted in dog/rat urine and can penetrate broken skin on swimming
Presentation:
- High spiking fevers
- Conjunctival haemorrhage
- jaundice
- Meningism
- Renal failure
Treatment:
- Amoxicillin, erythromycin
Describe anthrax
This is caused by bacillus anthracis and causes cutaneous painless round black lesions with a rim of oedema. It also causes massive lymphadenopathy, mediastinal haemorrhage and pleural effusion (Woolsorters disease).
Describe Lyme disease
Caused by borrelia.
Early localised: cyclical fevers, erythema chronicum migrans
Early disseminated: malaise, lymphadenopathy, hepatitis, carditis
Late persistent: arthritis, focal neurology, neuropsychiatric disturbance
Diagnosis: biopsy of edge of ECM
Treatment: doxycycline 2-3 weeks, IV ceftriaxone if CNS symptoms present.
Describe Q fever
Caused by coxiella burnetiid; it looks like atypical pneumonia. It is caught by cattle/sheep and usually presents 2- weeks after the infection with:
- Dry cough
- Fatigue
- Pleural effusion
- Diarrhoea
Treated with: doxycycline
