Micro - Zoonoses

Question 1

What are the levels of classification of zoonoses

Answer 1

Farm/wild vs companion and UK vs tropical

Farm/wild = cattle, poultry, goats, pigs
Companion = cats/dogs (ticks/mice/rodents), reptiles/amphibians, fish

Question 2

Give examples of Farm/wild animal zoonoses

Answer 2

UK: campylobacter, salmonella
Tropical: brucella, coxiella, rabies, VHF

Question 3

Give examples of companion animal zoonoses

Answer 3

UK: bartonella, toxoplasmosis, ringworm, psitticosis
Tropical: rabies, tick-borne diseases, spirilum minus

Question 4

Describe campylobacter infection (reservoir, transmission, presentation, management)

Answer 4

Reservoir = poultry, cattle
Transmission = contaminated food
Presentation: diarrhoea, bloating, cramps
Management: supportive

Question 5

Describe salmonella infection (reservoir, transmission, presentation, management)

Answer 5

Non-typhoidal (typhae and paratyphae are transmitted between humans)
Reservoir = poultry, reptiles/amphibians
Transmission = contaminated food, poor hand hygiene
Presentation: diarrhoea, vomiting, fever
Management: supportive ± ciprofloxacin or azithromycin

Question 6

Describe Bartonella henselae infection (reservoir, transmission, microscopy, types)

Answer 6

Reservoir = kittens > cats
Transmission = scratches, bites, licks of open wounds, fleas
Microscopy = curved, gram -ve rods
Causes cat scratch disease (immunocompetent) or bacillary angiomatosis (immunocompromised)

Question 7

Describe cat scratch disease (cause, presentation, investigations, management)

Answer 7

Caused by bartonella henselae in immunocompetent people
Presentation:
- Macule at the site of inoculation → becomes pustular
- Regional adenopathy
- Systemic symptoms (fever, night sweats, weight loss)
Ix: serology
Management: erythromycin, doxycylin

Question 8

Describe Bacilliary Angiomatosis (cause, presentation, investigations, management)

Answer 8

Caused by bartonella henselae in immunocompromised people
Presentation:
- Skin papules
- Disseminated multi-organ and vasculature involvement → bursting of blood vessels
- Can be fatal
Ix: histopathology + serology
Management: erythromycin, doxycyline, rifampicin + wash hands after handling cats

Question 9

Describe toxoplasmosis infection (reservoir, transmission, presentation, investigations)

Answer 9

Reservoir = cats, sheep
transmission = infected meat, faecal contamination
Presentation: fever + adenopathy, still-birth, visual/hearing/motor/cognitive loss, seizures, neuropathies
Ix: serology, Sabin-Feldman Dye test

Question 10

What is the management for toxoplasmosis infection during pregnancy

Answer 10

Toxoplasmosis PCR +ve in mother, -ve in baby → Spiramycin for 3-weeks (prevents vertical transmission)

Toxoplasmosis PCR +ve in mother, +ve in baby → Pyrimethamine + Sulfadiazine
- Treat baby for up to 1 year after delivery (if no TOP)
- Adjunct: Prednisolone

Question 11

Describe brucellosis infection (reservoir, transmission, presentation, investigations, management)

Answer 11

Reservoir = cattle, goats
Transmission = unpasteurised milk/cheese, mucosal splash, undercooked meat, aerosolisation/inhalation
Presentation = FLAWS, back pain, orchitis, focal abscess (psoas, liver)
Ix: blood/pus culture, serology
Management: doxycycline + gentamicin/rifampicin

Question 12

Describe coxiella burnetii infection (reservoir, transmission, presentation, investigations, management)

Answer 12

AKA Q fever
Reservoir = cattle, goats, sheep
Transmission = inhalation of secretions/waste/milk, unpasteurised milk
Presentation: flu-like illness, pneumonia, hepatitis, endocarditis, focal abscesses (para-vertebral/discitis)
Ix: serology
Mx: doxycycline ± hydroxychloroquine

Question 13

Describe rabies infection (reservoir, transmission, presentation, investigations, management)

Answer 13

With Lyssa virus
Reservoir = dogs, cats, bats
Transmission = bites, scratches, contact with infection fluid
Presentation: seizures, excessive salivation, fever, agitation, confusion, headache
Ix: serology, brain biopsy
Mx: Ig (direct exposure with no vaccine record), vaccinate

Question 14

Describe rate bite fever (reservoir, transmission, presentation, investigations, management)

Answer 14

Streptobacillus moniliformis or Spirillum minus
Reservoir = rates
Transmission = bites, infected urine/droppings
Presentation (2-10 days after bite):
1. Fevers, polyarthralgia, maculopapular rash
2. Endocarditis
Ix: joint fluid for MC&S, blood culture
Mx: penicillin

Question 15

Describe Hantavirus pulmonary syndrome (reservoir, transmission, presentation, investigations, management)

Answer 15

Reservoir = deer mouse (Sin Nombre), white-foots mouse, cotton rat, rice rat
Transmission = contact with infected urine/droppings
Presentation =
- “flu-like illness”
- Respiratory failure
- Bleeding
- Renal failure
Ix: serology, PCR
Mx: supportive

Question 16

Describe viral haemorrhagic fever (reservoir, transmission, presentation, investigations, management)

Answer 16

Reservoir = bats (ebola), rats (lassa), bats (marburg), Ticks (congo-crimean haemorrhagic fever)
Transmission = contact with infected fluids
Presentation: fever, myalgia, flu-like illness, bleeding
Presentation:”flu-like” illness, bleeding
Ix: serology, PCR
Mx: admit into side room + support

Question 17

Describe Lyme disease (reservoir, transmission, presentation, investigations, management)

Answer 17

Reservoir = tics → ixodes
Presentation = erythema migrans
Ix: ELISA
Mx: doxycycline

Question 18

What is the reservoir for leptospirosis

Answer 18

Dog/rate urine

Question 19

Describe anthrax

Answer 19

Caused by bacillus anthracis
Painless round black lesion → mediastinal haemorrhage
Mx: doxycycline