Crash course: Zoonoses Flashcards
What causes Brucellosis? What is it contracted from? When does it present?
Brucella spp.
Contracted from raw dairy + farm animals
After 2w incubation
Give 3 features of brucellosis presentation
Sudden onset high fever, rigours, headache, malaise, myalgias
Back/ joint pain, hepatosplenomegaly, FLAWSy
Which 2 ‘buzzword’ symptoms are associated with brucellosis
BACK PAIN as causes epidural abscess
EPIDIDYMO-ORCHITIS
Give 3 serious manifestations of brucellosis
Endocarditis
Osteomyelitis
CNS infection
What is used to diagnose and treat Brucellosis?
Dx: Cultures
Tx: Doxycycline + Streptomycin
What causes Rabies? How is it contracted? When does it present?
Various Lyssaviruses
Contracted from animals: dogs + bats
After 1-3m incubation
How does rabies present?
Initially: fever, headaches, malaise
Within days affects CNS: furious + dumb rabies
Excessive salivation, hydrophobia
How is rabies diagnosed?
Often clinically
Dx: Fluorescent antibody test
CSF PCR possible (bad sign)
Biopsy from nape of neck
What is pathogonomic for rabies?
Negri body on histology
(inclusion body in infected neurons)
How is rabies treated?
Only before symptomatic
If bitten: pre-emptive rabies vaccine + immunoglobulins
What causes plague? What is it contracted from? When does it present?
Yersinia pestis
Rat fleas
After hours- couple of days
Give 4 features of bubonic plague
Fevers
Rigors
Buboes: massive LNs, when aspirated contain dense black fluid
Dry gangrene
Give 4 features of pneumonic plague
Fevers
Rigors
Cough + bloody sputum
ARDS
Give 4 features of septicaemic plague
Fevers
Rigors
DIC
Peripheral gangrene
How is plague diagnosed and treated?
Dx: Microscopy, culture or PCR
Tx: Aminoglycosides or Doxycycline
What causes Leptospirosis? What is it contracted from? When does it present?
Leptospira spp.
Rat urine
After 1w incubation
What scenario may leptospirosis be contracted in?
swimming in lake with rat pee in (stagnant water)
How can leptospirosis present?
Fevers, chills, rigors, myalgia, pharyngitis ± haemoptysis
Conjunctival suffusion, jaundice, meningitis
Pulmonary or GI haemorrhages, renal failure, haemolysis
Give 2 buzzword symptoms of leptospirosis
JAUNDICE
CONJUNCTIVAL SUFFUSION (Dry conjunctivitis, no exudate)
What causes Bartonellosis? How is it contracted? When does it present?
Bartonella henselae
Cat scratches
After 1w incubation
How does Bartonellosis present?
Painless erythematous crusted papule at scratch site
Lymphadenopathy proximal to inoculation site
Fevers, malaise
What presentation is pathogonomic for Bartenollosis?
Parinaud oculoglandular syndrome:
Conjunctivitis + enlarged LN in front of ear
What causes Lyme disease? How is it transmitted? When does it present?
Borrelia spp.
Ixodes tick
After days-weeks incubation
How does early localised Lyme disease present?
Erythema migrans, esp. inoculation site
“Bulls-eye” or “target” rash
How does early disseminated Lyme disease present?
Fevers
Myalgias
Arthralgias
CNS: headache, meningitis
Cardiac: palpitations, heart block
How does late disseminated Lyme disease present?
Arthritis
Skin lesions
Polyneuropathies
How is Lyme disease diagnosed and treated?
Dx: Clinically if erythema migrans + exposure or rash biopsy/ serology
Tx: Doxycycline
Ceftriaxone if CNS involvement
What causes Leishmaniasis? How is it transmitted?
Leishmania spp.
Sand fly bites
How does cutaneous Leishmaniasis present?
Well demarcated lesion at site of inoculation
How does mucocutaneous Leishmaniasis present?
Follows cutaneous, destructive lesions around face
How does diffuse cutaneous Leishmaniasis present?
Widespread nodular rash
How does visceral Leishmaniasis present?
Gradual onset fever
Hepatosplenomegaly
Pancytopenia
Die of secondary infections if not treated
How is Leishmaniasis diagnosed and treated?
Dx: Microscopy
Tx: Amphotericin B (for visceral- the form that will kill)
Cutaneous harder to treat
What causes Anthrax? What is it found in? How is it spread?
Bacillus anthracis
Found in farm/ wild animals
Spread by spores in hair
What are the 3 major forms of presentation of Anthrax?
Cutaneous
GI
Pulmonary
How does cutaneous Anthrax present?
Boil that develops into an eschar
Lymphadenopathy
How does GI Anthrax present?
Haemorrhage necrotic ulcers
Lymphadenopathy
Perforation
How does pulmonary Anthrax present?
Chest pain
Haemoptysis
SOB
Haemorrhagic mediastinitis
What is an eschar?
Painless necrotic skin lesion
Deep, dark, black
What 2 buzzword symptoms/ signs are associated with anthrax?
Eschars
Widened mediastinum
List 4 dermatophytoses that can be treated topically
Tinea pedis – Athletes foot
Tinea cruris – Groin
Tinea corporis – Body
Tinea manuum – Hands/ palms
Give 2 dermatophytoses that require systemic treatment
Tinea capitis – Scalp/ hair
Tinea unguium – Finger/ toenails
Name 1 organism causing Tinea infection
Trichophyton rubrum
What causes Pityriasis versicolor? How does this present?
Malassezia furfur
Multiple brown/ tan/ hypopigmented lesions across trunk, abdo + face
What is the treatment for Pityriasis versicolor?
Ketoconazole 2% shampoo
What are 2 topical treatments for tinea infections?
Clotrimazole 1%
Terbinafine 1%
What are 2 oral treatments for tinea infections?
Itraconazole
Terbinafine
What causes candidiasis?
Candida spp.
How does candidiasis most commonly present?
Vaginal candidiasis (thrush)
+ skin infections
Which population is oral candidiasis associated with?
Asthmatics- use steroid inhalers (thus encourage to wash mouth out after use)
Which population is oesophageal candidiasis associated with?
Severe immunosuppression- HIV
Which population is disseminated candidiasis associated with?
Those with a central line
What tests are diagnostic of candidiasis?
Beta-D-glucan +ve
Galactomannan -ve
How can severe candidiasis be treated?
Amphotericin B
What causes Aspergillus?
Aspergillus spp
What is an aspergilloma? In which patients are these seen?
Ball of aspergillus that forms in pre-exisiting cavity
Occur in patients with pre-existing cavity e.g. TB, squamous cell lung cancer, bronchiectasis
What does invasive aspergillosis involve? In which patients does this occur?
Pulmonary + extra pulmonary
Immunocompromised/ those with a line infection
What is allergic bronchopulmonary aspergillosis?
Hypersensitivity reaction to colonisation
Seen in asthmatics, profound inflammatory response
NOT infection with aspergillus
What tests can be used to detect aspergillus?
Beta-D-glucan: +ve
Galactomannan: +ve
What is the treatment for aspergillosis?
Aspergilloma: Surgical removal
Invasive aspergillosis: Amphotericin B
ABPA: Prednisolone
What causes sporotrichosis? How is it contracted?
Sporothrix schenckii
Contracted from ROSE THORNs- seen in gardeners/ farmers
Describe presentation of sporotrichosis
Proximally spreading nodular necrotic rash from inoculation site
Can disseminate, producing abscesses in bone, joints, CNS
What causes Mucormycosis? In which patients is it seen?
Rhizopus + Mucor spp.
Patients that had covid esp. diabetics
Describe presentation of Mucormycosis
Rhinocerebral infection, necrotic, destroys tissue
Vascular invasion follows
Very high mortality
What is PrPc? What is its secondary structure?
Protein expressed on surface of neurones of brain
2 structure: Alpha-helical
What can PrPc misfold into? What causes this? What does this cause?
PrPSc: change in secondary structure: beta pleated sheets
Sporadically, familially or infectiously
Difficult to degrade, water-insoluble, forms big lumps of protein.
Accumulation results in neuronal cell death
How does PrPSc interact with normal PrPc?
PrPSc can make PrPc misfold
= propagation of protein that can’t be moved or degraded + are neurotoxic
What is the most common form of prion disease?
Creutzfeldt-Jakob disease
What are the 3 forms of CJD?
Sporadic: 85% = unknown endogenous cause
Familial: 5-15% = genetic mutation
Acquired: <1%
How can CJD be acquired?
Acquires first dose of misfolded protein exogenously
Iatrogenic: thus surgical instruments must be autoclaved
Variant: acquired from eating beef with mad-cow disease (prion disease)
What is the proper name for mad cow disease?
bovine spongioformencephalopathy
How is CJD diagnosed?
Clinically + supported by imaging
Can only be confirmed on biopsy postmortem
In which form of CJD can an alternative investigation be used to diagnose?
variant CJD
Prion protein found in tonsils
Ix: Tonsillar biopsy
Other than CJD, name 3 prion diseases
Kuru
Gerstmann-Sträussler-Scheinker disease
Fatal Familial Insomnia
What is Kuru disease?
Prion disease seen in Papau New Guinea
Spread through ritual cannibalism
What is Gerstmann-Sträussler-Scheinker disease?
Autosomal DOMINANT familial prion disease
Slower progression than others
Life expectancy 5y
What is Fatal Familial Insomnia?
Autosomal DOMINANT familial prion disease
Features prominent insomnia, paranoia, hallucinations
