Zoonoses Flashcards
What are zoonoses?
Infections that can pass between living animals and humans
The source of the disease is from the animal
Why are malaria, schistosomiasis and elephantitis not zoonoses?
Even though they are transmitted from animals, they depend on the human host for part of their life-cycle
What is anthroponosis?
Reverse zoonoses - humans infecting animals
Examples of anthroponosis
Influenza
Strep throat
Leishmaniasis
Chytridiomycosis
How have pathogens developed strategies to ensure their own survival/propagation?
Causing a chronic infection to survive
Have a non-human reservoir
Bacterial zoonoses
Salmonella Campylobacter Shigella Anthrax Brucella E-coli (verotoxigenic) Leptospirosis Plague Psittacosis (Ornitosis) Q fever Tularaemia
Viral zoonoses
Rabies Avian influenza Crimean-Congo haemorrhagic fever (CCHF) Ebola virus disease Lassa Fever Rift Valley fever West Nile Fever Yellow Fever
Parasitic zoonoses
Cysticercosis Echinococcosis Toxoplasmosis Trichinellosis Visceral larva migrans (toxocara)
Fungal zoonoses
Dermatophytoses
Sporotrichosis
Prion zoonoses
BSE/CJDV
Common zoonoses in the UK
Salmonella Campylobacter Toxoplasma (Psittacosis – Chlamydophila psittaci – atypical pneumonia – bird contact?) (Q-fever - Coxiella Burnetti) Ringworm/dermatophytosis
Uncommon zoonoses (now rarely seen in the UK)
Anthrax Rabies Bubonic plague Tularaemia Acute brucellosis
What is rabies?
Lyssavirus from the bite of an infected animal, mainly dogs
What is the incubation period of rabies in humans?
2 weeks to several months
What is the course of rabies?
To the brain from peripheral nerves
Presentation of rabies
Acute encephalitis
Acute encephalitis symptoms
Malaise, headache & fever Progressing to mania, lethargy & coma Over production of saliva & tears Unable to swallow & ‘hydrophobia’ Death by respiratory failure
Rabies prophylaxis
Human rabies immunoglobulin (HRIG)
Infiltrated round the bite (if possible)
+4 doses of rabies vaccine over 14 days
How are humans infected with brucellosis?
During milking infected animals
During parturition
Handling carcasses of infected animals
Consumption of unpasteurized dairy products
Brucella
Small, gram negative coccobacilli
Species of brucella
Melitensis
Suis
Abortus
Incubation period of brucellosis
5-30 days
What is the most common form of brucellosis?
Subclinical
Brucellosis treatment
Long acting Doxycycline for 2-3 months + Rifampicin, or + IM gentamycin for first week(s)
Add cotrimoxazole for 2 weeks in CNS disease
What is the most common causative organism of leptospirosis
Leptospira hardjo
What is leptospirosis?
Thin, highly mobile spirochaetes
Many reservoir hosts
Penetrate abraded skin or mucous membranes and cause systemic illness
Carriers of leptosprosis
Cattle
Rats
Presentation of leptospirosis
Undifferentiated fever
Myalgia
Headaches
Abdominal pain
Causative organism for lyme’s disease
Borrelia burgdorferi
Host organism for Lyme’s
Wild deer, transmitted by tick
Presentation of Lyme’s
Erythema migrans
Neuroborreliosis presentation
TRIAD
Peripheral facial nerve palsy
Radicular pain
Lymphocytic meningitis
Lyme treatment
Oral doxycycline or amoxicillin, or IV Ceftriaxone
