Zoonoses Flashcards
What are Zoonoses?
Infections that pass between living animals and humans, and the source of the disease is from the animal.
What are some common examples of diseases that are not zoonoses but may be confused for them?
Malaria
Schistosomiasis
Oncoceriasis
Elephantiasis
They depend on the human host for part of their life cycle so are not zoonoses.
What are Anthroponosis?
Reverse zoonoses.
Humans infect animals
What are some examples for anthroponosis?
Influenza (birds/pigs)
Strep throat (bacteria affecting dogs)
Leishmaniasis (parasite affecting dogs)
Chytridiomycosis (fungus affecting amphibians)
What are some techniques zoonoses have developed to survive/ propagate?
Have a non-human reservoir
Cause a chronic infection to survive.
What are some examples of Bacterial Zoonoses?
Salmonella Campylobacter Shigella Anthrax E.coli Plague Brucella
What are some examples of viral zoonoses?
Rabies Avian influenza Ebola virus Crimean-Congo Haemorrhagic. West Nile fever.
What are some examples of parasitic zoonoses?
Cysticercosis Echinococcosis Toxoplasmosis Trichinellosis Visceral larva migrans
What are some examples of fungal zoonoses?
Dermatophytoses
Sporotrichosis
What is an example of a prion zoonoses?
BSE/CJDv - e.g Mad cow disease.
What are some examples of common zoonoses in the uK?
Salmonella Campylobacter Toxoplasma Psittacosis - Chlamydophila psittaci (common in atypical pneumonia with bird contact). Q-fever - Coxiella Burnetti Ringworm/dermatophytosis.
What is Anthrax?
Uncommon zoonoses in the UK.
Spore forming bacteria that can live in the soil for years.
Common in Middle East and Afghanistan.
Cutaneous is most common but pulmonary is most severe.
What is Tularaemia?
‘rabbit fever’
Bacterial infection now rarely seen in the UK.
Hunters who come in contact with rabbits/hares/etc.
Mainly a skin infection.
What are some emerging zoonoses?
Avian influenza Nipah virus Rabies Brucellosis Monkeypox.
What is an emerging zoonoses?
Newly recognised or newly evolved zoonoses or one that has occurred previously but shows an increase in incidence or expansion in geographical, host or vector range.
What is Rabies?
Viral infection (lyssavirus) transmitters from the bite of an infected animal. Dog is main transmitter though bats, foxes, racoons, skunks, wolves, cats and monkeys also can.
What is the incubation period for rabies?
2 weeks to several months.
How does Rabies affect the body?
Travels to the brain via the peripheral nervous system.
Causes acute encephalitis which presents with:
Malaise, headache, fever Mania, lethargy, coma Overproduction of saliva & tears. Unable to swallow & hydrophobia. Death.
How is rabies diagnosed?
PCR of saliva
CSF
Post mortem on brain biopsy.
What is the treatment for Rabies?
Human rabies immunoglobulin (HRIG).
Infiltrated round the bite.
+4 doses of rabies vaccine over 14 days.
What is Brucellosis?
Bacterial infection where organisms are excreted in milk, placenta and aborted foetus.
Humans infected by milking infected animals, parturition , handling carcasses, unpasteurised dairy products.
What are the 3 main species of Brucella?
Melitensis - most virulent, goats, sheep, camels, Meditteranean.
Suis - pigs, N&S America, SE Asia.
Abortus - least virulent, cattle, buffalo, worldwide.
What is the incubation period of brucellosis?
5-30 days but up to 6 months.
What are the acute symptoms of brucellosis?
High undulant fever Weakness Headaches Drenching sweats Splenomegaly
What are the subacute symptoms of brucellosis?
Fever
Joint pains commonly in knee, hip and back sacral joints.
What are the chronic symptoms of brucellosis?
Flu-like symptoms Malaise Depression Chronic arthritis Endocarditis Meningitis Epididymo-orchitis Splenomegaly.
What is the treatment for Brucellosis?
Long acting Doxycycline for 2-3months + Rifampicin, or + intramuscular gentamicin for first weeks.
Add Cotrimoxazole for 2 weeks in CNS disease.
What is Leptospirosis?
Bacterial infection of Lepsirosa icterohaemorrhagica -a thin highly mobile spirochaetes.
Spread via rodents and water exposure.
Triad of flu-like symptoms, jaundice and renal failure.
How is leptospirosis diagnosed?
Microscopic agglutination test (MAT)
ELISA serology
PCR
Culture
How is leptospirosis treated?
Doxycycline for mild disease
Iv penicillin for severe.
Prompt dialysis
Mechanical ventilation.
What is Lyme Borrelios?
Lyme’s disease caused by borrelia burgdorferi. Transmitted by tick, lxodes ricinus (Europe).
Commonest in summer months - active > 4 degrees.
Highlands and South East England.
What is erythema migrans?
Dermatological presentation of Lyme’s disease.
Occurs 3-90days after bite but most commonly after 7.
Single or multiple red lesions that are target like. Not painful or itchy.
What is Acrodermatitis Chronica Atroficans (ACA)?
Rarer skin manifestation of Lyme’s disease.
Extensor surfaces of distal extremities.
Blush red discolouration progresses over months/years to atrophic phase.
Peripheral neuropathy common.
What is Lymphocytoma?
Bluish solitary painless nodule.
Common presentation of Lyme’s disease in children.
affect earlobe or areola.
What is Neuroborreliosis?
Triad of facial nerve palsy, radicular pain and lymphocytic meningitis.
15% of patients with lyme’s develop this.
2-6weeks after bite.
Preceded by erythema migrans in 30-50% of patients.
How is Lyme’s disease diagnosed?
Erythema Migrans - clinical
ACA and Lymphocytoma - clinical and high serology titres.
Arthritis - high serology titres from synovial fluid and PCR.
NB - clinical and lab findings.
What is the treatment for Lyme’s disease?
Oral doxycycline or amoxicillin, or IV Ceftriaxone.
Most manifestations treat for 21days (28 in arthritis or ACA).
