Lecture 8 Zoonoses Flashcards
What are zoonoses
Infections that can pass between living animals and humans
Name examples of reverse zoonoses
Influenza (virus affecting birds, pigs)
‘Strep throat’ (bacteria affecting dogs)
Leishmaniasis (parasite affecting dogs e.g.)
Chytridiomycosis (fungus affecting amphibians)
Name bacterial zoonoses
Salmonella Campylobacter Shigella Anthrax Brucella E-coli (verotoxigenic) Leptospirosis Plague Psittacosis (Ornitosis) Q fever Tularaemia
Name Viral zoonoses
Rabies Avian influenza Crimean-Congo haemorrhagic fever (CCHF) Ebola virus disease Lassa Fever Rift Valley fever West Nile Fever Yellow Fever
Name Parasitic zoonoses
Cysticercosis Echinococcosis Toxoplasmosis Trichinellosis Visceral larva migrans (toxocara
Name Fungal zoonoses
Dermatophytoses
Sporotrichosis
Name a prion zoonoses
CJD
What are common zoonoses in the UK
Salmonella Campylobacter Toxoplasma (Psittacosis – Chlamydophila psittaci) (Q-fever - Coxiella Burnetti) Ringworm/dermatophytosis
What is the incubation period in humans for rabies
2 weeks to several months
How does rabies causes acute encephalitis
Travels to the brain via peripheral nerves
What are the symptoms of acute encephalitis
Malaise, headache & fever
- Progressing to mania, lethargy & coma - Over production of saliva & tears - Unable to swallow & ‘hydrophobia’ - Death by respiratory failure
How is rabies diagnosed
PCR of saliva or CSF
Often confirmed PM on brain biopsy
How can rabies be prevented after bite
Give post-exposure prophylaxis
Human rabies immunoglobulin (HRIG)
infiltrated round the bite (if possible)
+4 doses of rabies vaccine over 14 days
Name 4 methods in which humans are infected with Brucellosis
During milking infected animals
During parturition
Handling carcasses of infected animals
Consumption of unpasteurised dairy products
What type of bacteria is Brucellosis
Small, gram negative coccobacilli
What is the incubation time of brucellosis
5-30 days (up to 6 months)
What are the Acute symptoms of a Brucellosis infection
Acute (now very rare in Scotland) Last 1-3 weeks High ‘undulant’ fever Weakness, headaches Drenching sweats Splenomegaly
What are the Subacute symptoms of a Brucellosis infection
Last over 1 month
Fever and joint pains (knee, hip, back SI joints)
What are the Chronic symptoms of a Brucellosis infection
Lasts for months or years Flu-like symptoms Malaise Depression Chronic arthritis Endocarditis Epididymo-orchitis Rarely meningism Splenomegaly
What are the Subclinical symptoms of a Brucellosis infection
Most common
50% of exposed have positive serology
How is Brucellosis treated
Long acting Doxycycline for 2-3 months + Rifampicin, or + intramuscular gentamycin for first week(s)
Add Cotrimoxazole for 2 weeks in CNS disease
How does Leptospirosis infect humans
Thin, highly mobile spirochaetes penetrate abraded skin or mucous membranes and cause systemic illness
What are the symptoms of Leptospirosis infection
Undifferented fever; myalgia, headaches & abdominal pain
How is Leptospirosis detected
Microscopic agglutination test (MAT) requires paired sera
ELISA
PCR
Culture- take at least one week on special media
How is Leptospirosis treated
Doxycycline for mild disease, IV penicillin for severe
AB may be more effective during early phase
Prompt dialysis
Mechanical ventilation
What is the vector for Lyme borrelios
Ixodes genus
Name a clinical feature of Lyme disease
Erythema Migrans
Acrodermatitis Chronica Atroficans (ACA)
Lymphocytoma
Neuroborreliosis(facial nerve palsy, radicular pain & lymphocytic meningitis)
Who does ACA commonly affect
Elderly people
What are the clinical features of ACA infection
Bluish-red discoloration over extensor surfaces – progresses over months to years to atrophic phase
Peripheral neuropathy common
How is Lyme disease diagnosed
Clinical diagnosis ACA and Lymphocytoma clinical & high serology titres Arthritis PCR NB, clinical + laboratory findings Neuro symptoms consistent with LNB CSF pleocytosis (WBC in CSF), often lymphocytic Paired blood and CSF serolgoy
What is the treatment for Lyme Disease
Oral Doxycycline or Amoxicillin, or IV Ceftriaxone
Most manifestations treat for 21 days (28 in arthritis or ACA)
