Zoonoses Flashcards
What is the WHO definition of a zoonoses?
Infections that are naturally transmitted between vertebrate animals and humans
Where is source of disease in zoonoses?
Animals
What are NOT zoonoses and why?
Malaria
Schistosomiasis
Oncoceriasis
Elephantiasis
Transmitted by animals, but depend on the human host for part of their life-cycle
What are anthroponosis?
An infectious disease in which a disease causing agent carried by humans is transferred to other animals
What are examples of anthroponosis?
Influenza
Strep throat
Leishmaniasis
Chytridiomycosis
What can zoonoses by caused by?
Virus, bacteria, parasites or fungi
What are examples of bacterial zoonoses?
Salmonella Campylobacter Shigella Anthrax Brucella E.coli Leptospirosis Plague
What are examples of zoonotic viruses?
Rabies Avian flu Crimean-Congo haemorrhage fever (CCHF Ebola Laa fever West Nile fever Yellow fever
What are examples of parasitic zoonoses?
Cysticercosis Echinococcosis Toxoplasmosis Trichinellosis Visceral larva migrans
What are examples of fungal zoonoses?
Dermatophytoses
Sporotichosis
What are the most common zoonoses in the UK?
Salmonella
Campylobacter
Toxoplasma
Ringworm/dermatophytosis
What are rare zoonoses for the UK?
Anthrax
Rabies
Bubonic plague
What are emerging zoonoses?
A zoonosis that is newly recognised or newly evolved, or that has occurred previously but shows an increase in incidence or expansion in geographical, host or vector range
What is rabies?
A viral infection transmitted from bite of infected animal
What are the main transmitters of rabies?
Dogs, bats, monkeys
What is the incubation period in humans for rabies?
2 weeks to several months
What does rabies do once in the body?
Travels to the brain via peripheral nerves and causes acute encephalitis
What are the signs/symptoms of rabies?
Malaise, headache, fever Progressing to mania, lethargy & coma Over production of salvia & tears Unable to swallow & hydrophobia Death by respiratory failure
How is diagnosis of rabies made?
PCR of saliva or CSF
What is the prognosis of rabies if untreated?
Fatal
What is the management for rabies?
Post-exposure prophylaxis
Human rabies immunoglobulin (HRI)
+4 doses rabies vaccine over 14 days
What is brucellosis?
Highly contagious zoonosis caused by ingestion of unpasteurized milk or undercooked meat from infected animals, or close contact with their secretions
What did brucellosis used to be an occupational hazard of?
Farmers, vets, slaughterhouses
How are the organisms excreted in brucellosis?
In milk, placenta and aborted foetus
How are humans infected by brucellosis?
During milking
During parturition
Handing carcasses
Consumption unpasteurised dairy products
What are the 3 species of brucella?
Melitensis
Suis
Abortus
What is the incubation period for brucellosis?
5-30 days (up to 6mo)
What are the 4 types of symptoms of brucellosis?
Acute
Subacute
Chronic
Subclincal (commonest)
What is the acute presentation of brucellosis and how does it typically last?
High undulant fever Weakness, headaches Drenching sweats Splenomegaly Lasts 1-3wks
What is the subacute presentation of brucellosis and how does it typically last?
Fever and joint pains
Lasts over 1mo
What is the chronic presentation of brucellosis and how does it typically last?
Flu-lie symptoms Malaise Depression Chronic arthritis Endocarditis Splenomegaly Epididymo-orchitis Lasts for months-years
What is the most common form of symptom presentation in brucellosis?
Subclinical
What is the treatment for brucellosis?
Long acing doxycycline for 2-3mo + rifampicin + IM gentamicin for 1st week
If CNS disease in brucellosis, what treatment should you add?
Cotrimoxazole for 2wks
What bacteria used to cause leptospirosis in fisherman and miners?
Leptospira icterohaemorrhagica
What is the common form of leptospirosis now?
Leptospira hardjo
What is leptospirosis caused by today?
Cattle
What are the signs/symptoms of leptospirosis today?
Fever
Meningism: headaches
Myalgia
Abdo pain
How does leptospirosis penetrate host?
Abraded skin or mucous membranes and cause systemic illness
What type of bacteria are leptospirosis?
Spirochaetes
What is the incubation period for leptospirosis?
2-30 days
How is leptospirosis transmitted to human host?
Direct contact with animal
Contact with environment (water) contaminated with urine
What happens in severe leptospirosis?
Weil’s disease: triad jaundice, AKI, bleeding
Pulmonary haemorrhage
What is Weil’s disease?
Severe form of leptospirosis
What are the investigations for leptospirosis?
Microscopic agglutination test (MAT)
ELISA serology
PCR
Culture
What is the treatment for leptospirosis?
Antibiotics Doxycline: mild IV penicillin: severe Dialysis Mechanical ventilation
How is lyme borrelios transmitted?
Ticks: I.ricinus
When are ticks most active (Lyme disease)?
> 4’C
Humidity
What is a sign of Lyme disease in 80-90% cases?
Erythema migrans
What is the diagnosis for Lyme disease?
Clinical diagnosis
Erythema migrans
Single or multiple lesions
How soon after the bike does erythema migrans usually present in Lyme disease?
3-90 days
What are presentations of Lyme disease?
Erythema migrans Acrodermatitis chronica atroficans Lymphocytoma Neuroborreliosis Cardiac disorders: carditis, heart block Arthritis
How does acrodermatitis chronica atroficans (ACA) present in Lyme disease?
Bluish-red discolouration on extensor surfaces of distal extremities
Progresses over months to years to atrophic phase
What is common in acrodermatitis chronica atroficans (ACA)?
Peripheral neuropathy
How does lymphocytoma present in Lyme disease?
Bluish solitary painless nodule
Usually earlobe or areola
How does neuroborreliosis present in Lyme disease?
Triad of facial nerve palsy, radicular pain & lymphocytic meningitis
What is the triad that presents in neuroborreliosis?
Facial nerve palsy
Radicular pain
Lymphocytic meningitis
When does the onset of neuroborreliosis symptoms present in Lyme disease?
2-6 wks after bite
What are more common presentations in Lyme disease in the US?
Cardiac disorders: carditis/heart block
Arthritis
How is Lyme disease diagnosed?
EM = clinical diagnosis
ACA & lymphocytoma = clinical and serology
Arthritis = serology/PCR from synovial fluid
NB = clinical and lab
What is the treatment for Lyme disease?
Antibiotics:
Oral doxycycline or amoxicillin or IV ceftriaxone for 21 days
What is Q-fever?
Bacterial infection caused by the bacteria Coxiella burnetii. The bacteria are most commonly found in cattle, sheep, and goats around the world. Humans typically get Q fever when they breathe in dust that was contaminated by infected animals
What are the clinical features of Q-fever?
Q fever does not always cause symptoms. Some people get flu-like symptoms within 2 to 3 weeks of being infected, such as: a high temperature (fever) aching muscles tiredness feeling sick a sore throat swollen glands Symptoms of Q fever usually last up to 2 weeks.
What is the management for Q-fever?
Antibiotics
What is toxoplasmosis?
A disease from infection with the Toxoplasma gondii parasite, one of the world’s most common parasites. Infection usually occurs by eating undercooked contaminated meat, exposure from infected cat feces, or mother-to-child transmission during pregnancy.
What are the signs/symptoms of toxoplasmosis?
Toxoplasmosis doesn’t usually cause any symptoms and most people don’t realise they have had it.
Some people get flu-like symptoms, such as:
high temperature (fever)
aching muscles
tiredness
feeling sick
sore throat
swollen glands
If you do have symptoms, they normally get better on their own within about 6 weeks.
What is psittacosis?
A zoonotic infectious disease in humans caused by a bacterium called Chlamydia psittaci and contracted from infected parrots, such as macaws, cockatiels, and budgerigars, and from pigeons, sparrows, ducks, hens, gulls and many other species of birds.
What are the signs/symptoms of psittacosis?
Acute respiratory disease
Flu-like symptoms
Severe pneumonia
What is the treatment for psittacosis?
Antibiotics
