zoonoses Flashcards
What is zoonosis
Infectious diseases that can be transmitted between humans and animals
what is enzoonotic
endemic to the area and usually human to human transmittion does not occur
What are the common UK zoonosis
Campylobacter
salmonella
toxoplasma
psittacosis
Q fever
ring worm
If a pathogen relies on a human in part of it’s life cycle is it zoonosis
No , common examples are - malaria, schistosomiasis, oncoceriasis and elephantiasis
What is anthroponosis with examples
reverse zoonosis - humans infecting animals e.g influenza, strep throat, leishmaniasis and chytridiomycosis
What organism causes lyme’s disease
Borrelia burgdorferi
How is lyme disease transmitted
by hard tick - ixodes ricinus
What is the presentation of lyme’s disease
Erythema migrans - the dart board look which occurs one to two weeks after the bite - it is a clinical diagnosis of Lyme disease
What are the symptoms of lyme disease
early signs - fever, chills, headaches and fatigue
Later signs - facial palsy, irregular heart beat, dizziness and erythema migrans
What is a complication of Lyme disease which affects the nervous system
Neuroborreliosis - triad of facial palsy, radicular pain (pain from back and hips into legs and thigh) and lymphocytic meningitis
What is the treatment for Lyme disease
First line - doxycycline
2nd line - amoxicillin - used first line in children
With neuro Lyme (Neuroborreliosis) - ceftriaxone is first line
What pathogens cause leptospirosis
Spriochete - L. icterohaemorrhagica and L. hardjo
How does leptospirosis spread
Usually a resovoir in rats and goes out in rat urine into water supply which is how it is transmitted to humans
If someone is doing water sports which zoonosis is most likely
Leptospirosis
What are the symptoms of leptospirosis
Undifferentiated fever, myalgia, headaches and abdominal paim
What is seen in severe leptospirosis
Weil’s disease - triad of jaundice, AKI and bleeding
Pulmonary haemorrhage
Fatality
What are the investigations for leptospirosis
Serology - study of blood serum - IgG and IgM
Microscopic agglutination test
What is the treatment of leptospirosis
First line - doxycycline
Second line - amoxicillin and azithromycin - if severe give IV ceftriaxone
How is rabies virus transmitted
Animal bite
What is the incubation time of rabies
very long - can range from months to years
Describe how rabies virus infects the body
The virus enters through the tissue through a bite by an animal - it then travels through he peripheral nervous system to the CNS and spinal cord - The virus then ascends the spinal cord and reaches the brain which causes encephalitis - it then spreads to salivary glands and other organs
Why is the bite location important in rabies
The further from the brain it is, the longer it will take to get up to the brain
What are the symptoms of rabies
Furious symptoms - more common -
Hydrophobia - due to virus in salivary gland not wanting their host to intake of water
insomnia
confusion
agitation
coma
Paralytic symptoms - less common -
Ascending flaccid paralysis from bite mark
fever
confusion
coma
What investigations are done in rabies
PCR of skin biopsy and of saliva
What is the treatment for rabies
milwaukee protocol - 5 different antivirals and anti-inflammatories
post exposure vaccine -
If fully immunised - 2 doses - one on day 0 and the other day 3-7
If not immunised - give HRIG - human specific rabies immunoglobulin around bite site and give 4 doses of post exposure vaccine : days 0,3,7,21
If immunocompromised and not vaccinated do the same as not immunised but add an extra dose of post exposure vaccine
What is ebola
A filovirus from africa
Filovirus- looks like a string
What are the host of ebola
Bats which then transmit to other animals which ten transmit to humans
What is the incubation period of ebola
2-21 days
What are the symptoms of ebola
Dry - fever, fatigue and aches and pains
Wet - vomiting, diarrhoea and haemorrhage - wet is the most worrying due to risk of dehydration and bleeding out
What investigations are done for ebola
PCR
Serology - IgM and IgG
What is the treatment for ebola
INMAZEB - 3 monoclonal antibodies that prevent the virus getting into host cells
EBANGA - 1 monoclonal antibody that works the same way as INMAZEB
What vaccinations are used in ebola
Ervebo - one dose during an outbreak
Zabdeno and MVAbea - one dose of each with a gap in between
How do people get infected with brucellosis
Unpasteurised milk products
How is toxoplasmosis transmitted
Infected cat poo
What are the symptoms of toxoplasmosis
fever, swollen glands and muscle aches
What transmits q fever to humans
cattle, sheep and other domesticated animals
How is psittacosis transmitted
From birds to humans
