Leptospirosis Flashcards
What do leptospira look like?
Gram negative, aerobic bacteria
* slender, motile, flexous and helically coiled
What are some of the characteristics of leptospira?
- Possesses an outer sheath, the outer layer of the spirochaete cell
- multilayered membrane that surrounds the periplasmic flagella
How many million human cases are there per year?
in the world
0.5
50 in the UK
What is leptospira biflexa?
Non-pathogenic but can contaminate surfaces
this means its hard to get out
Why is it to hard to culture leptospira?
- Slow-Growing, other bugs will outcompete it
- important that the sample is sterile
How do you culture leptospira?
Culture at 30 degrees, aerobically for 8 weeks
What is the main pathogenesis of leptospira?
How does it enter the body
gains entry via mucus membranes
once inside the body- > vascular damage and haemorrhage
What do you use to culture leptospira?
- Korthof broth
- Stuart broth
- Fletcher semisolid medium
What is the main test used to diagnose leptospira?
microagglutination test
Where does leptospira antibodies persist?
- Renal tubules
- Eyes
- Uterus
What samples may you take for diagnose?
- Midstream urine
- Liver tissue
- Kidney tissue
- Foetal tissue
- Blood
What animals are considered reservoirs of leptospirosis?
can be harboured in the kidneys of virtually all mammalian species
What species are the largest risk of infection for human beings
Rodents- they can shed leptospirosis throughout their life without clinical manifestations
How is leptospirosis transmissed to humans?
Infection may be acquired by direct or indirect contact- tissues or secretions, water with animal urine
How does leptospira enter the body
via a cut or damaged skin but can also pass across damaged or intact mucus membranes
Where in the world is leptospirosis most common?
tropical and subtropical areas with high rainfall
anywhere where humans come into contact with infected urine
What treatment is the most effective in early stages of infection
Humans
penicillin or doxycycline
What are the signs of acute haemorragic disease in dogs?
high fever, vomiting, prostration (lying down) and early death
What are the clinical signs of less acute leptospirosis in dogs
intense icterus, depression, fever, haemorrhages with blood in urine
What is uraemic leptospirosis associated with in dogs?
associated with extensive kidney damage
What are the clinical signs of leptospirosis in pigs?
- Fever
- Mastitis
- Infertility
- abortion and stillbirths
- fever, anorexia, jaundice
What are the clinical signs of leptospirosis in cattle?
- Milk drop syndrome
- abortion and neonatal mortality (abortion storms)
- Infertility
- jaundice, fever, haemoglobinuria
When is natural immunity established?
in a herd after the initial infection phase
all new animals that enter the herd are susceptible
What are the symptoms of leptospirosis in horses
Recurrent iridocyclitis (moon blindness- cant see well at night, poor peripheral vision, based on light intensities )
* Abortion
* Fever, anorexia, depression and icterus
What does leptospirosis in sheep look like?
- mainly sub-clinical
- depression, dyspnoea, haemoglobinuria
- high mortality in lambs
What is the vaccination for cattle?
Vaccination in cattle recommended at 5 months of age with annual
boosters
What is the vaccination for pigs?
– Vaccination in pigs recommended for sows prior to farrowing
What is the vaccination method for dogs?
– Vaccination in dogs recommended at eight weeks of age with annual
boosters
What is leptospira interrogans?
Pathogenic bacteria
Name 4 ways leptospira can cause damage once inside the body
- Damages the vascular endothelium resulting in haemorrhage
- Produces haemolysins/ lipids proteins that cause vascular damage
- Produces cytotoxic proteins
- Disseminated intravascular coagulation
When does antibody production begin?
a few days after the onset of leptospiraemia
a maternal antibody also develops however it is quite short lived
What do leptospira produce?
- Haemoxygenase
- Haemolysin
- Cytotoxic Protein
What is the difference between bacteraemia and septicaemia?
- Bacteraemia- bacteria in the blood
- Septiceamia- bacteria actively replicating in the blood
Name 5 ways you may be able to diagnose leptospira
- Clinical signs
- Antibodies in blood
- Culturing organisms
- Fluorescent antibody test
- PCR
What antibiotics would you use to control leptospira in animals?
- Doxycycline
- Streptomycin
- Penicillin
What do the aborted foetuses often look like?
Icteric, jaundiced yellow membranes
When are leptospirosis vaccinations recommended in cattle?
5 months of age with annual boosters
When are vaccinations in pigs recommended?
Prior to farrowing
When are vaccinations in dogs recommended?
eight weeks of age with annual boosters
How may you control leptospirosis in animals?
- Education
- Rapid diagnosis
- Removal of reservoirs
- Closed herds
- Biosecurity
