Leptospirosis 30% Flashcards
What is Leptospirosis?
Leptospirosis is caused by the filamentous, gram negative, motile spirochetes of the genus Leptospira. The genus has at least 16 species classified based on genetic relatedness and defined by agglutination cross absorption. There are over 200 serovars of L. interrogans that are classified into antigenically-related serogroups and the one associated with animal hosts.
Who gets lepto
The most common serovars:
canicola/ icterohemorrhagiae (dog- urban- rodent role in ictero)
grippo, pomona (dog- rural, suburban),
grippotyphosa (raccoon, marsupials, rodents)
pomona (cow, pig, horse)- uveitis/ abortions in horses, redwater dz in calves (most severe)
hardjo (cow) - redwater dz in calves (reservoir, less severe)
bratislava (rat, horse, cattle, swine- abortions late term)
autumnalis (mouse).
No cross immunity with serovars
Transmission of lepto
Leptospira organisms prefer warm, moist, alkaline environments. They are more likely to be found in stagnant or slow moving water. Environmental flooding can saturate the soils with organisms, prevent evaporation of contaminating animal urine, and prolong survival of organisms in surface water.
Leptospira spp. can remain viable for months in moist environments under optimal conditions, although they do not replicate outside of the host.
Peak incidence in dogs occurs July through November and often follows periods of heavy rainfall or flooding.
Localizes to kidneys and reproductive tract- shed in urine and reproductive fluids/ tissues for transmission- contact with infected water, urine with MMs. Animals can become infected with leptospires through contact with infected urine, via venereal or placental transfer, through bite wounds, or ingestion of infected tissues. Indirect transmission can occur through exposure of animals to water sources, soil, food, or bedding that is contaminated with infected urine or other tissues.
Leptospires can penetrate mucous membranes, wet or macerated skin, or broken skin.
Incubation-
Lepto
Infection to clinical signs 10-14 days
Diagnosis of lepto
Live/ kidney disease differential, gold standard Microscopic Agglutination Test MAT (IgM for acute and IgG for chronic) test- one titer not diagnostic, 4 fold titer changes titers, ELISA, Blood /urine PCR, can be detected 9 days after infection.
Treatment- Lepto
Penicillins (not good for leptospiuric phase?), macrolides, tetracyclines + fluid support, vaccine for prevention (multivalent for dogs, ungulates), eliminate carriers- rodents, herd management, wildlife seperation. Convalescent titers are recommended.
zoonotic lepto
Leptospirosis is a zoonotic disease. Veterinarians, farmers, animal caretakers, and sewer system workers are at increased risk of exposure. Exposure can also occur through recreational activities such as boating, freshwater swimming, and hunting. Immunocompromised people and children are at greater risk for infection.1 People have contracted leptospirosis in urban areas from exposure to infected rodent urine.
Clinical signs- Lepto
The disease affects virtually all mammals and has a broad range of clinical effects, from mild, subclinical infection to multiple-organ failure and death. Kidney, liver, and respiratory disease are key findings- fever, icterus, hemoglobinuria, renal failure, infertility, abortions, death.
Canine- 80-90% kidney disease, 20% liver disease
