Leptospirosis. Flashcards
what is ETIOLOGY PATHOGEN of leptospirosis
Leptospira interrogans
what are the CHARACTERISTICS OF LEPTOSPIRA INTERROGANS?
EPIDEMIOLOGY !!!!!!!!!
group: spirochetes
obligatory aerobes
hook-shaped ends
common zoonotic disease worldwide and is most common in the TROPICS
ALSO hawaii
what are the RESERVOIRS FOR LEPTOSPIRA INTERROGANS?
rodents and livestock and dogs
what is the TRANSMISSION OF LEPTOSPIROSIS?
excretion of the bacteria with urine - contaminate the wet soil which in turn contaminates the water
we intake the agent through our skin / mucous membranes and aerosols
humans are accidental host - and play no role in transmission
who are at RISK FOR LEPTOSPIROSIS ?
channel construction worker, farm workers,
water sports enthusiasts
what is the INCUBATION PERIOD OF LEPTOSPIROSIS INTERROGANS ?
one-two week
what are the SYMPTOMS OF LEPTOSPIROSIS INTERROGANS ?
there is variable course of the disease : such as mild flu like symptoms , organ failure to death
mild form - characterized by nonspecific symptoms that generally resolve spontaneously after a week.
In some of cases, the disease progresses rapidly to a severe form (icterohemorrhagic leptospirosis, or Weil disease)
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it is biphasic
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1) mild form - 1 week
acute spike in fever , headache , joint and muscle pain
abdominal symptoms - D+V
redness of the conjuctiva and measles like exanthema
PHOTOPHOBIA
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mild leptospirosis resolve spontaneously - progress to the severe form (Weil disease)
====== Severe leptospirosis (Weil disease, icterohemorrhagic leptospirosis)
lasts 5-7 days
due to systemic spread and multiorgan involvement.
vasculitis of the capillaries - Hemorrhage
Purpura
Pulmonary hemorrhage → hemoptysis
organ involvement :
liver - hepatitis , jaundice , hepatomegaly , acute liver failure
kidney - acute renal failure , interstitial nephritis (hematurea , oligourea)
neuro = lymphocyte meningitis
cardio - myocarditis and pericarditis
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MORBUS WEIL - jaundice , splenomegaly and renal failure
what is the DIAGNOSIS OF LEPTOSPIROSIS INTERROGANS ?
Dark-field microscopy of urine or blood samples
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Serological tests :
1) Four-fold rise in the level of IgM titers within one month of the onset of symptoms
(ELISA )
2 )micro agglutination test - Positive one week after the onset of symptoms.
Patient serum is incubated with Leptospira serovars, and titers are obtained for serovars that react with patient serum.
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PCR: detect leptospiral DNA in bodily fluids
positive only during the bacteremic phase (i.e. within the first week of symptom onset).
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Urine cultures become positive after the first week.
Leptospira cultures require special media (Fletcher medium) and take weeks
TREATMENT OF LEPTOSPIROSIS ?
mild leptospirosis: doxycycline, azithromycin, or aminopenicillins (ampicillin, amoxicillin)
For severe leptospirosis
IV penicillin G,
doxycycline,
or 3rd generation cephalosporins (e.g., ceftriaxone)
what is the PREVENTION OF LEPTOSPIROSIS INTERROGANS ?
wear protective clothing
avoid contact between contaminated water and wound
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chemoProphylaxis against
leptospirosis: doxycycline
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Disease control: implement appropriate pest control, vaccination of livestock and pets