Borrelia consensus Flashcards
Lyme disease is caused by
Borrelia burgdorferi bacteria
not free-living organisms and quickly die outside of a host
2-year enzootic life cycle that involves mammals and Ixodid ticks
>>>> but tick needs to feed several hours for infect
The best-documented naturally occurring syndromes attributed to B. burgdorferi infection in horses include
neuroborreliosis:
signs of cranial nerve dysfunction, radiculoneuritis, and meningitis
uveitis (often neuroocular infectin!!)
cutaneous pseudolymphoma
by dermal, papular to nodular lesions that occurred at the site of the tick bite
flow diagram für lyme diagnose
tests:
ELISA - if positive, conrfirm with
Western Blot: Can elucidate infection stage and vaccination status
positive result does not prove causation of current clinical signs
Which antibody might be useful in the detection of recent Lyme infection?
Antibody against the OspC protein
is believed to develop within 3–5 weeks after infection and generally disappears by 4–5 months as OspC expression is down-regulated after infection is established.
Predicitve values of Lyme tests?
LOW positive predictive value
high negative predictive value for negative tested horses
unless the horse is acutely infected (less than 1 month), immune-compromised or if infection is localized to an immune privileged site such as the eye and central nervous systems.
treatment of neuroborelliosis
parenteral high-dose penicillin (44,000 U/kg IV q 4–6h) or cefotaxime (25–50 mg/kg IV q 6–8h) might be most effective
if too expensive:
minocycline (4 mg/kg or greater PO q 12h)
more effective than doxycycline bc better passage of BBB
PROGNOSIS POOR, only one succesful case
vaccination against lyme?
maybe protein A (rOspA) vaccine.
but antibodies only persist for 4 months
how long is the treatment against borreliosis?
no clue
studies with experimentally infected poneys
3 month treatment course.
But seropositivity can persist for years so we cannot confirm if we actually killed the bacteria
