Most US lyme disease cases remain concentrated in the
pacific costal regions
In at least 60 to 80% of US patients Lyme diseases begins with a slowly expanding skin
lesion EM, which occurs at the site of tick bite.
The skin lesion is frequently accomapiened by flu like symptoms
The CDC clinical case definition for Lyme disease includes
the presence of EM or at least one objective late manifesting sign for musculoskeletal, neurologic or cardiovascular disease
a positive serological tests for antibody to B burdorferi.
many misdiagnosed patients actually have chronic fatigue syndrome or fibromyalgia,
both of which can causes similar symptoms such as joint stiffness or pain , fatigue and sleep disturbance
In the united states approximately 20 to 30 % of patients with lyme disease have
positive responses usually IgM isotype during this period.
However by covalence 2 to 4 weeks later about 70 to 80% have
seroreactivity even after antibiotic treatment.
After about 1 month, most patient with active infection have
IgG antibody responses
After antibiotic treatment antibody titers
fall slowly but IgG and IgM responses persists for many years after treatment
IgM response cannot be interpreted as a manifestations of a recent infection or
reinfection unless the appropriate clinical features are present .
antibody formed includeL
cryoglobulins, immune complexes, antibodies specific for B burgdorferi and anticardiolopin antibodies .
elevated titers for IgM are noted in
In the US the diagnosis is usually based on the
recognition of the characteristics clinical findings
history of exposure in an area in which the disease is endemic and except in patients with EM, an antibody response to B burgdorferi by enzyme--linked immunosorbent assay ELISA and western blot.
testing becomes important when the telltale bull's eye rash or
other characteristics of lyme diseases do not appear.
lyme disease is caused by
spirochete borrelia burgdorferi, transmitted by ixodid tick
deer tick l
lyme disease usually occurs in the
summer months and begins with a slowly expanding skin lesion
erythema chronic migrans
bull's eye rash
accompanied by flulike symptoms
the cdc case definition of lyme disease includes
the presence of EM or at least one objective late manifestation of sign of musculoskeletal neurologic or cardiovascular disease and a positive serologic test for antibody to B burdorferi
after skin lesions ( weeks to months later) we can see
cardiac or neurologic disease. this can be followed by arthritis and chronic neurologic disease ( weeks to years after onset)
serodiagnostic tests are insensitive during the first
several weeks of infection
specific IgM or IgG antibodies are usually not detectable in patients serum
unless symptoms have been present for at least 2-4 weeks .
in cases of lyme arthritis tests for antinuclear antibodies
rheumatoid factor and VDRL are generally negative , but there should be IgG specific antibodies to B burdoferi
lyme disease diagnosis is now based on the
relative value determined from diagnostic criteria as a score of 7 or greater makes lyme disease very likely
in the US diagnosis is usually based on the recognition of clinical findings
bulls eye rash
history of exposure in an area endemic to lyme disease except in patients with em
an antibody response to B burgdorferi by ELISA or western blotting
ELISA is at the
standard method most widely available and most commonly performed test method
PCR is the most
USEFUL in diagnosis early lyme disease the patient is still seronegative.
western blot can be used to verify
borderline or weak positive results