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Lyme Disease (Borrelia burgdorferi)
1996 Case Definition
Clinical description
A systemic, tickborne disease with protean manifestations,
including dermatologic, rheumatologic, neurologic, and cardiac
abnormalities. The best clinical marker for the disease is the
initial skin lesion (i.e., erythema migrans [EM]) that occurs
in 60%-80% of patients.
Laboratory criteria for diagnosis
- Isolation of Borrelia burgdorferi from
a clinical specimen or
- Demonstration of diagnostic immunoglobulin
M or immunoglobulin G antibodies to B. burgdorferi in
serum or cerebrospinal fluid (CSF). A two-test approach using
a sensitive enzyme immunoassay or immunofluorescence antibody
followed by Western blot is recommended (7).
Case classification
Confirmed: a) a
case with EM or b) a case with at least one late manifestation
(as defined below) that is laboratory confirmed.
Comment
This surveillance case definition was developed
for national reporting of Lyme disease; it is not intended to
be used in clinical diagnosis.
Definition of terms used in the clinical description
and case definition:
- Erythema migrans. For purposes of
surveillance, EM is defined as a skin lesion that typically
begins as a red macule or papule and expands over a period
of days to weeks to form a large round lesion, often with partial
central clearing. A single primary lesion must reach greater
than or equal to 5 cm in size. Secondary lesions also may occur.
Annular erythematous lesions occurring within several hours
of a tick bite represent hypersensitivity reactions and do
not qualify as EM. For most patients, the expanding EM lesion
is accompanied by other acute symptoms, particularly fatigue,
fever, headache, mildly stiff neck, arthralgia, or myalgia.
These symptoms are typically intermittent. The diagnosis of
EM must be made by a physician. Laboratory confirmation is
recommended for persons with no known exposure.
- Late manifestations. Late manifestations
include any of the following when an alternate explanation
is not found:
- Musculoskeletal system. Recurrent, brief attacks
(weeks or months) of objective joint swelling in one or
a few joints, sometimes followed by chronic arthritis in
one or a few joints. Manifestations not considered as criteria
for diagnosis include chronic progressive arthritis not
preceded by brief attacks and chronic symmetrical polyarthritis.
Additionally, arthralgia, myalgia, or fibromyalgia syndromes
alone are not criteria for musculoskeletal involvement.
- Nervous system. Any of the following, alone
or in combination: lymphocytic meningitis; cranial neuritis,
particularly facial palsy (may be bilateral); radiculoneuropathy;
or, rarely, encephalomyelitis. Encephalomyelitis must be
confirmed by demonstration of antibody production against B.
burgdorferi in the CSF, evidenced by a higher titer
of antibody in CSF than in serum. Headache, fatigue, paresthesia,
or mildly stiff neck alone are not criteria for neurologic
involvement.
- Cardiovascular system. Acute onset of high-grade
(2nd-degree or 3rd-degree) atrioventricular conduction
defects that resolve in days to weeks and are sometimes
associated with myocarditis. Palpitations, bradycardia,
bundle branch block, or myocarditis alone are not criteria
for cardiovascular involvement.
- Exposure. Exposure is defined as having
been (less than or equal to 30 days before onset of EM) in
wooded, brushy, or grassy areas (i.e., potential tick habitats)
in a county in which Lyme disease is endemic. A history of
tick bite is not required.
- Disease endemic to county. A county
in which Lyme disease is endemic is one in which at least two
confirmed cases have been previously acquired or in which established
populations of a known tick vector are infected with B.
burgdorferi.
References
7. CDC.
Recommendations for test performance and interpretation from the Second
National Conference on Serologic Diagnosis of Lyme Disease. MMWR
1995;44:590-1.
See also:
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