Synonyms:
Lyme borreliosis; Tickborne meningopolyneuritis; Borrelia burgdorferi
infection
Category:
Arthropod-Borne
Agent Type:
Bacteria
Acuity:
Acute-Moderate
Latency/Incubation:
3 days to 1 month; average about 1 week;
Initial
Symptoms: Erythema migrans is estimated to occur in 60-80% of cases. [CDC
case definition]
Comments:
FINDINGS: A red macule or papule (erythema migrans) is the initial finding
in 80% of patients. It appears at the site of the tick bite. In the classic
presentation, the macule or papule expands concentrically with central
clearing (annular shape), reaching a diameter of at least 5 cm. Regional
lymphadenopathy may accompany the skin lesion. Lyme disease does not develop
in experimental animals unless the tick has been attached for 24 hours or
longer. The rash appears 3 to 32 days after the tick bite. Weeks to months
after onset of the rash, about 1% to 2% of infected patients develop cardiac
manifestations. Syncope may result from third degree heart block. The heart
block is reversible in most cases. Months to years after onset, some
patients develop recurrent swelling in large joints. Lyme arthritis tends to
resolve spontaneously. About 15% of patients with erythema migrans develop
meningitis, cranial neuritis, or radiculitis within 3 months of being
infected. CSF findings include lymphocytic pleocytosis. [CCDM, p. 315-20;
ID, p. 1816-9] Most patients do not recall a tick bite because the nymph
stage of the deer tick is so small. Other stage 2 findings include
hematuria, urticaria, conjunctivitis, hepatitis, pharyngitis, cough, and
splenomegaly. Other possible findings (occurred in a few cases) are
orchitis, iritis, choroiditis, myelitis, and osteomyelitis. [PPID, p. 2802]
EPIDEMIOLOGY: Animal reservoirs include ticks, wild rodents, deer, and small
mammals. A vaccine became available in 1999, but it was withdrawn by the
only manufacturer in 2002. [CCDM, p. 315-20] Ticks in the nymph stage are
the most efficient transmitters of infection. About the size of a poppy
seed, the nymphs are often unnoticed. Lyme disease develops in about 10% of
people bitten by infected ticks. [Lexi-ID, p. 56] LABORATORY TESTING:
"Initial testing should use an enzyme immunoassay (EIA) or
immunofluorescent assay (IFA); specimens yielding positive or equivocal
results should be tested further by using a standardized Western immunoblot
assay. Specimens negative by a sensitive EIA or IFA do not need further
testing." [MMWR. February 11, 2005 / 54(05);125]
Diagnostic:
Clinical; Antibody tests; "Serological tests are poorly standardized
and must be interpreted with caution." [CCDM, p. 316] ELISA test
frequently negative in stage 1 (erythema migrans stage); [5MCC-2006] See
Comments.
Scope:
Throughout USA (90% of cases in MA, NY, NJ, CT, RI, PA, MN, WI, and CA.);
Ontario & British Columbia; cases reported in Europe, former USSR, China
& Japan;
General
Symptoms: arthralgia, fatigue, fever, myalgia;
Other Signs
& Symptoms: arrhythmia; pharyngitis; liver function test, abnormal;
lymphadenopathy; splenomegaly; headache; stiff neck; conjunctivitis, acute;
vision, impaired; cough; papules or plaques; skin lesion, annular-shaped;
urticaria; hematuria;
Complications:
arthritis, cranial neuropathy, encephalitis, epididymo-orchitis, meningitis,
myocarditis, osteomyelitis, pericarditis, peripheral neuropathy, transverse
myelitis, uveitis;
Common
Syndromes: Entry Wound with Lymph Nodes
Antimicrobic:
Yes
Vaccine: No
Vector:
Ticks
Reservoir:
Cattle; Deer; Dogs; Horses; Rodents; Wild
High-risk
activities: Travel to endemic area; Work or play in tick-infested area
