Lyme Disease Flashcards
Subtypes of lyme disease
B. afzelii, B. burgdorferi, B. garinii.
Where is lyme disease prevalent
- Europe (central and eastern)
- Asia (western Russia, Mongolia
- Northeastern China, and into Japan)
- Northeastern and north-central United States.
Predisposing factors for lyme disease
- Hiking
- Camping
- High tick population, summer & fall months
- Not performing tick checks, lack of PPE/covering
What transmits lyme disease
Bite oflyme-infected Ixodes(blacklegged) ticks
Incubation period for lyme disease
Typically 3–30 days
What time of year is lyme disease most transmitted
summer months (May – August) when ticks & mammals are active
Main reservoirs for Lyme disease
Rodents:
- White foot deer mice
- Chipmunks
- Squirrels
Vectors for lyme disease
- Blacklegged ticks (Ixodes scapularis) spreads the disease in the northeastern, mid-Atlantic, and north-central United States.
- Western Blacklegged tick (Ixodes pacificus) spreads the disease on the Pacific Coast
How long must the tick be attached for before lyme disease can be transmitted
36 to 48 hours
Why would most people not notice tick for lyme disease
Many people do not know tick is attached due to anesthetic chemicals in saliva – may be attached for days without host knowing.
Stages of Lyme Disease
- Early Localized Stage
- Acute/Early Disseminated Stage
- Late Disseminated Stage
- Malaise, headache, fever, myalgia, arthralgia,
Lymphadenopathy. - Erythema migrans (EM)—Red ring-like or homogenous expanding rash; Classic rash, not present in all cases.
- EM appears about 1 week after the initial infection.
- Begins as a slightly raised red lesion at the site of the tick bite
- After several days the rash expands out from the central lesion sometimes appearing as a “bulls-eye/target” lesion, but more often as a muddled circular rash.
- Serologic tests may be insensitive at this stage.
Early Localized Stage of Lyme Disease
- Multiple secondary annular rashes
- Flu-like symptoms
- Lymphadenopathy
- Conduction abnormalities, e.g., atrioventricular node block
- Myocarditis, pericarditis
- Bell’s palsy or other cranial neuropathy
- Meningitis
- Encephalitis
Acute/Early Disseminated Stage of Lyme Disease
Same symptoms as Acute Disseminated Stage, with Rheumatologic Manifestations
Late Disseminated Stage of Lyme Disease
When should serologic tests for Lyme Disease NOT be performed?
- Asymptomatic patient in endemic areas
- Asymptomatic patient after an Ixodes tick bite.
- Patient with non-specific symptoms (subacute myalgias, arthralgias, or fatigue)
