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)
Two-tiered serologic testing algorithm for Lyme Disease
- Acute/Early Disseminated: Two ELIZA test.
- Late Disseminated: Either two Eliza test, or 1 Eliza test, followed by 1 Western blot
Can dx of lyme disease be done without serologic testing?
Yes if characteristic EM rash in a person who has lived or recently been in an endemic Lyme disease area
Treatment of Lyme Disease
- Early Lyme (Erythema migrans)
Doxycycline 100mg PO BID x 14 days - Early disseminated - Bell’s Palsy
Doxycycline 100mg PO BID x 14 days - Late disseminated (Arthritis)
Doxycycline 100mg PO BID x 28 days
Lyme Disease prevention
- Doxycycline (200 mg) 1 dose
- Wear protective clothing
- Check skin for attached ticks and remove < 24 hours
- Tick checks Q12 hrs.
- Bug sprays and creams containing DEET
Disposition of Lyme Disease
Clinical suspicion of Lyme Disease will necessitate Med Advice and treatment at the IDC level.
What is “Post-Treatment Lyme Disease Syndrome”
Small percentage of cases, lingering fatigue, myalgia, and arthritis can persist for months to years
