ID E1- Tick Borne

What is the MC vector-borne disease in the US?

Lyme disease

What pathogen causes Lyme disease?

Borrelia burgdorferi

What types of tick bite is associated with Lyme disease?

Deer (aka lxode)

For Lyme disease, the tick must be attached for a minimum of how many days?

2 days

With Lyme disease, 85% of the time, infection occurs in which stage?

Nymph

3 stages of Lyme disease

1. Early localized

2. Early disseminated

3. Late disease

Which stage of Lyme disease:

Erythema migrans at site of tick bite, flu like sx

1. Early localized

Which stage of Lyme disease:

AV block, Neuro and ocular symptoms

2. Early disseminated

Which stage of Lyme disease:

Bells palsy

2. Early disseminated

Which stage of Lyme disease:

Weeks to months after infection

2. Early disseminated

Which stage of Lyme disease:

Months to years after infection

3. Late disease

Which stage of Lyme disease:

Monoarticular arthritis (large joints, ie knee)

3. Late disease

Which stage of Lyme disease:

Encephalopathy

3. Late disease

How is early localized (stage 1) Lyme disease diagnosed?

EM lesion + Patient history of being in endemic region

When diagnosing Lyme disease, what is the next step if EIA is positive, what is the next step?

Western blot

In patients with Lyme disease, which antibodies can persist for years?

IgM and IgG

When is no pharmacologic therapy warranted for Lyme disease?

Tick bite, NO rash & NON-endemic area

What is the treatment for Lyme disease: Engorged tick/endemic area, Erythema migrans, & Isolated facial nerve palsy?

Doxycycline

What is the treatment for Lyme disease: Early disseminated or Late disease?

IV Ceftriaxone

What is Post Treatment Lyme Disease Syndrome (PTLDS)?

Nonspecific symptoms that may persist for months after recommended abx treatment for Lyme disease, such as HA, fatigue, arthralgia

Does chronic Lyme disease respond to additional courses of abx?

No

When should patients receive abx prophylaxis for Lyme disease?

- Tick is adult/nymphal deer tick

- Tick attached for >36 hours

- Prophylaxis given within 72 hours of tick removal

- Local rate of infection with B. burgdorferi is >20%

- Doxy is NOT contraindicated (preg, lactating, <8 y/o)

What pathogen causes rocky mountain spotted fever (RMSF)?

Rickettsia rickettsii

What is the pathogenesis behind RMSF?

Tick attaches --> sheds bacteria into bite --> bacteria engulfed by endothelial cells --> spreads through bloodstream --> vasculitis and coagulation cascade

What ticks transmit RMSF?

Dog tick, RM wood tick

What population has the highest incidence of RMSF?

Kids <10

What is a hallmark symptom of RMSF?

Blanching, erythematous rash with macules

How does the rash associated with RMSF spread?

Begins on ankles/wrists, spreads to trunk, includes palms/soles in late disease

Does "spotless" RMSF have a better or worse prognosis?

Severe/fatal

What lab findings are associated with RMSF?

Thrombocytopenia, Hyponatremia, Elevated liver enzymes

What is the gold standard serologic test for diagnosis of RMSF?

Indirect immunofluorescence assay (IFA) with R. rickettsii antigen

What is the treatment for RMSF?

Doxycycline

What is the treatment for RMSF in pregnant women in 1st or 2nd trimester?

Chloramphenicol

"Gray baby syndrome" is associated with use of what drug if it’s given in 3rd trimester?

Chloramphenicol

What tick spreads ehrlichiosis?

Lone star tick

What tick spreads anaplasmosis?

Deer tick (same as Lyme)

What are hallmark lab features of ehrlichiosis & anaplasmosis?

Leukopenia, Thrombocytopenia, Elevated LFTs

What is the pattern of spread for the rash associated with ehrlichiosis?

Involves trunk, SPARES palms & soles

What is the treatment for ehrlichiosis & anaplasmosis?

Doxycycline