Lyme Disease

Lyme Disease Vector Distribution

Blacklegged Tick → Entire Eastern Half of US
Western Blacklegged Tick → Westside States

Lyme Disease Vector

Tick

Characteristics of B. Burgdorferi

No LPS (Not Gram+ or Gram-), Obligate Extracellular, Aerotolerant Anaerobe, No Respiration (ATP through Glycolysis + Fermentation), No Iron

Causative Agent of Lyme Disease

Borrelia Burgdorferi

Dead End Hosts of Lyme Disease

Humans + Deer

B. Burgdorferi Enzootic Cycle

Mice Infect Ticks → Ticks Infect Humans → Deer Helps Ticks Reproduce

Epidemiology of B. Burgdorferi/Lyme Disease

476,000 cases/year

Most Common Vector Borne Disease in US + Europe

Lyme Disease

Symptoms of Lyme Disease

Fever, Chills, Headache, Fatigue, Muscle/Joint Aches, Swollen Lymph Nodes

Signs of B. Burgdorferi/Lyme Disease

Erythema Migrans (Bullseye Rash): 80% of cases have this (much easier to miss on POC), arthritis, carditis, unilateral/bilateral palsy

Diagnosis of Lyme Disease (Patient From Endemic Area)

Tick Bite / EM Lesion

Diagnosis of Lyme Disease (Patient Not From Endemic Area)

Monitor for disease progression (if disease progresses, test for lyme disease)

Testing for Lyme Disease

Enzyme Immunoassay (EIA) OR Immunofluorescence Assay (IFA)

Problems with Lyme Disease Testing

False Positives + False Negatives, approved tests are based on serology (presence of antibodies against B. Burg): no approved direct molecular tests (because bacteria doesn’t stay in blood), Ixodes ticks can transmit up to 3 different borrelia species

What is the most common treatment for B. Burgdorferi?

Doxycycline

Post-Treatment Lyme Disease Syndrome

~20% of patients will have prolonged sequelae (lyme-like symptoms), unsure of cause

What is the best way to prevent B. Burgdorferi?

Prevent Tick Bites

Vaccine of B. Burgdorferi

None Available

Tick and Louse Borne Relapsing Fever

Caused by STRF/HTFR (Tick), BRF (Louse)

Relapsing Fever

Antigenic Variation to Avoid Antibodies

Symptoms of STRF

Fever, Headache, Muscle Aches, Chills, Shaking, Drenching Sweats, Low BP

Epidemiology of Replapsing Fever

55% patients hospitalized, geographic distribution constant, no deaths

Blood Smear

Look for Borrelia bacteria in Giemsa-Stained Blood Film (most effective early in illness)

Serologic Tests

Measure antibodies against Borrelia bacteria, most effect if sample is collected 14+ days after symptoms start

Polymerase Chain Reaction (PCR)

Molecular test that detects genetic material from the bacteria, can be used during asymptomatic periods or soon after treatment

Treatment of Relapsing Fever

LBRF: Single Oral Dose of Tetracycline, Doxycycline, Tetracyclines, Erythromycin
TBRF: Same But Longer Durations (7-10 Days)

Prevention of STRF

Treat cracks and crevices in walls with pesticides, use EPA registered insect repellent