BORRELIA

BORRELIA

Characteristics

  • Gram -
  • Spirochete
  • Motile
  • Non-spore forming
  • Non-encapsulated

Borrelia burgdorferi

Characteristics

  • Obligate pathogen

Reservoirs

  • Humans (not normal flora)
  • Animals (primarily deer and rodents)

Transmission

  • Vectorial (ticks)

Toxins

  • None in particular

Diseases

1. Early Localized Lyme Disease

  • A single large round flat painless enlarging erythematous rash with central necrosis (“erythema chronicum migrans”) at the site of initial infection, fever, headache, myalgias, and local lymphadenomegaly
  • Occurs 1 week after initial infection
  • Spontaneously resolves in < 1 month
  • Caused by Borrelia Burgdorferi infection of the skin
  • May progress to early disseminated lyme disease (see below)

2. Early Disseminated Lyme Disease

  • Disseminated small erythema chronicum migrans, relapsing arthritis, carditis leading to AV block, meningitis, cranial nerve damage leading to cranial nerve neuropathies, peripheral nerve damage leading to peripheral neuropathies, and generalized lymphadenomegaly
  • Occurs 1-3 months after initial infection
  • Caused by Borrelia burgdorferi septicemia
  • May progress to late disseminated lyme disease.

3. Late Disseminated Lyme disease

  • Chronic arthritis and permanent central neuronal damage leading to encephalopathies
  • Occurs 3-6 months after initial infection
  • Occurs in 10% of untreated patients
  • Caused by Borrelia burgdorferi accumulation in tissues

Treatment

  • Broad spectrum penicillins (if early localized lyme disease and/or early disseminated lyme disease)
  • Third generation cephalosporins (if late disseminated lyme disease)

Borrelia recurrentis

Characteristics

  • Obligate pathogen

Reservoirs

  • Humans (only reservoir, not normal flora)

Transmission

  • Vectorial (body lice)

Toxins

  • None in particular

Diseases

1. Relapsing Fever

  • High fever, headache, myalgias and disseminated skin rashes for <1 week " afebrile period for > 1 week " progressively shorter and milder periods of fever and progressively longer afebrile periods until it completely disappears
  • Caused by Borrelia recurrentis septicemia

Treatment

Narrow spectrum penicillins (Amoxycillin).

Tetracyclines

Lab Diagnosis

  • Giemsa staining of blood smear
  • Detection of IgM OR rising titer of IgG
  • PCR

Control

  • Louse, tick & rodent control
  • Hygienic measures