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Lyme disease
Borrelia
Borrelia burgdorferi sensu stricto
Borrelia garinii
Borrelia afzelii
Life cycle of ticks
Life cycle of ticks
Two adult deer ticks
Ticks are pretty small…
Stage one (early infection)
Erythema migrans
• 3 days to 1 month
following bite
• Occurs in 60-80% (ie
doesn’t always occur)
• Expands to
characteristic “bulls
eye”
Stage one (early infection)
Not all rashes are Lyme disease
• Allergic reactions to tick saliva usually
occur within hours to a few days after the
tick bite, usually do not expand, and
disappear within a few days.
• Erythema migrans persists longer, but
usually subsides within 3-4 weeks.
Stage two (dissemination stage)
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Fatigue
Fever
Headache
Muscle and joint pain
Lymphadenopathy
Secondary annular skin lesions
Stage three (persistent infection)
• Months or years following bite
• Typically involves intermittent episodes of
joint pain
• Meningitis
• Bell's palsy, numbness, pain
• Cardiac arrhythmias
• Migratory pain to joints, tendons, muscle
and bone.
Stage three (persistent infection)
• Rheumatological
Chronic Lyme arthritis in11% - erosion of
cartilage and/or bone
• Neurological
Depression, disturbances in memory,
mood, or sleep patterns, tingling, numbness
Diagnosis
• Serodiagnosis to detect anti-borrelia
antibodies is not useful until in later stages
of illness.
• B. burgdorferi can be cultured from 80% or
more of biopsy specimens taken from early
erythema migrans lesions. However, the
diagnostic value of this procedure is limited
because of the need for special
bacteriologic media (BSK medium) and
protracted observation of cultures.
Treatment
• Doxycycline
• Late treatment can result in persistent
symptoms
Prevention
• Avoid tick-infested areas, especially in May,
June, and July
• Insect repellent containing DEET
• Wear a hat and a long-sleeved shirt
• Walk in the centre of trails to avoid overhanging
grass and brush.
• After being outdoors, remove clothing and wash
and dry it at a high temperature
• Remove ticks
• Preventive antibiotic treatment with erythromycin
or doxycycline?
Summary
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A third of patients don’t have a rash
Stage 2 symptoms are vague
Stage 3 consequences are serious
Diagnosis is difficult
Awareness of the disease is poor