Borrelia burgdorferi and Lyme disease

Lyme disease, the most common arthropod-borne disease in the United States, is primarily caused by the bacterium Borrelia burgdorferi.

It is a spirochete, helically shaped, motile.

Lyme disease is characterized by three clinical stages.

The first stage is characterized by erythema chronicum migrans (ECM), an erythematous eruption at the location of the bite.

The second stage occurs when the disease disseminates, producing arthritis, and cardiac manifestations.

The third stage, the last and infectious stage, is characterized by ocular and joint findings.

Borrelia parkeri cause relapsing fevers.

Epidemic or louse-borne relapsing fever is caused by Borrelia recurrentis.

Tick-borne relapsing fever is caused by Borrelia hermsii.

• Lyme disease is caused by B. burgdorferi transmitted by the bites of Ixodid ticks.
• The natural reservoir hosts are rodents, deer and other mammals.
• Mainly found in USA and Europe.
• Other causative agents include: B. afzelii and B. garinii which cause atypical Lyme disease in Europe.
• B. burgdorferi mainly grows in the midgut of the ticks belonging to Ixodes ricinus group( I. pacificus in NW USA and I. scapularis in eastern and midwestern USA). I. damminii is a variant of I. scapularis and this  name is now no longer in use.
• Infection occurs by regurgitation of the gut contents during biting.
• Ticks of I. ricinus group have a life cycle that carries over two calender years.
• Humans are most often infected by  the bite of a nymph because nymphs are so rarely noticed and removed. 

Borrelia burgdorferi can be maintained in nature indefinitely by a tick vector.

This organism is the tick-transmitted spirochete that causes Lyme disease.

The tick, Ixodes dammini, can infect both the white-footed mouse and large mammals such as deer during its life cycle, making them reservoirs.

The tick itself is a reservoir, however, since it acquires the disease through transovarial passage of the organism.

Together, these factors make Lyme disease an endemic infection with little hope for eradication.

Infectious diseases that mimic vasculitis are:

• Bacterial endocarditis
• Disseminated gonococcal infection
• Pulmonary histoplasmosis
• Coccidioidomycosis
• Syphilis
• Lyme disease
• Rocky Mountain spotted fever
• Whipple’s disease

• Serum electrolytes, renal and hepatic function, fasting blood glucose (FBS), HbA1c, urinalysis, 
• Thyroid function tests, B12, folate, erythrocyte sedimentation rate (ESR), 
• Rheumatoid factor, antinuclear antibodies, serum protein electrophoresis, and urine for BJP.

• Antineutrophil cytoplasmic antibodies (ANCA), cryoglobulins, hepatitis serology, 
• Western blot for Lyme disease, HIV, and cytomegalovirus (CMV) titer.

Ans. is ‘a’ i.e., B. burgdorferi

• Erythma migrans (erythma chronicum migrans) is characteristic lesion of stage-I of Lyme diseae, caused by Borrelia burgdorferi.

Ans. is ‘c’ i.e., Lymphogranuloma vernerum

. Amongst the given options only option a and b are caused by Borrelia burgdorferi ( Lyme’s disease). Erythema migrans (erythema chronicum migrans) is stage 1 (local infection) and acrodermatitis chronica atrophicans is seen in stage 3 (persistant infection).

Ans. is ‘b’ i.e., A tick-borne illness caused by Borrelia burgdorferi 

.   Borrelia burgdorferi is the causative agent of Lyme’s disease.

.   Borrelia burgdorferi is transmitted by the bite of Ixodid ticks.