Lyme Disease

  Lyme Disease by P.K.Ghatak,MD.

Lyme disease was unknown in the USA but in 1970 an outbreak of a tick borne disease in Lyme, Connecticut established its name and proved to be the most common vector borne disease in the USA. About 30,000 cases of Lyme disease is reported each year. The bacterium belongs to Spirochete family and Lyme disease is due to Borrelia burgdorferi. Other important member of this family is syphilis.

Spirochetes are gram negative, spiral in shape measuring 3 to 500 micrometer long and 0.03 to 3 micrometer in diameter and is motile due to presence of variable numbers of flagella arranged along the axis

The vector is a tick – Ixodes scapulars, Rarely another tick - Amblyomma americium (Lone star tick) transmit the spirochetes in the southern states.

Population from Maine to Maryland and New Jersey, Pennsylvania, Wisconsin are prone to increase tick bites due  to increasing number of deer in the woods.

The adult tick must feed 48 - 72 hours during that time, B. burgdorferi enters the wound form the tick's saliva contamination.

The incubation varies from a few days to several weeks following the tick bite.

Based on the time of presentation and symptoms the disease is conveniently separated into 3 groups.

1. Initial. Skin rash and slight fever. The skin rash is the hallmark of Lyme disease at this stage. The rash is red to violet in color, target like lesions called Erythema marginatum.

2. Early disseminated disease usually develop in 2 -3 weeks but may be late, as late as 10 weeks. The presenting symptoms is painful selling of one knees or ankle, musculoskeletal pain, conjunctivitis, heart block, and Bell's palsy.

3. Late or chronic. After months of quiet period, the asymmetrical arthritis of hands and spine, headaches, peripheral neuropathy, muscle weakness, cranial nerve palsy develop and persists for a long time inspire of treatment.

The skin rashes are due to an inflammatory reactions from the presence of spirochetes in the skin. The spirochete may enter fibroblasts and live in them near permanently. In early state 50% patients are seropositive, it becomes 100 % as weeks and months progress. Arthritis develop from cross reaction of the spirochetal membrane protein with the hosts' connective tissue and neural tissues. The newly formed complex is antigenic. The antibodies react with the complex and organ damages take place from released pro-inflammatory cytokines. People  having HLA-DR$ and HLA-DR2 are likely suffer most.

Chronic neurological manifestations are the results from the presence of the remnant DNA of the spirochetes in the nervous system of the victims which triggers an excess production of Interferon alpha.

CDC recommends the following procedures.

Initial stage: ELISA immunoassay of IgM and IgG.

Confirmatory stage: Western blot testing.

a). Symptomatic for less than 30 days. Perform both IgM and IgG Western blot tests.

b). Symptomatic for more than 30 days,  only IgG Western blot test is advised.

c).New newer test- C6 peptide test, which was prevalent in Europe, has been approved as an alternative to Western blot test. C6 peptide test is less expensive and equally sensitive as Western blot test.

Initial stage: The preferred antibiotics is Doxycycline by mouth for 10 to 21 days. Children, pregnant and lactating women should have Amoxicillin or Cefuroxime axetil PO for 10 to 21 days.

With cardiac or, neurological or, musculoskeletal involvement the treatment should be continued for 28 days.

In late stage: Parenteral Ceftriaxone, or Cefuroxime or, Penicillin G in high doses given for 14 to 28 days.

Post-treatment Lyme Disease:

About 20% patients who completed recommended treatment continue to be moderately symptomatic for 6 months or longer. The common symptoms are fatigue, musculoskeletal pain, hearing loss, headaches, ambulatory and balance problems, parenthesis, depression and sleeping difficulties, and other symptoms.

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