Lyme Disease Diagnosis

What sample is needed for Lyme Disease Diagnosis?

1. Whole blood or citrated blood is needed.
2. Other samples are CSF and synovial fluids in the acute stage.

What is the indication for the serological test for Lyme disease?

• It is advised for the diagnosis of Lyme disease.

What are the precautions for Lyme Disease Diagnosis?

• Spirochetal diseases like syphilis or leptospirosis can give a false-positive reaction.

How will you define Lyme disease?

1. Lyme disease is an infectious disease caused by bacteria transmitted by infected ticks.
2. Lyme disease is caused by the spirochete Borrelia burgdorferi by several tick vectors.
3. The most common vector in the Northeast and North-central United States of America is the deer tick, Ixodes dammini.
4. The Pacific coast states have Ixodes pacificus, the western black-legged tick, which is morphologically classified as a hard tick.

What is the causative Agent of Lyme Disease?

1. Lyme disease was first diagnosed in Lyme, Connecticut, in 1975.
2. The spirochete Borrelia burgdorferi causes Lyme disease.
3. The bite of a deer tick causes this disease (Ixodes dammini or pacificus).
4. These ticks are the best vector for Lyme disease.
5. This isn’t easy to grow in culture.
6. It takes a long time to grow.
7. Culture is successful in 50% of cases.
8. Culture of blood and CSF yields poor results.
9. Serological tests are more helpful.
10. Its diagnosis was established in early 1980.

How will you discuss the epidemiology of Lyme disease?

1. The three major affected areas are:
   1. Northeastern states like New Jersey to Connecticut.
   2. Far Eastern states.
   3. Upper midwestern states.
   4. Cases are reported in Canada, Europe, and Australia.

What are the reservoirs of Lyme Disease?

1. Rodents and deer serve as the natural reservoir for these ticks. Other animals are sheep and cattle.
2. In the Northeast and North-central United States of America, the deer tick is called Ixodes dammini.
3. In the Pacific coastal states, it is called Ixodes pacificus.

What is the morphology of Borrelia (Lyme Disease)?

1. These are 0.18-0.25 × 4.3 μm. These are flexible helical spirochaetes.
2. These are Gram-negative organisms.
3. Culture: These are microaerophilic and grow at 34 °C in a specialized medium.
4. The tick (Ixodes dammini) has a 2-year, three-form life cycle.
   1. Larval stage: The very young tick is called the larval stage.
   2. The larval ticks are very small and have only 3 pairs of legs, like insects.
   3. Nymph stage: These ticks have four pairs of legs, as in the adult stage.
   4. Adult stage: These ticks are 4-legged.

What is the presentation of Lyme disease?

1. In 50% to 80% of patients, 1 to 6 weeks after a tick bite (range: 3 to 68 days), a reddish, macular, spreading lesion with central clearing appears (erythema chronicum migrans). It looks like a bull’s-eye.
2. This chronic inflammatory disease first shows a distinct skin lesion, Erythema migrans (erythema chronicum migrans).
   1. It starts at the site of the bite as a red macule.
   2. There is a central clearing at the site of the bite.
3. This lesion usually fades within 2 to 3 weeks and is usually accompanied by low-grade fever, weakness, fatigue, and regional lymphadenopathy.
4. This characteristic skin lesion should strongly suggest Lyme disease.
5. 10% of patients develop anicteric hepatitis.
6. 7% of patients develop transient ECG abnormalities or myocardial inflammation after about 5 weeks following tick bites.
7. In the second stage of illness, aseptic meningitis or peripheral nervous system abnormalities, such as Bell’s palsy or Bannwarth’s polyneuritis syndrome, occur after about 4 weeks following tick bites.
8. Erythema migrans.
9. Late Lyme disease:
   1. Lyme arthritis: There is migratory arthralgia, and myalgia is frequently present.
   2. Cardiovascular involvement.
   3. Neurological involvement and presentation.
10. In the third stage of the disease, about 40% of the patients develop recurrent arthritis.
    1. This is the most common form of involvement, with one or more joints, most often the knee.
    2. The joint involvement starts 6 weeks to 6 months after the tick bites.

What are the signs and symptoms of Lyme Disease?

1. This disease was first diagnosed in Lyme, Connecticut, in 1975.
2. Skin lesion: This disease usually starts in summer with skin lesions called erythema migrans.
3. This lesion usually appears at the site of the deer tick bite.
4. Characteristically, there are:
   1. Fever.
   2. A headache and a stiff neck.
   3. There is fatigue.
   4. There is muscle and joint pain.
   5. These patients may develop arthritis and meningitis.
   6. Migratory arthralgias and myalgias are frequently seen in these patients.
5. About 10% of the patients develop anicteric hepatitis.
6. There is chronic meningoencephalitis and peripheral neuritis.
7. In CVS: myocarditis, pericarditis, and conduction defects.
   1. About 7% of the patients develop ECG changes or myocardial inflammation, usually after 5 weeks of the tick bite.
8. Arthritis stage: In the third stage of the disease, about 40% of the patients develop recurrent arthritis.
9. This is the most characteristic sign of arthritis of the large joints, and it is often recurrent.

How will you diagnose Lyme Disease?

1. ESR is raised in 50% of the cases.
2. WBCs are raised in about 10% of the cases.
3. Aspiration of the joint synovial fluid has findings similar to those of rheumatoid arthritis.
4. CSF:
   1. When there are meningeal or peripheral nerve symptoms, the following usually show;
   2. Increased WBCs, predominantly lymphocytes.
   3. Normal glucose.
   4. Mildly increased protein.
   5. An oligoclonal band like multiple sclerosis.
   6. CSF IgM antibodies are present.
5. The culture:
   1. Blood culture is positive in the second stage of the disease.
   2. CSF culture is positive in the second stage of the disease, with S/S in about 10% of the cases.
   3. Biopsy of the erythema migrans skin lesion can be used for culture.
   4. The transport medium used is, in particular, BSK.
   5. The culture medium used is Kelly’s medium and BSK II.
6. Antigen detection: Urine shows excreted  B. burgdorferi.
7. PCR: Polymerase chain reaction (PCR). It shows 80% positivity when the sample is taken from the skin lesion.
8. Antibody detection: This is the most common method.
   1. It is negative when IgM and IgG antibody levels are low.
   2. The IgM titer peak occurs between the 3rd and 5th weeks after disease onset.
      1. Then, it declines.
      2. A single high titer of specific IgM is diagnostic.
   3. IgG is low during the first few weeks of the disease and reaches its maximum level by 4 to 6 months.
   4. In the early stage, the serologic tests are rarely positive.

9. Indirect immunoassay.
10. Enzyme-linked immunosorbent assay has replaced the indirect immunoassay. ELIZA is the preferred diagnostic method.
11. The Western blot method is the confirmatory test.
12. Skin biopsy of the affected area surrounding the erythema migrans.
    1. Silver stain reveals spirochetes.
    2. The special stain used is the Warthin-Starry silver stain for a skin biopsy.
13. CDC criteria:
    1. Isolation of B. burgdorferi.
    2. Positive IgM and IgG antibodies in Blood or CSF.
    3. The positive antibody titer is observed in convalescent- or acute-stage sera.
14. Test results are positive:
    1. In the earliest stages of the disease, skin lesions are rarely positive.
    2. After the onset of skin lesions, 3 to 4 weeks after onset is around 40%.
    3. In the second stage of the disease with systemic disease, around 65% are positive.
    4. In the third stage of the disease, it is around 90%-95%.
    5. One of the studies shows the following results:
       1. Active Lyme disease = 23%.
       2. Previous Lyme disease = 20%.
       3. No evidence of Lyme disease = 57%.

How will you treat Lyme Disease?

1. This disease is usually treated with amoxicillin and doxycycline for 3 weeks.
2. Sometimes, IV therapy may be needed.
3. These are also sensitive to penicillin and tetracycline.

Questions and answers:

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