What is the interpretation of a Lyme antibody screen result of less than 0.90, which is considered negative (N), for a patient (P1)?

From the Guidelines

The Lyme antibody screen result is negative, with a value less than 0.90 index, which is below the threshold for a positive result, indicating no serological evidence of Lyme disease infection at this time. This result is consistent with the guidelines for laboratory diagnosis of Lyme disease in the United States, which recommend a 2-tiered serologic analysis consisting of an enzyme-linked immunoassay or immunofluorescence assay, followed by reflexive immunoblotting 1. The sensitivity of this 2-tiered testing is low (30%–40%) during early infection, but specificity is high (>95%) during all stages of disease 1. Some key points to consider in the interpretation of this result include:

• The timing of the test in relation to the onset of symptoms, as antibodies may take time to develop after initial infection 1
• The clinical presentation, including symptoms such as erythema migrans rash, fever, fatigue, headache, or joint pain, which may suggest Lyme disease despite a negative serology result 1
• The exposure history, including recent tick exposure in an endemic area, which may increase the likelihood of Lyme disease 1 In the absence of clinical symptoms suggestive of Lyme disease, no treatment for Lyme disease is necessary based on this negative result. However, if clinical symptoms are present and there was a recent tick exposure in an endemic area, consider repeating the test in a few weeks as antibodies may take time to develop after initial infection 1.

From the Research

LYME AB SCREEN Results

The provided LYME AB SCREEN result is <0.90, which is considered negative.

• This result indicates that the patient is unlikely to have Lyme disease.
• However, it is essential to consider the patient's clinical presentation, medical history, and other diagnostic tests to confirm the diagnosis.

Treatment of Lyme Disease

According to the studies, the following antibiotics are effective for treating Lyme disease:

• Amoxicillin 2, 3, 4, 5, 6
• Doxycycline 3, 5, 6
• Cefuroxime 3, 5, 6
• Ceftriaxone 4, 5, 6
• Azithromycin 4

Erythema Migrans Treatment

For patients with erythema migrans, the following antibiotics are recommended:

• Oral amoxicillin 2, 4, 6
• Doxycycline 3, 5, 6 It is crucial to note that doxycycline should not be used in pregnant or breast-feeding women, or children under 8 years old, due to the risk of tooth and bone disorders in children 6.

Diagnosis and Prevention

Diagnosis of Lyme disease is usually made clinically, and treatment should be started promptly to prevent progression to later stages of the disease 5, 6.

• Routine antibiotic prophylaxis is not justified after a tick bite, even in an endemic area, as the risk of infection is low 6.
• Patients should be monitored for signs and symptoms of erythema migrans, and antibiotic treatment should only be prescribed if the condition develops 6.