Quality statement 2: Repeat ELISA tests

Quality statement

People with suspected Lyme disease without erythema migrans who have a negative enzyme-linked immunosorbent assay (ELISA) test carried out within 4 weeks of their symptoms starting have the test repeated 4 to 6 weeks later if Lyme disease is still suspected.

Rationale

The timing of the initial ELISA test is important for diagnosing Lyme disease in people without erythema migrans. If the test is performed too early (within 4 weeks of symptom onset) the person may not have developed antibodies to the bacteria that causes Lyme disease, resulting in a 'false negative' result. People in whom Lyme disease is still suspected and who had a negative initial ELISA test result may have had the test too early. Repeating the test 4 to 6 weeks after the first test supports an accurate diagnosis. The diagnostic process is summarised in NICE's visual summary of the recommendations for testing for Lyme disease.

Quality measures

Structure

Evidence of local arrangements to provide repeat ELISA tests 4 to 6 weeks after an initial negative ELISA test result for people without erythema migrans in whom Lyme disease is still suspected.

Data source: Local data collection, for example, service specifications and written clinical protocols.

Process

Proportion of people without erythema migrans who had a negative initial ELISA test within 4 weeks of symptoms starting, and in whom Lyme disease is still suspected, who have a repeat ELISA test 4 to 6 weeks after the first test.

Numerator – the number in the denominator who have a repeat ELISA test 4 to 6 weeks after the first test.

Denominator – the number of people without erythema migrans who had a negative initial ELISA test within 4 weeks of symptoms starting, and in whom Lyme disease is still suspected.

Data source: Local data collection, for example, an audit of patient records.

What the quality statement means for different audiences

Service providers (such as primary care and local microbiology laboratories) have local arrangements in place to ensure that people without erythema migrans in whom Lyme disease is still suspected after an initial negative ELISA test result for Lyme disease within 4 weeks of onset of symptoms have the test repeated 4 to 6 weeks later. If there is no local diagnostic service, the sample is tested at the Rare and Imported Pathogens Laboratory (RIPL).

Healthcare professionals (such as GPs and clinicians in secondary care) repeat an ELISA test 4 to 6 weeks after the first test for people without erythema migrans in whom Lyme disease is still suspected after an initial negative ELISA test result for Lyme disease within 4 weeks of onset of symptoms. They are aware of local arrangements to support ordering the repeat test.

Commissioners (such as clinical commissioning groups and NHS England) commission local microbiology laboratory services to perform a repeat ELISA test 4 to 6 weeks after the first test for people without erythema migrans if Lyme disease is still suspected after an initial negative ELISA test result for Lyme disease within 4 weeks of onset of symptoms. If there is no local diagnostic service, the sample is tested at the RIPL.

People without erythema migrans who had a negative blood test for Lyme disease in the 4 weeks after their symptoms began, but continue to have symptoms, have another blood test 4 to 6 weeks after their first test. This will help to make sure they are correctly diagnosed.

Source guidance

Lyme disease (2018) NICE guideline NG95, recommendation 1.2.17

Definition of terms used in this quality statement

ELISA test

An ELISA test for Lyme disease, which detects antibodies produced in response to infection by the bacteria that causes Lyme disease (different species of Borrelia). The diagnostic process is summarised in NICE's visual summary of the recommendations for testing for Lyme disease.

[NICE's guideline on Lyme disease, recommendation 1.2.17, terms used in this guideline, evidence reviews for diagnostic tests and expert opinion].