Ticked off: cases of Lyme disease are on the increase in Ireland
LYME disease which is transmitted to humans by bites from ticks infected with bacteria is on the rise in Ireland.
There were eight cases reported in 2012, but last year this had risen to 21. Lyme disease is diagnosed by medical history and physical examination.
The infection is confirmed by blood tests which look for antibodies produced by an infected person’s body in response to the infection.
These normally take several weeks to develop and may not be present in the early stages of the disease. The standard Lyme disease diagnostics is a two-stage approach and involves using a sensitive enzyme immunoassay (EIA) as an initial screening step.
Screening EIAs can be insufficiently specific, giving false-positive reactions in the presence of other similar bacteria, and certain other viral infections, including glandular fever. In addition, blood samples from patients with autoimmune disorders and other inflammatory conditions can also lead to false-positive results. Samples giving positive or equivocal results in screening tests are further investigated in a second-stage immunoblot tests.
Use of immunoblot testing greatly increases specificity. This two-stage approach gives a great degree of certainty around the diagnosis of Lyme disease. All clinical laboratories in Ireland must undergo continuous quality assurance to ensure the quality of the diagnostics they provide is maintained.