Original title: Trends in Lyme disease incidence in England, 2013 to 2024
Janie Olver, Mark Gideon Burdon, Eva Emanuel, Ali Datoo +6 · September 2026
Official counts of Lyme disease in England only tally lab tests, which misses people diagnosed by their doctors based purely on symptoms. Because of this, official figures underestimate true sickness. Experts use a multiplication factor to scale up lab numbers to estimate total cases, but the old multiplier relied on records from 1998 to 2016 and is outdated. Researchers studied laboratory and doctor records from 2013 to 2024 to find current trends and update this calculation. They found that positive lab tests did not change substantially across those years. Meanwhile, cases diagnosed by family doctors increased significantly, rising by an average of 498 extra cases each year. Because clinic diagnoses climbed while lab counts stayed flat, the best estimate of the multiplier jumped from 2.35 to 6.20 for the years 2020 – 2024. Using this new number helps officials accurately calculate total symptomatic Lyme cases.
Imagine counting the number of people who visit a national park by only counting those who buy a ticket online. Many visitors pay at the gate or have annual passes, so the online count misses them. To get the true number, you multiply the online count by a factor that accounts for the missing visitors. Over time, more people start using the gate or passes, so the old multiplier is too low. Here, the lab-confirmed cases are like online ticket sales, and the multiplication factor needs updating because more patients are now diagnosed in primary care without lab tests.
Accurate Lyme disease numbers matter for public health planning and patient care. The previous estimate missed thousands of cases each year because it relied on outdated data. This study shows the true burden is much larger, which should lead to better funding for prevention, diagnosis, and treatment in England.
The abstract doesn't say explicitly, but it notes the previous factor was outdated due to changes in guidance, implying the new factor may also need future revision. The estimates are based on data from England and may not generalize to other regions or time periods.
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Trends in Lyme disease incidence in England, 2013 to 2024 — Janie Olver, Mark Gideon Burdon, Eva Emanuel et al. — medRxiv — doi:10.64898/2026.09.11.26362844
Abstract licence: CC BY
Explanation generated by Synthesis from the abstract — it is not the original paper. This is a preprint, so it hasn't necessarily been peer reviewed.