"Sharp Increase in Lyme Disease Cases Linked to Reporting Changes in 2022"
After the implementation of a revised surveillance case definition for Lyme disease in 2022, reported cases in the United States increased by 68.5% compared to the average during 2017–2019, with the highest relative increase among older adults. The change likely reflects modifications in surveillance methods rather than a true change in disease risk. The revised approach improves standardization of surveillance data across high-incidence jurisdictions but hinders comparison with historical data. Limitations include under- and overreporting, and changes in laboratory testing may have influenced the reported incidence.