Lyme disease case counts in U.S. rose by almost 70% in 2022 due to change in how it's reported

NEW YORK — Lyme disease cases in the U.S. jumped nearly 70% in 2022, which health officials say is not due to a major increase of new infections but instead a change in reporting requirements.

Reported cases surpassed 62,000 in 2022, after averaging about 37,000 a year from 2017 through 2019, the Centers for Disease Control and Prevention said in a report released Thursday. Numbers for 2023 will be released later this year.

Lyme disease is the most common tick-borne infection in the U.S., occurring mostly in the Northeast, Midwest and mid-Atlantic states.

An estimated 476,000 Americans are diagnosed with it each year, but only a fraction are officially reported.

Traditionally, health departments received positive lab tests and went back to doctor’s offices to gather more information about the patients. But reporting fell off in 2020 and 2021 when health department staffers were busy working on covid-19.

Starting in 2022, all that’s required to report cases — at least in high-incidence states — is a positive lab test. It’s possible that better, more sensitive testing is being used more and that may have contributed to the increase, but it’s too early to tell, CDC officials said.