Volume 27, Number 10—October 2021
Effects of COVID-19 Pandemic on Reported Lyme Disease, United States, 2020
||% Decrease in testing volume (95% CI)||Absolute difference in % positive (95% CI)|
|Total tests||% Positive||Total tests||% Positive|
|First tier†||925,939||9.6||691,453||9.2||25.3 (25.2–25.4)||0.3 (0.2–0.4)|
|Total||1,348,740||10.0||1,012,069||9.5||25.0 (25.1–24.9)||0.5 (0.4–0.6)|
*Percent positive indicates the percentage of the total laboratory tests that were positive for each test tier and overall. The percent decrease in testing volume shows the percentage decrease in total tests performed by tier and overall for 2020 compared with 2019. Two-tier testing for Lyme disease is recommended, whereby specimens positive or equivocal on the first tier are subjected to the second tier. Additional details about testing tiers are available at https://www.cdc.gov/lyme/diagnosistesting/index.html.
†First-tier tests include enzyme immunoassays for IgM/IgG combined, IgM alone, and C6 antigen.
‡Second-tier tests include immunoblot for IgM or IgG.