Methods: We used the 2009-2016 Truven Health MarketScan® Databases to identify MLI and MLI investigations. MLI were defined using International Classification of Diseases (ICD)-9/10 diagnostic codes in two ways: a priori, using the Council of State and Territorial Epidemiologists (CSTE) measles case definition or empirically, using ICD codes on insurance claims with a measles diagnostic code. MLI investigations were defined as MLI occurring up to 5 days prior to a measles diagnostic code or billing code for measles serology testing. We computed annual rates of MLI investigations per 100,000 population.
Results: We identified approximately 35.5 million MLI using the a priori definition. Of these, 24,010 had a measles serology code within 5 days; median age was 30 and 51% were aged 18–34 years. Using the empirical definition we identified approximately 46 million MLI. Of these, 29,940 were coupled with a measles serology code; median age was 31 and 50% were aged 18–34 years. The median annual rates for MLI investigations were 3.2 (a priori) and 4.3 (empirical) per 100,000 population.
Conclusion: Maintaining measles elimination requires continued vigilance by clinicians and high-quality case-based surveillance. The estimated rates of MLI investigations in this U.S. population exceeded the PAHO standard, suggesting that the quality of U.S. measles surveillance is robust.
P. Gastanaduy, None
J. Routh, None
R. Harpaz, None