The 30,000 cases of Lyme disease reported to the Centers for Disease Control and Prevention (CDC) each year are just the tip of the iceberg. According to a new CDC estimate, more than 300,000 Americans are diagnosed with the tick-borne disease each year. The new number was presented at the 2013 International Conference on Lyme Borreliosis and Other Tick-Borne Diseases, being held in Boston. Although the disease has been diagnosed in almost every state, most cases reported to the CDC are in the Northeast and upper Midwest—96% of cases come from 13 states. The new estimate comes from a multi-pronged approach: gathering case reports from doctors, sifting through health insurance claims, analyzing data from clinical laboratories (which do the tests necessary to diagnose Lyme disease), and surveying the public for self-reported Lyme disease.