Lyme disease is a nationally notifiable disease, recognized and tracked by the federal government Centers for Disease Control and Prevention (CDC) for surveillance purposes. Surveillance data provides important information for assessing public health risks and allocating research dollars. Per the CDC, “The goal of Lyme disease surveillance is not to capture every case, but to systematically gather and analyze public health data in a way that enables public health officials to look for trends and take actions to reduce disease and improve public health.” However, these statistics have important implications for individual patients as well.
In this post, Bay Area Lyme Research Grant Director and Advisory Board Member Wendy Adams discusses some important changes to the CDC definitions of Lyme disease and some concerning implications for patients in the state of California.
In January, the Centers for Disease Control and Prevention (CDC) in Atlanta published an updated Lyme Disease (Borrelia burgdorferi) 2017 Case Definition. Lyme disease case definitions have been published since 1995, and the previous definition was published in 2011. The CDC actually is not responsible for this definition; instead it is the Council of State and Territorial Epidemiologists (CSTE) that is responsible for Lyme disease surveillance. Each state has its own State Epidemiologist (see info about CA here). Despite being a federal agency, the CDC can offer input on these definitions but the CSTE is not obligated to accept those suggestions.
The case definition for Lyme disease is only intended to be used to determine cases for surveillance purposes and not to represent the full incidence of Lyme in a given area. However, this subtlety is often confusing for doctors who see these low case numbers as proof that they do not need to consider a Lyme diagnosis in CA. The low numbers also are convenient for insurance companies who inappropriately use this narrow definition as diagnostic criteria to deny coverage for patients whose cases don’t meet the definition.