Study Shows Increase of Non-Lyme Tick-Borne Diseases

A study by Elizabeth Lee-Lewandrowski, PhD, MPH, et al, published in The American Journal of Clinical Pathology from the Department of Pathology, Massachusetts General Hospital and Harvard Medical School, evaluated trends in non-Lyme disease tick-borne disease (NLTBI) blood testing at Quest Diagnostics laboratory located in New Jersey. The study took place over the course of seven years and included polymerase chain reaction (PCR) and serological tests. Testing data from Quest Diagnostics were analyzed both nationally and at the state level from 2010 through 2016. The study showed that:

  • testing and positivity for most NLTBIs increased dramatically over the course of the study,
  • testing criteria was not as stringent as required for public health reporting, but the study showed that the number of positive cases generally exceeds those reported by the Centers for Disease Control and Prevention (CDC),
  • frequency of NLTBI in US is seasonal but testing activity and positive test results are present throughout all months of the year, and
  • positive results for NLTBI testing originated primarily from a limited number of states, signifying a geographic concentration and distribution.

The study shows a significant increase in the number of reported cases of many NLTBI from 2004 to 2016, including a 6.6-fold (875 to 5,750) increase in anaplasmosis and ehrlichiosis combined. It also uncovered a significant underreporting of Lyme disease and Q fever to the CDC. Since reporting for tick-borne illnesses (TBI) generally use the same reporting system as Lyme disease,  the researchers indicate the possibility that underreporting also occurs for other TBI. The study outlines laboratory-developed tests (LDTs) that have not been cleared by the US Food and Drug Administration (FDA) but have been approved by Clinical Laboratory Improvement Amendments (CLIA) regulations. Said LDA President Pat Smith, “Although the findings are not surprising to many in the Lyme community, it is imperative that we have this data to support the increases in many of these non-Lyme tick-borne diseases. Increased awareness will result in medical professionals being more likely to consider other tick-borne diseases in people who have been bitten by ticks.”  See entire AJCP article here.