CPT® Code 86666

The CPT® Code 86666 refers to the laboratory test for antibodies to Ehrlichia, which are a group of bacteria that can lead to various diseases in both humans and animals. These bacteria are primarily transmitted through the bite of infected ticks, making tick exposure a significant risk factor for infection. There are four known species of Ehrlichia that can cause illness in humans, which are transmitted by different types of ticks. The lone star tick, scientifically known as Amblyomma americanum, and the blacklegged ticks, including Ixodes scapularis found in the Northeastern United States, Ixodes pacificus in the Western United States, and Ixodes ricinus in Europe, are the primary vectors for these infections. When a person is infected with Ehrlichia, they may experience a range of symptoms, including fever, headache, fatigue, and muscle aches, which can vary in severity. The testing for Ehrlichia antibodies typically employs an indirect hemagglutination (IHA) methodology, which is a common laboratory technique used to detect the presence of specific antibodies in the blood. The test can differentiate between two types of immunoglobulins: IgG and IgM. IgG testing is utilized to determine if there has been a current or past infection, while IgM testing is specifically aimed at identifying a current infection with a particular Ehrlichia species. It is important to note that if both IgG and IgM tests are conducted, each test must be reported separately to ensure accurate documentation and coding for laboratory services.