Just what we need – another tick-borne virus that mimics ehrlichiosis or anaplasmosis and is endemic in the lower Midwest and parts of the Southeast and Atlantic coast of the United States. Yet here it is. Human illness was first reported in northeast Missouri in 2012. It is known to be associated with Lone star ticks, with reservoirs including white tailed deer and several other mammals.
It has up to a 2-week incubation period. So, living in or having recently traveled to an endemic area is an important historical clue. Most infections present with headache, fever, fatigue, nausea, diarrhea, and/or muscle and joint pain. There may be a nonspecific rash but nothing like the classic Lyme disease or Rocky Mountain spotted fever rashes. The illness may be severe enough to lead to hospitalization, particularly when laboratory tests results, such as leukopenia, thrombocytopenia, and/or elevated liver function studies, raise the specter of other serious illnesses.
There is no commercial test, so the diagnosis is by serology and/or reverse transcription–polymerase chain reaction by the Centers for Disease Control and Prevention. Clinicians considering the diagnosis should contact their state health department for instructions on sample collection, processing, and shipment.
The good news is that it appears to be self-limited. There is no specific treatment or vaccine, so management is by supportive treatment.
Christopher J. Harrison, MD, is professor, University of Missouri Kansas City School of Medicine, department of medicine, infectious diseases section, Kansas City. He has no financial conflicts of interest.