Borrelia miyamotoi Disease in the Northeastern United States: A Case Series.

Background: The first recognized cases of Borrelia miyamotoi disease (BMD) in North America were reported in the northeastern United States in 2013.
Objective: To further describe the clinical spectrum and laboratory findings for BMD.
Design: Case series.
Setting: Patients presenting to primary care offices, emergency departments, or urgent care clinics in 2013 and 2014.
Participants: Acutely febrile patients from the northeastern United States in whom the treating health care providers suspected and ordered testing for tick-transmitted infections.
Measurements: Whole-blood polymerase chain reaction (PCR) testing was performed for the presence of specific DNA sequences of common tickborne infections (including BMD). Serologic testing for B. miyamotoi was performed using a recombinant glycerophosphodiester phosphodiesterase (rGlpQ) protein. Clinical records were analyzed to identify the major features of acute disease.
Results: Among 11,515 patients tested, 97 BMD cases were identified by PCR. Most of the 51 case patients on whom clinical histories were reviewed presented with high fever, chills, marked headache, and myalgia or arthralgia. Twenty-four percent were hospitalized. Elevated liver enzyme levels, neutropenia, and thrombocytopenia were common. At presentation, 16% of patients with BMD were seropositive for IgG and/or IgM antibody to B. miyamotoi rGlpQ. Most (78%) had seropositive convalescent specimens. Symptoms resolved after treatment with doxycycline, and no chronic sequelae or symptoms were observed.
Limitation: Findings were based on specimens submitted for testing to a reference laboratory, and medical records of only 51 of the 97 case patients with BMD were reviewed.
Conclusion: Patients with BMD presented with nonspecific symptoms, including fever, headache, chills, myalgia, and arthralgia. Laboratory confirmation of BMD was possible by PCR on blood from acutely symptomatic patients who were seronegative at presentation. Borrelia miyamotoi disease may be an emerging tickborne infection in the northeastern United States.
Primary Funding Source: IMUGEN.