Borrelia miyamotoi (BMD) relapsing fever group spirochetes are increasing in numbers in ticks in the United States

Dr. Richard Horowitz


Borrelia miyamotoi (BMD) relapsing fever group spirochetes are increasing in numbers in ticks in the United States. This spirochete can be transmitted transovarially from the mother tick directly to her eggs, between 6-73% of the time, increasing the prevalence of infected ticks. This article discusses the transmission time for Bm disease, concluding that "single I. scapularis nymphs effectively transmit B. miyamotoi relapsing fever group spirochetes while feeding..and that transmission can occur within the first 24 hours of nymphal attachment, with the probability of transmission increasing with the duration of nymphal attachment.". Clinicians therefore need to be aware that infection is possible during the first 24 hours of tick feeding, similar to Lyme disease spirochetes (if they are in the salivary glands of infected ticks). Since standard Lyme testing will not pick up Borrelia miyamotoi infection, clinicians need to be vigilant for clinical presentations that can be confused with viral infections, i.e., high fever, chills, marked headache, and myalgia (muscle pains) or arthralgia (joint pains). Some patients have required hospitalization secondary to the severity of the illness. Elevated liver enzyme levels, neutropenia (low neutrophil counts), and thrombocytopenia (low platelet counts) can also be seen, resembling an infection with Anaplasma/Ehrlichia (and BMD does respond to treatment with doxycycline). In prior scientific publications, only 16% of patients presenting with BMD were seropositive for IgG and/or IgM antibody to B. miyamotoi rGlpQ, so PCR should also be considered in patients with a history of tick bites and appropriate clinical manifestations ( Borrelia miyamotoi Disease in the Northeastern United States: A Case Series. Philip J. Molloy, MD et al. Ann Int Med, 21 July 2015)