Case control study: Serological evidence that Borrelia miyamotoi disease occurs nationwide in Japan

Area of Science:

• Medical Entomology
• Infectious Diseases
• Serology

Background:

• Borrelia miyamotoi disease (BMD) is an emerging tick-borne illness transmitted by Ixodes ticks.
• BMD has been reported in several countries in the Northern Hemisphere since 2011.
• Ixodes ticks are also vectors for Lyme disease borreliae, complicating diagnosis.

Purpose of the Study:

• To conduct the first serological surveillance for Borrelia miyamotoi disease (BMD) in Japan.
• To determine the prevalence and geographical distribution of anti-GlpQ antibodies in suspected Lyme disease cases.
• To assess the association between BMD and Lyme disease.

Main Methods:

• Retrospective analysis of 459 clinically suspected Lyme disease cases.
• Serological testing for antibodies against the glycerophosphodiester phosphodiesterase (GlpQ) antigen of B. miyamotoi.
• Comparison of seroprevalence in a healthy cohort and a suspected Lyme disease group.
• Western blot assay for concomitant seropositivity to Lyme disease borreliae.

Main Results:

• Twelve out of 459 suspected Lyme disease cases were seropositive for anti-GlpQ antibodies.
• Seroprevalence of anti-GlpQ was significantly higher in the suspected Lyme disease group compared to a healthy cohort.
• Seropositive cases were identified across multiple regions of Japan (Hokkaido-Tohoku, Kanto, Chubu, Kinki, Kyushu-Okinawa) from spring to autumn.
• The Chubu region showed the highest seroprevalence (6.3%), correlating with known B. miyamotoi presence in local Ixodes ticks.
• Three of the twelve seropositive cases also showed seropositivity for Lyme disease borreliae.

Conclusions:

• Borrelia miyamotoi disease (BMD) is endemic throughout Japan.
• The findings highlight the importance of considering BMD in differential diagnoses for suspected Lyme disease cases in Japan.
• Co-infection with Lyme disease borreliae is possible and warrants further investigation.