Climatic and ecological conditions at the locations of human infection with Borrelia miyamotoi

Objective. To evaluate the climatic and ecological conditions favoring tick-borne borreliosis caused by Borrelia miyamotoi. Materials and methods. Patients with tick-borne borreliosis (TBB) reported the date and location of tick bite within about 1—3 km. The ecological and climatic conditions at infection locations were estimated from satellite remote sensing and meteorological observations using the VEGA web-based monitoring system developed by the Space Research Institute. The indicators under consideration included predominant types of vegetation, the average daily temperature and relative humidity, daily precipitation, and the normalized difference vegetation index (NDVI) as an indicator of the green vegetation. Results. We analyzed 77 human cases of B. miyamotoi infection diagnosed in 2010—2012 and 21 human cases in 2003 versus 55 human cases of «classical» tick-borne borreliosis with erythema migrans (Lyme disease) in 2010—2012 in the Republic of Udmurtia. We also analyzed 39 human cases of B. miyamotoi infection diagnosed in the Sverdlovsk Region in 2009. The ecological and climatic conditions at the tick bite locations were similar in the Republic of Udmurtia and the Sverdlovsk Region and did not differ at the locations of B.miyamotoi and B. burgdorferi sensu lato infections. Conclusion. We expect that human B.miyamotoi infection may be found, wherever I. persulcatus ticks are present and the infection caused by B. burgdorferi sensu lato is endemic, i.e. in most Russian regions.

B. miyamotoi, tick-borne borreliosis, B. miyamotoi, ecological and climatic conditions at the locations of infection