Results and Prospects for Cooperation between Russia and Mongolia on the Problems of Tick-Borne Infections

Abstract

This article presents the results of a quarter of a century of cooperation between the Scientific Center for Family Health and Human Reproduction Problems (Irkutsk, Russia) and the National Centers for Zoonotic Infections (Ulaanbaatar and Sükhbaatar, Mongolia), as well as the current ecological and epidemiological situation and perspectives of future collaborative research. The current situation in the natural foci of tick-borne infections in the transboundary Russian–Mongolian territories indicates the need to continue joint research and improve existing monitoring. Based on the results of field research, laboratory diagnostics of biomaterials, and data on the official incidence of tick-borne infections, the epidemiological situation in near-border foci in Russia and Mongolia started worsening. In the territories of the taiga and forest-steppe landscapes of Mongolia, the taiga tick, the main vector of tick-borne encephalitis (TBE) and ixodid tick-borne borreliosis (Lyme disease), occurs with varying frequency and abundance. The second in importance and width of distribution is the steppe tick, which annually reaches several hundred per surveillance count in April–May in the steppe habitats. Up to 81% of the studied ticks contain viral and bacterial pathogens and can transmit these pathogens of dangerous diseases to humans. Since 2005, TBE has been diagnosed in 393 patients, Lyme disease in 276, and North Asian tick typhus in 2003, and patients with mixed infection were also diagnosed. More than half of the tick-borne disease cases were registered in Selenge aimag bordering Russia, which is one of the most affected in Mongolia in terms of tick-borne infections. For 18 years, the mortality comprised 0.9% (23 fatal cases). According to the official data of Rospotrebnadzor in the Republic of Buryatia in the border Tunkinsky district, the incidence of TBE had increased from one case in 2020 to six in 2022, whereas Lyme disease increased from four to seven cases. The results presented here indicate the need for urgent actions to prevent a further increase in tick-borne diseases.