Peculiarities of directions and causal agents’ distribution of tick-borne encephalitis in the Republic of Moldova

Abstract

The aim of the study is to determine the circulation of tick-borne encephalitis (TBE) causal agents in the Ixodidae ticks population and the evaluation of the TBE threat to public health. The species of ticks Ixodes ricinus, Dermacentor reticulatus, D. marginatus and Haemaphysalis punctata can be often met in the ecosystems of the Republic of Moldova. The species I. ricinus is the most numerous and widespread one, the fact that shows its high epidemiological significance. At the same time the species D. reticulatus, D. marginatus and H. punctata are the potential directions of TBE maintaining the TBE viruses in the environment. The laboratory results got by the enzyme-linked immunosorbent assay (ELISA) have indicated the TBE virus antigen in of 25.2% of the ticks, collected in the period of 2009-2012. Using the polymerase chain reaction method it has been established that on average the RNA of TBE virus has been 8.1% of all tested tick samples. The specific antibodies to tick-borne encephalitis virus have been identified in 9 (4%) tested human specimens. The rationalization of the system of epidemiological surveillance and control of tick-born encephalitis consists in developing and implementing a definition of the case for report on the basis of clinical and laboratory criteria, as well as the communication with epidemiological station, and studying to obtain standardized and comparable data