Vol 20, No 4 (2015)

As a result of the application of experimental test systems "ELISA-IgM-dengue", "ELISA-IgM-WN" and "ELISA-IgM-TBE" when examining sera from patients with dengue fever (DF), West Nile fever (WNF) and tick-borne encephalitis (TBE) there was established the possibility of a clear differential diagnosis of these related flavivirus infections. Application of the ELISA-IgG test systems fail to provide such an opportunity due to cause of pronounced cross-reactions of group-IgG antibodies. In the article there are presented data on dynamics of IgM and IgG antibodies in patients with dengue fever. Detection of specific IgG in the first days of the disease may indicate to a secondary nature of infection and the possibility of the development of hemorrhagic syndrome.

There was performed the analysis of long-term dynamics ofmorbidity of certain nosologicalforms ofacute intestinal infections (AII) of the population of the Perm region and the Russian Federation in 2000-2014. There are summarized results of the epidemiological investigation of AII outbreaks recorded in the Perm region in 2009-2014. It was found that in recent years in the territory of the Perm region and the Russian Federation as a whole against the background of significant reduction or stabilization of the population incidence of certain bacterial AII there was noted the gain in the population incidence of viral AII. According to the materials of the Perm region in recent years, there were most frequently recorded food outbreaks of salmonellosis and food outbreaks of norovirus and rotavirus infections involving water as an intermediate factor of transmission.

A comparative analysis of the virus infection carrier state and distribution of genetic types of the virus of tick-borne encephalitis (TBE) among invertebrates (2 species of ticks, Ixodes persulcatus Schulze and Ixodes pavlovskyi Pomerantsev 1946) and vertebrate reservoir hosts (4 species of small rodents: the red vole Myodes rutilus Pallas, gray-sided vole Myodes rufocanus Sundevall, field mouse Apodemus agrarius Pallas, birch mice Sicista betulina Pallas and 1 species of insectivores - common shrew Sorex araneus L (1758)), dominating on the territory of the Novosibirsk region in 2009-14 years, was performed with the use of virological and molecular biological methods. Frequency detection of RNA and / or E protein in mammals (70,9 ± 3,0%) were shown to considerably exceed levels of virus infection carrier state rate of ticks (3,4 ± 0,4). In the circulation of three major types of TBE - Far East (FE), Siberian (NIB) and European (Eur) in natural populations in mono - or polytype forms in mites Sib type prevailed (p <0,01), in small mammals - ET type (p <0.001). At the same time the number of genome equivalents FE type in average accounted for 3.2 • 10 4 copies in the mite; Sib and Eur - about 10 and 100 times lower, respectively. In the blood of wild rodents, the amount of RNA ofFE of type TBEV ranged from 2.4 • 10 5 mL, of Sib type - 2.4 • 10 2. With account of blood volume of mammals consumed by larvae and nymphs, the falling of several hundreds and thousands of viral genomes such as DV and only single type of RNA Sib IRB, respectively, is possible in the tick. Passaging TBE isolates from wild reservoir hosts in laboratory mice lead to the transformation of the original genetic composition. In minimal genetic rearrangements ofpathogenic isolates of TBE in infected mice-suckers the transformation of apathogenic isolates was significant. The polytype composition of natural populations of TBE should be considered in the development of diagnostic and preventive preparations.

In the paper there are presented the main tendencies of the epidemic process in rotaviral infection in the one of the southern region of Ukraine during the span of 1998-2013. There was established the prevalence of the contact-house way of the transmission in 1-year-old infants. There were determined the most spread P and G genotypes of the agent, their widely spread combinations and the dynamic changes of genotypes in this region.