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Genetic characterization of wild-type measles viruses (MVs) is an important component of laboratory surveillance of measles. In this study, a phylogenetic analysis was performed of the nucleoprotein gene sequences of 228 MVs isolated in the Russian Federation between 2003 and 2007. Five genotypes, D4, D5, D6, D8, and H1, were detected. From 1999 through the first 6 months of 2003, the most prevalent genotype in the European part of Russia was D4. All genotype D4-type viruses were closely related to each other (with overall sequence diversity of ≤0.9%), suggesting the presence of a single endemic MV strain. After 2003, viruses with closely related sequences within genotype D6 (≤0.9% sequence diversity) were prevalent. During this time, there was a low level of indigenous transmission of genotype D6, and genotype D6 viruses were imported from neighbouring countries, which led to the identification of two lineages of genotype D6, i.e. D6a and D6b. Lineage D6a was closely related to viruses isolated in Turkey, Kazakhstan, and Uzbekistan, whereas lineage D6b was linked to a large outbreak in Ukraine in 2005–2006. Genotypes H1, D5 and D8 were associated with sporadic cases and clusters of transmission linked to importations. Enhanced vaccination interrupted the transmission of the previous endemic lineage D4 in 2003 and of lineage D6a in 2005, although an accumulation of susceptible individuals in the population allowed for prolonged circulation of lineage D6b. These data on MV genotype distribution, in conjunction with the epidemiological data for measles, show considerable progress in measles control and suggest that regional elimination is possible. [ABSTRACT FROM AUTHOR]

Introduction of live measles vaccines into daily practice resulted in a pronounced reduction of measles morbidity in many countries, that allowed WHO to develop the measles eradication program. Russian Federation has commenced realization of the eradication program for local measles cases in the country, (measles elimination) in 2002. and had achieved significant success by 2007. For 4 years (2007 -2010) the parameter of measles morbidity in Russian.Federation did not exceed the WHO measles elimination criteria - no more than 1 measles case per 1 million population. However, the situation for measles began to deteriorate from 2011, reflecting the growth of measles morbidity in many regions of the world. The main reason for measles morbidity growth was accumulation of a contingent,of individuals not immunized against measles against the background of internal and external population migration. Under the condition ofconstant maintenance of a high vaccination coverage of the population (above 95%) on thewhole territory of Russia, the objective of measles elimination in the country can be successively met.

Successful implementation of the Russian Federation's national measles elimination program has been ensured by high vaccine coverage (>95%) of the target population (with 2 doses of measles-containing vaccine), case-based laboratory investigation of measles, and active surveillance of measles cases among patients with rashes and/or fever. As a result, the incidence of measles has decreased to <1 case per 1,000,000 population (2007-2009); no circulation of D6 genotype, which was endemic in the Russian Federation, has been observed since the second half of 2007; and the proportion of imported measles cases of different genotypes increased to 19.8% in 2007 from 1% in 2003. To confirm successful elimination of indigenous measles, a documentation system was initiated in the Russian Federation., (© The Author 2011. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved.)