[Molecular epidemiology of parvovirus infection in Belarus].

The paper analyzes a 994 nucleotide fragment of the NS1/VP1u region junction of 84 parvovirus B19 samples obtained from the sera of erythema infectiosum patients in Belarus in 2006. All the strains belong to genotype 1 as defined by Servant et al. (2002) and form two major clusters within this genotype (1A and 1B) with a clearly distinct geographic distribution. Cluster 1A mainly included B19 strains from Minsk where an outbreak of erythema infectiosum was observed during sample collection. Cluster 1B comprises parvovirus B19 strains obtained from sporadic cases in different parts of the country. The nucleotide variability within cluster 1B (1.1%) was almost two times higher than that within cluster 1A (0.6%). The comparison of the Belarus strains with all parvovirus B19 sequences from the GenBank revealed 22 unique nucleotide substitutions in the new strains, 18 (81.8%) of which were nonsynonymous. A high percentage of parvovirus B19 IgM positive sera were also PCR positive (94.0%; n = 63/67) indicating that both methods are suitable for diagnosis of the infection.

[Laboratory diagnostics and monitoring of virus circulation in surveillance system for rubella in Belarus].

AIM: To summarize data on laboratory diagnostics of prenatal and postnatal rubella and molecular monitoring of rubella virus circulation in Belarus obtained during implementation of rubella elimination program. MATERIALS AND METHODS: Serum samples from 2314 persons were tested on the presence of IgM to rubella virus and measles virus (in case of negative result on rubella) using respective enzyme immunoassays. Virological testing using RT-PCR as well as genotyping on the basis of E1 gene fragment sequencing were also performed. Two viruses isolated in Belarus were set as reference strains of genotypes 1G and 1h. RESULTS: Implementation of laboratory diagnostics allowed to differentiate cases of rubella from other exanthematous infections, significantly increase the number of laboratory-confirmed cases among all reported cases, and show presence of endemic circulation of rubella virus strains of 3 different genotypes (1G, 1E, and 1h) in Belarus (2004-2006). In 2006, when relatively high incidence of rubella was reported in the country (24.39 per 100,000 population), the risk of congenital rubella syndrome was not less than 9 per 100,000 births. Conducted in October 2005-May 2006 additional rounds of immunization against rubella (>1 million people were vaccinated) decreased incidence to single cases. CONCLUSION: Obtained data show achievability of indigenous rubella elemination by 2010. Revealed genetic diversity of rubella virus strains allowed to update the International classification of wild rubella viruses.