Phylogenetic analysis of 166 human parvovirus B19 sequences from 11 different countries attributed 91.57% to genotype 1, 5.42% to genotype 3b, and 3.01% to genotype 3a. Very similar viruses of genotype 1 circulated widely in Europe and Israel. Genotype 3b seems to show an increasing spread outside of Africa.Human parvovirus B19 (B19V) infections are usually associated with mild disease, but in immunocompromised and anemic patients, as well as during pregnancy, severe complications can occur. Based on the genetic variability of 994 nucleotides (nt) of the NS1/VP1-unique region junction, three distinct genotypes of B19V have been proposed (13). A recent report presented evidence that certain complications might be preferentially associated with certain virus genotypes (6). Several studies demonstrated that previously published or commercially available assays show differences in their diagnostic performance, including the inability to detect certain genotypes, especially genotype 3, subtype 3b (1, 5). Despite these important implications for the diagnosis of B19V, little is known about the genotypes prevalent in many countries.Serum samples collected between 2000 and 2008 mostly from rash/fever patients negative for both measles and rubella from 11 different countries were analyzed for B19V (Table 1). A nested PCR was performed with the forward primers e1855f and e1863f (13) and reverse primers B19-R1 (5Ј-GGGAACT TCCGGCAAACTTCCTTG-3Ј) and B19-R2 (5Ј-GTAGTCTT TTACTACTTGTGCTTG-3Ј), yielding fragments of 1,239 and 1,168 nt. Previously published reverse primers (13) have a maximum of three (e2953r) and four (e2960r) mismatches compared to B19V GenBank sequences, including 3Ј and 5Ј
The suspected measles case definition captures rubella cases. Therefore, measles surveillance will be improved in the course of the control and eventual elimination of rubella transmission. One aspect of rubella control, virologic surveillance, is reviewed here. A systematic nomenclature for rubella viruses (RVs) based on 13 genotypes has been established and is updated when warranted by increases in information about RVs. From 2005 through 2010, the genotypes of RVs most frequently reported were 1E, 1G, and 2B, and genotypes 1a, 1B, 1C, 1h, 1j, and 2C were less frequently reported. Virologic surveillance can support rubella control and elimination. Synopses of rubella virologic surveillance in various countries, regions, and globally are given, including characterization of viruses from imported cases in a country that has eliminated rubella and studies of endemic viruses circulating in countries without rubella control objectives. Current challenges are discussed.
The WHO European Region 2010 goal will not be met, as indigenous transmission of MV has not been interrupted. As the region begins to document its process of elimination verification to monitor progress toward the goal, countries will need to ensure that genotyping is performed in all measles outbreaks.
The sequence of the 300 nucleotides region of the measles virus genome was determined that includes a part of the 3'-untranslated region of the matrix (M) gene, the intergenic region and a part of the 5'-untranslated region of the fusion (F) gene [M-F region] for vaccine strain Leningrad-16 and 14 wild-type isolates. The data obtained demonstrate the variability of this long non-coding M-F region. No mutations in this region of the genome were found which seem to be specific for vaccine strains of measles virus (MV).
The nucleoprotein genes of 49 measles virus (MV) strains circulating in Russia between 2000 and 2006 and in Vietnam in 2003 were analyzed by genotype-specific PCR and the results were compared with their sequences. The sequences revealed the presence of genotypes H1 and H2 in the center (Nha Trang) and the north (Hanoi) of Vietnam, respectively. The relative diversity of the H2 strains suggested an endemic circulation of these viruses in the capital. In contrast genotype H1 strains from Nha Trang were homogenous genetically, which may indicate a recent importation. The strains obtained from 12 different regions of the Russian Federation were assigned to the genotypes H1, D4, and D6. Most strains (81.4%) were correctly genotyped by a multiplex PCR method which was sensitive to genotype-specific mutations [Kremer et al. (2004): J Clin Microbiol 42: 3017-3022]. Ambiguous or negative results for some clade H and genotype D6 strains were due to point mutations in the type-specific primer binding sites. After exchanging a single nucleotide in both the clade H- and the genotype D6-specific primers, all strains were assigned correctly to their genotype. A simplified procedure for use in Vietnam was developed to distinguish directly between genotypes H1 and H2 and any non-H genotype. These results demonstrate that our multiplex PCR method can be adapted easily to new sequence variants or specific epidemiological situations, and thus be very useful for rapid genotyping of large number of samples even in laboratories which do not have sequencing facilities.
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