Phylogenetic Analysis of Rubella Virus Strains from an Outbreak in Madrid, Spain, from 2004 to 2005

Abstract

Rubella virus (RUBV) usually causes a mild exanthematous disease that is frequently accompanied by adenopathy and occasionally by arthralgia. Complications of this infection are rare and include encephalopathy and thrombocytopenia. However, the most severe consequence of this virus is its teratogenicity. It can cause congenital rubella syndrome (CRS) when it occurs in pregnant women, particularly during the first trimester of pregnancy (10).The direct detection of RUBV RNA in clinical specimens, in addition to the detection of RUBV-specific immunoglobulin M, is a critical factor in the early laboratory diagnosis of recent or congenital infection (18,27). Currently, the European region of the World Health Organization (WHO) aims to eliminate not only measles but also rubella and to reduce the incidence of CRS to less than one case per 100,000 live births by 2010 (38, 39). For this purpose, epidemiological surveillance based on the laboratory diagnosis of each suspected case and the characterization of the genotype of the circulating strains are included in the WHO's recommendations. In the most recent WHO update, the standard nomenclature for the classification and designation of wild-type RUBV strains recognizes nine definitive and four provisional genotypes (40), expanding the nomenclature established in 2005 (37), which was based on 739 nucleotides (nt) (nt 8731 to 9469) from the E1 gene sequence. This sequence encodes amino acids (aa) 159 to 404 (of the 481 aa) of the E1 glycoprotein. Although our knowledge of the geographic distribution of RUBV genotypes has grown substantially since 2003, the genotypes present in many countries and regions remain unknown (9), even though rubella is still recognized as a globally important disease in a general public health context (41). RUBV is considered monotypic with cross-neutralization among different genotypes.In Spain, monovalent RUBV vaccine was introduced in the late 1970s, when it was administered in schools to 11-year-old girls (1). In 1981, one dose of the measles-mumps-rubella combined vaccine was introduced in the regular immunization schedule at the age of 15 months for all children. In 1996, a second dose at 11 years of age was introduced (5). In 1999, this second dose was given to 4-year-old children (3). Currently, the seroprevalence of RUBV in the community of Madrid exceeds 95% in all age groups and reaches 98.6% among women of childbearing age (16 to 45 years) (4). Nevertheless, the pattern is very different in other regions around the world and RUBV infection remains endemic in many areas, such as Latin America (15). The rubella vaccine was only introduced in Latin American countries in the late 1990s, so that many adult immigrants to Spain are not immunized. These circumstances led to a small outbreak in Madrid in 2003 (31) and a larger one in 2004 and 2005 (2, 27) among Latin American immigrants. The main aim of this study was to characterize the RUBV strain involved in the latter outbreak, which represents the first data concerning RUBV genotypes i...

Epidemiological and molecular assessment of a rubella outbreak in North‐Eastern Italy

“…WHO Laboratory Network for measles and rubella viruses surveillance reported the global distribution of RUBV genotypes, showing that in Europe genotype 1E and 1G are predominant [WHO, 2006; Hubschen et al, 2007]. More recently, the circulation of genotype 1j was documented in Spain, possibly introduced by persons from Latin America [Martinez‐Torres et al, 2009]. Genotype 2B is autochthonous in the Far East, namely Japan and Korea, and in South Africa, although it is now considered an imported European genotype [Jin and Thomas, 2007; Novo et al, 2009].…”

Role of the Laboratory in the Diagnosis of Viral Exanthems~!2009-11-20~!2009-11-25~!2010-02-16~!

“…The latter assay which is based on amplification of fragments of 289 base pairs (pb) of the rubella virus glycoprotein E1 gene, of 229 pb of the measles virus nucleoprotein gene and of 94 pb of the PVHB19 protein VP1 gene, has shown excellent sensitivity for the detection of measles and PVHB19, with a lower sensitivity for rubella. It has recently been confirmed that the addition of betaine, a reducing agent, to the amplification reaction, significantly improves the sensitivity of assays used for detecting the rubella virus genome [12].…”

Vigilancia microbiológica del sarampión y la rubéola en España: red de laboratorios

“…En el virus de la rubéola el genotipado se basa en una secuencia de 739 nt (del nt 8731 al nt 9469) de la región codificante del gen E1 13 . Para describir un nuevo genotipo se necesita la secuencia completa de la región del genoma que codifica las proteínas estructurales (3192 nt) de dos cepas de referencia para cada genotipo.…”