M. Mosquera

Molecular Identification of Mumps Virus Genotypes from Clinical Samples: Standardized Method of Analysis

ABSTRACT A sensitive nested reverse transcription-PCR assay, targeting a short fragment of the gene encoding the small hydrophobic protein (SH gene), was developed to allow rapid characterization of mumps virus in clinical samples. The sensitivity and specificity of the assay were established using representative genotypes A, B, C, D, E, and F. Mumps virus RNA was characterized directly from cerebrospinal fluid (CSF) samples and in extracts of mumps virus isolates from patients with various clinical syndromes. Direct sequencing of products and subsequent phylogenetic analysis enabled genetic classification. A simple web-based system of sequence analysis was established. The study also allowed characterization of mumps virus strains from Argentina as part of a new subgenotype. This PCR assay for characterization of mumps infections coupled to a web-based analytical program provides a rapid method for identification of known and novel strains.

A measles outbreak in children under 15 months of age in La Rioja, Spain, 2005-2006.

This paper describes a measles outbreak in La Rioja, Spain, which began in December 2005 and mainly affected children under 15 months of age who were not yet immunised with MMR vaccine. The measles cases were detected by the mandatory reporting system, under which laboratories must report every confirmed measles case. Cases were classified in accordance with the National Measles Elimination Plan: suspected and laboratory-confirmed. In the period 14 December 2005 to 19 February 2006, 29 suspected cases of measles were investigated, and 18 were confirmed. The mean incubation period was 13.8 days (range: 9 to 18). Of the 18 confirmed cases, only two were in adults. MMR vaccination was recommended for all household contacts, as well as for children aged 6 to 14 months who attended the daycare centres where the cases had appeared. At these centres, the second dose of MMR was administered ahead of schedule for children under three years of age. It was recommended that the first dose of MMR vaccine be administered ahead of schedule for all children aged 9 to 14 months. During an outbreak of measles, children aged 6 months or older, who have not previously been vaccinated against measles, mumps and rubella, should receive a first dose as soon as possible, and those who have had a first dose should receive a second dose as soon as possible, provided that a minimum of one month has elapsed between the two doses.

CIRCULATION OF MUMPS VIRUS GENOTYPES IN SPAIN FROM 1996 TO 2007.

ABSTRACT Although the WHO recommends the use of genotyping as a tool for epidemiological surveillance for mumps, limited data on mumps virus (MV) genotype circulation that may be used to trace the patterns of virus spread are available. We describe the first complete series of data from Spain. The small hydrophobic region was sequenced from 237 MV-positive samples from several regions of Spain collected between 1996 and 2007. Six different genotypes were identified: A, C, D (D1), G (G1, G2), H (H1, H2), and J. Genotype H1 was predominant during the epidemic that occurred from 1999 to 2003 but was replaced by genotype G1 as the dominant genotype in the epidemic that occurred from 2005 to 2007. The same genotype G1 strain caused concomitant outbreaks in different parts of the world (the United States, Canada, and the United Kingdom). The remaining genotypes (genotypes A, C, D, and J) appeared in sporadic cases or small limited outbreaks. This pattern of circulation seems to reflect continuous viral circulation at the national level, despite the high rates of vaccine coverage.

Measles risk groups in Spain: implications for the European measles-elimination target.

The European Region has set itself the goal of eliminating measles by 2010. Incidence has increased in recent years. This study sought to investigate outbreaks in Spain in the period 2005-2007, in order to identify measles-vulnerable groups and compare Spain to other European countries which have also had measles outbreaks. The pattern observed for Spain proved different to that of other European countries, i.e., whereas young adults and infants aged under 15 months were affected in Spain, children aged under 9 years comprised the predominant group in other European countries. Measles cases in Spain reflect low coverage when vaccination began, a pattern that could be repeated in neighbouring countries. Vaccination efforts should thus be targeted at vulnerable groups, namely: young adults; health professionals; travelling communities; and adopted infants and foreigners from countries with important pockets of susceptibles.

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

ABSTRACT An outbreak of rubella affected 460 individuals in 2004 and 2005 in the community of Madrid, Spain. Most of the patients were nonvaccinated Latin American immigrants or Spanish males. This study presents the first data on rubella virus genotypes in Spain. Forty selected clinical samples (2 urine, 5 serum, 3 blood, 2 saliva, and 28 pharyngeal exudate samples) from 40 cases were collected. The 739-nucleotide sequence recommended by the World Health Organization obtained from viral RNA in these samples was analyzed by using the MEGA v4.0 software. Seventeen isolates were obtained from 40 clinical samples from the outbreak, including two isolated from congenital rubella syndrome cases. Only viral RNA of genotype 1j was detected in both isolates and clinical specimens. Two variations in amino acids, G253C and T394S, which are involved in neutralization epitopes arose during the outbreak, but apparently there was no positive selection of either of them. The origin of the outbreak remains unknown because of poor virologic surveillance in Latin America and the African countries neighboring Spain. On the other hand, this is the first report of this genotype in Europe. The few published sequences of genotype 1j indicate that it comes from Japan and the Philippines, but there are no epidemiological data supporting this as the origin of the Madrid outbreak.

Assessment of RNA amplification by multiplex RT-PCR and IgM detection by indirect and capture ELISAs for the diagnosis of measles and rubella.

Sanz JC, Mosquera M, Ramos B, Ramírez R, de Ory F, Echevarria JE. Assessment of RNA amplification by multiplex RT‐PCR and IgM detection by indirect and capture ELISAs for the diagnosis of measles and rubella. APMIS 2010; 118: 203–9.

Mumps Virus Genotyping: Basis and Known Circulating Genotypes~!2009-11-20~!2009-11-26~!2010-02-16~!

Although mumps virus (MV) is considered antigenically monotypic, twelve different genotypes of MV based on genetic variation in the SH gene (A to L) are currently recognised by the WHO. Both dominance of a single genotype and co-circulation of different genotypes in the same geographical area, as well as temporal replacement of genotypes have been described in different countries. The different histories of genotype importation, variations in vaccine coverage and the use of different vaccine strains in each country results in a complex picture that could be the cause of the different geographical patterns of mumps virus genotype circulation observed in different countries. Lack of full cross-protection between different genotypes has been reported and has been suggested as a cause of vaccine failure, especially for vaccine strains belonging to genotype A, which is genetically distant to the remaining genotypes that include most of the currently circulating wild strains. Finally, a differential ability to invade the neural system has been suggested for some particular strains belonging to genotype D.