Measles virus genotype circulation in Spain after implementation of the national measles elimination plan 2001–2003

Abstract

Molecular characterization of measles virus is important for disease surveillance and for monitoring elimination of the virus throughout the world. Furthermore, knowledge of genotype distribution in as many countries as possible, is useful for tracing the origin of a strain, especially in countries without endemic measles disease, where most cases are imported. Data on genotypes circulating in Spain from 1970 to 1997 showed the prevalence of genotypes C1, C2, and D6, with subsequent replacement of each other. After the establishment of the Spanish Measles Elimination Plan, genotyping with a new retrotranscriptase polymerase chain reaction (RT-PCR) was undertaken directly on 92 specimens, corresponding to 90 patients, which were positive for measles by a different diagnostic RT-PCR. Genotypes B3, D4, D8, A, C2, H1, and D7 were found in different autonomous communities (Madrid, Balearic Islands, Valencia Community, Extremadura, Andalusia, Canary Islands and Murcia) between 2001 and 2003 with none of these genotypes being prevalent. After the introduction of the vaccine in 1978, the incidence of the disease decreased from 150,000 cases in 1977 to 64 in 2002. This could be the reason for the change observed in the pattern of measles genotype circulation, since this pattern was reported in countries at an advanced stage of eradication of measles. This report considers that Spain is on the way to eradicating measles.

Molecular epidemiology of circulating measles virus in Ireland 2002–2007

“…Measles genotypes are not geographically confined; however, there are predominant circulating clades in certain areas. For example, in Italy and France the main reported genotype is D7 [Zandotti et al, 2004;Ciofi Degli Atti et al, 2006], whereas, other countries in Europe, such as in Germany and Spain, have reported the presence of a broad diversity of circulating strains genotypes B3, C2, D4, D5, D6, D7, G2, and H1 [Tischer et al, 2004;Mosquera et al, 2005] More recently during 2005 and 2006, in the World Health Organisation (Kremer et al, 2008) European Region major epidemics were associated with genotypes D4, D6, and B3, although other genotypes were found after importation from other continents (B2, D5, D8, D9, G2, and H1) [Kremer et al, 2008].…”

High Genetic Diversity of Measles Virus, World Health Organization European Region, 2005–2006

“…D4 viruses are still endemic on the Indian subcontinent as well as in East and South Africa (5,27). Although some outbreaks and sporadic cases associated with genotype D4 had been reported from Europe, the corresponding viruses were mostly imported from other continents and differed considerably from the more recent strains (6,11,30). In 2005-2006, genotype D4 was found in 16 of the 27 countries in which MV has been genotyped; most of the corresponding viruses were related to the outbreak in Romania.…”

“…The low genetic diversity of D6 strains suggests that enhanced vaccination has largely reduced the cocirculation of highly diverse D6 variants in Europe. Moreover, genotypes C2 and D7, which were frequently identifi ed in Europe until 2004 (4)(5)(6)(7)(8)(10)(11)(12), were no longer found during the past 2 years, despite greatly improved virologic surveillance. Genotype C2 had been continuously identifi ed in the European Region since the early 1970s, and genotype D7 had partially replaced genotypes C2 and D6 in Germany during 2000-2004 (6).…”

“…Genotype C2 has been continuously detected in the European Region since the early 1970s and is therefore considered to be the indigenous genotype of Europe (4,5). D6 viruses have been regularly reported from different countries of the European Region since the early 1990s (4)(5)(6)(7)(8)(9)(10)(11)(12), and genotype D6-associated outbreaks or sporadic cases on other continents were mostly due to MV importations from Europe (13)(14)(15) (Figure 1). These observations thus provide overwhelming evidence for the endemic circulation of genotype D6 in Europe at least during the past 15 years.…”

Improving molecular tools for global surveillance of measles virus

“…Based on these sequences, 24 genotypes have been identified [6,7]. Since 1998, the standard genotyping RT-PCR assay from the CDC recommended a primer pair designated MV60/MV63.3 [8] though other primers were also used throughout LabNet [9][10][11][12][13][14]. Several new MeV genotypes have been described since the introduction of the standard genotyping method [15][16][17]; however, only limited sequence data were available for the primer binding sites of the more recent strains and the analytic sensitivity of the primers had not been evaluated.…”