Genetic characterization of measles virus in the Philippines, 2008–2011

Abstract

BackgroundLarge outbreaks of measles occurred in the Philippines in 2010 and 2011. Genetic analysis was performed to identify the genotype of measles virus (MeV) that was responsible for the large outbreaks.MethodsA total of 114 representative MeVs that were detected in the Philippines from 2008 to 2011 were analyzed by sequencing the C-terminal region of nucleocapsid (N) gene and partial hemagglutinin (H) gene and by inferring the phylogenetic trees.ResultsGenetic analysis showed that genotype D9 was the predominant circulating strain during the 4-year study period. Genotype D9 was detected in 23 samples (92%) by N gene sequencing and 93 samples (94%) by H gene analysis. Sporadic cases of genotype G3 MeV were identified in 2 samples (8%) by N gene sequencing and 6 samples (6%) by H gene analysis. Genotype G3 MeV was detected mainly in Panay Island in 2009 and 2010. Molecular clock analysis of N gene showed that the recent genotype D9 viruses that caused the big outbreaks in 2010 and 2011 diverged from a common ancestor in 2005 in one of the neighboring Southeast Asian countries, where D9 was endemic. These big outbreaks of measles resulted in a spillover and were associated with genotype D9 MeV importation to Japan and the USA.ConclusionGenotype D9 MeV became endemic and caused two big outbreaks in the Philippines in 2010 and 2011. Genotype G3 MeV was detected sporadically with limited geographic distribution. This study highlights the importance of genetic analysis not only in helping with the assessment of measles elimination program in the country but also in elucidating the transmission dynamics of measles virus.Electronic supplementary materialThe online version of this article (doi:10.1186/s13104-015-1201-1) contains supplementary material, which is available to authorized users.

Nationwide Molecular Epidemiology of Measles Virus in Japan Between 2008 and 2017

“…The sequence analysis of MV strains has confirmed that certain D9 strains in Japan have the identical N450 nucleotide sequences to the Philippine D9 strains (Centeno et al, 2015). The D9 strains were first detected in the Philippines in 2007 and have been predominant until 2012 in the Philippines (Fuji et al, 2011; Centeno et al, 2015; Takashima et al, 2015). Outbreaks between 2010 and 2011 in the Philippines were presumably caused by several D9 strains with different N450 sequences (Centeno et al, 2015).…”

“…Between 2010 and 2011, large D9 outbreaks have occurred in the Philippines (Centeno et al, 2015; Takashima et al, 2015), and many cases in Japan had travel history to the Philippines (National Institute of Infetious Diseases [NIID], and Tuberculosis and Infectious Disease Control Division, Ministry of Health, Labor and Welfare [MHLW], 2011a,b; National Institute of Infetious Diseases [NIID], and Tuberculosis, and Infectious Disease Control Division, Ministry of Health, Labor, and Welfare [MHLW], 2012a,b; Centeno et al, 2015). The sequence analysis of MV strains has confirmed that certain D9 strains in Japan have the identical N450 nucleotide sequences to the Philippine D9 strains (Centeno et al, 2015). The D9 strains were first detected in the Philippines in 2007 and have been predominant until 2012 in the Philippines (Fuji et al, 2011; Centeno et al, 2015; Takashima et al, 2015).…”

“…The D9 strains were first detected in the Philippines in 2007 and have been predominant until 2012 in the Philippines (Fuji et al, 2011; Centeno et al, 2015; Takashima et al, 2015). Outbreaks between 2010 and 2011 in the Philippines were presumably caused by several D9 strains with different N450 sequences (Centeno et al, 2015). D9 virus was also exported from the Philippines to Taiwan and Australia in 2010 and 2011, respectively (Jayamaha et al, 2012; Cheng et al, 2013).…”