title: Molecular Characterization of Human Respiratory Syncytial Virus in the Philippines, 2012-2013.
abstract: Human respiratory syncytial virus (HRSV) is a major cause of acute lower respiratory tract infections in infants and children worldwide. We performed molecular analysis of HRSV among infants and children with clinical diagnosis of severe pneumonia in four study sites in the Philippines, including Biliran, Leyte, Palawan, and Metro Manila from June 2012 to July 2013. Nasopharyngeal swabs were collected and screened for HRSV using real-time polymerase chain reaction (PCR). Positive samples were tested by conventional PCR and sequenced for the second hypervariable region (2nd HVR) of the G gene. Among a total of 1,505 samples, 423 samples were positive for HRSV (28.1%), of which 305 (72.1%) and 118 (27.9%) were identified as HRSV-A and HRSV-B, respectively. Two genotypes of HRSV-A, NA1 and ON1, were identified during the study period. The novel ON1 genotype with a 72-nucleotide duplication in 2nd HVR of the G gene increased rapidly and finally became the predominant genotype in 2013 with an evolutionary rate higher than the NA1 genotype. Moreover, in the ON1 genotype, we found positive selection at amino acid position 274 (p<0.05) and massive O- and N-glycosylation in the 2nd HVR of the G gene. Among HRSV-B, BA9 was the predominant genotype circulating in the Philippines. However, two sporadic cases of GB2 genotype were found, which might share a common ancestor with other Asian strains. These findings suggest that HRSV is an important cause of severe acute respiratory infection among children in the Philippines and revealed the emergence and subsequent predominance of the ON1 genotype and the sporadic detection of the GB2 genotype. Both genotypes were detected for the first time in the Philippines.
authors.affiliation: Tohoku University Graduate School of Medicine, Sendai, Japan.
authors.forename: Rungnapa
authors.initials: R
authors.lastname: Malasao
authors.affiliation: Tohoku University Graduate School of Medicine, Sendai, Japan.
authors.forename: Michiko
authors.initials: M
authors.lastname: Okamoto
authors.affiliation: Tohoku University Graduate School of Medicine, Sendai, Japan.
authors.forename: Natthawan
authors.initials: N
authors.lastname: Chaimongkol
authors.affiliation: Tohoku University Graduate School of Medicine, Sendai, Japan.
authors.forename: Tadatsugu
authors.initials: T
authors.lastname: Imamura
authors.affiliation: Tohoku University Graduate School of Medicine, Sendai, Japan.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Tohma
authors.affiliation: Tohoku University Graduate School of Medicine, Sendai, Japan.
authors.forename: Isolde
authors.initials: I
authors.lastname: Dapat
authors.affiliation: Tohoku University Graduate School of Medicine, Sendai, Japan.
authors.forename: Clyde
authors.initials: C
authors.lastname: Dapat
authors.affiliation: Tohoku University Graduate School of Medicine, Sendai, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Suzuki
authors.affiliation: Tohoku University Graduate School of Medicine, Sendai, Japan.
authors.forename: Mayuko
authors.initials: M
authors.lastname: Saito
authors.affiliation: Tohoku-RITM Collaborating Research Center on Emerging and Reemerging Diseases, Muntinlupa City, Philippines.
authors.forename: Mariko
authors.initials: M
authors.lastname: Saito
authors.affiliation: Tohoku-RITM Collaborating Research Center on Emerging and Reemerging Diseases, Muntinlupa City, Philippines.
authors.forename: Raita
authors.initials: R
authors.lastname: Tamaki
authors.affiliation: Biliran Provincial Hospital, Naval City, Philippines.
authors.forename: Gay Anne Granada
authors.initials: GA
authors.lastname: Pedrera-Rico
authors.affiliation: Eastern Visayas Regional Medical Center, Tacloban City, Philippines.
authors.forename: Rapunzel
authors.initials: R
authors.lastname: Aniceto
authors.affiliation: Ospital ng Palawan, Puerto Princesa City, Philippines.
authors.forename: Reynaldo Frederick Negosa
authors.initials: RF
authors.lastname: Quicho
authors.affiliation: Research Institute for Tropical Medicine, Muntinlupa City, Philippines.
authors.forename: Edelwisa
authors.initials: E
authors.lastname: Segubre-Mercado
authors.affiliation: Research Institute for Tropical Medicine, Muntinlupa City, Philippines.
authors.forename: Socorro
authors.initials: S
authors.lastname: Lupisan
authors.affiliation: Tohoku University Graduate School of Medicine, Sendai, Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Oshitani
mesh_terms: D000293:Adolescent; D000595:Amino Acid Sequence; D001483:Base Sequence; D002648:Child; D002675:Child, Preschool; D019143:Evolution, Molecular; D005838:Genotype; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008969:Molecular Sequence Data; D010679:Philippines; D010802:Phylogeny; D018357:Respiratory Syncytial Virus Infections / Q000821:virology*; D018113:Respiratory Syncytial Virus, Human / Q000235:genetics*; D012141:Respiratory Tract Infections / Q000821:virology; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA