Molecular epidemiology and disease severity of human respiratory syncytial virus in Vietnam.
Respiratory syncytial virus (RSV) is a major cause of acute respiratory infections (ARIs) in children worldwide and can cause high mortality, especially in developing countries. However, information on the clinical and molecular characteristics of RSV infection in developing countries is limited. From April 2010 to May 2011, 1,082 nasopharyngeal swabs were collected from children with ARI admitted to the Children's Hospital 2, Ho Chi Minh City, Vietnam. Samples were screened for RSV and genotyped by reverse transcription-PCR and sequencing. Demographic and clinical data was also recorded. RSV was found in 23.8% (257/1,082) of samples. RSV A was the dominant subgroup, accounting for 91.4% (235/257), followed by RSV B, 5.1% (13/257), and 9 cases (3.5%) were mixed infection of these subgroups. The phylogenetic analysis revealed that all group A strains belonged to the GA2 genotype. All group B strains belonged to the recently identified BA genotype, and further clustered into 2 recently described subgenotypes BA9 and BA10. One GA2 genotype strain had a premature stop codon which shortened the G protein length. RSV infection was significantly associated with younger age and higher severity score than those without. Co-infection with other viruses did not affect disease severity. RSV A caused more severe disease than RSV B. The results from this study will not only contribute to the growing database on the molecular diversity of RSV circulating worldwide but may be also useful in clinical management and vaccine development.
Department of Developmental Medical Sciences, School of International Health, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
Dinh Nguyen
DN
Tran
Thi Minh Hong
TM
Pham
Manh Tuan
MT
Ha
Thi Thu Loan
TT
Tran
Thi Kim Huyen
TK
Dang
Lay-Myint
LM
Yoshida
Shoko
S
Okitsu
Satoshi
S
Hayakawa
Masashi
M
Mizuguchi
Hiroshi
H
Ushijima
D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D017720:Molecular Epidemiology; D018357:Respiratory Syncytial Virus Infections / Q000453:epidemiology* / Q000628:therapy / Q000821:virology*; D012136:Respiratory Syncytial Viruses / Q000235:genetics* / Q000472:pathogenicity* / Q000502:physiology; D012621:Seasons; D014744:Vietnam / Q000453:epidemiology