Characterization of hospital and community-acquired respiratory syncytial virus in children with severe lower respiratory tract infections in Ho Chi Minh City, Vietnam, 2010

Human respiratory syncytial virus (RSV) is an important community and nosocomial pathogen in developed countries but data regarding the importance of RSV in developing countries are relatively scarce. During a 1-year surveillance study in 2010, we took serial samples from children admitted to the Emergency Unit of the Respiratory Ward of Children's Hospital 1 in Ho Chi Minh City, Vietnam. RSV was detected within 72 hours of admission to the ward in 26% (376/1439; RSV A: n = 320; RSV B: n = 54; and RSV A and B: n = 2). Among those negative in the first 72 hours after admission, 6.6% (25/377) acquired nosocomial RSV infection during hospitalization (RSV A: n = 22; and RSV B: n = 3). Children with nosocomial RSV infection were younger (P = 0.001) and had a longer duration of hospitalization (P < 0.001). The rate of incomplete recovery among children with nosocomial RSV infection was significantly higher than among those without (P < 0.001). Phylogenetic analysis of partial G gene sequences obtained from 79% (316/401) of positive specimens revealed the co-circulation of multiple genotypes with RSV A NA1 being predominant (A NA1: n = 275; A GA5: n = 5; B BA3: n = 3; B BA9: n = 26; and B BA10: n = 7). The RSV A GA5 and RSV B BA3 genotypes have not been reported from Vietnam, previously. Besides emphasizing the importance of RSV as a cause of respiratory infection leading to hospitalization in young children and as a nosocomial pathogen, data from this study extend our knowledge on the genetic diversity of RSV circulating in Vietnam