Respiratory syncytial virus infections in children in rural Nepal: a prospective community-based study
Background: Acute lower respiratory tract infections are responsible for the greatest burden of deaths in children worldwide. Respiratory syncytial virus (RSV) is the most important cause of viral pneumonia. No prior studies have evaluated the disease burden and transmission patterns of RSV in a community-based rural setting in south Asia.
Methods: A prospective randomized controlled trial of clean cookstove installation was conducted in rural Nepal. Households with children age 1-36 months were enrolled and followed through weekly home visits. In a subsample of households, mid-nasal swabs were collected from children with symptoms of a respiratory illness and tested for RSV and 11 other respiratory viruses by PCR. RSV sequencing was performed using a semi-nested PCR assay.
Results: From July 2011 to September 2013, 258 children in 247 households experienced 298 illness episodes. Among these households, the median number of household members was 9 (IQR: 7, 13), of whom 3 (IQR: 2, 4) were under age five. Eighty-eight (36%) households had members who smoked. RSV was detected in 76 (26%) illness episodes; 31 (41%) episodes had other respiratory viruses detected, including 20 (65%) with rhinovirus. Clinical data are available for 36 children with 46 RSV illness episodes; median age at illness was 11 months (SD: 6) and 12 (33%) were male. RSV illness episode symptoms included refusal to feed (n=22; 48%), chest indrawing (n=8; 17%), cyanosis (n=1; 2%), and lethargy or unconsciousness (n=13; 28%). Mean respiratory rate was 24 (SD: 5), and mean oxygen saturation was 97% (SD: 3%). RSV peaked in September to January in all 3 years. Subtype A was detected in 61 and subtype B in 14 samples. Only RSV A was detected in 2011-2012, while both subtypes circulated in 2012-2013. Three geographic clusters of RSV were detected in Season 1. One cluster of six illness episodes occurred in one village between October and December 2011 (Figure 1). Identical genotypes were observed to cluster in 2011-2012 as well.
Conclusion: In a rural setting in south Asia with home-based surveillance, RSV caused a significant burden of illness in young children. There was a clear seasonality to RSV over 3 years, with temporal and geographic clustering of RSV by subtype and genotype.
H. Y. Chu,
S. Leclerq, None
S. Khatry, None
E. Martin, None
V. Vaidya, None
I. Palileo, None
J. Kuypers, None
J. Tielsch, None
J. A. Englund, Gilead: Consultant and Investigator, Consulting fee and Research support
Chimerix: Investigator, Research support
Roche: Investigator, Research support
GlaxoSmithKline: Consultant, Investigator and Member, DSMB (DataSafety Monitoring Board), Consulting fee, Payment for DSMB participation and Research support
Ansun Biopharma: Investigator, Research support