Ruzin A, Pastula ST, Levin-Sparenberg E, Jiang X, Fryzek J, Tovchigrechko A, Lu B, Qi Y, Liu H, Jin H, Yu L, Hackett J, Villafana T, Esser MT. 2018. Characterization of circulating RSV strains among subjects in the OUTSMART-RSV surveillance program during the 2016-17 winter viral season in the United States. PLoS One 13(7):e0200319.
Respiratory syncytial virus (RSV) is an established cause of serious lower respiratory dis-
ease in infants, elderly and high-risk populations. The OUTSMART surveillance program
aims to characterize patient populations and currently circulating RSV strains, and monitor
temporal and geographic evolution of RSV F and G proteins in the U.S.
The OUTSMART 2016–17 study collected RSV-positive samples from 25 RSVAlert®
laboratories from 4 U.S. regions and Puerto Rico during November 2016 through March 2017.
Frequencies of A and B subtypes and genotypes were determined for several demographic
and geographic variables. To gauge the representativeness of the OUTSMART patients,
results were compared to discharge data from the NEDS and NIS databases.
A total of 1,041 RSV-positive samples with associated demographic data were obtained
and the RSV F gene and second variable region of the G gene were sequenced. The major-
ity of samples (76.0%) came from children under 2 years old: <1 year (48.4%), 1–2 years
(27.6%). The OUTSMART patient sample was similar to NEDS and NIS for age, gender,
and geographic location. Both OUTSMART and national RSV cases peaked in January. Of
OUTSMART samples, 45.3% were subtype A, 53.7% were subtype B and 1.0% were mixed
A and B. The percentage of RSV B cases increased with increasing age. Hospitalization
(length of hospital stay, LOS, >24 hrs) occurred in 29.0% of patients of which 52.0% had
RSV B. Outpatients (LOS <24 hrs) were 64.4% of total of which 73.3% were diagnosed in
the ER and discharged, while only 6% were diagnosed in other outpatient settings.
The OUTSMART 2016–17 study was representative of the U.S. RSV experience. Geo-
graphic and temporal information from the RSV surveillance program will be used to estab-
lish a molecular baseline of RSV F and G sequence variability and to help inform
development of novel agents for RSV prophylaxis and treatment