Modelling estimates of the burden of Respiratory Syncytial virus infection in adults and the elderly in the United Kingdom.
BACKGROUND
Growing evidence suggests respiratory syncytial virus (RSV) is an important cause of respiratory disease in adults. However, the adult burden remains largely uncharacterized as most RSV studies focus on children, and population-based studies with laboratory-confirmation of infection are difficult to implement. Indirect modelling methods, long used for influenza, can further our understanding of RSV burden by circumventing some limitations of traditional surveillance studies that rely on direct linkage of individual-level exposure and outcome data.


METHODS
Multiple linear time-series regression was used to estimate RSV burden in the United Kingdom (UK) between 1995 and 2009 among the total population and adults in terms of general practice (GP) episodes (counted as first consultation ≥28 days following any previous consultation for same diagnosis/diagnostic group), hospitalisations, and deaths for respiratory disease, using data from Public Health England weekly influenza/RSV surveillance, Clinical Practice Research Datalink, Hospital Episode Statistics, and Office of National Statistics. The main outcome considered all ICD-listed respiratory diseases and, for GP episodes, related symptoms. Estimates were adjusted for non-specific seasonal drivers of disease using secular cyclical terms and stratified by age and risk group (according to chronic conditions indicating severe influenza risk as per UK recommendations for influenza vaccination). Trial registration NCT01706302 . Registered 11 October 2012.


RESULTS
Among adults aged 18+ years an estimated 487,247 GP episodes, 17,799 hospitalisations, and 8,482 deaths were attributable to RSV per average season. Of these, 175,070 GP episodes (36 %), 14,039 hospitalisations (79 %) and 7,915 deaths (93 %) were in persons aged 65+ years. High- versus low-risk elderly were two-fold more likely to have a RSV-related GP episode or death and four-fold more likely be hospitalised for RSV. In most seasons since 2001, more GP episodes, hospitalisations and deaths were attributable to RSV in adults than to influenza.


CONCLUSIONS
RSV is associated with a substantial disease burden in adults comparable to influenza, with most of the hospitalisation and mortality burden in the elderly. Treatment options and measures to prevent RSV could have a major impact on the burden of RSV respiratory disease in adults, especially the elderly.
Independent Consultant, 9 Dowles Close, Birmingham, B29 4LE, United Kingdom. dmfleming9dc@btinternet.com.
Douglas M
DM
Fleming
Sage Analytica, 4550 Montgomery Ave., Suite 4915 St. Elmo Ave, Ste. 205, Bethesda, MD 20814, USA. rtaylor@sageanalytica.com.
Robert J
RJ
Taylor
Sage Analytica, 4550 Montgomery Ave., Suite 4915 St. Elmo Ave, Ste. 205, Bethesda, MD 20814, USA. rlustig@sageanalytica.com.
Roger L
RL
Lustig
Sage Analytica, 4550 Montgomery Ave., Suite 4915 St. Elmo Ave, Ste. 205, Bethesda, MD 20814, USA. Cynthia.schuck@gmail.com.
Cynthia
C
Schuck-Paim
GSK Vaccines, Av Fleming 20, Parc de la Noire Epine, 1300, Wavre, Belgium. Francois.F.Haguinet@gsk.com.
François
F
Haguinet
GSK Pharmaceuticals, Stockley Park West, 1-3 Ironbridge Road, Heathrow, Uxbridge, Middlesex, UB11 1B S, United Kingdom. David.J.Webb@GSK.com.
David J
DJ
Webb
GSK Pharmaceuticals, Stockley Park West, 1-3 Ironbridge Road, Heathrow, Uxbridge, Middlesex, UB11 1B S, United Kingdom. John.W.Logie@GSK.com.
John
J
Logie
GSK Vaccines, Av Fleming 20, Parc de la Noire Epine, 1300, Wavre, Belgium. Gonzalo.X.Matias@gsk.com.
Gonçalo
G
Matias
GSK Vaccines, Av Fleming 20, Parc de la Noire Epine, 1300, Wavre, Belgium. Sylvia.M.Taylor@GSK.com.
Sylvia
S
Taylor
D000293:Adolescent; D000328:Adult; D000368:Aged; D002908:Chronic Disease; D016208:Databases, Factual; D005260:Female; D006760:Hospitalization; D006801:Humans; D007252:Influenza Vaccines / Q000276:immunology; D007251:Influenza, Human / Q000453:epidemiology / Q000517:prevention & control; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D018357:Respiratory Syncytial Virus Infections / Q000453:epidemiology* / Q000401:mortality / Q000821:virology; D012136:Respiratory Syncytial Viruses / Q000302:isolation & purification; D012621:Seasons; D006113:United Kingdom / Q000453:epidemiology; D055815:Young Adult
D007252:Influenza Vaccines