title: Rates of hospitalizations for respiratory syncytial virus, human metapneumovirus, and influenza virus in older adults.
abstract: BACKGROUND
  We performed a prospective study to determine the disease burden of respiratory syncytial virus (RSV) and human metapneumovirus (HMPV) in older adults in comparison with influenza virus.
  
  
  METHODS
  During 3 consecutive winters, we enrolled Davidson County (Nashville, TN) residents aged ≥ 50 years admitted to 1 of 4 hospitals with acute respiratory illness (ARI). Nasal/throat swabs were tested for influenza, RSV, and HMPV with reverse-transcriptase polymerase chain reaction. Hospitalization rates were calculated.
  
  
  RESULTS
  Of 1042 eligible patients, 508 consented to testing. Respiratory syncytial virus was detected in 31 participants (6.1%); HMPV was detected in 23 (4.5%) patients; and influenza was detected in 33 (6.5%) patients. Of those subjects aged ≥ 65 years, 78% received influenza vaccination. Compared with patients with confirmed influenza, patients with RSV were older and more immunocompromised; patients with HMPV were older, had more cardiovascular disease, were more likely to have received the influenza vaccination, and were less likely to report fever than those with influenza. Over 3 years, average annual rates of hospitalization were 15.01, 9.82, and 11.81 per 10,000 county residents due to RSV, HMPV, and influenza, respectively.
  
  
  CONCLUSIONS
  In adults aged ≥ 50 years, hospitalization rates for RSV and HMPV were similar to those associated with influenza.
authors.affiliation: Department of Medicine, VA TN Valley Health Care System, Nashville, Tennessee 37205, USA.
authors.forename: Kyle
authors.initials: K
authors.lastname: Widmer
authors.forename: Yuwei
authors.initials: Y
authors.lastname: Zhu
authors.forename: John V
authors.initials: JV
authors.lastname: Williams
authors.forename: Marie R
authors.initials: MR
authors.lastname: Griffin
authors.forename: Kathryn M
authors.initials: KM
authors.lastname: Edwards
authors.forename: H Keipp
authors.initials: HK
authors.lastname: Talbot
mesh_terms: D000368:Aged; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data / Q000639:trends; D006801:Humans; D007251:Influenza, Human / Q000453:epidemiology* / Q000821:virology; D008297:Male; D029121:Metapneumovirus / Q000302:isolation & purification; D008875:Middle Aged; D009975:Orthomyxoviridae / Q000302:isolation & purification; D018184:Paramyxoviridae Infections / Q000453:epidemiology* / Q000821:virology; D011446:Prospective Studies; D018357:Respiratory Syncytial Virus Infections / Q000453:epidemiology* / Q000821:virology; D018113:Respiratory Syncytial Virus, Human / Q000302:isolation & purification; D012141:Respiratory Tract Infections / Q000453:epidemiology* / Q000821:virology; D013714:Tennessee / Q000453:epidemiology