title: Prolonged seasonality of respiratory syncytial virus infection among preterm infants in a subtropical climate.
abstract: OBJECTIVE
  There is limited epidemiological data on the seasonality of respiratory syncytial virus (RSV) infection in subtropical climates, such as in Taiwan. This study aimed to assess RSV seasonality among children ≤24 months of age in Taiwan. We also assessed factors (gestational age [GA], chronologic age [CA], and bronchopulmonary dysplasia [BPD]) associated with RSV-associated hospitalization in preterm infants to confirm the appropriateness of the novel Taiwanese RSV prophylactic policy.
  
  
  METHODS
  From January 2000 to August 2010, 3572 children aged ≤24-months were admitted to Taipei Mackay Memorial Hospital due to RSV infection. The monthly RSV-associated hospitalization rate among children aged ≤24 months was retrospectively reviewed. Among these children, 378 were born preterm. The associations between GA, CA, and BPD and the incidence of RSV-associated hospitalization in the preterm infants were assessed.
  
  
  RESULTS
  In children aged ≤24 months, the monthly distribution of RSV-associated hospitalization rates revealed a prolonged RSV season with a duration of 10 months. Infants with GAs ≤32 weeks and those who had BPD had the highest rates of RSV hospitalization (P<0.001). Preterm infants were most vulnerable to RSV infection within CA 9 months.
  
  
  CONCLUSIONS
  Given that Taiwan has a prolonged (10-month) RSV season, the American Academy of Pediatrics' recommendations for RSV prophylaxis are not directly applicable. The current Taiwanese guidelines for RSV prophylaxis, which specify palivizumab injection (a total six doses until CA 8-9 months) for preterm infants (those born before 28(6/7) weeks GA or before 35(6/7) weeks GA with BPD), are appropriate. This prophylaxis strategy may be applicable to other countries/regions with subtropical climates.
authors.affiliation: Department of Pediatrics, Division of Neonatology, Mackay Memorial Hospital, Taipei, Taiwan.
authors.forename: Chyong-Hsin
authors.initials: CH
authors.lastname: Hsu
authors.affiliation: Department of Pediatrics, Division of Neonatology, Mackay Memorial Hospital, Taipei, Taiwan.
authors.forename: Chia-Ying
authors.initials: CY
authors.lastname: Lin
authors.affiliation: Department of Pediatrics, Division of Infectious Disease, Mackay Memorial Hospital, Taipei, Taiwan.
authors.forename: Hsin
authors.initials: H
authors.lastname: Chi
authors.affiliation: Department of Pediatrics, Division of Neonatology, Mackay Memorial Hospital, Taipei, Taiwan.
authors.forename: Jui-Hsing
authors.initials: JH
authors.lastname: Chang
authors.affiliation: Department of Pediatrics, Division of Neonatology, Mackay Memorial Hospital, Taipei, Taiwan.
authors.forename: Han-Yang
authors.initials: HY
authors.lastname: Hung
authors.affiliation: Department of Pediatrics, Division of Neonatology, Mackay Memorial Hospital, Taipei, Taiwan.
authors.forename: Hsin-An
authors.initials: HA
authors.lastname: Kao
authors.affiliation: Department of Pediatrics, Division of Neonatology, Mackay Memorial Hospital, Taipei, Taiwan.
authors.forename: Chun-Chih
authors.initials: CC
authors.lastname: Peng
authors.affiliation: Department of Pediatrics, Division of Neonatology, Mackay Memorial Hospital, Taipei, Taiwan.
authors.forename: Wai-Tim
authors.initials: WT
authors.lastname: Jim
mesh_terms: D061067:Antibodies, Monoclonal, Humanized / Q000627:therapeutic use; D000998:Antiviral Agents / Q000627:therapeutic use; D001997:Bronchopulmonary Dysplasia / Q000175:diagnosis; D002980:Climate; D005260:Female; D005865:Gestational Age; D006760:Hospitalization / Q000639:trends; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D007234:Infant, Premature; D008297:Male; D000069455:Palivizumab; D018357:Respiratory Syncytial Virus Infections / Q000188:drug therapy / Q000453:epidemiology*; D012189:Retrospective Studies; D013624:Taiwan / Q000453:epidemiology
chemical_list: D061067:Antibodies, Monoclonal, Humanized; D000998:Antiviral Agents; D000069455:Palivizumab