title: Pediatric hospitalizations for croup (laryngotracheobronchitis): biennial increases associated with human parainfluenza virus 1 epidemics.
abstract: Croup is a common manifestation of respiratory tract infection in children, and human parainfluenza virus 1 (HPIV-1) is the agent most commonly associated with croup. In the United States, HPIV-1 produces a distinctive pattern of biennial epidemics of respiratory illness during the autumn months of odd-numbered years. National Hospital Discharge Survey data for croup hospitalizations among patients <15 years old between 1979 and 1993 were examined along with laboratory-based surveillance data on HPIV-1 activity in the United States. The mean annual number of croup hospitalizations was 41,000 (range, 27,000-62,000/year). Ninety-one percent of hospitalizations occurred among children <5 years of age. Minor peaks in croup hospitalizations occurred each year in February, and major peaks occurred in October of odd-numbered years, coincident with peak HPIV-1 activity. Each biennial epidemic of HPIV-1 was associated with 18,000 excess croup hospitalizations nationwide.
authors.affiliation: Division of Viral and Rickettsial Diseases, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA.
authors.forename: A
authors.initials: A
authors.lastname: Marx
authors.forename: T J
authors.initials: TJ
authors.lastname: Török
authors.forename: R C
authors.initials: RC
authors.lastname: Holman
authors.forename: M J
authors.initials: MJ
authors.lastname: Clarke
authors.forename: L J
authors.initials: LJ
authors.lastname: Anderson
mesh_terms: D000258:Adenovirus Infections, Human / Q000453:epidemiology; D000293:Adolescent; D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D003440:Croup / Q000453:epidemiology* / Q000821:virology; D004196:Disease Outbreaks; D005260:Female; D006760:Hospitalization; D006801:Humans; D007223:Infant; D007251:Influenza, Human / Q000453:epidemiology; D008297:Male; D010222:Parainfluenza Virus 1, Human; D018184:Paramyxoviridae Infections / Q000453:epidemiology; D010850:Picornaviridae Infections / Q000453:epidemiology; D011019:Pneumonia, Mycoplasma / Q000453:epidemiology; D011159:Population Surveillance; D010253:Respirovirus Infections / Q000453:epidemiology*; D012621:Seasons; D012737:Sex Factors; D014481:United States / Q000453:epidemiology