title: An outbreak of 2009 pandemic influenza A (H1N1) virus infection in an elementary school in Pennsylvania.
abstract: In May 2009, one of the earliest outbreaks of 2009 pandemic influenza A virus (pH1N1) infection resulted in the closure of a semi-rural Pennsylvania elementary school. Two sequential telephone surveys were administered to 1345 students (85% of the students enrolled in the school) and household members in 313 households to collect data on influenza-like illness (ILI). A total of 167 persons (12.4%) among those in the surveyed households, including 93 (24.0%) of the School A students, reported ILI. Students were 3.1 times more likely than were other household members to develop ILI (95% confidence interval [CI], 2.3-4.1). Fourth-grade students were more likely to be affected than were students in other grades (relative risk, 2.2; 95% CI, 1.2-3.9). pH1N1 was confirmed in 26 (72.2%) of the individuals tested by real-time reverse-transcriptase polymerase chain reaction. The outbreak did not resume upon the reopening of the school after the 7-day closure. This investigation found that pH1N1 outbreaks at schools can have substantial attack rates; however, grades and classrooms are affected variably. Additional study is warranted to determine the effectiveness of school closure during outbreaks.
authors.affiliation: Centers for Disease Control and Prevention/Council of State and Territorial Epidemiologists Applied Epidemiology Fellowship Program, Pennsylvania Department of Health, Harrisburg, Pennsylvania, USA. tmarchbanks@stlouisco.com
authors.forename: Tiffany L
authors.initials: TL
authors.lastname: Marchbanks
authors.forename: Achuyt
authors.initials: A
authors.lastname: Bhattarai
authors.forename: Ryan P
authors.initials: RP
authors.lastname: Fagan
authors.forename: Stephen
authors.initials: S
authors.lastname: Ostroff
authors.forename: Samir V
authors.initials: SV
authors.lastname: Sodha
authors.forename: Mària E
authors.initials: ME
authors.lastname: Moll
authors.forename: Bruce Y
authors.initials: BY
authors.lastname: Lee
authors.forename: Chung-Chou H
authors.initials: CC
authors.lastname: Chang
authors.forename: Brent
authors.initials: B
authors.lastname: Ennis
authors.forename: Phyllis
authors.initials: P
authors.lastname: Britz
authors.forename: Anthony
authors.initials: A
authors.lastname: Fiore
authors.forename: Michael
authors.initials: M
authors.lastname: Nguyen
authors.forename: Rakhee
authors.initials: R
authors.lastname: Palekar
authors.forename: W Roodly
authors.initials: WR
authors.lastname: Archer
authors.forename: Thomas L
authors.initials: TL
authors.lastname: Gift
authors.forename: Rebecca
authors.initials: R
authors.lastname: Leap
authors.forename: Benjamin L
authors.initials: BL
authors.lastname: Nygren
authors.forename: Simon
authors.initials: S
authors.lastname: Cauchemez
authors.forename: Frederick J
authors.initials: FJ
authors.lastname: Angulo
authors.forename: David
authors.initials: D
authors.lastname: Swerdlow
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D004196:Disease Outbreaks; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D017053:Infection Control / Q000379:methods; D053118:Influenza A Virus, H1N1 Subtype / Q000302:isolation & purification*; D007251:Influenza, Human / Q000453:epidemiology* / Q000821:virology*; D007407:Interviews as Topic; D008297:Male; D008875:Middle Aged; D010414:Pennsylvania / Q000453:epidemiology; D012574:Schools; D055815:Young Adult