%0 Journal Article %T Influenza B outbreak in a primary school in Adelaide, Australia, 2011 %A Louise Flood %A Jane Raupach %A Katina D'Onise %A Deidre Russo %J Western Pacific Surveillance and Response %D 2012 %I World Health Organization %X Introduction: This report describes a 2011 seasonal influenza B outbreak in a metropolitan primary school in Australia with 179 students.Methods: Epidemiological, microbiological and environmental investigations were undertaken. A retrospective cohort study was conducted using a questionnaire that included demographic data, details of illness, chronic health conditions and vaccination status. Influenza-like illness (ILI) was defined as fever plus cough and/or sore throat. Analysis of ILI was undertaken with the chi-squared test and FisherĄ¯s exact test.Results: Seventy-two questionnaire respondents (75%) reported illness during the outbreak ¨C 43 with ILI, giving an attack rate of 45%. There was no association between ILI and age or chronic lung disease. Six (6%) students were vaccinated against influenza before the outbreak; although four became ill, none satisfied the ILI case definition. Seven students were positive for influenza B including two confirmed as B/Brisbane/60/2008-like; one student was positive for rhinovirus and another for metapneumovirus. The recommended influenza vaccine matched the circulating influenza strains.Discussion: This cohort study estimated a high ILI attack rate and demonstrated low influenza vaccine coverage within the setting of a primary school. Gastrointestinal symptoms, in addition to constitutional and respiratory symptoms, were common. %K influenza B %K primary school %K Adelaide %K Australia %K 2011 %U http://ojs.wpro.who.int/ojs/index.php/wpsar/article/view/163/172