School dismissal found to aid in stopping the spread of influenza

A non-research investigation by the Chicago Department of Public Health suggests that school dismissal in the beginning of an influenza pandemic may decrease transmission between students when in conjunction with other community mitigation strategies.
In accordance with Centers for Disease Control and Prevention guidelines, a Chicago, Ill., elementary school closed down for one week in 2009 after identifying a case of pandemic (H1N1) 2009 influenza infection. The CDPH investigated respiratory illnesses among students and their households during the period surrounding the school closure, Emerging Infectious Diseases reports.
Of the 170 households that completed the survey, 39 households, or 23 percent, reported 58 illnesses that met the definition of acute respiratory illness. Thirty-seven of those illnesses met the influenza-like illness definition. Thirty-four of the houses, or 60 percent, of the illnesses reported the onset of symptoms before or on the day of school dismissal.
The onset of 60 percent of reported illnesses occurring on or before the day of school dismissal suggested that unrecognized transmission was already occurring in the school or community. The results also indicated that at least some illness among the school's households originated from sources other than the school and support the approach to consider school dismissal only in conjunction with other community mitigation strategies, according to Emerging Infectious Diseases.
School closures were concluded to have substantially decreased 2009 H1N1 influenza in the Hong Kong Special Administrative Region, People's Republic of China, where all primary schools, child care centers and kindergartens were immediately closed for 14 days after the identification of local cases.
CDC researchers Nicole J. Cohen said that longer dismissal periods need to be balanced by the adverse impact on education, socioeconomic impact on families and the loss of student services, Emerging Infectious Diseases reports. Cohen determined that further investigation is needed to evaluate the impact and efficacy of school dismissal, including the timing of dismissal in relation to recognition of cases in a community or school and the impact of dismissal relative to other strategies of community mitigation.