Pandemic (H1N1) 2009 Virus in Swine Herds, People’s Republic of China

illness among school A households originated from sources other than the school and support the approach of considering school dismissal only in conjunction with other community mitigation strategies. In Hong Kong Special Administrative Region, People’s Republic of China, where all primary schools, kindergartens, and child care centers were immediately closed for 14 days after identifi cation of the fi rst local case of pandemic (H1N1) 2009, school closures were concluded to have substantially decreased transmission (4). The applicability of these fi ndings to communities where such sweeping measures might be less acceptable is unclear. If school dismissal is considered as a strategy, dismissal early in the pandemic most likely would have the most impact, depending on duration of dismissal, other mitigation measures, and compliance with social distancing recommendations (which was mixed during the 2009 pandemic [3,5]). Polling of parents whose children experienced school dismissal showed high acceptance of short-term (3–5 days) dismissals and low economic impact, especially on lower income families (3,6). However, dismissal for longer periods needs to be balanced by the adverse impact on education, loss of student services, and socioeconomic impact on families (7–9). This investigation was limited by the relatively low response rate; however, demographics for the sample in our study were similar to those of the school as a whole (3). Other limitations included the exclusive use of reported symptoms to document illness, possible unrecognized asymptomatic cases, and absence of similar data from later in the pandemic. The 1-week closure period might not have provided enough information to capture any effect, and comparative data were not available from schools that were not dismissed during the pandemic. Further investigation is needed to evaluate the effi cacy and impact of school dismissal, including the timing of dismissal in relation to recognition of cases in a school or community and the impact of school dismissal relative to other community mitigation strategies.