We determined the prevalence of influenza-like illness (ILI) among employees of a suburban Ohio school district. In a survey of 412 of 841 employees (49%), 120 (29%) reported ILI symptoms during the school year, and 92 (77%) reported working while ill. Age >/= 50 years and asthma were significantly associated with reporting of ILI symptoms. Encouraging school employees to receive the seasonal influenza vaccine and to stay home when ill should be part of a comprehensive influenza prevention strategy. More than 7.3 million people are employed in more than 130,000 schools in the United States. School settings place teachers, other employees, and students at risk for influenza infection. As part of a health hazard evaluation, we determined the prevalence of influenza-like illness (ILI) among employees of a suburban Ohio school district. Methods: The school district includes 5 elementary schools, 1 middle school, and 2 high schools and serves nearly 7,800 students. Using a cross-sectional study design, we invited all 841 school district employees to complete a Web-based survey in March 2013. As a public health response, in accordance with guidelines in US Title 45 Code of Federal Regulations, Part 46, this evaluation did not require Institutional Review Board approval. The anonymous survey included questions regarding demographics, work, medical history, receipt of the 2012-2013 influenza vaccine, and ILI symptoms since the start of the school year. ILI was defined as being sick with fever and either sore throat or cough at any time from August 22, 2012, through survey completion. Characteristics of employees who reported ILI symptoms were compared with those of employees who did not report symptoms, and characteristics of employees who reported working while ill were compared with those of employees who did not do so. Bivariate analyses included the Student t test, X(2) test, and Fisher exact test, as appropriate. All tests were 2-tailed; statistical significance was set at P < .05. EpiInfo 126.96.36.199 (Centers for Disease Control and Prevention, Atlanta, GA) was used for survey tool creation and statistical analysis. Results: Of the 841 employees, 412 (49%) completed the survey. The respondents' median age was 46 years (range, 22-71 years). The majority were female (82%) and self-identified their race as white (99%). Occupational groups included educational (teachers, aides, and paraprofessionals; 75%), operational (bus drivers, maintenance/custodial workers, and food services workers; 7%), and administrative/other support (18%) employees. Workplaces included elementary school (45%), middle school (14%), high school (30%), and other (11%). Of 394 respondents who answered questions about their medical history, 345 (88%) did not report any medical conditions that put them at greater risk for influenza complications. The others (n = 49) reported asthma (5%), diabetes mellitus (3%), heart disease (2%), and a weakened immune system (4%). A total of 238 respondents (58%) reported receiving the 2012-2013 influenza vaccine. In total, 120 respondents (29%) reported ILI symptoms occurring between August 22, 2012 and survey completion. Most reported ILI symptoms (67%) occurred between December 2012, and February 2013. Four respondents with ILI symptoms reported influenza diagnosed by nasopharyngeal swab. The prevalence of reported ILI by occupational group was 30% for education employees, 21% for operational employees, and 28% for administrative/other support employees. The median time taken off work because of ILI was 1 day (range, 0-7 days). Of the 120 respondents who reported ILI symptoms, 92 (77%) reported working while feeling ill, including 71 (77%) educational, 5 (5%) operational, and 16 (17%) administrative/other support employees. Eight respondents reported working <1 day, 60 reported working 1-3 days, and 22 reported working =4 days. The most common main reasons cited for working while ill were feeling a professional obligation to students (28%) and not believing that their illness was contagious (23%).
Marie A. de Perio, MD, Medical Officer, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, 4676 Columbia Parkway, R-10, Cincinnati, OH 45226