BACKGROUND: Following detection of pandemic influenza A H1N1 (pH1N1) in Dallas/Fort Worth, Texas, a school district (intervention community, [IC]) closed all public schools for eight days to reduce transmission. Nearby school districts (control community [CC]) mostly remained open. METHODS: We collected household data to measure self-reported acute respiratory illness (ARI), before, during, and after school closures. We also collected influenza-related visits to emergency departments (ED(flu)). RESULTS: In both communities, self-reported ARIs and ED(flu) visits increased from before to during the school closure, but the increase in ARI rates was 45% lower in the IC,0.6% before to 1.2% during, than in the CC, 0.4% before to 1.5% during (RR(During/Before)=0.55, p=0.001; aOR(During/Before)=0.49, p<.03). For households with school age children only (no children 0-5 years), IC had even lower increases in adjusted ARI than in the CC (aOR(During/Before)=0.28, p<.001). The relative increase of total ED(flu) visits in the IC was 27% lower (2.8% before to 4.4% during) compared to the CC (2.9% before to 6.2% during). Among children 6-18 years old, the percentage of ED(flu) in IC remained constant (5.1% before vs. 5.2% during), while in the CC it more than doubled (5.2% before vs. 10.9% during). After schools re-opened, ARI rates and ED(flu) visits decreased in both communities. CONCLUSIONS: Our study documents a reduction in ARI and ED(flu) visits in the intervention community. Our findings can be used to assess the potential benefit of school closures during pandemics.

Despite limited evidence regarding their utility, infrared thermal detection systems (ITDS) are increasingly being used for mass fever detection. We compared temperature measurements for 3 ITDS (FLIR ThermoVision A20M [FLIR Systems Inc., Boston, MA, USA], OptoTherm Thermoscreen [OptoTherm Thermal Imaging Systems and Infrared Cameras Inc., Sewickley, PA, USA], and Wahl Fever Alert Imager HSI2000S [Wahl Instruments Inc., Asheville, NC, USA]) with oral temperatures (≥ 100 degrees F = confirmed fever) and self-reported fever. Of 2,873 patients enrolled, 476 (16.6%) reported a fever, and 64 (2.2%) had a confirmed fever. Self-reported fever had a sensitivity of 75.0%, specificity 84.7%, and positive predictive value 10.1%. At optimal cutoff values for detecting fever, temperature measurements by OptoTherm and FLIR had greater sensitivity (91.0% and 90.0%, respectively) and specificity (86.0% and 80.0%, respectively) than did self-reports. Correlations between ITDS and oral temperatures were similar for OptoTherm (rho = 0.43) and FLIR (rho = 0.42) but significantly lower for Wahl (rho = 0.14; p < 0.001). When compared with oral temperatures, 2 systems (OptoTherm and FLIR) were reasonably accurate for detecting fever and predicted fever better than self-reports.