2010 Volume 25 Issue 5 Pages 277-280
The preventive effect against influenza-like illness by low-concentration chlorine dioxide gas was examined among Japan Ground Self Defense Force soldiers and civilians at a particular camp assigned for this study. The chlorine dioxide gas-exposed group consisted of all individuals who worked in a particular building, and the unexposed group consisted of all individuals who worked in the neighboring building. After this trial, a questionnaire survey was carried out to establish the demographic data of each group, how many members had influenza-like illness in each group, and how many members were immunized against influenza. The results showed that the relative risk of influenza-like illness after chlorine dioxide gas exposure was 0.32 (95% confidence interval between 0.15 and 0.69), although the vaccination rate in the exposed group was lower than the unexposed group. This result suggests that chlorine dioxide gas has preventive effects against influenza-like illness.