Abstract
Influenza is a global problem infecting 5–10% of adults and 20–30% of children annually. Non-pharmaceutical interventions (NPIs) are attractive approaches to complement vaccination in the prevention and reduction of influenza. Strong cyclical reduction of absolute humidity has been associated with influenza outbreaks in temperate climates. This study tested the hypothesis that raising absolute humidity above seasonal lows would impact influenza virus survival and transmission in a key source of influenza virus distribution, a community school. Air samples and objects handled by students (e.g. blocks and markers) were collected from preschool classrooms. All samples were processed and PCR used to determine the presence of influenza virus and its amount. Additionally samples were tested for their ability to infect cells in cultures. We observed a significant reduction (p < 0.05) in the total number of influenza A virus positive samples (air and fomite) and viral genome copies upon humidification as compared to control rooms. This suggests the future potential of artificial humidification as a possible strategy to control influenza outbreaks in temperate climates. There were 2.3 times as many ILI cases in the control rooms compared to the humidified rooms, and whether there is a causal relationship, and its direction between the number of cases and levels of influenza virus in the rooms is not known. Additional research is required, but this is the first prospective study suggesting that exogenous humidification could serve as a scalable NPI for influenza or other viral outbreaks.
Highlights
Non-pharmaceutical interventions (NPIs) can complement traditional vaccination and antiviral medications for infectious disease
NPIs are significant for diseases like influenza, which have not shown to be well managed by vaccination alone
The 2014–15 influenza season illustrates why alternative approaches such as NPIs could prove to be valuable in disease prevention
Summary
Non-pharmaceutical interventions (NPIs) can complement traditional vaccination and antiviral medications for infectious disease. Annual influenza epidemics are estimated to infect 5–10% of adults and 20–30% of children resulting in 3 to 5 million cases of severe illness and 250,000 to 500,000 deaths[1] These infections account for 10% of global respiratory hospitalizations in children under 18 years of age[2]. Influenza and respiratory syncytial virus (RSV) accounted for over 50% of hospitalizations (all ages) from respiratory infections with an additional 706 outbreaks of influenza-like illness (ILI) reported in schools[5]. This increase in influenza was attributed to antigenic drift, leaving the vaccine largely ineffective. The 2014–15 influenza season illustrates why alternative approaches such as NPIs could prove to be valuable in disease prevention
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
