Prevent the Flu: Chitosan in Air Filters, Facemasks and Hand Washing


Home / Prevent the Flu: Chitosan in Air Filters, Facemasks and Hand Washing

Influenza virus. Photo by: Renjith Krishnan

The influenza virus, also known as the flu, is a contagious respiratory illness that affects an estimated five to 20 percent of Americans each year, according to the Centers for Disease Control and Prevention (CDC). The CDC also reports that 36,000 Americans die from the flu each year. The elderly, young children, pregnant women and people with a compromised immune system are at high risk for developing the flu. In the United States the flu typically occurs between October and May, with infections peaking in February. There have been many advancements in preventative measures for the flu, from antibacterial wipes to vaccines. The latest anti-flu prevention method? Air filters that can trap the flu virus before it reaches you.

Air Filters That Protect You

The flu virus is spread through respiratory droplets when an infected person sneezes or coughs. These droplets then land on another person or a surface. When you touch the infected surface and then touch your nose, eyes, or mouth, you can transfer the virus to yourself and become infected as well.

The American Chemical Society reported that scientists, Xuebing Li, Peixing Wu, and their colleagues have developed air filters that can protect you against the flu virus. Li, Wu and collegues have combined chitosan, made from ground shrimp shells, with a substance to which the flu virus attaches when infecting cells. This combination was added to the filters of facemasks, and air filters, and found to be effective at trapping the flu virus.

Effectiveness of Surgical Facemasks

During the H1N1 pandemic of 2009, (commonly known as Swine Flu) there were times of limited vaccinations and medication due to shortages. This forced medical and public health professionals to rely on other ways of preventing infection. These nonpharmaceutical interventions included hand washing, also known as hand hygiene, and the use of surgical face masks.

People in Mexico wore facemasks during the H1N1 pandemic. Photo by: Henry Merino

In the 2009 study, “Facemasks and Hand Hygiene to Prevent Influenza Transmission in Households,” published in the Annals of Internal Medicine, by Benjamin Cowlings, BSc, PhD, Kwok-Hung Chan, BSc, PhD, and colleagues found that a combination of facemaks and handwashing was effective at preventing the H1N1 flu. This study was conducted in Hong Kong with 407 people who tested positive for the influenza A or B virus.

There were 259 households involved in the study, and a total of 794 household members. The study divided the households into three groups: 134 households were the control group, there were 136 households for hand hygiene, and 137 households for hand hygiene and facemasks.

Out of the 259 households, sixty people (8 percent) became sick with the influenza virus seven days after the interventions began. The hand hygeine groups (with and without facemasks) seemed to reduce the transmission of influenza virus, but not significantly when compared to the control group. The authors concluded that the group that used the facemasks and performed hand hygiene was more effective at reducing the transmission of the influenza virus within 36 hours of patient symptom onset.

Effectiveness of Air Filters

HEPA filter for flu prevention: Image by LadyofHats

Most air filters cannot capture viruses because the viruses are so small, some less than .03 microns. Using a combination of HEPA air filters, ultraviolet light, and electrostatic filters may work together to achieve the best results. There are many factors that can inhibit the elimination of viruses when using a combination system. The Air Purifier Guide reports:

“EPA studies have found that the effectiveness of hybrid units can be limited if airflow is not properly configured which can cause increased air resistance that could allow the air to bypass the cleaning mechanisms. Correct placement of portable residential air cleaners is also considered crucial to capturing airborne viruses.”

One type of HEPA filter called the HyperHEPA has the capability to filter out particles down to .003 microns with 99.5 percent efficiency. These highly advanced air filters are used in some hospitals. However, there is still no standardized test to measure the effectiveness of removing viruses from the air.

Prevent the Flu

Until these high-tech products are proven to effectively prevent the influenza virus, and are available for consumers, the best way to prevent the flu is washing your hands, covering your cough and sneeze, and getting the yearly flu shot if recommended by your physician. The flu can lead to serious medical complications and even death. If you have any questions or concerns, you should speak with your health care provider.


Centers for Disease Control and Prevention. “Seasonal Influenza.” Accessed on November 9, 2011.

American Chemical Society. “New material for air cleaner filters that capture flu viruses.” November 2, 2011. Accessed on November 9, 2011.

Centers for Disease Control and Prevention. “Key Facts About Influenza and Flu Vaccine.” October 4, 2011. Accessed on November 9, 2011.

World Health Organization. “Influenza.” Accessed on November 9, 2011.

Cowling, Benjamin J., Kwok-Hung Chan, Vicky J. Fang, Calvin K.Y. Cheng, Rita O.P. Fung, Winnie Wai, Joey Sin, et al. (2009). “Facemasks and Hand Hygiene to Prevent Influenza Transmission in Households.Annals of Internal Medicine 151 (7) (October 6): 437 -446. Accessed November 8, 2011.

Aiello, Allison E., Genevra F. Murray, Vanessa Perez, Rebecca M. Coulborn, Brian M. Davis, Monica Uddin, David K. Shay, Stephen H. Waterman, and Arnold S. Monto. (2010). “Mask use, hand hygiene, and seasonal influenza-like illness among young adults: A randomized intervention trial.Journal of Infectious Diseases201 (4) (February 15): 491 -498. Accessed November 9, 2011.

Air Purifier Guide. “Do Air Purifiers Really Remove Viruses?” Accessed on November 9, 2011.

*This article does not constitute medical advice.*

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