Schematic illustration and magnification of an organism being infected with flu: Influenza virus (circular object) attaches to a host membrane below, producing protein (blue kidney shaped object) to assist infection.
Photo courtesy of the National Institute of General Medical Sciences
Flu season is approaching rapidly. The US Centers for Disease Control and Prevention (CDC) estimates that US flu related deaths can vary from 3,000 to 49,000 people depending on the year. The CDC recommends the following flu prevention tips :
- Everyone 6 months of age and older should get a flu vaccination
- Wash your hands frequently to help reduce the spread of flu
- Stay home if you are sick with the flu (CDC recommends you stay home for at least 24 hours after your fever is gone)
- Avoid close contact with people who are sick
- Cover your mouth and nose with a tissue when coughing or sneezing
- Avoid touching your eyes, nose or mouth
- Clean and disinfect frequently touched surfaces at home, school or work, especially when someone is sick.
- Get plenty of sleep, be physically active, manage your stress, drink plenty of fluids and eat nutritious food
How Flu Spreads
The flu virus spreads by passing from one human host to another, either directly by close personal contact or indirectly through contact with an infected surface, such as a door knob or computer keyboard. It is worth noting that the virus can live on an inanimate surface for approximately two to eight hours after being deposited. According to CDC, for that reason, it is not necessary to close schools to clean or disinfect against the flu, as the virus dies on surfaces overnight. Environments occupied around the clock, however, such as homes, eldercare or hospital facilities are subject to continual contamination.
Despite the short lifespan of a flu virus particle on a surface, there is ample opportunity for it to spread in all environments. That is why frequently touched surfaces should be cleaned and sanitized or disinfected routinely, especially during flu season.
Cleaning and Disinfecting against Flu
Standard cleaning and disinfecting practices are sufficient to remove or kill flu viruses, which are relatively fragile microbes. Remember: cleaning, sanitizing and disinfecting are all separate and distinct activities. Cleaning physically removes dirt, grime and some germs; it does not necessarily kill them. According to the Environmental Protection Agency, sanitizers reduce, but do not necessarily eliminate microorganisms from the inanimate environment to levels considered safe as determined by public health codes or regulations. Disinfectants are used on hard inanimate surfaces and objects to destroy or irreversibly inactivate infectious fungi and bacteria but not necessarily their spores. CDC notes that disinfection destroys most recognized pathogenic microorganisms but not necessarily all microbial forms (e.g., bacterial spores). Depending on concentrations used, the following may be used as either sanitizers or disinfectants: hypochlorites, including chlorine bleach, chlorine dioxide, iodophors, peroxyacetic acid and quaternary ammonium compounds.
Visibly soiled surfaces should be cleaned followed by sanitizing or disinfecting. If a surface is not visibly soiled, products that claim to both clean and disinfect may be used. Soiled surfaces must be cleaned with a general cleaner before they are sanitized or disinfected to avoid the sanitizer/disinfectant being depleted in the cleaning process. Use EPA-registered sanitizers or disinfectants with labels that indicate their effective against Influenza A. A fresh chlorine bleach solution may be used as a disinfectant according to these CDC directions:
- Add one tablespoon of regular strength1 or two teaspoons of high strength2 bleach to one quart of water. (For a larger supply of disinfectant, add ¼ cup of regular strength bleach or two and one-half tablespoons of high strength bleach to one gallon of water.)
- Apply the solution to the surface with a cloth; Let the solution remain wet on the surface for 3-5 minutes.
- Rinse the surface with clean water.
As with all chemical products, pay attention to hazard warnings and product directions. Use gloves and eye protection as needed. Do not mix cleaners and disinfectants unless instructed to do so. Never mix chlorine bleach and ammonia as dangerous gases may result.
Getting Ready for the 2014-15 Flu Season
Understanding how flu spreads is key to developing your personal strategy for avoiding flu. Have a strategy that is both proactive and reactive. Proactively shore up your bodily defenses by getting a flu vaccination and maintaining a healthy diet and lifestyle. React smartly when the flu enemy appears around you: take measures that you know will reduce your exposure to flu, including avoiding close contact with the sick and disinfecting commonly touched surfaces. And, finally, be kind: If you do get the flu, take steps to avoid passing it to others.
Ralph Morris, MD, MPH, is a Physician and Preventive Medicine and Public Health official living in Bemidji, MN.
Regular strength bleach is 5.25% chlorine bleach.
High strength bleach is 8.25% chlorine bleach.