It’s time-honored advice to don a hat and coat to avoid “catching a cold.” Even so, cold-and-flu season still arrives with a proliferation of coughing, sneezing and fevers. How does it spread and what are the best ways to reduce risk?
According to the Centers for Disease Control, an average of 5 to 20 percent of Americans contract influenza, the flu, each year. It typically peaks between December and February. An estimated 200,000 people are hospitalized annually due to flu-related complications.
“You’re more germ than you are human. About 10 percent of your cells are really yours and the rest are microbes and viruses,” said Dr. Paul Pottinger, a UW Medicine infectious disease specialist. “Germs are everywhere and usually harmless. It’s that small number, like the flu, that are a real drag.”
How do you “catch” germs?
Someone sneezes at the grocery store. Should you hold your breath and outrun the germ cloud?
“Flu and colds are caused by viruses and transmitted from one person to another through droplets,” Pottinger said. “While very small, they’re still big enough that gravity affects them. They fall usually within a 4- to 6-foot radius from the sneeze or cough.”
Some viruses, such as measles, are highly contagious in airborne form, but are rare in the U.S. Other viruses, such as Ebola, are only transmitted through direct contact with blood or bodily fluids.
“You aren’t going to get Ebola just from sitting next to someone,” said Dr. Yuan-Po Tu, who oversees Flu Services at The Everett Clinic’s Urgent Care Walk-In Clinics and is a member of the Ebola Preparedness Team. “For all the concern, influenza is far more transmissible and deadly than Ebola in the U.S.”
The length of time a cold or flu virus survives depends on the circumstances. It can last in the environment from just minutes to usually a few hours. Germs particularly thrive in warm, moist, humid conditions.
“It also depends on the surface. It’s easier for it to live on wood surfaces, tougher for it to survive on metal. Plastic is in between,” Pottinger said.
Common points of infection include computer keyboards, doorknobs and particularly phones.
“Germs don’t jump,” Tu said. “Someone sneezes on the phone and that now has the virus. Someone else reverses the process, touching the phone and then rubbing their eyes or nose. There has to be direct contact. It can’t just hopscotch from object to person.”
Stopping the spread
A few simple and effective precautions dramatically reduce the risk of spreading and/or catching cold-and-flu viruses. Hand washing tops the list.
“The official recommendation is 20 seconds with soap and water,” Tu advised. “Alcohol hand rubs, such as Purell, are also pretty effective in most cases. The only time that’s not true is diarrheal illnesses, where soap and water do a better job.”
Tu also recommends coughing into a sleeve or elbow rather than the hand, which more easily spreads the virus.
“You tend to be most contagious at the onset of a respiratory illness and probably even about 24 hours before the coughing and body aches start,” Tu said. “Also, we strongly encourage anyone with a fever over 100 degrees (Fahrenheit) to stay home.”
Continue to take precautions even after you improve. According to Pottinger, patients continue to “shed” the virus and can infect others even as their own symptoms abate.
“If you’re finally well enough to return to work, congratulations. However, keep practicing careful respiratory hygiene to protect others,” Pottinger said.
Experts, including Pottinger and Tu, cannot stress enough the importance of receiving yearly flu vaccinations.
“Immunization is about helping yourself as well as others,” Pottinger said. “Maybe you have a strong immune system and don’t get the flu or only a light case. What many people don’t appreciate, though, is you can still give it to others who can unintentionally become very sick or even die.”
Those at most risk include individuals with comprised immune systems ranging from chemotherapy patients to chronic conditions such as diabetes. Senior citizens, those over 65 years old, and young children under 2 years are also at particularly high-risk.
“We call it ‘cocooning protection’ around the most vulnerable,” Tu said. “There is no approved vaccination for newborns less than six months of age. In a situation like that, everyone around them — adults, siblings, caregivers — needs to be vaccinated.”
New options are available to those who previously avoided vaccines due to health concerns or allergies. Many pharmacies stock or can order mercury- or antibiotic-free vaccines. As of 2014, a flu vaccine not cultured in eggs is available for those with allergies.
Flu vaccines change yearly to combat different virus strains. It is developed months in advance of flu season based on the best available information. Given this, efficacy varies from year to year.
“Even if the risk reduction was only 50 percent one year, that still cuts your changes in half. I’d take that. It’s way better than nothing,” Pottinger said.
- 5 to 20 percent of Americans get the flu each year and an estimated 200,000 people are hospitalized annually due to complications.
- Drs. Pottinger and Tu recommend staying home as long as you have a fever over 100 degrees Fahrenheit or sneezing is not under control.
- Healthy adults can infect others 1 day before symptoms develop and 5 to 7 days after becoming sick. Children are contagious for longer than 7 days.
- According to Dr. Tu, 33 to 50 percent of toddlers get the flu on any given winter.
- Flu symptoms generally start 1 to 4 days after the virus enters the body. Symptoms include: fever, headache, body aches, fatigue, cough, sore throat, runny/stuffy nose.
- According to Dr. Pottinger, consider yourself “lucky” to experience a low-grade fever or body aches after receiving the flu vaccination. It means the body is mounting a solid inflammatory response, which indicates the shot is taking hold.
- You cannot spread influenza from the flu vaccination.
- For the most current information regarding yearly influenza outbreaks, visit FluView at cdc.gov.