Daily Archives: 03.01.2016

What do you know about flu?

By Mary Elizabeth Dallas | Reviewed by Farrokh Sohrabi, MD


“Getting the flu is miserable,” says Christopher A. Ohl, MD, a professor of infectious diseases at Wake Forest Baptist Medical Center in Winston-Salem, North Carolina. “It means missed work, school, and vacations.” There are simple steps you can take to avoid the flu this season, but first you need to know your influenza facts.

See if you have what it takes to protect yourself and your loved ones this flu season.


How long can flu viruses generally survive on a hard surface?

“Up to eight hours” is correct. Flu viruses can generally survive on hard surfaces for up to eight hours, according to the Department of Health and Human Services (HHS). Large airborne droplets sneezed or coughed from the nose or mouth of an infected person can land on nearby surfaces, like floors, tables, and countertops, Dr. Ohl explains. Flu viruses can also be transferred from an infected person’s hands to commonly used objects like light switches, phones, and doorknobs, where others can pick them up, he notes. Flu viruses prefer low humidity and low temperatures, and under these conditions they could potentially survive for up to 48 hours on hard, nonporous surfaces like plastic and stainless steel. If these surfaces are moist or wet, flu viruses could survive even longer, according to HHS.

To avoid getting the flu or spreading the virus to others, it’s essential to wash your hands frequently with soap and water or use an alcohol-based hand sanitizer, and to avoid touching your eyes, nose, and mouth, which can spread germs, advises Susan Rehm, MD, vice chair of the department of infectious disease and executive director of physician health at the Cleveland Clinic in Ohio. If used correctly, certain chemicals – including chlorine, hydrogen peroxide, iodine-based antiseptics, and alcohols – can help get rid of flu viruses lingering on surfaces, according to the Centers for Disease Control and Prevention (CDC).


How far can the flu spread in the air when a person sneezes or coughs?

“About 6 feet” is correct. You don’t need to be in close contact with someone who has the flu to become infected. People with the flu can spread it to others about 6 feet away, according to the National Institute of Allergy and Infectious Diseases (NIAID). Most people don’t realize how easily the flu can be transmitted through the air, Dr. Rehm notes. “If people have the flu when they cough, sneeze, or even talk, the flu virus goes into the air and people who are in a radius of up to 6 feet or possibly even farther may be breathing in flu particles and getting sick,” she says. Visualize Pigpen, the character from the Peanuts comic strip with a dusty haze around his head, Ohl suggests. If you get into that cloud or within 6 feet of someone with the flu, you’re at risk.


How long do you need to wash your hands to get rid of germs?

“At least 20 seconds” is correct. One of the most important things you can do to avoid getting the flu or infecting others is to keep your hands clean, the CDC advises. But, for this to be effective, you need to wash your hands correctly. That means scrubbing with soap and water for at least 20 seconds. “It’s the friction that makes the difference,” Rehm explains, “not the type of soap you use.” Scrub both the fronts and backs of your hands as well as the spaces between your fingers, Rehm suggests. After you’ve finished, air-dry your hands or use a clean towel.

Make good hand hygiene a habit. Routinely wash your hands before eating, as well as after preparing food, using the bathroom, changing a diaper, blowing your nose, coughing, or sneezing, the CDC recommends. If you aren’t near a sink with running water, use an alcohol-based hand sanitizer that contains at least 60 percent alcohol.


Can you spread the flu to others before you develop symptoms?

“Yes” is correct. Even before people realize they’re sick, they can spread the flu to others, the CDC cautions. Symptoms of the flu, such as fever, chills, and body aches, usually develop one to four days after the virus enters the body. Unlike a cold, which can develop gradually and worsen over the course of a few days, the flu usually comes on very suddenly, Rehm notes.

Most healthy adults may be able to infect other people up to 24 hours before these symptoms appear, the CDC states.


In general, how long are people with the flu contagious?

“Five to seven days” is correct. Most healthy adults could infect other people with the flu for five to seven days after they get sick, according to the CDC. “Once a fever hits, you are the most contagious,” Ohl says. “Generally, the highest level of contagiousness is when you feel the worst.” Your symptoms may be less severe after a few days, but it’s important to remember that you are still contagious. It may take up to two weeks for some people to fully recover from the flu. In order to avoid spreading the virus to others, the rule of thumb is to stay home for at least 24 hours after your fever is gone, Ohl adds. “Be a good citizen and stay home,” he says. “It’s not the time to get up and go to work. Your colleagues don’t want to be around you if you have the flu.” Children with the flu and those with weakened immune systems may be contagious for longer than seven days, NIAID notes.


Once you get a flu shot, how long does it take for the vaccine to become effective?

“About two weeks” is correct. The seasonal flu vaccine is not effective right away: It takes about two weeks for your body to make the antibodies that will protect you from the flu, according to HHS. During this time, if you are exposed to the virus, you are still at risk for infection because you’re not yet immune. That’s why it’s important to take the time to get a flu shot early in the fall before flu season kicks into high gear, Rehm notes. “Every year, flu season is a little bit different,” she says. “A couple of years it peaked in December, and many years it peaked at the end of February. The biggest problem with immunization is missed opportunities.”

Bottom line: Don’t continuously put off getting a flu shot. Since the timing, severity, and length of flu season vary from year to year, getting vaccinated early on can help minimize your risk for infection, Rehm advises.


You can’t get the flu if you get a seasonal flu shot.

“False” is correct. There is still a chance you could get the flu if you are vaccinated. The effectiveness of the seasonal flu vaccine depends on your age and health status, and also on the similarity between the viruses selected to make the vaccine and the viruses actually circulating in the community, the CDC explains. More than 100 national influenza centers in more than 100 countries conduct ongoing flu surveillance. The World Health Organization uses this information to make recommendations about which flu strains to include in the vaccine for the Northern Hemisphere, according to the CDC. If the viruses included in the vaccine are a close match to those in circulation, the vaccine will be more effective. Even if the vaccine and circulating flu viruses are not closely matched, the vaccine may still offer some level of protection, reduce the severity of the illness, and help prevent serious flu-related complications, the agency explains. “The flu vaccine remains the No. 1 way to prevent the flu,” Rehm says.

“Even in years where it’s not as effective, having some degree of protection is better than none, which is what you get if you don’t get the vaccine.”


Once flu symptoms develop, antiviral medications are most effective if taken within:

“48 hours” is correct. Antiviral drugs are most effective against the flu if they are taken within 48 hours of the patient’s developing symptoms, the CDC reports. These prescription medications are available as pills, in liquid form, and as an inhaled powder. Some can also be given intravenously. Antiviral drugs are not a cure for the flu, but they can reduce its severity. They can ease your symptoms, prevent serious flu-related complications, and help you recover a day or two sooner, the CDC points out. Even if the ideal 48-hour window passes, some people with the flu — particularly those with chronic medical conditions — may still benefit from taking antivirals, Rehm notes. “These drugs are the only things that can actually prevent the flu virus from replicating,” she says. “They are very specific.”


How many people in the United States die from the flu or flu-related complications each year?

“Between 3,000 and 49,000” is correct. The flu is a serious illness and shouldn’t be taken lightly. It’s estimated that annual flu-related deaths in the United States range between 3,000 and 49,000 people, according to the CDC. To put this into perspective, nearly 34,000 people are killed in car accidents in this country each year, Rehm points out. Every year, 5 to 20 percent of the U.S. population gets the flu, and more than 200,000 people are hospitalized because of flu-related complications, the CDC reports. Young children, older people, pregnant women, and people whose immune systems are weakened from disease or medication are at greater risk. But it’s important to realize that anyone can develop serious flu-related complications, Rehm cautions.


In recent years, 80 to 90 percent of people who died from the flu were:

“Adults age 65 and older” is correct. During recent flu seasons, 80 to 90 percent of those whose deaths were ruled flu-related were 65 and older, the CDC reports. As you get older, your immune system weakens, increasing your risk for the flu and flu-related complications, HHS explains. As a result, older people have the option of getting a high-dose flu vaccine that will trigger a stronger response from their immune systems.

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