How long is a cold contagious reddit

So you came down with the flu and you are finally feeling better, but you still have a pesky lingering cough and runny nose. Are you still contagious? Can you return to work, school and all those holiday parties you have planned without infecting others?

Infectious disease specialist and CAN Community Health medical director Dr. Tanya Schreibman answers our questions about contagiousness and how we can safely navigate the holiday season.

When do you become contagious with the flu?

"You are theoretically contagious for 24 hours before you experience symptoms," says Schreibman. "This might be scary for some people, because they don't know they are sick and going out and about. But it's common to be spreading germs before you even feel sick."

How long are you contagious for?

"It depends on the person, but the highest rate of contagious period would be three to four days while symptomatic," says Schreibman. "From symptom onset to three to four days, you are most critically contagious. But on average, you remain contagious five to seven days after becoming sick."

Are you still contagious if you have a lingering cough or runny nose?

According to Schreibman, that is hard to say. Any flu symptoms can last as long as one to two weeks. And, "theoretically, during that time, you could still be contagious, especially kids and those with a weakened immune system," says Schreibman.

So, you can still be contagious with a lingering cough or runny nose, but for no longer than two weeks. This is why Schreibman advises that people should err on the side of caution, especially with Covid-19 still a concern.

"I've noticed in my work that people are more cautious," says Schreibman. "It's tricky when you have kids in school, like I did. You never want to send kids to school with a runny nose these days, since everyone is being cautious. It can be difficult to determine when to send them back, but use your best judgment and seek advise from your doctor."

How is the flu spread? Is it different or similar to Covid-19?

"Both are spread similarly, through droplets in the air when an infected person sneezes, coughs or talks without a barrier, like a mask or face shield," says Schreibman. "The flu virus can travel up to six feet, so if you are in the same room as a sick person, breathe the same air or even touch a contaminated surface, you are at higher risk of infection." This slightly differs from the Covid-19 virus, which studies have shown you are less likely to catch through touch.

Are you less contagious if you've received the flu vaccine? Can you still get the flu after vaccination?

According to Schreibman, you can absolutely get the flu even when vaccinated, but information on the efficacy of this year's shot is not yet known. And if you can still contract the flu, you are still just as contagious to others.

"The vaccine could help mitigate or lessen symptoms, but not level of contagiousness," says Schreibman.

Have Covid-19 measures also worked at reducing influenza numbers this year?

The number of flu cases dropped last year because of all the measures put in place to prevent Covid, like mask wearing and social distancing. Now that many of those rules have been eased, there's a higher risk of a flu spread, according to Schreibman's analysis of recent data.

"Organizations like the Centers for Disease Control and Prevention will continually update flu numbers," says Schreibman. "Right now, it's showing low levels nationwide, but it is on the rise."

If you get the flu, when should you be healthy enough to return to work, school and festivities?

"The CDC recommends that when recovered from the flu, you can return to work or school 24 hours after symptoms disappear or after fever is gone without the use of medications like ibprofen or acetaminophen," says Schreibman. "Four to five days after symptoms have started, on average, is when people can return to work safely."

However, Schreibman warns that levels of contagiousness can vary from person to person. She advises staying on the safe side: staying home, working from home and using telehealth and Zoom.

 For more information on influenza numbers this year, click here. To learn more about Schreibman, visit CAN Community Health's website or call (941) 366-0134.

If you get to the office and notice your throat is a bit sore, it may be time to head home.

“When you are infected with a cold, you’ll be most contagious about a day before you show symptoms,” said Dr. Jane Heffernan, a professor at York University’s Faculty of Science who specializes in infectious diseases.

“[You’re still contagious] five to seven days after you show symptoms.”

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In other words, you’re most likely to pass on the virus around the same time you realize you’re getting sick, and just shortly after.

While many people assume you need to have obvious signs of a cold, like a runny nose or cough to pass it on, it may come as a surprise that the virus is transmittable before your symptoms begin.

“If you have friends or family members that have a cold, then you’ve probably been exposed to it,” Heffernan explained. “The best thing to do is to make sure you are practicing proper hand washing.”

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How colds spread

According to the Canadian Centre for Occupational Health and Safety (CCOHS), there are more than 200 viruses that can cause colds, but the main family of viruses are the rhinoviruses. These viruses can live on surfaces for hours after contamination, Heffernan said.

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When you’re infected with a cold (even when you aren’t showing symptoms), respiratory droplets that contain the virus spread through mucus membranes, which include our eyes, nose and mouth, said Jessica Mudry, an assistant professor of professional communication at Toronto’s Ryerson University and an expert in public health messaging. “Those are the three entry points or gateways.”

Mudry said that when you have a cold, you are likely touching your nose or mouth often to deal with the discomfort and obvious symptoms like a cough or runny nose. When you do this, the virus ends up on your hands, which is how it lands on things you touch like a door handle or keyboard, for example.

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“If I have a cold and I wash my hands, I probably don’t have the virus on my hands. But if I then touch my nose and go and shake someone’s hand, I’ve just taken some of the virus out of my nose… and put it on someone else’s… body,” she explained.

“If that person goes and washes their hand, chances are they won’t get a cold. But if they take that hand… and then touch one of their mucus membranes, there’s a possibility that the virus can then take up residence.”

Your cold is likely less contagious near the end of its life, clocking in around day seven or eight, depending on the severity of your illness. “The [virus] ramps up, comes to a peak, then ramps back down,” Heffernan said.

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How to prevent passing on a cold — or catching one

Like Mudry pointed out, it’s easy to pass on a cold.

The CCOHS states since colds are highly contagious, they’re one of the leading reasons why people miss work each year. The centre estimates that adults suffer two to five colds annually.

One simple way to stop spreading germs? Keep your hands clean.

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“Washing your hands is so important because we tend to touch our eyes, our nose and our mouth, and if we have some of the virus on our hands, [it can be transmitted],” Mudry said.

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Heffernan echoes this, and added that practicing safe social distance from other people helps prevent passing on the virus, too. This means minimizing close contact with people who have a cold, and avoiding skin-to-skin touching.

But, if you practice hand washing and social distance, you shouldn’t be too concerned with passing on or catching a cold.

“The thing is, a lot of people have natural behaviours and don’t necessarily adopt the practices that may be optimal,” Mudry said.

So if you’re really sick, it’s best to take the day off and stay indoors. That way, you’re giving your body time to fight the virus, and reducing the chance you’ll give it to someone else.