Are you contagious? Check when you're most likely to spread COVID, the flu and other common illnesses
It's that time of year! People are spreading holiday cheer — and germs, leading to sicknesses like COVID, flu, RSV, pneumonia and more. But how long are you contagious?
Dr. Carla Garcia Carreno, Children's Medical Center Plano director of infection prevention and control, is already seeing upticks in RSV, COVID and flu in her area, she told CBS News.
Luckily, there are ways to help prevent illness, including social distancing, washing our hands and getting vaccinated.
But if you do end up coming down with something, here's what to know to keep others safe this holiday season.
How long is COVID contagious?
People with COVID-19 can be infectious from one to two days before and up to eight to 10 days after symptoms begin, according to the Centers for Disease Control and Prevention.
"The majority of transmission appears to occur during the early periods of infection, particularly in the 1 to 2 days before symptoms start and within the first few days of symptom onset," its website notes.
Asymptomatic individuals can also transmit the virus.
So how do we know when it's safe to be around others? You no longer have to wait to test negative. Instead, the CDC has shared simplified guidelines for when to end isolation after contracting the virus: fever-free for 24 hours and improved symptoms.
"Once the person is fever-free for 24 hours without the use of any fever-reducing medicines like ibuprofen, they should be a little bit out of the woods ... but also your respiratory symptoms need to be improving," Garcia Carreno said.
After this period, you can start going out but it's a good idea to still take precautions to keep others safe.
"For example, try to social distance from others, and, if possible, wear a mask. That's usually recommended for an additional five-day period," she said.
In addition to COVID, these guidelines also apply to other respiratory infections, including flu and RSV, Garcia Carreno said.
How long is the flu contagious?
In most people infected, influenza viruses can be detected starting one day before symptoms begin and up to five to seven days after becoming sick, according to the CDC.
"People with flu are most contagious during the first three days of their illness. Some people, including young children and people with weakened immune systems may be contagious for longer periods of time," the agency's website states.
The CDC's update guidelines apply here, meaning you can return to normal after being fever-free for 24 hours without medication and have improved symptoms.
Garcia Carreno said the use of medications like Tamiflu also don't change these timelines.
"The use of antivirals shouldn't be a factor for prolonging the spread of the of the illness," she said.
While antiviral medications can help with symptoms, people should still monitor fever and symptoms based on the CDC's updated guidelines.
How long is the stomach flu contagious?
People sick with stomach flu, also known as viral gastroenteritis or norovirus, will get better within 1 to 3 days — but they can still spread the virus to others for days after.
"You can still spread norovirus for 2 weeks or more after you feel better," the CDC website states.
Norovirus is a gastrointestinal virus, not a respiratory virus like other illnesses we see this time of year, Garcia Carreno explained.
"It's also very contagious, but it's more contagious via vomiting and diarrhea, so it's through fecal (and) oral (transmission)," she said. "So hand washing is really important, and it's important to say that usually we need bleach products for norovirus to be inactivated."
If somebody is sick with norovirus at home, Garcia Carreno advises sterilizing or decontaminating the restroom that person used.
In addition to hand-washing to ward off illness, it's also a good idea to avoid sharing cups and utensils with others to prevent both gastrointestinal and respiratory viruses, she said.
How long is RSV contagious?
People with RSV are usually contagious for three to eight days, according to the CDC. They may also become contagious a day or two before they start showing symptoms.
"Some infants and people with weakened immune systems can continue to spread the virus for 4 weeks or longer, even after they stop showing symptoms," the agency notes.
The same CDC guidelines for COVID and flu also apply to RSV — people can end isolation after being fever-free for 24 hours without fever-reducing medicines and have improved symptoms.
How long is pneumonia contagious?
In general, the rule that applies to other respiratory viruses is also used for bacterial pneumonia, Garcia Carreno said, meaning once someone is fever-free for 24 hours and seeing symptom improvements they should not be as contagious.
"Also, for the majority, of these pneumonias, you usually are not contagious after 24 hours of antibiotics. So once you have received 24 hours of effective or appropriate antibiotics ... the contagiousness will decrease," she said.
How long is the common cold contagious?
You're most contagious when symptoms are at their worst, according to the Cleveland Clinic, which is usually the first three days.
But you can still spread the sickness beyond that timeframe.
"You can be contagious for up to two weeks, even spreading a cold a day or two before you have symptoms," the clinic's website reads.
The classic common cold virus is rhinovirus, and the same rules will apply for rhinovirus (as other respiratory viruses)," Garcia Carreno said, but warned rhinovirus is "one of the most contagious viruses" even if its symptoms are milder.
