Table of ContentsView AllTable of ContentsFlu Transmission ExplainedWhen You’re ContagiousFlu Prevention
Table of ContentsView All
View All
Table of Contents
Flu Transmission Explained
When You’re Contagious
Flu Prevention
Influenza, more commonly known as the flu, is most often spread when a person comes into contact with droplets or aerosols that contain mucus from an infected person.
But is the flue airborne? Some research shows that approximately half of flu cases may stem from airborne transmission.It can also be spread from surfaces. Knowing how the flu is spread can help you prevent infection and minimize your risk.
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The flu is a virus that is most often spread when someone comes into contact withdropletsfrom an infected person. These droplets are produced when a person with the flu coughs or sneezes, spreading infected mucus around them for up to 6 feet.
Droplets vs. Aerosols
Droplets are heavy. They generally sink to the ground within about 6 feet of the infected person. That means if you stay more than 6 feet away, you are less likely to become infected. Scientists believe that most flu transmission happens when a person inhales these droplets or enters their eye, nose, or mouth.
If the flu isairborne, that means the infectious virus can spread even if you stay more than six feet away. Researchers are still unclear about how much of the flu is spread via airborne transmission, but one study indicates that at least half of transmission happens via airborne particles.
Through Human Contact
When you’re close to someone, you’re more likely to come into contact with their respiratory secretions, such as mucus from the upper respiratory tract. The flu virus can also live on the skin of someone who has the virus, when these respiratory droplets or other bodily fluids fall to the skin. When you come into contact with these fluids, you can be exposed to the flu virus and contract influenza.
On Surfaces
Occasionally, the flu can be spread when you touch a surface that has the virus on it, and then touch your own eyes, nose, or mouth, allowing the virus to enter your body.This is called surface transmission. The flu can survive for up to 48 hours on hard objects like doorknobs.It survives for a shorter time on cloth and other porous surfaces.
After you’ve come into contact with the virus, you can develop symptoms anywhere fromone to four days later. You can begin spreading the flu one day before symptoms appear. You’re contagious forup to seven days,but most likely to infect someone else in the first three to four days of illness.
Flu Prevention
To reduce your chances of contracting the flu:
Flu Season and COVID Prevention
During the early years of the COVID-19 pandemic, there was a dramatic decrease in flu cases, especially during the 2020-2021 flu season.
Researchers believe that this was largely due to COVID-related precautions including social distancing affecting flu rates. Flu activity rose during the 2021-2022 flu season, but preliminary estimates from the CDC show that there were fewer hospitalizations and deaths than in previous flu seasons.
The 2022-2023 year was similar to flu seasons prior to the pandemic. It also peaked earlier in the season than previous years. Classified as moderately severe, the season resulted in an estimated 31 million symptomatic illnesses, 360,000 hospitalizations, and 21,000 deaths due to the flu.The 2023-2024 season closely mimicked the year before.
As some of the COVID-related precautions have been lowered since then, researchers predict upcoming flu seasons to be more severe.
Summary
Influenza is primarily spread through airborne transmission via aerosols. These tiny particles are released when an infected person coughs, sneezes, or talks and can float through the air for a long time. However, research indicates that some transmission of the flu happens from coming into contact with an infected surface.
Many of the same precautions that people have adopted to prevent the spread of COVID can also reduce your risk of spreading or contracting influenza, such as getting vaccinated and frequently washing your hands.
Scientists are still studying how, precisely, the flu is spread. However, they know that
10 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Centers for Disease Control and Prevention.How flu spreads.Cowling BJ, Ip DKM, Fang VJ, et al.Aerosol transmission is an important mode of influenza A virus spread.Nat Commun. 2013;4:1935. doi:10.1038/ncomms2922Centers for Disease Control and Prevention.How To Clean and Disinfect Schools To Help Slow the Spread of Flu.Centers for Disease Control and Prevention.Vaccine effectiveness: how well do flu vaccines work?Centers for Disease Control and Prevention.Healthy habits to prevent the flu.Centers for Disease Control and Prevention.2020-2021 Flu Season Summary.Centers for Disease Control and Prevention.Past Seasons Estimated Influenza Disease Burden.Centers for Disease Control and Prevention.Influenza Activity in the United States during the 2022–2023 Season and Composition of the 2023–2024 Influenza Vaccine.Centers for Disease Control and Prevention.Influenza Activity in the United States during the 2023–2024 Season and Composition of the 2024–2025 Influenza Vaccine.Ali ST, Lau YC, Shan S, et al.Prediction of upcoming global infection burden of influenza seasons after relaxation of public health and social measures during the COVID-19 pandemic: a modelling study.Lancet Glob Health. 2022;10(11):e1612-e1622. doi:10.1016/S2214-109X(22)00358-8
10 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Centers for Disease Control and Prevention.How flu spreads.Cowling BJ, Ip DKM, Fang VJ, et al.Aerosol transmission is an important mode of influenza A virus spread.Nat Commun. 2013;4:1935. doi:10.1038/ncomms2922Centers for Disease Control and Prevention.How To Clean and Disinfect Schools To Help Slow the Spread of Flu.Centers for Disease Control and Prevention.Vaccine effectiveness: how well do flu vaccines work?Centers for Disease Control and Prevention.Healthy habits to prevent the flu.Centers for Disease Control and Prevention.2020-2021 Flu Season Summary.Centers for Disease Control and Prevention.Past Seasons Estimated Influenza Disease Burden.Centers for Disease Control and Prevention.Influenza Activity in the United States during the 2022–2023 Season and Composition of the 2023–2024 Influenza Vaccine.Centers for Disease Control and Prevention.Influenza Activity in the United States during the 2023–2024 Season and Composition of the 2024–2025 Influenza Vaccine.Ali ST, Lau YC, Shan S, et al.Prediction of upcoming global infection burden of influenza seasons after relaxation of public health and social measures during the COVID-19 pandemic: a modelling study.Lancet Glob Health. 2022;10(11):e1612-e1622. doi:10.1016/S2214-109X(22)00358-8
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Centers for Disease Control and Prevention.How flu spreads.Cowling BJ, Ip DKM, Fang VJ, et al.Aerosol transmission is an important mode of influenza A virus spread.Nat Commun. 2013;4:1935. doi:10.1038/ncomms2922Centers for Disease Control and Prevention.How To Clean and Disinfect Schools To Help Slow the Spread of Flu.Centers for Disease Control and Prevention.Vaccine effectiveness: how well do flu vaccines work?Centers for Disease Control and Prevention.Healthy habits to prevent the flu.Centers for Disease Control and Prevention.2020-2021 Flu Season Summary.Centers for Disease Control and Prevention.Past Seasons Estimated Influenza Disease Burden.Centers for Disease Control and Prevention.Influenza Activity in the United States during the 2022–2023 Season and Composition of the 2023–2024 Influenza Vaccine.Centers for Disease Control and Prevention.Influenza Activity in the United States during the 2023–2024 Season and Composition of the 2024–2025 Influenza Vaccine.Ali ST, Lau YC, Shan S, et al.Prediction of upcoming global infection burden of influenza seasons after relaxation of public health and social measures during the COVID-19 pandemic: a modelling study.Lancet Glob Health. 2022;10(11):e1612-e1622. doi:10.1016/S2214-109X(22)00358-8
Centers for Disease Control and Prevention.How flu spreads.
Cowling BJ, Ip DKM, Fang VJ, et al.Aerosol transmission is an important mode of influenza A virus spread.Nat Commun. 2013;4:1935. doi:10.1038/ncomms2922
Centers for Disease Control and Prevention.How To Clean and Disinfect Schools To Help Slow the Spread of Flu.
Centers for Disease Control and Prevention.Vaccine effectiveness: how well do flu vaccines work?
Centers for Disease Control and Prevention.Healthy habits to prevent the flu.
Centers for Disease Control and Prevention.2020-2021 Flu Season Summary.
Centers for Disease Control and Prevention.Past Seasons Estimated Influenza Disease Burden.
Centers for Disease Control and Prevention.Influenza Activity in the United States during the 2022–2023 Season and Composition of the 2023–2024 Influenza Vaccine.
Centers for Disease Control and Prevention.Influenza Activity in the United States during the 2023–2024 Season and Composition of the 2024–2025 Influenza Vaccine.
Ali ST, Lau YC, Shan S, et al.Prediction of upcoming global infection burden of influenza seasons after relaxation of public health and social measures during the COVID-19 pandemic: a modelling study.Lancet Glob Health. 2022;10(11):e1612-e1622. doi:10.1016/S2214-109X(22)00358-8
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