Your Complete Guide to How Cold and Flu Germs Spread

As the seasons change, so does the familiar chorus of coughs and sneezes. You clicked here because you want to understand how cold and flu germs actually travel from person to person. Knowing the facts is the best way to protect yourself and your family, and we’ve gathered all the essential information for you.

What Are Cold and Flu "Germs"?

When we talk about “germs” in the context of colds and the flu, we are primarily referring to viruses. These microscopic invaders are the true culprits behind your seasonal sniffles and body aches.

The Common Cold: This is most often caused by rhinoviruses, but over 200 different viruses can lead to cold symptoms. Colds are generally milder than the flu.
The Flu: This is caused exclusively by influenza viruses (Types A, B, and sometimes C). The flu is a more serious respiratory illness that can lead to significant complications.

These viruses have one main goal: to replicate. To do that, they need to get from an infected person into a new host. Understanding their travel methods is key to stopping them in their tracks.

What Really Spreads Germs? The Top 3 Routes of Transmission

Viruses don’t have wings or legs; they rely on us to move them around. The ad you saw showed someone sneezing, which is a major clue. Here are the primary ways these respiratory viruses spread.

1. Airborne Droplets from Coughs and Sneezes

This is the most common and direct way cold and flu viruses spread. When an infected person coughs, sneezes, sings, or even just talks, they expel tiny droplets of moisture from their nose and mouth. These droplets are loaded with virus particles.

If you are standing close by, typically within six feet, you can breathe in these droplets directly. They then land on the mucous membranes of your nose, throat, or lungs and begin to multiply.

A Sneeze’s Power: A single sneeze can generate up to 40,000 droplets and propel them at speeds approaching 100 miles per hour. These droplets can travel across a room.
A Cough’s Reach: A cough is less powerful but can still produce around 3,000 droplets that travel a significant distance.

This is why health experts advise covering your mouth and nose when you cough or sneeze, preferably into your elbow instead of your hands.

2. Contact with Contaminated Surfaces (Fomites)

Respiratory droplets don’t just hang in the air forever. They have to land somewhere. They settle on everyday objects and surfaces, which are scientifically known as fomites.

Imagine someone with the flu sneezes into their hand and then touches a doorknob, a keyboard, or a grocery cart handle. The virus is now waiting on that surface. If you touch that same doorknob and then touch your eyes, nose, or mouth, you have just given the virus a direct pathway into your body.

Virus Survival Time: The lifespan of these viruses on surfaces can be surprising. Influenza virus, for example, can survive on hard, nonporous surfaces like stainless steel and plastic for up to 48 hours. On softer surfaces like cloth or paper, their survival time is much shorter, often just a few minutes to a few hours.
High-Touch Hotspots: Common surfaces that spread germs include light switches, remote controls, elevator buttons, gas pump handles, and your own cell phone.

This transmission route is why frequent and proper handwashing is one of the most effective ways to prevent getting sick.

3. Direct Personal Contact

This method is straightforward. If you have close contact with someone who is sick, you can easily catch their illness. This includes actions like:

Shaking hands: If someone has coughed into their hands and you shake their hand, the virus is transferred.
Hugging or kissing: This close contact can easily transmit airborne droplets.
Sharing items: Using the same cup, utensils, or towel as an infected person can also lead to transmission.

Practical Steps to Stop the Spread of Germs

Now that you know how germs travel, you can take specific, actionable steps to protect yourself.

Wash Your Hands Frequently: This is your number one defense. Wash your hands with soap and water for at least 20 seconds, which is about the time it takes to sing “Happy Birthday” twice. Be sure to scrub the backs of your hands, between your fingers, and under your nails.
Use Hand Sanitizer: When soap and water are not available, use an alcohol-based hand sanitizer. Make sure it contains at least 60% alcohol to be effective. Brands like Purell and Germ-X are widely available and meet this standard.
Avoid Touching Your Face: Your eyes, nose, and mouth are the main portals of entry for viruses. Make a conscious effort to keep your hands away from your face, especially when you are in public places.
Clean and Disinfect Surfaces: Regularly wipe down high-touch surfaces in your home and workspace. Use an EPA-registered disinfectant spray or wipe. Products from brands like Clorox and Lysol are effective at killing cold and flu viruses.
Practice Respiratory Etiquette: Always cover your mouth and nose with a tissue when you cough or sneeze, then throw the tissue away immediately. If you don’t have a tissue, use the crook of your elbow.
Keep Your Distance: If you know someone is sick, try to maintain a safe distance to avoid inhaling their respiratory droplets. If you are the one who is sick, stay home to avoid spreading your germs to others.

Frequently Asked Questions

Can I get the flu just from being out in the cold weather? No, this is a common myth. Cold weather itself cannot make you sick. You get sick from being exposed to a virus. However, cold weather often forces people to spend more time indoors in closer contact with others, which can increase the chances of a virus spreading.

How long is a person with a cold or the flu contagious? For the flu, people are most contagious in the first 3-4 days after their illness begins. However, you can actually start spreading the virus a day before you even show symptoms and can remain contagious for up to a week. For the common cold, you are typically contagious for a few days before symptoms appear and can remain so for up to two weeks.

Do face masks help prevent the spread of germs? Yes, they can be an effective tool. A mask worn by a sick person can help contain their respiratory droplets, preventing them from spreading to others. A mask worn by a healthy person can offer a layer of protection against inhaling droplets from others, though it is most effective when combined with other measures like handwashing and social distancing.