6 Common Viruses and How You Can Avoid Spreading Them

With cold and flu season fast approaching, there’s no doubt that you’ll be extra thorough in your efforts to protect yourself from germs and viruses this year. Before COVID-19, did you ever think about how long you could be contagious after catching a cold or having bronchitis, strep throat or the flu? If not, the answers just might surprise you.

As you’re being extra cautious to avoid catching or spreading the coronavirus, keep these helpful guidelines from family medicine physician Matthew J. Goldman, MD in mind so you don’t pass the following common illnesses on to others.

Are you contagious or not?

Common Cold

When are you probably the most contagious? Within the first 48-72 hours.

How long could you be contagious with a cold? Up to 2 weeks.

How does a common cold spread? Hand contact or droplets in the air.

How do you avoid infecting others?

• Cough/sneeze into your elbow and not your hands.
• Stay home until symptoms improve and your fever resolves.

Hand hygiene: Clean your hands often with soap and water/alcohol-based hand sanitizers.

Flu

When are you probably the most contagious? Within the first 48 hours.

How long could you be contagious with the flu? Up to 10 days.

How does the flu spread? Coughing/sneezing (sends large amounts of flu virus into air).

How do you avoid infecting others?

• Stay on top of hand hygiene.
• Cough or sneeze into your elbow and not your hands.
• Stay home until symptoms improve and fever resolves.

Hand hygiene: Clean your hands often with soap and water/alcohol-based hand sanitizers.

Sore Throat/Strep

When are you probably the most contagious? Within the first 48-72 hours.

How long could you be contagious with a sore throat or strep? Three to four weeks if left untreated. You could be contagious with strep 24 to 48 hours after you start antibiotics. 

How does a sore throat or strep spread? Saliva or nasal mucus/discharge (especially strep). 

How do you avoid infecting others?

• Avoid close contact with others.
• Don’t share utensils or drinks.

Extra hand hygiene: Wash your hands with plain soap and water for 20-30 seconds; scrub your nails, wrists and between your fingers. Rinse thoroughly.

Bronchitis

When are you probably the most contagious? Within the first 48-72 hours.

How long could you be contagious with bronchitis? Up to 3 weeks.

How does bronchitis spread? Through droplets in the air and contaminated surfaces.

How can you avoid infecting others?

• Be sure to step up your hand hygiene.
• Promptly discard used tissue and wash your hands.
• Get tested for the flu.

Extra hand hygiene: Wash your hands with plain soap and water for 20 to 30 seconds; scrub your nails, wrists and between your fingers. Rinse your hands thoroughly.

Pneumonia

When are you probably the most contagious? Within the first 48-72 hours.

How long could you be contagious with pneumonia? Up to three weeks.

How does pneumonia spread? Coughing or sneezing (you can infect anyone within 6 feet). 

How can you avoid infecting others?

• Extra hand hygiene.
• Wash your hands before making meals.
• Promptly discard used tissue and wash your hands.
• Environmental cleaning.

Environmental cleaning: Frequently disinfect surfaces where infected droplets can collect.

Stomach Virus

When are you probably the most contagious? Within the first 24-48 hours.

How long could you be contagious with a stomach virus? It varies. Wait 48-72 hours after your symptoms resolve to return to school or work.

How does a stomach virus spread? Sharing food or utensils, contaminated surfaces or close contact.

How can you avoid infecting others?

• Extra hand hygiene.
• Environmental cleaning.
• Avoid close contact with others.

Environmental cleaning: Frequently disinfect surfaces where infected droplets can collect.