Viruses: How They Spread, How They're Treated

News Team's picture
By News Team on March 13, 2020

Viruses are different than just about anything else we encounter in our lives. A virus is a microscopically tiny “parasite” that first attaches itself to our cells, and then gets inside so that it can use our cells’ genetic machinery to "grow" through replication. While they are organic microbes, they are not considered “living” since they cannot exist outside a host—in our case, our body’s cells.

The surprising news is that we are infected with viruses regularly without any resulting illness. That’s because our cells are protected by our immune system, which responds quickly and in force to eliminate viruses when they are detected.
Our "host" cells become more at risk of illness when the effects of the replicating virus are stronger than our immune response. 

Preventing Viral Illness

Regardless of where they originate, viral illnesses such as coronavirus disease 2019 (“COVID-19”)—which is caused by the novel coronavirus SARS-CoV-2—most often spread through person-to-person contact.
The best way to protect yourself and your family is to wash your hands regularly and thoroughly with soap and water. Watch this World Health Organization video to see a demonstration of effective hand washing—including advice to turn off the tap with your elbow or a paper towel.

The U.S. Centers for Disease Control and Prevention (CDC) recommends washing your hands:

  • Before, during and after preparing food
  • Before eating food
  • Before and after caring for someone who is sick
  • Before and after treating a cut or wound
  • After using the toilet
  • After changing diapers or cleaning up a child who has used the toilet
  • After blowing your nose, coughing or sneezing
  • After touching an animal, animal feed or animal waste
  • After handling pet food or pet treats
  • After touching garbage 

During large outbreaks such as the current SARS-CoV-2/COVID-19 outbreak, also:

  • Wash your hands anytime you return home from public places
  • Wash your produce before putting it away
  • Regularly sanitize door handles and other “high-touch” surfaces—
    • Tabletops
    • Bathroom fixtures and toilets
    • Phones
    • Keyboards and tablets
    • Bedside tables 

If soap and clean water are not available, use an alcohol-based liquid or foam hand sanitizer to avoid getting sick or spreading infection.

In addition to keeping your hands clean, keep them away from your face. The mucous membranes and moisture in our eyes, nose and mouth act as open doors for viruses.
Remember, touching a surface that has an active virus on it will not make you sick—as long as you wash your hands.
Another point to remember is that this advice relates to all common viral infections—such as the common cold and the flu—and should be practiced throughout the year, especially during flu season.

Treating Viral Illness

The vast majority of people who contract COVID-19 from exposure to SARS-CoV-2 virus will experience mild flu-like symptoms and recover on their own without medical intervention.

If You Get Sick

If you experience flu-like symptoms such as a fever and respiratory distress with coughing or sneezing, take the following steps to take care of yourself without putting others at risk:

  • Stay home except to get medical care
  • Call your health care provider or walk-in clinic before seeking care so that they can be prepared to treat you while protecting others
  • Avoid work, school and public areas—call on friends and family to help you with groceries, or use a grocery-delivery service
  • Avoid public transportation
  • Stay away from others at home—set up the TV in a spare bedroom and use a separate bathroom if possible
  • Avoid sharing household items
  • Limit contact with pets—while this virus has not affected pets or other animals, some coronaviruses can be transmitted between humans and animals and the CDC recommends having others care for your pets while you are sick.

If you are sick, this is the time to use a facemask. Note that facemasks will not protect healthy people from exposure—they are designed for people who are ill to prevent spreading the virus when they cough or sneeze. A mask also makes it easier to avoid touching your face and transmitting the virus to your hands when you are ill.
In addition, take a three-step approach to coughing and sneezing:

  1. Cover your mouth and nose with a tissue
  2. Throw used tissues in a lined trash can
  3. Immediately wash your hands

This article was reviewed March 12, 2020 by Thomas M. Kerkering, M.D., F.A.C.P., F.I.D.S.A., Professor of Medicine, Section of Infectious Diseases, Virginia Tech Carilion School of Medicine.

Carilion Clinic message saying wash your hands and stay home when you are sick

Visit for up-to-date information about our response to COVID-19. Call our Community Hotline for general questions about symptoms, resources, guidelines and more,

COVID-19 Community Hotline

Monday - Friday, 8 a.m - 5 p.m.

Do not call the Community Hotline to make appointments, or to request testing or test results. For information about COVID-19 and your personal health, talk with your primary care provider