- With Mayo Clinic internist
James M. Steckelberg, M.D.
read biographyclose windowBiography of
James M. Steckelberg, M.D.
James Steckelberg, M.D.
Dr. James Steckelberg is chairman of the Division of Infectious Diseases at Mayo Clinic, a consultant and a professor of medicine at Mayo Medical School.
A native of Fremont, Neb., Dr. Steckelberg was a Rhodes Scholar and graduated from the Mayo Graduate School of Medicine as a resident in internal medicine and a fellow in infectious diseases, and is board certified in both. He is the former director of the Infectious Diseases Research Laboratory at Mayo Clinic.
Dr. Steckelberg belongs to numerous professional organizations. He is a founding member of the Musculoskeletal Infection Society of America and a fellow with the American College of Physicians and the Infectious Diseases Society of America. He has served on many Mayo Clinic committees and is a member of the Department of Medicine Leadership Committee and the executive committee of the Division of Infectious Diseases. He also served on the editorial boards of "Mayo Clinic Proceedings" and "Antimicrobial Agents & Chemotherapy" and has been an editorial reviewer for more than a dozen publications.
Dr. Steckelberg's research interests include experimental models of infection, epidemiology of infection, and antimicrobial resistance and therapy of bacterial infections.
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Question
Bacterial infection vs. viral infection: What's the difference?
What's the difference between a bacterial infection and a viral infection?
Answer
from James M. Steckelberg, M.D.
Simply put, bacterial infections are caused by bacteria and viral infections are caused by viruses. But they're also different in other ways.
Bacteria are single-celled "living" microorganisms that reproduce by dividing. Most bacteria can grow on nonliving surfaces, such as countertops and doorknobs. Not all bacteria are harmful. Some bacteria are even beneficial to your health. But when infectious bacteria enter your body, they can make you sick. Bacteria make toxins that can damage the cells they've invaded. Some bacterial infections, such as strep throat and tuberculosis, are contagious. Others are not.
Unlike bacteria, viruses are not "living" organisms but capsules of genetic material. They require living hosts — such as people, plants or animals — to multiply. Otherwise, they can't survive. When a virus enters your body, it invades some of your cells and takes over the cell machinery, redirecting it to produce the virus. The virus may eventually kill the host cells. Some viral infections, such as influenza and HIV, are contagious. Others are not.
The distinction between bacterial and viral infections is important. Why? Because medications that are effective against one aren't effective against the other.
Bacterial infections are treated with antibacterial antibiotics. Antiviral antibiotics are available for some types of viral infections — but not all. Taking antibacterial antibiotics when you have a viral infection won't treat the viral infection and may even be harmful. Consult your doctor for advice on a specific condition.
