How can my doctor tell whether my illness is caused by a virus or bacteria? Though there is no easy way to tell for sure, infections caused by bacteria often take on certain characteristics. They tend to last longer, cause a fever of 100.4 degrees or greater, and may make people sick enough to be hospitalized. Evidence shows that infections lasting 10 days or longer are more likely caused by bacteria, and infections lasting less than that are caused by viruses.
At this point, you might be shaking your head in disbelief, or asking “How can that be?” You might even wonder why your doctor isn’t treating you “just in case.” After all, 10 days is a long time to wait when you are feeling ill. The answer is tri-fold:
1. Antibiotics don’t work for viruses. Most of the time, these common infections are caused by viruses. Antibiotics work by destroying bacterial cell membranes and bacterial replication. Since viruses don’t have these components, antibiotics do nothing to fight them.
2. Antibiotics have side effects. If you take antibiotics for a viral infection, you are putting yourself at risk for side effects. All antibiotics may cause diarrhea and nausea. Some are hard on your kidneys, liver or other body parts. Some side effects can be life threatening, such as an allergic reaction. Every antibiotic can have side effects.
3. Using antibiotics to treat viruses causes superbugs. Superbugs are bacteria that become resistant to antibiotics. This happens when antibiotics are inappropriately used to treat viral infections. When someone gets an infection caused by a superbug, antibiotics don’t work. Thousands of people die from these infections every year. Infants, young children and elderly are at greatest risk. These deaths are preventable – but only if antibiotics are used correctly.
The next time you see your provider for an infection, try to be a good steward of antibiotic use. If he or she determines that you do not need antibiotics, realize the greater impact you have by avoiding these medications for viral illnesses.
Antibiotics aren't always the answer. Unnecessary prescriptions for antibiotics create new, drug-resistant strains of common diseases.
According to the CDC, at least 30% of antibiotics prescribed in U.S. outpatient settings are unnecessary, meaning that no antibiotic was needed at all. Any time antibiotics are used, they can cause side effects and contribute to the development of antibiotic resistance.
Prescribing antibiotics carefully and using them wisely is the key to preventing the spread of antibiotic-resistant illnesses, and ensures that these life-saving drugs will be available for future generations.
- Questions and answers about antibiotic resistance CDC
What You Can Do
- Ask your healthcare professional about the most appropriate treatment for you or your loved ones' illness. If antibiotics are not needed, ask about the best way to feel better while your body fights off the virus.
- Take antibiotics exactly as prescribed. Talk with your doctor or pharmacist if you have any questions about your antibiotics.
- More about how bacteria become resistant
When are antibiotics needed?
Colds, flu, sore throats and coughs are usually caused by viruses, not bacteria. Antibiotics should only be used when prescribed by a doctor to treat bacterial infections. Antibiotics won't help you recover from a viral infection.
- Ear infections: There are several types; many need antibiotics, but some do not.
- Sinus infections: Most sinus infections are caused by a virus, but antibiotics are needed for some long-lasting or severe cases of bacterial sinusitis.
- Sore throat: Viruses cause most cases of sore throat. One major kind of bacterial infection (streptococcus infection) does require antibiotics.
- Colds: Colds are caused by viruses and may last for two weeks or longer. Antibiotics have no effect on colds, but your doctor may have suggestions for obtaining comfort while the illness runs its course.
- How to treat common conditions with and without antibiotics
Antibiotic Stewardship
Antibiotic stewardship is the effort to measure and improve how antibiotics are prescribed by clinicians and used by patients. Improving antibiotic prescribing and use is critical to effectively treat infections, protect patients from harms caused by unnecessary antibiotic use, and combat antibiotic resistance.
- More about Antibiotic Stewardship
Antibiotic Awareness Week
U.S. Antibiotic Awareness Week is November 18-24, 2021.
U.S. Antibiotic Awareness Week (USAAW) is a collaboration of the CDC, state-based programs, nonprofit partners, and for-profit partners. You can join official USAAW events or host your own. There are many ways to get involved!
- More about U.S. Antibiotic Awareness Week CDC
More information
- Antibiotic Use CDC
- Antibiotic Resistance Q & A CDC
- Antibiotic Do’s & Don’ts CDC
- Common Illnesses and Antibiotic Use CDC
- For Healthcare Professionals: Antibiotic Use CDC