What are bacteria and viruses?
Bacteria and viruses are germs that can cause infections and disease, but they are very different in other ways. Most bacteria can live on their own, outside the body. Viruses can only live inside cells of the body. Most bacteria are good and play an important role in nature. Only some bacteria can cause infections and diseases.
What are antibiotics?
Antibiotics are drugs that kill bacteria, tiny germs that can cause infections and disease. Antibiotics have been used for many years to treat illnesses caused by bacteria. Many people are familiar with the antibiotic penicillin, which was discovered during the 1920s by Alexander Fleming. Antibiotics come in pill form, as syrups, as salves and ointments, and are also given by injection. Antibiotics kill both good and bad bacteria. Unnecessary and inappropriate use of these drugs can cause problems, such as antibiotic resistance. Antibiotics should be used only when needed. Antibiotics do not kill viruses and should not be used to treat viral illnesses, such as colds and the flu.
When do you need an antibiotic?
Antibiotics treat bacterial infections. A healthcare provider will decide if you need them. Some examples of when you might need an antibiotic include:
- Strep throat
- Urinary tract infections
- Bacterial pneumonia
- Some skin infections
When aren't antibiotics needed?
Antibiotics can help the body fight bacterial infections, but they are not appropriate for everything.
They are not helpful when:
- You have an infection that is caused by a virus (like a cold or the flu).
- You don't have an infection but instead have some other medical problem.
- Bacteria are found in a urine culture from a specimen you gave, but you do not have any symptoms of infection. It is normal for many older people without symptoms of a urinary tract infection to have bacteria in their urine, especially those in long-term care.
How can antibiotics cause problems?
Antibiotics can save lives but can also cause problems. Older people have more side effects from medicines, which can lead to health problems throughout the body.
Antibiotics can sometimes:
- Interfere with other drugs you may be taking.
- Cause nausea and vomiting.
- Cause diarrhea, including the kind due to C. difficile, an infection that can lead to severe symptoms.
- Cause rash or other allergic reactions.
- Harm your kidneys or other organs.
- Create bacteria that are resistant to antibiotics.
What is antibiotic resistance?
Antibiotics normally work by killing germs called bacteria. Sometimes not all the germs are killed after taking antibiotics. The strongest bacteria survive and multiply—they are “resistant” to the antibiotic. A person can get sick again, and this time the germs are harder to kill because the antibiotics no longer work. This is called antibiotic resistance and makes some infections difficult to treat.
Why is antibiotic resistance a problem?
Resistance can lead to a longer illness, more health care visits, and the need for even stronger medications. Antibiotic resistance is also a global problem because it reduces the effectiveness of these drugs for all of us. Many bacteria that cause infections are becoming more resistant to commonly used antibiotics. New drugs are slowly being developed to treat resistant bacteria.
What causes antibiotic resistance?
Antibiotic resistance is a natural process. Every time a person takes antibiotics, sensitive bacteria are killed but resistant bacteria may survive and multiply.
Unfortunately, the problem of antibiotic resistance is made worse when antibiotics are used inappropriately or when they are not needed. This can happen with animals as well as people. Antibiotic overuse, and misuse, can create the conditions for the development of antibiotic-resistant bacteria. Millions of antibiotics are prescribed each year when not needed. Fortunately, patients and healthcare providers can work together to reduce antibiotic resistance.
How does inappropriate antibiotic use contribute to antibiotic resistance?
Antibiotic resistance is natural but happens faster when antibiotics are misused or overused. For example, antibiotics do not work against diseases caused by viruses but are sometimes inappropriately prescribed and taken to treat viral illnesses. Every time a person takes antibiotics, sensitive bacteria are killed but resistant bacteria may survive and multiply. Treating viral illnesses with antibiotics is a problem because it can lead to the development of resistant bacteria without treating the illness.
How can I tell if an infection is bacterial or viral?
This can be very difficult. Consult your healthcare provider to be sure. Depending on the symptoms of the illness, sometimes healthcare providers can be sure about the cause of the illness without ordering a test. For example, colds and the flu are viral illnesses. Sometimes it is necessary for a healthcare provider to order a test to determine whether an illness is due to a virus or bacteria.
Knowing what causes an illness is important, because antibiotics do not kill viruses and should not be prescribed or taken to treat viruses.
Remember: antibiotics do not kill viruses!
What can I do to prevent antibiotic resistance?
- Talk with your healthcare provider about the benefits and risks of antibiotics.
- Do not take an antibiotic for a viral infection like a cold or the flu. Antibiotics should be used only to treat bacterial infections.
- Take antibiotics exactly as prescribed.
- Do not save any antibiotics for the next time you get sick. Learn how to safely dispose of unused medicines.
- Do not demand antibiotics when a healthcare provider says they are not needed.
- Do not take antibiotics prescribed for someone else. The antibiotic may not be right for your illness. Taking the wrong medicine may delay correct treatment and may allow bacteria to multiply.
- Parents, remember that these "rules" apply to children who have been prescribed antibiotics.
What are some bacterial infections that are resistant to common antibiotics?
The following infections have become resistant to (unable to be treated by) certain common antibiotics. As a result, these infections are now more difficult to treat than in the past. Explore the links to learn more about these types of antibiotic resistant infections:
- Methicillin-resistant Staphylococcus aureus (MRSA)
- Carbapenem-resistant Enterobacteriaceae (CRE)
- C. difficile