Despite repeated warnings from experts during the past decade, too many Americans still think antibiotics will cure the common cold or the flu, according to a recent poll by the Centers for Disease Control and Prevention (CDC) and The Pew Charitable Trusts. Nearly 90 percent of the poll's respondents knew that antibiotics could treat bacterial infections, such as strep throat and some ear infections. But more than a third also believed, erroneously, that antibiotics treated viral infections, such as colds and other upper respiratory infections.

That common misconception has fueled a growing problem of antibiotic resistance, where more strains of bacteria no longer succumb to the antibiotic drugs in our current arsenal. Experts now call it a public health issue.

Widespread antibiotic use—and abuse—has allowed the microorganisms that the antibiotics were designed to kill to mutate and adapt to the drugs. These bacterial strains continue to survive and multiply, leading to the emergence of so-called drug-resistant superbugs like Mycobacterium tuberculosis, which causes TB infections; Staphylococcus aureus, the cause of "Staph" infections, including MRSA; and vancomycin-resistant enterococci, or VRE, which cause mostly hospital-acquired infections of the urinary tract, heart valves, bloodstream and brain.

Older adults and people with chronic illnesses are particularly vulnerable to various infections from group B streptococcus, Clostridium difficile, Klebsiella pneumoniae, MRSA and VRE.

More-stubborn UTIs

Take, for example, a urinary tract infection (UTI), the second most common infection in the United States. Typically caused by a strain of E. coli, UTIs were once easily banished with several days of antibiotics. Today, they're proving more difficult to treat, as the usual first-line antibiotics fail to clear the infection and physicians must then prescribe more-powerful drugs, accompanied by more side effects.

If a UTI goes unchecked, it may progress to kidney infection, kidney damage or sepsis, a systemic and life-threatening infection that occurs when bacteria infect the blood. When initial antibiotics fail, the results are

  • a longer, more complicated illness;
  • more clinical visits;
  • a need for stronger and more expensive drugs;
  • increased hospitalizations;
  • and more deaths.

Older adults are more likely to have other health conditions and tend to suffer more antibiotic side effects, such as nausea, diarrhea and stomach pain, than younger people.

What you can do

When you’re ill, it’s understandable to want to shorten your misery and avoid a more serious infection, especially if you have other health conditions, which may be complicated by a nasty bug. But taking an unnecessary antibiotic does no good and may cause far more harm. Follow these tips to help you get well and avoid contributing to antibiotic resistance:
  • Don’t take leftover antibiotics from a prior illness. Without a diagnosis, you can’t know whether your infection is caused by the same bacteria or whether it’s caused by bacteria at all.
  • Don’t press for an antibiotic prescription. Hearing your doctor tell you to rest, drink plenty of fluids and use over-the-counter remedies like aspirin and saline nasal spray can fall short of expectations when you’re ill. Ask whether an antiviral medication is available for your illness.
  • Ask if you're taking the right antibiotic for your illness. A sensitivity test, which tests your bacteria culture, may determine which antibiotic will kill the bacteria causing your illness. It typically takes 48 hours to get results.
  • Take any antibiotic exactly as prescribed. Continue the drug even if you feel better. If you stop the drug before all the bacteria is killed, surviving bacteria can grow and "learn" to resist the drug next time.
  • Stay well. Practice good hand-washing and hygiene habits to protect from infections. Eat right, exercise and get adequate rest to bolster your immune system.
  • Get vaccinated. Be sure to receive all the recommended immunizations, such as an annual flu shot and shingles and pneumonia vaccinations.

Doctor's Viewpoint

Michele F. Bellantoni, MD, Associate Professor, Medicine; Medical Director, Johns Hopkins Bayview Care Center

Many people mistakenly believe you can build up a tolerance to antibiotics as a result of overuse. But antibiotic resistance is not caused by an individual becoming resistant to antibiotics—it's caused by bacteria becoming resistant to antibiotics.

These new bacteria strains are a growing threat to our communities: They spread quickly and infect many people, and the resistant infections are difficult to treat. Even someone who has never taken antibiotics may contract an infection caused by drug-resistant bacteria and pass it to others in the community.

Source: Prepared by the Editors of The Johns Hopkins Medical Letter: Health After 50

Publication Review By: the Editorial Staff at

Published: 29 Jul 2013

Last Modified: 28 Jan 2015