"We're seeing that doctors are over-prescribing because of patient expectations, because of fear of making the wrong diagnosis," she says. "And, of course, patients are demanding antibiotics in many cases from their providers as well."
Antibiotics can also be misused when the drugs are not taken under expert supervision. In many countries, antibiotics require a doctor's prescription. But Hicks says that's not true everywhere.
"In certain areas, antibiotics can be obtained without prescription, so there may be more inappropriate antibiotic use in some of those settings."
The CDC says about half the antibiotics used in the U.S. each year are prescribed unnecessarily, costing more than a billion dollars in the United States alone.
Overuse of antibiotics can lead to drug-resistant bacteria that have to be treated with more powerful and often more expensive drugs. And sometimes there are no drugs that work effectively, which increases the danger to people who are infected.
The U.S. campaign for the smart use of antibiotics parallels similar efforts in Europe and Canada, which Hicks says underscores the international nature of the threat.
"Resistant bacteria don't respect country or national boundaries and can easily travel on planes. Antibiotic resistance anywhere is really antibiotic resistance everywhere."