The federal Centers for Disease Control and Prevention is testing two programs aimed at curbing misuse of antibiotics in U.S. hospitals, part of a continuing effort to fight the growth of drug-resistant bacteria.

One initiative electronically tracks antibiotic use at 70 hospitals. The other pilot is working on practical strategies to ensure antibiotics are given in a timely and appropriate manner at eight hospitals.

Antibiotic resistance is a global problem, and at least 50 percent of antibiotic use in American hospitals is inappropriate, experts say.

“What we know from study after study is that antibiotics are given when they are not needed or given for too long or in the wrong dose,” said Arjun Srinivasan, an epidemiologist heading the efforts at the CDC.

Unlike drugs prescribed in doctors’ offices, antibiotics given in hospitals are generally stronger, “cover more bugs” and, as a result, raise more concerns about resistance, said Sara Cosgrove, an infectious disease physician who heads the antibiotic use program at Johns Hopkins Medical Center.

“If we make bad decisions in the hospital, we can make bugs that no drug can treat,” she said.

Infection control has been a higher priority for hospitals in recent years, but only “minuscule effort” has been devoted to “wise antibiotic use,” she said.

Every time a person takes antibiotics, sensitive bacteria are killed, but resistant germs might be left to grow and multiply. Repeated and improper uses of antibiotics are the primary causes of the increase in drug-resistant bacteria, experts say.

If a microbe is resistant to many drugs, treating the infections it causes can become difficult or even impossible. Someone with an infection that is resistant to a certain medicine can pass that resistant infection to another person, spreading a hard-to-treat illness from person to person.

In outpatient settings, such as doctors’ offices, misuse typically occurs when patients mistakenly push for antibiotics when they have a cold or the flu, which are caused by viruses and cannot be treated with these drugs. Physicians too often end up prescribing them because “the prescriber is thinking, ‘I can take 20 minutes to explain this or I could just write this,’ ” Cosgrove said.

Research released last week shows a pattern of outpatient antibiotic overuse in parts of the United States, particularly in the Southeast, according to the Center for Disease Dynamics, Economics & Policy, a nonprofit organization in the District. The five states with the highest antibiotic use are West Virginia, Kentucky, Tennessee, Louisiana and Alabama. The findings are based on antibiotic sales data obtained from a consulting firm that tracks pharmaceutical sales.

Such information does not exist for hospitals.

The CDC is testing an antibiotic-use tracking system in 70 hospitals that are in the networks of health departments for Houston and for Illinois, Michigan and Utah. The system electronically extracts information from the hospital’s pharmacy database, allowing hospital officials to know what drugs are used, in what quantity and in what parts of the hospital, such as an emergency room or intensive care unit.

The goal is for thousands of hospitals to eventually use the same tracking system to monitor antibiotic use and for that information to be tracked by the CDC. Hospitals must already have in place a bar-coding system or other system that electronically documents the drugs they use.

In the past, hospitals had to extract information about antibiotics manually, a labor-intensive process.

“As a result, a lot of places didn’t do it,” Srinivasan said. “It’s difficult to make something better if you can’t measure it.”

The other CDC program is testing practical ways that hospitals can make sure the right antibiotics are being used. In collaboration with the Institute for Healthcare Improvement, experts have designed a playbook of practical steps that hospitals can follow.

They include strategies to ensure that proper antibiotics are identified at the outset, that patients receive them for the appropriate amount of time, and that critical antibiotic information is handed off between departments and shifts, said Diane Jacobsen, an epidemiologist who heads the antibiotic-use project at IHI.

Although some hospitals perform better than others, the pilot is trying to determine what interventions work the best across the board. The eight hospitals in the program range from a 69-bed facility in Alabama to large, urban academic medical centers, such as Ronald Reagan UCLA Medical Center in Los Angeles.