Fewer doctors are incorrectly prescribing antibiotics, but federal experts still say too many pediatricians uselessly prescribe the bacteria fighters against viral illnesses.

The U.S. Centers for Disease Control and Prevention found a 25 percent decline in how often doctors use antibiotics against sore throats, colds and upper respiratory infections -- common illnesses that are considered viral and therefore immune to an anti-bacterial threat.

Nearly 60 percent of antibiotics prescribed in office settings in 2007-08 were given to patients with viral maladies such as ear infections, bronchitis and other respiratory infections -- an "inappropriately high" rate, according to the federal agency.

"We still have a long way to go," said Dr. Lauri Hicks, a CDC epidemiologist who worked on the study, released earlier this month by the agency.

Unlike bacterial infections, viruses can't be fixed in the medicine-vaporizes-sickness sense. They leave a child's system to fight the infection on its own. Until the body nudges the virus out, doctors can only control symptoms with medicines such as acetaminophen or ibuprofen, upsetting parents looking for an easy cure.

"Parents are spending their time and money on a visit to the doctor, and we say, 'Go home, there's nothing we can do,'" said Dr. Matthew Good, a pediatrician at Highland Pediatrics in Hixson. "It's frustrating for everybody."

Since antibiotics are useless against viruses, Good said, parents should press pediatricians on "what they're prescribing and why they're prescribing it" when the bacteria/virus line appears to be blurry.

"If they're not giving you a good answer, question it some more," Good said.

More than $1 billion is spent annually on unnecessary antibiotics for adult upper respiratory infections, the CDC said. Incorrect prescriptions lead to longer-lasting illnesses since the antibiotics aren't working, leading to more doctor visits and more expensive medications, according to an agency fact sheet.

Most harmful bacteria are killed whenever someone takes antibiotics, but some germs survive and adapt against future antibiotic doses, making the drugs less effective against bacterial infections, according to the CDC.

Decreasing inappropriate antibiotic use is the best way to control overall resistance to treatment, the agency said.

According to a 2010 study by the nonprofit Henry J. Kaiser Family Foundation, Tennessee is the second most-medicated state, ranking behind West Virginia. Alabama, Kentucky and Arkansas completed the top five medicated states.