The Center for Disease Control and Prevention (CDC) has released a report stating two million Americans become ill from antibiotic-resistant bacteria per year, the New York Times reported.

Of those two million people, 23,000 per year die from such illnesses. It is the first report that gives a quantitative value on diseases that resist drugs designed to fight those illnesses.

Before the report, many were left to guesstimate, which were often higher than what the CDC actually found. In their report, the CDC researchers removed cases in which a drug-resistant disease was present, but not the explicit cause of death.

"They have come up with hard numbers where it has been only guesswork," said Dr. Stuart B. Levy, a microbiology professor at Tufts University and Alliance for the Prudent Use of Antibiotics president. "This sets a baseline we can all believe in."

The CDC estimated in 2007 that 100,000 people per year died annually from infections they picked up at hospitals. At the time, researchers believed these infections were resistant to some antibiotics, but not necessarily the most widely used ones. The report released Monday puts a solid number to what officials previously had to estimate.

"This is a floor," said Dr. Steven Solomon, director of the CDC's office of antimicrobial resistance. "We wanted the cleanest number, the least subjective number."

Dr. Stevenson said it was intended for the researchers to be conservative in quantifying the amount of deaths directly caused by drug-resistant diseases. This way, he said, the calculations could be most objective.

Around 70 percent of U.S. antibiotics are used on farms to speed the growth of farm animals, the San Francisco Chronicle reported. The antibiotics are used to prevent diseases among the animals raised in feedlots. This creates an ideal environment for the infection microbes to build up a resistance to the antibiotics.

But the Animal Health Institute, a lobbying organization that defends pharmaceutical companies, disputed the findings.

"Of the 18 specific antibiotic-resistant threats discussed in the report, only two have possible connections to antibiotic use in food animals," it said in a statement.

CDC director Thomas Frieden said it is a rapidly growing problem because while patients demand drugs to cure their illness, but most of those antibiotics are ultimately useless.

"Widespread use of antibiotics in agriculture has resulted in increased resistance in infections in humans," Frieden said. "Patients demand antibiotics and feel their doctor has not done an adequate job if they don't get a prescription."