WASHINGTON (IPS)�Contrary to previous estimates, the amounts of antibiotics used in animal agriculture dwarf those used in human medicine, warns a new report by a public interest organization. The high quantities of antibiotics used in the rearing of pigs, cows and chickens is significant, says the Union of Concerned Scientists (UCS), because of the growing specter of antibiotic-resistant disease.

In order to maximize livestock industry profits, farm animals in the United States are routinely fed antibiotics to promote growth and prevent infections. This practice has medical experts concerned because the excessive use of antibiotics can breed strains of drug-resistant bacteria, which may infect people and be untreatable. In 1999, medical journals were filled with stories about diseases�like pneumonia, food poisoning and blood-borne infections that are increasingly difficult, if not impossible, to treat because of new antibiotic-resistant strains of diseases.

"The bottom line is that our data suggest that agricultural use of antibiotics is likely to be a larger part of the antibiotic-resistance problem than is currently thought,�� says Margaret Mellon, an author of the report and director of the UCS�s food and environment program. According to the 109-page report, 70 percent of total antibiotic production is devoted to non-therapeutic use, meaning growth promotion and disease prevention, in three livestock sectors.

The total use of antibiotics in healthy livestock�hogs, poultry and cattle�has climbed from 15.4 million lbs. in the mid-1980s to 24.2 million lbs, it says. By contrast, the report finds only less than 3 million lbs. of antibiotics are used in human medicine.

"Feeding antibiotics to animals from birth to slaughter may modestly improve meat industry profits, but it puts everyone�s health at risk,�� says Charles Benbrook, an economist who helped write the report.

The antibiotics of greatest concern from a resistance standpoint are those that are used in human medicine and those that are chemical relatives of those used in human medicine, says the report. Animal drugs chemically related to human drugs are important, the group explains, because micro-organisms often develop resistance to whole families of drugs.

Because of this concern, the European Union has prohibited the non- therapeutic use of anti-microbials in agriculture that are important in human medicine, such as penicillin, tetracycline, and streptogamin. Some individual European countries, like Sweden, which has banned the use of all antibiotics for growth promotion, have more strict regulations.

About 13.2 million lbs. of antibiotics used each year by U.S. livestock producers are the types of drugs that would be banned in Europe because they are used in human medicine, says the report.

The UCS devised a methodology for calculating antibiotic use in livestock operations from publicly available information, including herd size, approved drug lists and dosages.

Until now, the only available data on the amounts of antibiotics used on livestock was from the Animal Health Institute, a trade group representing drug makers. Last year, the industry group released a report saying that all antibiotics use in animals, both therapeutic and non-therapeutic, accounted for only 17.6 million lbs.

The institute also says that 32 million lbs. were used in people, a figure about 10 times higher than that calculated by the UCS.

The release of the report was timed to come before meetings held by the Food and Drug Administration from Jan. 22-24 to discuss antibiotic use in livestock. The federal agency recently took its first action to curb the use of antibiotics in livestock when it announced it would cancel its approvals of two drugs used for poultry.

The UCS report recommends that the government establish a system to compel companies that sell antibiotics for livestock use to provide annual reports on the quantity of these drugs sold.

"The government should act now to collect the needed data,�� says Ms. Mellon. "The price of complacency could set us back to an era where untreatable infectious diseases are regrettably commonplace.��