US and Canadian doctors are estimated to overprescribe antibiotics by 50 percent, the WHO report said. Impoverished developing countries have the opposite problem. Many patients can't afford the full course needed to cure an infection. Antibiotics may be sold at market stalls where people buy a few doses without a doctor's exam. In Vietnam in 1997, researchers found more than 70 percent of patients were prescribed inadequate doses to cure serious infections.
Animals add to the problem.
Half the world's antibiotics are used on the farm, sometimes to treat illness but mostly to help healthy animals grow bigger. That encourages drug-resistant germs that cause food poisoning, WHO said. Poor nations can't afford more expensive alternatives and, to make matters worse, untreated gonorrhea is fueling spread of the AIDS virus. In Estonia, Latvia, and parts of Russia and China, more than 10 percent of tuberculosis patients have strains resistant to two powerful medicines. Overall, up to 2 percent of the world's 16 million TB sufferers have multi-drug resistant strains, particularly frightening because TB is airborne, spread when people cough.