There may be as many as 300,000 new cases of drug-resistant tuberculosis a year in the world, and 79 percent of them are "superstrains," resistant to any three of the four first-line drugs, a World Health Organization survey has found. Patients in the former Soviet bloc countries are 10 times as likely to have drug-resistant strains as those elsewhere in the world, the survey said. The researchers said the drug-resistance problem might be much bigger than they could measure, particularly in countries like India and China, where they had surveyed only a few areas, and in Bangladesh, Indonesia, Nigeria and...