Micro biologist Ayesha Khan works on research in a lab at the County of San Diego Health and Human Services in San Diego, California April 26, 2009. Governments around the world rushed on Sunday to check the spread of a new type of swine flu that has killed up to 81 people in Mexico and infected around a dozen in the United States
REUTERS/MikeBlake (UNITED STATES HEALTH SOCIETY SCI TECH ENVIRONMENT)