Senior microbiologist for the County of San Diego Health and Human Services Agency Anna Liza Manlutac (L) and microbiologist Ayesha Khan work in a lab at the country health lab 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/Mike Blake (UNITED STATES ENVIRONMENT HEALTH SOCIETY SCI TECH)
REUTERS/MIKE BLAKE