ONa narrow Road on the main centers for disease control and prevention (CDC) is Building 21, the crescent -shaped head office of the first American public health agency. In a room bordered by television screens, the researchers monitor the epidemic of measles which killed a second American in the southern plains last week and the epidemic of birds now ravaging herds in each state. The agency management occupies the 12th floor. Military quality security ensures that only authorized visitors and the CDCThe local workforce of around 5,000 civil servants has access.