Dr. Isabelle Nuttall is a top

World Health Organization

official in Geneva. She says a lot of progress has been made... in preparing for another epidemic, but not nearly enough, despite commitments to be ready for a serious outbreak by 2012.

"Countries committed to work to implement surveillance systems, to be able to have good laboratories in place, to be able to report and inform their population, containment measures if need be, to be able to stop the spread of diseases," said Nuttall. "I do realize it’s a lot of work but we are not there yet.”

Outbreaks are common around the world. Dr. De Cock at the CDC says people should be vigilant, but not unduly worried, and he points to H5N1 virus, or avian influenza, as an example. “It seems not to be transmissible from person to person; nonetheless, infectious diseases can change in their epidemiology," he explained.

Earlier this year, an outbreak of influenza in Mexico prompted people to line up en masse to get vaccinated. Ninety percent of the reported 1,600 cases of flu were from the H1N1 strain, which has also been on the upsurge in northwestern India.

WHO has set up the

Global Outbreak Alert and Response Network