About four years ago, the CDC launched a national program , which gave state health agencies an application that can transmit and receive epidemic data with federal agencies basic in near real-time. The data, which comes from larger hospitals, laboratories and other health data sources, is compiled by the CDC and offers states a big-picture view of where a potential epidemic may be spreading.

For example, if a number of people going to hospitals with flu-like symptoms -- or if there's a run on a particular type of medical test -- that data is reported through BioSense to the CDC from the state health agencies. The CDC then cross-references that information with data it receives from large national health care providers, pharmacies and other government agencies such as the U.S. Department of Veterans Affairs.

"They then overlay it in sophisticated ways in Atlanta along with views back to every state so they can go in and query it to see what's happening where they are," Damos said. But there is no precise data about individual patients and whether specific cases of Swine Flu have been confirmed. And out of the approximately 7,500 hospitals in the U.S., only several hundred are feeding into the CDC's BioSense health data network.

In 2004, federal officials rolled out the (NEDSS), which allows the exchange of specific, standards-based health data using secure Internet connections. The system data includes patient names, test results, diagnoses and treatments. To boost interoperability, NEDSS relies on standardized reporting templates that can be used with commercial software and minimizes proprietary data. Each state chooses the applications it uses to gather health care data so it can be collected in a central state-level database.

The electronic reports are far more accurate than the paper-based reports of earlier decades because of the standardization of data formats, Danos said. All states are moving toward the use a NEDSS-compliant system, according to Danos, but not all hospitals, medical laboratories or private physician practices are yet on board with the system. Just 16 states are currently live on the NEDSS reporting system.