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With the recent outbreak of E.coli, physicians are reminded once again about the importance of disease surveillance and reporting. Without it, the outbreak would never have been uncovered and more sickness and possible death might have resulted.

As soon as E.coli was suspected, Dr. Tim Jones, deputy state epidemiologist with the Tennessee Department of Health, immediately issued a warning to Tennesseans not to eat fresh spinach or fresh spinach products.

"When you think that now there are cases of this E.coli in about 30 or 40 states, and the first state to report it only had three cases but had doctors on the ball who made a phone call, it's pretty miraculous how it all came together," Jones said. "When the CDC got that, they were able to link that strain with others and start tracking it across the country, all because of one initial phone call."

Tennessee healthcare workers discovered the state's first case of E.coli 0157:H7 last month when a Davidson County resident became ill on Sept. 10, just four days before the Sept. 14 national alert by the Food and Drug Administration advising people to avoid all fresh spinach or products with fresh spinach. Fortunately, the patient has fully recovered, and due to efficient state and national workers who did their job, as of Oct. 1, there have been no more cases in Tennessee.

Jones said outbreaks probably occur quite often, but unfortunately, his department only hears about 10 percent of the diseases legally reportable.

"Most reports come from labs. They're usually pretty good about reporting what they find," Jones said. "But doctors are notoriously poor about reporting. They don't have time, don't think about it and assume labs are doing it. We'd like to report physicians are reporting, but we're also realistic."

Because of advances in computerized collecting and the automated transporting of data and electronic imaging, laboratory findings such as the Escherichia coli O157:H7 are easily captured and transmitted to local health departments and then onto the state health department. In turn, state health departments transmit findings to the Centers for Disease Control and Prevention, which then locates the source of the outbreaks. Still, someone has to actually make the call that it should be reported.

CDC press officer Dave Daigle called the discovery of the recent E.coli outbreak an example of how well the reporting process does work.

"The detection of the recent E.coli outbreak showed a great success for our PulseNet, our system that sends a DNA fingerprint of disease from state labs to us here," Daigle said. "We saw a strain in Wisconsin and the same strain appeared from Washington, two different states with the identical strain, so we were able to identify and track it very quickly."

In recent years, Tennessee was selected to be one of 10 states to receive extra funding for the CDC Foodborne Diseases Active Surveillance Network (FoodNet) project, the principal foodborne disease component of CDC's Emerging Infections Program (EIP). FoodNet is a collaborative project of the CDC, ten EIP sites, the USDA and the FDA. Through it, state health department officials conduct active surveillance for the CDC by visiting every state lab in Tennessee.

Jones said, "It's a model program. A lot of what we know now about foodborne disease came from FoodNet. It's a gold standard by which we can do extra studies to fill those gaps. It's an early warning system, not perfect, but it works well."

Daigle said while there is a standard list of reportable diseases which can be found on CDC's Web site, each year the Council of State and Territorial Epidemiologists meets to review that list and decide what diseases should be on it.

"States can also add to that list if they choose," Daigle said. "The reporting procedures are state laws, not federal and while they are highly recommended, there is no enforcement."

The relatively new National Electronic Disease Surveillance System (NEDSS) and bioterrorism preparedness initiatives support integration of electronic data from various sources. But, while the electronic system is better than paper, the CDC has identified five challenges with automated reporting systems: sensitivity, specificity, completeness, coding standards, and end-user acceptance.

Sensitivity is often reduced in automated systems because of someone's failure to forward reports from the county of diagnosis to the county of residence, ongoing adjustments to the data extraction program, failure of data extraction at the clinical laboratory, difficulties deciphering reportable diseases from test results, and problems in the transmission of files by local health jurisdictions.

Specificity is also compromised. With automated reporting, there's an increase in both reportable and non reportable conditions, and negative reports, duplicate and false-positive reports are increased.

On some occasions, reports come in incomplete. Without all fields entered, there is lack of sufficient data needed by health departments.

Another challenge is data standards. Although both the Systemized Nomenclature of Medicine (SNOMED®) and Health Level Seven (HL7) standards have been adopted and are available, many labs use their own coding which makes that data arrive in multiple formats that are difficult to decipher.

In the end, it takes cooperation on the front lines where the determination is made if a disease meets the definitions for reportable and notifiable conditions and then someone actually does the reporting.

"We try to minimize the inconvenience for doctors to report, by letting them just pick up the phone and call us or have their nurse call," Jones said. "It's always hard to convince doctors seeing patients where public health fits and how it helps, rather than it just being something that gets in their way."



December 2006

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