Researchers surfing the Internet for AIDS statistics today will be presented with conflicting pictures of the epidemic in Chicago. That’s because the two agencies responsible for tracking epidemiological data in Chicago–”the Illinois Department of Public Health and the Chicago Department of Public Health–”report numbers on their Web sites that differ by as many as 640 cases each year since 2000.

In 2005, the latest year for which nonprovisional AIDS data are available, the Chicago health department reports 878 diagnosed cases in Chicago, while the Illinois health department records 801 reported cases. The biggest disparity was logged for 2002, when the Chicago health department reported 1,040 diagnoses, compared to the Illinois health department’s 1,680 reports.

One reason for the disparities might be how and how often the two agencies’ Web sites are updated.

Nanette Benbow, director of surveillance at the Chicago health department, said her agency updates its Web statistics about twice a year, though it receives new data on a daily basis.

The Illinois health department, meanwhile, receives up-to-date surveillance data from the Chicago health department on a biweekly basis. But its data prior to 2005 haven’t been updated on its site “in quite some time,” said Melaney Arnold, Illinois health department’s communications manager.

“The department is in the process of creating new material that will replace existing Web information,” Arnold said. “The data is constantly changing–”even data that is 10 years old changes. When we run a report, however, we make sure to use the most up-to-date data. We are just unable to get the updated information on the Web site at this time, but we’re working on it.”

John Peller, director of government relations at the AIDS Foundation of Chicago, said the Illinois health department’s failure to post up-to-date AIDS data is simply a question of resources.

“The [Illinois health department] doesn’t have the resources to provide the kind of public information on HIV and AIDS that would give service providers and the media and members of the general public accurate statistics on the HIV and AIDS epidemic in Illinois,” he said.

Peller also emphasized the importance of keeping accurate data–”whether on Web sites or in published reports–” noting that the U.S. Centers for Disease Control and Prevention and other agencies allocate HIV and AIDS funding based on surveillance data. Out-of-date statistics could mean the funding doesn’t get distributed where the needs are.

“The bottom line for us is that the HIV and AIDS statistics that are reported tie directly to funding,” he said. “It is absolutely essential that we have in place –¦ the best surveillance in the country, and that includes the ability to provide timely and complete reports to the community.”