The Centers for Disease Control and Prevention on Monday announced a new surveillance system to better track HIV infections, scrapping an existing method that doesn't indicate how recently patients were infected. The new system no longer relies on AIDS case data submitted by state health departments--half of which don't report those cases because of privacy laws--but on anonymous data from 35 sites around the country to create a nationally representative snapshot of new infections, CDC researchers said. Federal health officials also will now use two antibody tests that indicate whether a patient had been infected in the last six months. With some HIV-positive people living for more than a decade without developing AIDS, the old tracking method did not reflect recent HIV infection trends.
"The new system applies this technology and allows us to distinguish a new infection from an old infection," said Ronald Valdiserri, deputy director of the CDC's National Center for HIV, STD, and TB Prevention. "It gets at the question everyone wants answered, which is how many new cases of HIV are occurring."
The new reporting system will provide statistics from areas that represent 93% of the country's HIV population, according to Robert Janssen, director of the CDC's HIV and AIDS Prevention division. To help collect the data, the CDC will send a total of $13 million to states participating in the program.
CDC officials say the new set of antibody tests is about 95% accurate. "It relies on the fact human beings go through a fairly predictable process of antibody development" after infection by HIV, Valdiserri said. "Early on in the infection, you don't have too many antibodies to HIV. Over time, the longer you're infected, the more antibodies you're able to produce."
By knowing where recent HIV infections are, health officials can shift resources to tackle the new cases. The government has been trying to cut new HIV cases--currently about 40,000 a year--in half.