Targeting hospital screening for HIV.

An estimated 1 million persons living in the United States today have already been infected with the AIDS-causing human immunodeficiency virus (HIV). Though an estimated one-fifth of them entered a hospital in 1990, most of those patients probably did not know about their HIV infection, suggests a new study by the Centers for Disease Control (CDC) in Atlanta.

If U.S. hospitals in the most AIDS-prone communities were to offer voluntary and confidential HIV screening and counseling to all patients age 15 to 54, in just one year they might identify up to 110,000 persons who unknowingly harbor HIV, the CDC study indicates. Indeed, the investigators conclude, this approach might steer many newly infected and still asymptomatic people into treatment, prolonging their lives and helping to limit the spread of the virus.

Though many researchers have recommended that hospitals test or offer HIV testing to all patients, such screening is expensive and money for testing and counseling remains tight, notes Robert S. Janssen, who led the new study. He and his co-workers sought a cost-effective way to identify people with HIV infection.

In their study, they conducted HIV assays on 196,000 anonymous but systematically collected blood samples - essentially leftovers of samples obtained for other purposes. Participating hospitals identified each sample only by the unsuspecting donor's age, sex, ethnic background, medical condition, and in-patient or outpatient status.

"Two-thirds of the HIV-positive patients in the 20 hospitals studied [entered] with conditions other than symptomatic HIV infection or AIDS," Janssen and his co-workers report in the Aug. 13 NEW ENGLAND JOURNAL OF MEDICINE. Though HIV showed up in every medical category from psychiatry and violent assault to obstetrics and gynecology, age proved a strong discriminator. Patients 15 to 54 years old constituted half of those hospitalized, but represented 82 percent of HIV-infected individuals entering with conditions other than those characteristic of AIDS or HIV infection.

Most important, Janssen believes, was the study's "identification that the AIDS diagnosis rate for a hospital can serve as a surrogate marker" for HIV-infection rates, which vary widely by region. Hospitals don't compile AIDS diagnosis rates today, he says. But doing so would cost nothing - and would "probably take only 5 minutes" using hospitals' own annual tallies of discharged patients and local health departments' tallies of AIDS diagnoses attributed to each institution, Janssen contends.

The study indicates that hospitals with one or more newly diagnosed cases of AIDS per 1,000 discharges probably have enough patients with undiagnosed HIV infection to warrant screening.

Thomas C. Quinn of the Johns Hopkins University School of Medicine in Baltimore says the CDC report makes a persuasive argument for targeted, voluntary HIV screening. However, he asks, "Who's going to pay for it?"