HIV-1 seroprevalence in an inner-city public hospital.

In a hospital-based seroprevalence survey for human immunodeficiency virus type 1 (HIV-1) infection, a stratified sampling method based on age and gender was used to collect 5429 blood samples at an inner-city hospital. Sentinel Hospital Surveillance System (SHSS) criteria developed by the Centers for Disease Control and Prevention were used to classify patient diagnoses into two categories by the likelihood of being associated with HIV-1 infection. The two categories were those with high likelihood of association with HIV-1 (SHSS-ineligible) and those with low likelihood of association with HIV-1 infection (SHSS-eligible). Of the 5429 blood samples, 4262 were SHSS-eligible and 1167 were SHSS-ineligible. After personal identifies were removed, specimens were tested by ELISA and confirmed by Western blot analysis. The overall prevalence rate of HIV-1 infection was 0.98%. The seroprevalence rate was almost 2.6 times higher in high-association patients compared with low-association patients (1.89% versus 0.73%, P < .001). Results from this study indicate a high unsuspected HIV-1 seroprevalence rate in a subpopulation (SHSS-eligible) considered to have diagnoses with low likelihood of association with HIV-1 infection. These patients may better approximate HIV-1 seroprevalence in the general population of the area served by the hospital than would a sample of all patients. Monitoring HIV-1 seroprevalence in the SHSS-eligible group will be a useful measure for community serosurveillance for HIV-1 infection.