The HIV-1 seroprevalence rate of injured patients admitted through California emergency departments. California HIV-1 Emergency Department Seroprevalence Study Group.

STUDY OBJECTIVES

To measure the HIV seroprevalence of injured emergency department patients in a number of California hospitals and to examine the relationship between ED seroprevalence and local AIDS incidence.

DESIGN

Prospective blinded testing for HIV-1 antibody was performed on routinely collected blood samples.

SETTING

Ten California hospitals; group 1 included three hospitals from counties of high AIDS incidence (more than 40 cases per 100,000 population), group 2 included three hospitals from counties of intermediate AIDS incidence (20 to 40 cases per 100,000 population); and group 3 included four hospitals from counties of low AIDS incidence (less than 20 cases per 100,000 population).

TYPE OF PARTICIPANTS

Eligible patients were all adult trauma victims admitted to a participating hospital through the ED during a consecutive three-month period occurring between June and November 1989.

MEASUREMENTS

HIV-1 antibody testing was done using enzyme immunoassay confirmed by immunofluorescence assay. Equivocal results were confirmed by Western blot. Mann-Whitney U test, chi 2 test, and multiple logistic regression were used where appropriate.

RESULTS

There were 2,264 patients with adequate blood samples for serologic testing. The seroprevalence rates for hospitals in groups 1, 2, and 3 were significantly different (chi 2 = 8.44, P = .02): Group 1, 2.5% (19 of 756: 95% confidence interval [CI], 1.5% to 3.9%); group 2, 0.9% (10 of 1,078; CI, 0.5% to 1.7%); and group 3, 0.5% (two of 430; CI, 0.06% to 1.7%).

CONCLUSION

This study suggests that local AIDS incidence rates do not necessarily predict the seroprevalence rates of injured patients who are admitted through local EDs.