Sherlock C H, Strathdee S A, Le T, Sutherland D, O'Shaughnessy M V, Schechter M T
Department of Pathology, University of British Columbia, Vancouver, Canada.
AIDS. 1995 Aug;9(8):945-50. doi: 10.1097/00002030-199508000-00017.
To conduct an anonymous HIV seroprevalence survey to establish a baseline estimate of HIV seroprevalence in a general population; to evaluate serum pooling and alternative testing strategies as cost-saving measures.
Prospective anonymous HIV seroprevalence study using outpatient laboratory specimens.
Two large non-hospital-associated outpatient chemistry testing laboratories in the major population centers in British Columbia, Canada. PATIENTS AND SERA: Leftover sera received for chemistry screen testing in outpatient laboratories were provided to the study after chemistry testing was completed. Those from patients aged < 15 and > or = 55 years were excluded.
Patient identifiers were erased from samples. Sera were pooled 10:1 and tested by viral lysate enzyme-linked immunosorbent assay (ELISA). Sera from HIV-positive pools were tested individually. All individual HIV-positive specimens were retested for verification of positivity using a recombinant protein ELISA.
HIV seroprevalence rates were stratified by sex, age group, and geographic area; and costs of pooling and alternative algorithm strategy were compared with those of conventional methods.
A total of 80,238 sera were collected from 66,658 individuals (53% women, 47% men). Of these, 276 men (88.3 per 10,000) and 24 women (6.8 per 10,000) were HIV-seropositive. The highest rates were in those aged 30-34 years, for both men and women. Using pooling and non-Western blot verification saved US$2.07 per specimen, or 80% of the cost for conventional testing.
The anonymous outpatient laboratory setting is practicable to obtain a reasonable estimate of HIV seroprevalence rates in a general population. Such studies can be made cost-effective by pooling sera and using alternative confirmatory strategies.
