Human immunodeficiency virus seroprevalence in community-based primary care practices, 1990-1992. A report from the Ambulatory Sentinel Practice Network
R. S. Miller, L. A. Green, P. A. Nutting, L. Petersen, L. Stewart, G. Marshall and D. S. Main
Ambulatory Sentinel Practice Network, Denver, USA.
OBJECTIVE: To estimate the seroprevalence of human immunodeficiency virus
type 1 (HIV-1) infection in primary care practices. METHODS: Fifty-four
practices in the United States participated in an anonymous, unlinked HIV
seroprevalence study between January 1990 and December 1992. Residual blood
samples drawn for routine clinical tests from patients 15 to 49 years of
age were centrally tested for the HIV-1 antibody for 1 month of each
quarter. Information about patient demographics, clinician-recognized risk
factors, the known HIV status of the patient, and whether the blood was
drawn for HIV testing was recorded with each specimen. RESULTS: Of 21,998
specimens collected, 99 (0.45%) were seropositive. Of these 99 seropositive
persons, 31.3% (a seroprevalence of 0.15%) were not suspected by their
clinicians of being infected with HIV. Seroprevalences in men (0.96%)
exceeded those in women (0.22%), and rates in rural practices (0.18%) were
lower than in urban practices (0.71%). Among patients with unsuspected HIV
infection, however, the gender differences, especially in rural areas, were
less pronounced. Risk factors for HIV infection were infrequently noted.
There was an increase in the overall seroprevalence during the 1990 to 1992
study period (0.36% to 0.53%); however, this trend was not statistically
significant. CONCLUSIONS: Within a 3-year period, clinicians in at least
two of five primary care practices can expect to encounter patients
infected with HIV, regardless of practice location. Also, nearly one third
of the patients with HIV infection will not be suspected of having this
condition by their clinician.
