Trends in human immunodeficiency virus diagnoses among women in the United States, 1994-1998.

OBJECTIVE: Since the introduction of combination antiretroviral therapy in 1996, acquired immune deficiency syndrome (AIDS) data no longer provide information about trends in human immunodeficiency virus (HIV) incidence; therefore, we used HIV surveillance data to describe recent trends in HIV diagnoses among women.
METHODS: Using HIV cases reported from 25 states with confidential HIV reporting, we examined new HIV diagnoses from 1994 to 1998 among women born between 1950 and 1979 by five-year birth cohorts. We adjusted for reporting delays and anticipated reclassification of cases reported without exposure risk.
RESULTS: During the period, 24 171 cases of HIV infection were diagnosed among women. The annual number increased 4% from 1994 to 1995, then declined 12% from 1995 to 1998. The annual number of diagnoses attributed to heterosexual contact (HC) among women age 15 to 19 in 1994 (born 1975-1979) increased 117% from 1994 to 1998. Among older women, HC-related diagnoses remained stable or declined. The annual number of diagnoses attributed to injection drug use (IDU) among women age 15 to 19 in 1994 increased 90% from 1994 to 1998. The number of IDU-related diagnoses among older women declined between 31% and 59%. Diagnosis rates were higher among HC-related cases than among IDU cases. The rate for IDU-related diagnoses declined by nearly half over the period, but remained stable for HC-related diagnoses.
CONCLUSIONS: HIV diagnoses among women decreased slightly between 1994 and 1998. As the youngest cohort of women reached the age where risk behaviors are initiated, however, the number of diagnoses attributed to IDU increased and the number of diagnoses attributed to HC more than doubled. It is in this youngest cohort, where risk behaviors have only recently been initiated, that HIV diagnoses most closely approximate trends in HIV incidence.