Increase in heterosexual transmission of HIV in international Pacific Northwest region (United States and Canada).

The rise in heterosexual syphilis transmission across North America has drawn attention to the risk of a comparable trend for HIV. After an increase in HIV diagnoses among individuals reporting only heterosexual contact in Washington state we coordinated with jurisdictions across the US-Canada border to analyze regional trends. In 2023, presumed heterosexual HIV diagnoses in the international Pacific Northwest increased by 70% vs. 2018-2023 with increases of 82% in Oregon and Washington.