Health officials, worried about outbreak, investigate HIV cluster in North Seattle

 This microscope image from the Centers for Disease Control and Prevention shows HIV particles. (Cynthia Goldsmith / AP)

This microscope image from the Centers for Disease Control and Prevention shows HIV particles. (Cynthia Goldsmith / AP)

The diagnoses are among 19 HIV cases reported so far this year among heterosexuals in King County. For all of last year, that number was seven, according to the health agency.

A cluster of eight people in North Seattle, described as heterosexuals, drug users, and recently homeless, have been diagnosed with HIV infections since February, and health officials worry their cases could represent a new pattern of transmission for the virus that has been in steep decline.

Officials suspect changes in drug use are to blame.

“There could be a large outbreak potentially,” said Dr. Jeff Duchin, health officer for Public Health – Seattle & King County. “There may be a large number of people vulnerable to new HIV infections which would be a very big problem.”

The diagnoses are among 19 HIV cases reported so far this year among heterosexuals in King County. For all of last year, that number was seven, according to the health agency. It has averaged 10 for the past decade.

Gay and bisexual men are most at risk to contract HIV in Washington state. Statewide, 461 cases were diagnosed each year from 2012-2016, on average, according to state Department of Health statistics. Of those cases, an average of 290 each year were among gay and bisexual men.

The recent Seattle cluster is a departure from the typical pattern of infection, and particularly concerning because it involves homeless people who might not have access to health care or might be missed by HIV-prevention services.