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. ... 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. Featured Video Gay and bisexual...