A Seattle judge has ordered an HIV-positive man to stop spreading the disease and to seek treatment after he infected eight people in four years.
The man, known only as "AO" in court documents, is required to show up for counselling and to protect future sexual partners. Officials maintain they are not trying to criminalise sexual activity but to protect public health.
The man could face fines or jail time if he does not comply.
About 50,000 people in the US are newly infected with HIV every year, according to the Centers for Disease Control and Prevention (CDC). About 16% of the 1.1 million people living with the virus do not know they are infected.
AO tested positive for HIV in 2008 and spread the virus to at least eight people in 2010-14, according to court documents viewed by local news media.
He had done so despite receiving HIV counselling - including how to practise safe sex - five times, the Seattle Times reports.
In a statement, the King County Public Health department said it had only sought a cease-and-desist order against an HIV-positive individual once before, in 1993.
"We're not trying to criminalise sexual behaviour here," Dr Matthew Golden, director of public health at the county's HIV programme, told the Seattle Times.
"We are trying to protect the public's health. And we're trying to make sure that everyone gets the care they need, including the person involved in this."