Indiana Gov. Mike Pence authorized a short-term needle-exchange program and other steps Thursday to help contain the spread of HIV in a county tied to 79 new infections since January, all of them linked to intravenous drug use. 

Pence issued an executive order declaring a public health emergency in Scott County, about 30 miles north of Louisville, Kentucky. He ordered the state health department to set up a command center to coordinate HIV and substance-abuse treatment and establish a mobile unit to enroll people in a state-run health program.

Most of the infections involve people who shared a syringe while injecting a liquid form of the prescription painkiller Opana, according to state epidemiologist Pam Pontones.

Indiana law normally forbids needle-exchange programs, which allow people to turn in used hypodermic needles and get clean ones in an effort to keep diseases such as HIV and hepatitis from spreading. Pence says he opposes them as part of anti-drug policy.

But the governor said he agreed to a limited exchange in Scott County because of the emergency nature of the infections. He said the Centers for Disease Control and Prevention also recommended a needle-exchange program because all of the HIV cases have now been linked to IV drug use.

In addition, the state has launched a public-awareness campaign to focus on drug treatment, infection prevention, safe sex, needle disposal and HIV testing and treatment.

"This is all hands on deck. This is a very serious situation," Pence said Thursday at a news conference.

Pence's executive order will run for 30 days, at which time he will consider whether to extend it for another 30-day period.

All of those infected either live in Scott County or have ties to the county.

The number of cases tied to the county is up from 26 a month ago and is expected to continue to climb. Health officials said Wednesday that they were trying to contact as many as 100 people tied to those with confirmed infections of the virus that causes AIDS.

The county typically sees about five HIV cases each year, health officials said this week.