Indiana Gov. Mike Pence (R) this week declared a public health emergency for Scott County, a rural part of the state that has seen an alarming number of new HIV cases in the past few months, all of which have been among injection drug users.

Calling this an epidemic and a “crisis of drug abuse,” Pence—who has vehemently opposed needle exchange programs in the past—issued a temporary order allowing health officials in the county to hand out clean needles for at least the next 30 days.

There have been 79 confirmed HIV diagnoses since December, and others are under investigation. Scott County, in a typical year, would see about five new HIV cases. The outbreak appears to have begun with people who shared needles to inject Opana, a type of oxymorphone that is only available by prescription.

It is prescribed less frequently than other similar pain medications like OxyContin because it is so strong. Some of those infected also report injecting other drugs, including methamphetamine.

Scott County is a rural area close to the Kentucky border with about 24,000 residents, 19 percent of whom live below the poverty line. County officials told Business Insider that they have fought narcotics use in the area for years and that addiction to prescription drugs has been the main issue.

Using an unclean needle is considered one of the most efficient ways to transmit HIV. Research has estimated, for example, that for every 10,000 times a woman has penile-vaginal intercourse with an infected male partner, four would likely end up with HIV transmission. In contrast, for every 10,000 times an uninfected person shares needles with an infected person, 63 would likely end up in HIV transmission.

Sharing dirty needles is not the only way injection drug users can transmit HIV—it can also happen by sharing water to clean needles and syringes, sharing bottle caps or spoons used to heat drugs and dissolve them in water, and sharing filters (such as cotton balls) to filter out particles before injecting drugs.

Whether or not a person becomes infected depends in large part on the quantity of blood to which they are exposed, and the viral load of the person with whom they are sharing (the more blood and the more virus in the blood, the higher the chance of transmission).

This is why many public health organizations support programs that make clean needles available for drug users. A position paper signed by numerous organizations—including AIDS United, amFAR, and the Human Rights Campaign—argued for such programs:

Infected needles result in 3,000-5,000 transmissions of HIV each year and an estimated 10,000 transmissions of the hepatitis C virus. Syringe Exchange Programs (SEPs) are a proven cost-effective approach for preventing transmission of HIV and viral hepatitis among injection drug users, reducing risk of “accidental pricks” to sanitation workers and police, and engaging injection drug users in substance abuse treatment programs.

SEPs are controversial, as some people fear that providing needles will encourage drug use and send the wrong message to the community. A federal law prevents the government from funding such programs and about half of the states, including Indiana, have banned such programs.

Pence has supported his state’s ban on needle exchange, saying that SEPs are not good anti-drug policy.

In the midst of a clear public health crisis, however, Pence is putting this view aside for now. Pence said that after meeting with federal advisers, he has decided to make an exception for Scott County.

“I’m going to put the lives of the people of Indiana first,” he said.

State officials are setting up a mobile command center in Scott County, and experts from the U.S. Centers for Disease Control and Prevention (CDC) have been in the area since Monday.

“I have deep compassion for people who are trapped by this addiction and we want to make sure people know they’re no alone,” Pence said in an interview, according to The New York Times. “There is help, there is treatment, and we’re surging into the county now to make that available.”