FORT WAYNE, Ind. — A public health emergency has been declared in Allen County, allowing officials to create a needle-exchange program to combat the spread of hepatitis C and HIV among drug users.

The Indiana State Department of Health on Thursday declared the emergency for the county that includes Fort Wayne. Allen County’s commissioners previously approved the needle exchange.

Needle exchanges provide clean syringes to intravenous drug users to prevent needle-sharing that spreads hepatitis C, HIV and other diseases. Similar public health emergencies already have been declared in seven other Indiana counties.

A law allowing counties to request approval for needle exchanges was approved last year in response to an HIV outbreak in Scott County, about 30 miles north of Louisville, Kentucky, that has been the worst such outbreak in state history.