Scott County, a poor area where needle-sharing by drug users is common, has seen 79 new cases in recent weeks, up from an annual average of five.
The US state of Indiana has declared a medical emergency following an HIV outbreak which "reached epidemic proportions" in part of the state.
According to BBC, Scott County, a poor area where needle-sharing by drug users is common, has seen 79 new cases in recent weeks, up from an annual average of five and 26 cases just one month ago.
The outbreak which was first identified in late January has seen state governor, Mike Pence authorising health officials to implement a needle exchange programme, a remedy he has opposed in the past.
"With additional state resources and new tools provided by this emergency declaration, I am confident that together we will stop this HIV outbreak in its tracks."
State epidemiologist Pam Pontones said almost all of the cases originated from illegal drug users sharing syringes.
A large majority of the victims had shared a needle with an infected person while injecting Opana, a prescription painkiller.
The number of infections are expected to rise, and officials are working to contact as many as 100 other people linked to those with confirmed cases.
The order will authorise local health officials to create a temporary needle exchange programme under the supervision of the state health agency.