Washington, April 25 (IANS): A county in the US state of Indiana has been hit with an HIV outbreak, with 142 people testing positive since late last year, health authorities said.

Urgent action is needed to prevent further spread of the virus in Indiana's Scott county, which has a total population of 4200 people, the US Centre for Disease Control and Prevention (CDC) said on Friday.

"New cases of HIV are still being identified every day," Indiana state health commissioner Jerome Adams said.

Health officials began investigating the outbreak in January, after Indiana disease intervention specialists reported 11 confirmed HIV cases which were from Scott county.

The majority of cases were in residents of the same county and were linked to syringe-sharing partners injecting the prescription opioid oxymorphone, a powerful oral semi-synthetic opioid analgesic, the CDC said.

A report released by the CDC called injection drug use in this county "a multi-generational activity" because as many as three generations of a family and multiple community members injected together.

The report also found that syringes and drug preparation equipment are frequently shared.

A CDC emergency response team including disease intervention specialists and epidemiologists has been sent to Scott county.