State health leaders say a fast-spreading outbreak of HIV cases has hit the southeastern part of the state and is tied largely to drug abuse involving a powerful painkiller. The State Department of Health says more than two dozen people have tested positive for the virus that causes AIDS since mid-December and another four have preliminary HIV-positive status. Most of the cases are linked to people injecting the prescription painkiller Opana, while a small number are tied to sexual transmission of the virus. Disease specialists are now interviewing those infected about their needle-sharing habits and sex partners. Health officials also are working to identify, contact and test individuals who may have been exposed.