WASHINGTON — In 1988, arch-conservative Senator Jesse Helms successfully pushed Congress to prohibit federal dollars from being used to distribute sterile syringes to intravenous drug users, equating an effort meant to slow the spread of AIDS and other diseases to federal endorsement of drug abuse.

Mr. Helms, a North Carolina Republican, fretted that the ban would not last since it could be lifted if the surgeon general certified that needle exchanges were effective. He need not have worried. Despite ample health research showing that such programs can reduce the spread of disease, the ban on federal funding of needle exchanges has remained intact except for some easing when Democrats controlled the budget process for 2010 and 2011.

Now, with a severe outbreak of H.I.V. and hepatitis due to a surge in heroin use in states including Indiana, Kentucky and West Virginia, the question of whether to let federal money support needle exchanges is back. Still, in contrast to a new willingness by state politicians to accept needle exchanges, Congress appears unlikely to overturn the moratorium even with drug problems hitting hard in states represented by those responsible for the spending bills that impose the ban.

Representative Harold Rogers, the Republican who is chairman of the House Appropriations Committee, has seen drug addiction spread in his rural district in southeastern Kentucky, leading him to direct money home for both treatment and law enforcement. But a spokeswoman says he remains opposed to needle exchanges, which he considers a matter of local discretion.