The July 1 editorial "How to Spread HIV in D.C." supported needle-exchange programs. The rationale for these programs is attractively simple: Exchange used needles and syringes for clean ones, use a clean set for each injection, and never share your materials.

A search of the published literature from 1994 to the present through the National Library of Medicine's medline cites more than 200 articles on needle exchange. Only a few report data derived from epidemiologically sound studies that could serve as a basis for conclusions on the efficacy of these programs. None provides data clearly supporting the effectiveness of needle exchange in reducing HIV transmission among those injecting drugs.

The data from four studies, however, strongly indicate that needle exchange is ineffective in reducing HIV transmission among study participants. Three of these studies were published in the American Journal of Epidemiology and the fourth in the journal AIDS.

All were conducted among large populations of injecting drug users involved with well-established needle-exchange programs -- one in Amsterdam, one in Montreal, one in Vancouver and one in Seattle. The last study was directed at hepatitis B and C virus transmission, where the authors found the incidence of both types of hepatitis to be highest among users of needle exchanges.

The authors suggested that the substantial reduction in risk behavior necessary to reduce HIV transmission in their study population had not been achieved, though HIV was not included in their study.

Although the reasons for failure in these studies are not clear, a major reason is probably that success depends on a sustained level of rational behavior among participants whose behavior is too often irrational.

In view of the evidence indicating that needle-exchange programs are ineffective, resources required for their operation could be better used supporting standard public health measures that have been missing in the District's battle against HIV.

FRED J. PAYNE

Medical Adviser

Children's AIDS Fund

Washington