Clean Needle Use May Be Slowing Spread of AIDS
The alarming rate of AIDS virus infection among intravenous drug users in San Francisco, New York and several other cities appears to be stabilizing, according to surprising new findings that suggest that there may be hope of controlling the epidemic in that pivotal group.
Researchers said the findings, published in part today in the Journal of the American Medical Assn., suggest that it is possible to persuade drug users to use clean needles--and thus perhaps to slow the spread of AIDS among drug users, their sexual partners and their children.
Some experts, however, warned against misinterpreting the findings. The infection rate may be leveling off in those cities, but users are still becoming infected. Some already infected may be dropping out of the groups being studied, while new, uninfected users enter.
“It’s not that nobody’s getting infected anymore,” said Andrew Moss, a UC San Francisco epidemiologist studying intravenous drug users in that city. “It’s that a lot of people have cleaned up their act, and a smaller number of people are getting infected.”
The study published today by a team of prominent AIDS researchers, tracks the once-soaring rise in human immunodeficiency virus infection among drug users in Manhattan. It concludes that the infection rate has hovered for the last four years between 55% and 60%.
That apparent stabilization is in contrast to the pattern seen in the previous five years in the Manhattan study, which involved nearly 700 subjects. The rate of infection during that period leaped from 9% in 1978 to 38% in 1980 to 50% in 1983, the authors calculated based on analysis of stored blood samples.
The leveling off also defies traditional infectious disease patterns, in which the increase in the infection rate is highest after half the population becomes infected. This pattern has been evident in the case of hepatitis B, which is believed to infect 80% to 95% of New York intravenous drug users.
“It’s clearly encouraging in the sense that we haven’t seen the massive explosion continuing,” said Samuel Friedman, a researcher with Narcotic and Drug Research Inc., a nonprofit group affiliated with the New York State Division of Substance Abuse Services.
The researchers suggested that cities such as Los Angeles, with relatively low infection rates, could benefit by implementing aggressive AIDS prevention programs among drug users--similar to those that have been in place in San Francisco and New York for several years.
The study was headed by Don C. Des Jarlais, AIDS research coordinator in the state substance abuse services division. The other co-authors include researchers with three large New York City hospitals and the federal Centers for Disease Control.
Similar patterns of relatively stable rates of human immunodeficiency virus infection have also begun to emerge in San Francisco, Stockholm and Innsbruck, Austria, according to the Manhattan study and AIDS researchers in San Francisco.
John Watters, a UC San Francisco epidemiologist studying thousands of intravenous drug users on the street and entering drug abuse treatment, said in an interview that the rate of infection among heterosexual users appears to have remained steady at about 14% since early 1987. That rate had jumped from below 5% in 1983 to 10% in 1985, according to other studies.
Pioneer Programs
“I think it provides hope that you really can have an effect with this population,” Watters said. In particular, he pointed to pioneering AIDS-education and prevention programs begun in San Francisco in 1986 and targeted to intravenous drug users.
Watters and others nevertheless cautioned against excessive optimism.
“The fact that (the infection rate) is not going down, and there’s evidence that new infection continues right up to the present, is worrisome,” said Timothy J. Dondero of the Centers for Disease Control. “If it’s stable at a relatively high level, that’s pretty bad.”
The reasons for the apparent stabilization are not clear.
One contributing factor may lie in the way studies are designed, relying at least in part on drug users entering treatment programs. Some infected users drop out of the pool--because of illness, for example. Although they remain infected, they are no longer counted.
Meanwhile, new drug users are entering the pool. Chances are, they are not yet infected. They would tend to “dilute” the group being studied, helping stabilize the infection rate somewhere below 100% saturation.
Perhaps most significantly, the researchers believe that the leveling off reflects the fact that some drug users are using needles more safely than in the past--for example, not sharing needles with others and sterilizing their equipment with bleach before each use.
Researchers said it would behoove cities such as Los Angeles, where the virus arrived late among drug users and the infection rate is still low, to take advantage of the opportunity to avert a dramatic rise by setting up aggressive AIDS prevention programs.
“You’ve (Los Angeles) been lucky. It reached you late,” said Friedman. Pointing out that the infection rate in Bangkok, Thailand, jumped from 18% to 40% in 1988 alone, he added, “You’ve got a moment, maybe, where the dynamics are going in your favor.”
Efforts to educate the estimated 80,000 to 130,000 intravenous drug users in Los Angeles County about the risk of spreading infected blood in shared needles have been slowed by an official unwillingness to support programs believed to have worked in other cities.
Four of the five county supervisors voted last August to reject plans to distribute bleach kits and condoms to drug users, suggesting that such a practice would be immoral. The plan had the backing of the county Department of Health Services and the county Commission on AIDS.
Currently, 30 county-financed outreach workers are assigned to educate intravenous drug users about AIDS virus transmission and prevention. The county also has plans to increase human immunodeficiency virus testing for drug users in drug-abuse treatment programs.
Robert Frangenberg, director of the county AIDS program, said in an interview that he agrees with the Manhattan researchers’ statement in their study that Los Angeles and comparable cities may be facing a prime opportunity to avert a dramatic rise in infection.
“I think it’s a great preventive health opportunity,” Frangenberg said. “If we could distribute bleach and condoms and expand the number of people in the community providing (AIDS prevention) services, I think that could be helpful.”
Scientists have developed a molecular picture of an enzyme that the AIDS virus needs to grow. (Business, Page 4.)
