A Publication from The Kaiser Forums; Sponsored by The Henry J. Kaiser Family Foundation
Edited by: Jeff Stryker, Center for AIDS Prevention Studies University of California-San Francisco; Mark Smith, M.D., M.B.A. -

HIV is only the latest concern in this regard. More than half a century ago, a winter outbreak of malaria was reported in Chicago, Ill., New York, N.Y., St. Paul, Minn., and San Francisco, Calif., despite the absence of the probable vector--mosquitoes. Officials discovered that drug users infected with malaria parasites had spread the disease by sharing contaminated needles. The next summer, the general population also suffered when mosquitoes bit malaria-infected drug users and transmitted the infection.10

HIV poses a risk beyond drug injectors. Sharing contaminated injection equipment threatens not only the sharers but also their sexual partners, their offspring, and successive ranks of sexual partners. The consensus is that the greatest danger for the self-sustaining spread of HIV infection outside of the groups currently at high risk comes from the reservoir of infection among injection drug users.11

Needle-Sharing Dynamics

There are numerous reasons why users inject drugs that can be smoked or snorted. Injection is more economical, as it requires less of the drug to achieve the same high. More immediate relief from withdrawal symptoms may be gained by injection.12

Drug injection can be an adaptation to a situation in which the only drugs available are of inconsistent, low, or unknown purity. Previously, heroin was the drug of choice among injectors; today, a variety of other drugs--such as cocaine and amphetamines--are injected, sometimes in combination with heroin. Injection is also a social phenomenon. Virtually all injectors are initiated into the practice by friends, lovers, or dealers who not only supply the drug but also provide equipment and guidance for its use.13 Studies have shown that new users average ten to twenty injections before they obtain their own equipment.14

The social bond forged during initiation into drug injection is an important aspect of needle sharing. Refusing to share with someone with whom the user has shared previously may signal mistrust or suspicion. If groups of needle sharers were insular, they might afford protection against the spread of infection. Unfortunately, there is enough sharing among the groups to promote the spread of infection. The overwhelming majority of injection drug users share equipment at some point. Needle sharing does not appear to be confined to drug users of a particular background, class, or personality type,15 and needle sharing habits may vary among regions of the country. There has been some disagreement about whether sharing occurs more frequently among black and Hispanic users. Injection practices--for example, injecting into the muscle or under the skin rather than intravenously--vary considerably among subcultures of drug users and among users of different drugs. Successive use of the same set of injection equipment by multiple users may not be viewed as sharing, because those who share the equipment may never even meet each other. Users who do not share injection equipment may nevertheless risk contamination by mixing and sharing drugs in a process known as "frontloading."16

Various phenomena encourage the use and sharing of contaminated injection equipment. In New York City and other large cities, "shooting galleries" provide a haven for drug use. Drug users may be reluctant to carry injection equipment when they are near shooting galleries or on their way from purchasing drugs, as this is when they are most likely to be arrested.12 Drug dealers may rent needles and syringes for their customers' use. In such cases, one set may be reused scores of times, with only a perfunctory rinse between injections. The cost and scarcity of sterile needles and syringes also are reasons for sharing.
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