Faculty Bibliography

Blood specimens from 165 intravenous drug users who were seropositive for the human immunodeficiency virus (HIV), from 158 seropositive homosexual men with lymphadenopathy, and from 77 patients with acquired immunodeficiency syndrome (AIDS) were assessed immunologically. Immunologic parameters were analyzed by the Guttman scalogram technique to determine if immunologic abnormalities occurred in a nonrandom pattern. The following four patterns emerged: (i) seropositivity for HIV with no immunologic abnormalities; (ii) seropositivity for HIV with a depressed T4/T8 cell ratio; (iii) seropositivity with a depressed T4/T8 cell ratio and T4-cell depletion; and (iv) seropositivity with a depressed T4/T8 cell ratio, T4-cell depletion, and lymphopenia. Ninety-two to 100% of subjects in each of the three groups of patients were found \'to scale\' because the abnormalities occurred in the cumulative, ordered fashion described. This nonrandom occurrence of abnormalities indicates an ordered progression of immunologic abnormalities in individuals infected with HIV, a finding useful in the staging of both symptomatic and asymptomatic HIV-seropositive subjects.

A cohort of 334 intravenous (IV) drug users from New York City drug treatment programs were followed over a mean 9-month period. Among the 165 who were seropositive at enlistment, four developed clinical AIDS, for an annual rate of 3%. Elevated IgA was a significant predictor of developing AIDS. Among 72 subjects who were initially seronegative and who were re-interviewed, four were seropositive at follow-up, for a seroconversion rate of 7% per year among seronegatives. Among seropositive subjects who did not develop AIDS or fatal AIDS related complex (ARC), continued drug injection was associated with rate of T4 cell loss, and there was a non-significant trend for males to lose T4 cells more rapidly than females. While it was not possible to distinguish the mechanism underlying the relationship between continued drug injection and T4 cell loss, seropositive IV drug users should be warned that continued injection may lead to increased HIV-related immunosuppression as well as, if injection equipment is shared, risking viral transmission to others

Research on the epidemiology of HIV infection among IV drug users is still at a relatively early stage. Multilocation studies that would permit better geographic comparisons are greatly needed. Multi-method studies within single geographic areas are also needed to assess possible biases with respect to sample recruitment and data collection procedures. The continuation of the epidemic provides a changing historical context that complicates any comparisons. Despite these problems, there are some consistencies that can be seen across studies. Studies of HIV seroprevalence among IV drug users show wide variation among cities in the United States and Europe. The time that the virus was introduced into the IV drug using group within the city is one factor in explaining these differences; other cross-city factors have yet to be identified. Once HIV has been introduced into the IV drug use group within a particular geographic area, there is the possibility of rapid spread up to seroprevalence levels of 50% or greater. Thus, a currently low seroprevalence rate should not be seen as a stable situation. Frequency of injection and sharing of equipment with multiple other drug users (particularly at shooting galleries) have been frequently associated with HIV exposure. Being female, ethnicity (in the USA) and engaging in prostitution also may be associated with increased risk for HIV exposure, suggesting that prevention programs should include special consideration of sex and ethnic differences. Studies of AIDS risk reduction show that substantial proportions of IV drug users are changing their behavior to avoid exposure to HIV. This risk reduction is probably more advanced in New York, with its high seroprevalence and incidence of cases, but is also occurring in cities with lower seroprevalence and limited numbers of cases. The primary forms of risk reduction are increasing the use of sterile equipment, reducing the number of needle sharing partners, and reducing the frequency of injection. These behavior changes are very similar to the frequently identified behavioral risk factors associated with HIV exposure, suggesting that they should be effective in at least slowing the spread of HIV among IV drug users. No linkage of risk reduction to decreases in seroconversion has yet been shown, however, and greater risk reduction is clearly required. A variety of prevention strategies will probably be needed to reduce the spread of HIV among IV drug users. Prevention of initiation into drug injection is an undeniable long-term goal for the control of HIV infection, but there is very little research being conducted in this area.

We report here the results of a survey of 308 intravenous drug abusers recruited from hospital-based methadone maintenance or drug detoxification programmes located in Manhattan, New York City. Complete interviews and serological analyses for antibodies to human immunodeficiency virus (HIV) using both enzyme-linked immunosorbent and Western blot assays were obtained from 290 (94%) of the subjects. HIV antibodies were found by both assays in 147 (50.7%) of the tested subjects; conflicting results were found in three (1%) of the subjects; and negative results on both tests were found in 140 (48.3%) of the subjects. Logistic regression analysis identified significant relative risks for HIV infection associated with the frequency of drug injection and the proportion of injections in 'shooting galleries'. Additional risk among men was associated with a history of homosexual relations. Traditional efforts taken by subjects to clean syringes between uses, such as washing with water or alcohol, showed no evidence of being protective. Programmes aimed at prevention of HIV infection should focus on reducing use of shooting galleries and sharing of needles and syringes as well as reducing intravenous drug abuse generally

Gays and intravenous (i.v.) drug users are the two largest risk groups for AIDS. Gays, unlike drug users, have formed many organizations to deal with AIDS. Data are presented indicating that gay individuals have more risk-reducing behavioral changes than have i.v. drug users. It is also shown that i.v. drug users are more likely to protect themselves if their acquaintances do so. It is suggested that collective self-organization can lead to peer support for risk reduction and that this can help i.v. drug users to reduce their risks on an ongoing basis. Difficulties that face i.v. drug users' attempts to organize collectively and examples of i.v. drug user collective organization to deal with AIDS and other problems are discussed.