Comnnentary Perspectives on HIV/AIDS Epidemiology and Prevention from the Eighth International Conference on AIDS Kenneth G. Castro, MD, Ronald 0. Valdiserm, MD, MPH, and James W. Curran, MD, MPH
Introduction More than 11 000 researchers, clinical and public health practitioners, and persons with human immunodeficiency virus (HIV) infection convened at the Eighth International Conference on AIDS/Third Sexually Transmitted Disease World Congress, held from July 19 to 24, 1992, in Amsterdam, the Netherlands. Advances in the epidemiology and prevention of HIV infection were reported in the more than 3000 posters and presentations at the meeting. This report summarizes progress made in three selected areas that were highlighted during the meeting's scientific session and a fourth area that received widespread media attention: (1) the epidemiology of HIV infection and acquired immunodeficiency syndrome (AIDS) in heterosexual women; (2) tuberculosis as an increasing opportunistic pathogen in HIV-infected persons; (3) prevention research, practice, and policy; and (4) preliminary reports of severe immunodeficiency in persons without evident HIV infection.
Epidemiology of HWVand AIDS in Women Natural history studies show similarities in the survival of HIV-infected women and HIV-infected men when health care, stage of disease, and zidovudine (AZT) use were controlled for. In one particular US study in which 54% (75) of 139 women were asymptomatic at entry, compared with 37% of 111 men, the gender-specific differences in progression to AIDS and survival were not statistically significant.1 In a study of 254 HIV-infected women and 422 HIV-infected men in Italy for whom seroconversion could be accurately estimated within 2 years, there
were no significant gender differences in progression to AIDS.2 The authors observed that women aged 25 years and older at seroconversion progressed to AIDS more rapidly than did women younger than 25 years, a finding previously reported for HIV-infected men with hemophilia. In a third study, a survival analysis of HIV-infected persons with estimated seroconversion showed no significant difference in disease progression by gender.3 Important risk factors for HIV infection among women who inject drugs were described. In one study of drug-use paraphemalia practices, 74% of 50 HIV-infected women reported recently sharing injection equipment, compared with 34% of 125 HIV-infected men (P < .01).4 Findings from another study offered a possible explanation: among 39 heterosexual couples in a methadone maintenance program, women commonly used injection equipment after men.5 Several reports focused on the prevalence of uterine cervical abnormalities in HIV-infected women. One report compared colposcopic findings in HIV-infected and uninfected women receiving methadone maintenance treatment. Squamous intraepithelial lesions were reported in 25% (28) of 111 HIV-infected women and in 10% (11) of 107 women who were not infected with HIV (P = .005).6 Although no statistically significant differKenneth G. Castro and James W. Curran are with the Office of the Associate Director (HIV) and Ronald 0. Valdiserri is with the National Center for Prevention Services, all at the Centers for Disease Control, Atlanta, Ga. Requests for reprints should be sent to Kenneth G. Castro, MD, Office of the Associate Director (HIV), Centers for Disease Control, 1600 Clifton Rd, NE, Mailstop D-21, Atlanta, GA 30333.
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Commetay ences by HIV status in cervical disease progression or persistence of abnormal cytology were observed after standard gynecologic care of early cervical lesions, most studies followed relatively few women after treatment. The prevalence of cervical dysplasia increased as HIV-related immunodeficiency progressed. For example, in one study the mean CD4+ T-cell count was 264 per microliter in women with abnormal Papanicolaou smears, compared with a mean value of 524 per microliter in women with normal smears.7 In another study, a mean CD4+ T-cell count of less than 213 per microliter was reported in 29 HlV-infected women with grade I, 1, or Ill cervical intraepithelial neoplasia (CIN) cytology, compared with a mean CD4+ T-cell count of less than 436 per microliter in 69 HIVinfected women with normal cytology.8 Several studies reported a significantly higher frequency of candida esophagitis and other mucocutaneous ftngal infections in women than in men.' 9g10 Women with HIV infections were more likely to have a history of vaginitis and to have a positive vaginal culture for Candida albicans as their CD4 T-lymphocyte count declined, particularly as it dropped below 200 per microliter." In summaly, the findings presented at the conference indicate that the progression of HIV infection to AIDS and the survival of HIV-infected persons do not seem to differ significantly between women and men. As previously observed in cohorts of HIV-infected men, age influences HIV disease progression in women. The prevalence of cervical abnormalities is high in HIV-infected women, and the rate rises as HIV-related immunodeficiency increases. Candida esophagitis and other mucocutaneous fungal infections are more common opportunistic pathogens in HIV-infected women than in HIV-infected men.
Tubenuosis and HIVInfection Studies consistently demonstrated a relatively high prevalence of tuberculosis and HIV coinfection. The World Health Organization estimated that approximately 4.4 million persons worldwide are infected with both tuberculosis and HIV; about 110 000 of these reside in North America.12'13 Estimates of the proportion of tuberculosis attributable to HIV ranged from 28% to 43%14-16 The prevalence of HIV infection ranged from 15% among 281 patients hospitalized with tuberculosis in Johannes1466 American Journal of Public HealthN
burg to 90% in 235 patients hospitalized with tuberculosis who were tested for HIV in New York City.17"18 Among patients initially reported with HIV or AIDS, there was extensive variation in the extent of recognized tuberculosis. The prevalence ranged from less than 1% in a cohort of 58 HIV-infected persons who participated in zidovudine treatment trials in New York City19 to 38% of 261 autopsied HIV-infected patients in C6te D'Ivoire.20 The highest rate of tuberculosis (87%) was reported among 15 autopsied AIDS patients in India.21 Patients with HIV infection and clinical tuberculosis showed evidence of substantial inmunodeficiency. Among HIV-infected patients diagnosed with tuberculosis in Italy, 81% had CD4+ T-cell counts of less than 200 per microliter.22 In Zimbabwe, 171 HIV-infected patients hospitaized with tuberculosis had a median CD4+ T-ceil count of 251 per microliter. This median count improved to 389 per microliter after 1 year of therapy (P = .02).23 In 222 HIV-infected patients from Zaire with pulmonary tuberculosis, 33% had CD4+ T-cell counts of less than 200 per microliter, another 38% had CD4+ T-ceil counts in the range of 200 to 500 per microliter, and 29% had CD4+ T-ceil counts higher than 500 per microliter.24 In the same study, 55% of persons with CD4+ T-cell counts lower than 200 per microliter were anergic to tuberculin. Among HIV-infected patients in Italy without symptoms of tuberculosis, 17% of those with CD4+ T-cell counts of less than 200 per microliter reacted to tuberculin, comparedwith 23% of patients with CD4+ T-celi counts higher than 500 per microliter.2 These studies confirm other reports that suggest that in HIV-infected persons, the tuberculin skin test is useful for the diagnosis of latent tuberculosis but loses its utility as HIV disease progresses and C7D4+ T-cell counts decline. In a multicenter European study, no signifcant differences in treatment failures were observed among 567 HIV-infected persons with active tuberculosis who were randomized to receive three (isoniazid, rifampin, pyrazinamide) vs four (three plus ethambutol) antituberculosis drugs.25 In Zaire, relapse was observed among 17.6% of 34 HIV-infected women postpartum after documented completion of treatment for tuberculosis (drug regimen not stated).26 The benefit of antituberculosis prophylaxis in HIV-infected persons was clearly demonstrated in a study from Haiti. Only 5.5% (2 of 36) of tuberculin-positive HIV-infected persons taking isoniazid and vitamin B6 de-
veloped active tuberculosis, compared with 37.5% (6 of 16) of tuberculin-positive WHV-infected persons who took only vitamin B6 over that time period.27 Sckell and colleagues also documented the benefit of isoniazid prophylaxis in preventing tuberculosis among tuberculin-positive HIV-infected drug users in methadone maintenance programs. This benefit may extend to anergic HIV-infected persons in that population.28 One study reported no statistically significant differences in tuberculosis infectiousness by HIV status,29 confirming previous reports. The problem of multidrug-resistant tuberculosis in the United States was also highlighted. Valway, Fischl, and Mullen summarized the nosocomial outbreaks of multidrug-resistant tuberculosis in New York and Florida.30-32 Most cases occurred among HIV-infected patients who had previously been hospitalizd, or who had been seen at the ambulatoxy clinic, within the same institution experiencing the outbreak. Nosocomial transmission was often confirmed by matching restriction fragment length polymorphism, or DNA fingerprint, pattems among Mycbacterim tuberulosis isolates within the institution, affirming the usefulness of combining epidemiologic and molecular genetic data during investigations of outbreaks of multidrug-resistant tuberculoSiS.33 Case-fatality rates exceeded 72%, and the interval from the tuberculosis diagnosis to the time of death ranged between 4 and 16 weeks. Outbreaks of multidrug-resistant tuberculosis in correctional facilities were also reported, and cases occurred among immunosuppressed health care workers and a prison
guard.
Prevention Several studies confirmed that proper and consistent condom use is associated with lower HIV infection rates. But the risks and benefits of spermicide use for preventing HIV infection, including the potential role of spermicide-mediated epithelial disruption in facilitating HIV infection, are not yet clear.3435 Neither an increased nor a decreased risk for HIV infection was noted in women who used oral contraceptives.36-39 Male circumcision was associated with significantly lower rates of HIV infection in a cross-sectional study of gay men in Seattle and in both cross-sectional and prospective studies of heterosexual men with genital ulcer disease in Kenya and New York.40A4l Finally, in Italian studies of disNovember 1992, Vol. 82, No. 11
commutay cordant partners, long-term zidovudine therapy was associated with a significant reduction in HIV transmission to uninfected partners.4'2'43 These different transmission rates remained signiicant after sexual activity, condom use, and stage of disease were controlled for. Investigators continue to add to the knowledge base descnbing the deterninants of high-risk sexual behavior as well as protective behavior. Data from a variety of study settings involving various populations show that adopting and maintaining safer sexual behaviors requires more than the provision of adequate information. For example, among the female sex partners of injecting drug users, self-reported condom use with male partners is significantl associated with peer endorsement of condoms, perceived efficacy of condoms, the perception that condoms are pleasurable, and perceived selfefficacy in using condoms.44"45 Similarly, for women enrolled in methadone maintenance programs, peer support of condom use as a risk reduction practice was significantl associated with clients' selfreported use.46 Among 209 sexually active HIV-infected women from New Jersey, the perception that condoms decrease sexual enjoyment was among the significant factors that decreased condom use and perceived self-efficacy in discussing condoms with a male partner was among the significant factors that increased condom use.47 The adoption of safer sexual practices among gay men was significantly influenced by peer group norms, most notablywhen the social norms were thought to endorse safer sexual practices."8'49 The prevalence of unsafe sexual behavior was shown to be increased for certain populations of younger gay men,50'51 especially for those in racial and ethnic minority groups.52 In a survey of 258 young gay men from San Francisco, 43% of those aged 17 to 19 years reported practicing unprotected anal intercourse.5' Among Black homosexual men receiving services at six public sexually transmitted disease clinics in Los Angeles, the prevalence of HIV infection increased from 23% in October 1988 to 40% in September 1991 (P < .05), while it decreased for White and Hispanic homosexual men.52 These changes may reflect decreased or inappropriate perceptions of risk, skills deficits in the ability to negotiate safer sex, or incomplete identification with or integration into existing gay social networks.53 Attitudinal barriers, including low perceptions ofrisk and negative opinions about barrier November 1992, Vol. 82, No. 11
methods, have been associated with the failure of lesbians to adopt safer sexual practices.54,55 School-based HIV education programs are associated with decreases in risky sexual practices among American high school students. Preliminary findings from the United States National Youth Risk Behavior Survey indicated that the percentage of students in grades 9 through 12 who received HIV instruction in school increased from 54% in 1989 to 83% in 1991, while the percentage of students who reported having had sexual intercourse decreased from 59%0o to 54%. There were also significant declines in the percentages of high school students who reported two or more lifetime partners (40%o in 1989 to 35% in 1991) and four or more lifetime partners (24% in 1989 to 19% in 1991).56 Yet failure to adequately gauge HlV risk and lack of skills needed to negotiate and practice safer sex were shown to be major impedinents to prevention for sexually active adolescents in other studies.57-W The use of contaminated injection equipment remains avery important mode of HIV transmission in the United States.61-65 Of AIDS cases reported in 1991, 34.6% were associated directly or indirectly with injection drug use.63 Fiftysix HIV seroconversions were reported by Friedman and colleagues among a cohort of 4644 HIV-seronegative injecting drug users in 14 US cities. HIV seroconverters were significantly more likely than seronegative injecting drug users to report renting or borrowing used syringes (relative risk = 2.16, 95% CI = 1.08, 1.46)." Evidence that the use of noninjected drugs, including alcohol, is associated with HIV infection continues to accumulate.66"67 Frequent unsafe sexual practices, such as the sale of sex for drugs, increase the risk of HIV infection among crack cocaine users.->73 In the prevention policy arena, information on national condom promotion campaigns and needle exchange programs was highlighted. The consistent and correct use of condoms would substantially reduce the spread of HIV infection and other sexually transmitted diseases, but some have raised the possibility that condom promotion campaigns could result in earlier initiation of sexual activity, more frequent sexual intercourse, or both. Swiss researchers found that their country's public education campaign promoting condom use was associated with an increase in self-reported consistent condom use among persons aged 17 to 30
years from 8% in January 1987 to 52% in October 1991.74 Furthermore, an evaluation of the campaign revealed that it had not increased the proportion of adolescents (aged 16 to 19 years) who engaged in sexual intercourse over a 3-year period.75 To develop effective condom promotion campaigns, it will be necessary to develop messages that are consistent with the audiences' behavioral intentions,76 culturally sensitive,77 and responsive to peergroup norms.78 One group of researchers reported that potential controversies over promoting condom use can be minimized by consensual decision making and policy development.79 Enrolling injecting drug users in treatment has been shown to decrease their risk of acquiring H1V infection.W-82 For example, Woody and colleagues compared 152 injecting drug users enrolled in methadone treatment programs with 103 opiate-using injecting drug users who had not been in treatment during the previous 12 months.81 The cumulative incidence rate of HIV infection was significantly higher for those who were not in methadone treatment (22%) than for those who remained in methadone treatment (3.5%) (P < .005). However, the number of injecting drug users in the United States and worldwide continues to outstrip the supply of available drug treatment services.83,84 Some have advocated needle and syringe exchange programs as a means of decreasing the frequency of sharing injection equipment. Information was provided on such programs in London, Glasgow, Paris, Berlin, Toronto, Montreal, Vancouver, Portland, Tacoma, New Haven, and New York City. Researchers from New York City found that injecting drug users who used the program were more likely to be HIV infected and that there was no difference in injection frequency between injecting drug users who were enrolled in needle and syringe exchange programs and those who were not.85 In Portland, similar needle practice behaviors were noted between exchangeprogram clients and injecting drug users recruited from street outreach, although the former reported lower frequencies of reusing syringes without cleaning and were, understandably, less likely to discard syringes in public places.86 In Tacoma, the HIV seroprevalence rate among 265 exchange-program clients was 2%, compared with a seroprevalence rate of 8% among 93 non-clients.87 Additional scientific evaluations of needle and syringe exchange programs are needed to
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Canmuntai
inform policy decisions and to resolve the controversies surrounding these programs. Results on the behavioral outcomes of publicly funded HIV counseling and testing programs were mixed. Several researchers reported reductions in unsafe drug use88-91 and sexual practices88'89'91-95 following counseling and testing, primarily for those who learned they were seropositive. Other researchers failed to observe a change in behaviors as a result of HV counseling and testing.9-98 These diverse results indicate that although individual knowledge of HIV serostatus can play an important role in the adoption of safer behaviors, it is probably not the only factor; nor does such information have consistent behavioral effects across different groups. Numerous reports from across the country indicate that the programtic response to HV prevention continues to involve a diverse combination ofgovemmental and nongovemmental organizations. In both industiaized and developing countries, community-based organizations are incrasing reconized as integral partners in HIV prevention programs.
Opportnist Infections and Assoaed CD4+
T-lymphoytopeni in Pe mons wtout Evidn HlVInfection Preliminary press reports and discussions among scientists at the meeting regarding persons with persistently low CD4+ T-cell counts and AIDS-like illnesses stirred much interest in Amsterdam. The Centers for Disease Control established a national surveillance system to determine the prevalence and distnbution of this condition and published preliminary reports.99.100 Additional information about HIV-negative persons with severe immunodeficiency was discussed at a follow-up meeting in Atlanta.101 By the time of the follow-up meeting, 30 US casepatients with CD4+ T-cell counts persistently below 300 per microliter and no evident HIV infection had been reported to the Centers for Disease Control. Of these, 13 had AIDS-defining illnesses, 12 were symptomatic with non-AIDS-defining illnesses, and 5 were asymptomatic. Absolute CD4+ T-cell levels ranged between 17 and 296 per microliter. There was no geographic clustering of these case-patients; many are persons at risk for HIV infection. Dates of CD4+ 1468 American Journal of Public Health
T-cell tests were available for 27 casepatients; 6 had their first lowest CD4+ T-cell count documented during the period from 1983 to 1987, 8 during 1988 to 1990, and 13 during 1991 to 1992. These case-patients resided in 15 states and ranged in age from 18 to 70 years. The observed high proportion of persons at risk for HIV infection probably reflects an ascertainment bias because these persons are likely to have lymphocyte subset determinations as part of their medical evaluations. The heterogeneous epidemiologic profile suggests that these cases represent an apparently unusual disorder, different disease entities, or both. Preliminary laboratory investigations descnbed intracistemal viral particles and reverse transcriptase activity in a few of these case-patients, but no convincng evidence was presented of the existence of a virus associated with the syndrome. The significance of these findings remains unclear. Additional epidemiologic and laboratory investigations are in progress to help clarify these observations.
Conclusion The Eighth International AIDS Symposium in Amsterdam provided updated scientific and programmatic information to thousands of interested participants working in the fields of HIV and AIDS throughout the world. As in other scientific areas, the amount of information presented in epidemiology and prevention was overwhelming; however, the scientific progress made was steady but incremental. Meanwhile, the national and international public health burden of the HIV epidemic increases each year. In the United States, between 415 000 and 535 000 cases of AIDS will have been diagnosed by the end of 1994, and well over a quarter of a million persons will be living with severe HIV disease at that time.102 Direct health care costs in the United States for persons with HIV infection or AIDS are projected to reach $13.5 billion in 1994.103 The future course of the worldwide HIV epidemic cannot be accurately predicted, but the forecasts that a minimum of 30 to 40 million people will be infected by the end of this decade are sobering.104 To stem transmission worldwide, a safe and effective vaccine is urgently needed. Currently, in the absence of such a vaccine, it is crucial for all of the world's communities to apply the best science-based prevention methods available. O
References Except for citations from published reports, the referenced materials were presented at the Eighth Intemational Conference on AIDS, July 19-24,1992, Amsterdam, the Netherlands. The numbers provided correspond to the session in which the information was presented or to numbers published in the program oforal and poster abstracts. 1. Szabo S, Miller LHI, Sacks HS, et al. Gender differences in the natural history of HIV infection. MoCO030. 2. Dorrucci M. Italian seroconversion study: age accelerates progression from HIVseroconversion to AIDS in women.
MoCO033. 3. Brettle RP, Richardson AM, Bums SM, Fielding K, Leen CLS. Survival analysis by gender and risk group for HIV in Edinburgh. MoCO066. 4. Hindin R, Bigelow C, Vickers-Lahti M, Lewis B, McCuskerJ. Genderdifferences in sharing behavior among intravenous drug users (IVDUs). PoC4254. 5. Clark LL, Calsyn DA, Saxon AJ, Jackson TR, Wrede IAF. HIV risk behaviors of heterosexual couples in methadone maintenance. PoC4656. 6. Klein RS, Adachi A, Fleming I, Ho GYF, Burk R. A prospective study of genital neoplasia and human papillomavirus (HPV) in HIV infected women. TuB0527. 7. Regevik N, Sen P, Raska K, et al. Cervical human papillomavirus (HPV) in women infected with human imnmunodeficiency virus (HIV) and its correlation with immune status and Papanicolaou smear abnormalities. TuBQ528. 8. Anastos K, Denenberg R, Solomon L, Rein S. Relationship of CD4 cell counts to cervical cytologic abnormalities and gynecologic infections in 150 HIV-infected women. TuB0532. 9. Benson C, Sha B, Urbanski P, Pottage J, Kessler H. Women with HIV disease: clinical progression and survival in a cohort followed at a university medical center. MoCX034. 10. MayerK,JesdaleB, FlaniganT, etal.The prevalence of specific illnesses in HIVinfected US women with associated CD4 counts. PoC4371. 11. DuerrA. Gynecologic conditions in HIVinfected women in Brooklyn, New York. PoB3051. 12. Valdespino JL. Epidemiology of tuberculosis. Session 64 presentation. 13. Curran JW. Public policy implications of the tuberculosis/HIV epidemics. Session 64 presentation. 14. Chintu C, Bhat GJ, Luo C, Kabika M, Raviglione MC, O'Brien RJ. Fatal skin reactions in children treated for tuberculosis in Zambia. PoB3859. 15. Aisu T, Raviglione MC, Narain JP, et al.
Monitoring HlV-associated tuberculosis in Uganda: seroprevalence and clinical features. PoC4023. 16. BroekJvd, Borgdorff MW, PakkerNG, et al. Risk of HIV infection for developing active tuberculosis. PoC4417. 17. Martin DJ, SimJGM, SoleG, Shalekoff S, Rymer L. CD4+ lymphocyte counts in
African tuberculosis patients with and without HIV superinfection. PoB3097.
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Conmeutai 18. Agins B, Felder H, Osten W, Burke G, DiFerdinando G. HIV seroprevalence in hospitalized patients with tuberculosis. PoC4665. 19. BaileyE, DiamondG, Simberkoff M. Frequency of recurrent TB and positive skin test in a cohort of ARC earlyvs late AZT treatment in a cooperative trial. PoB3070. 20. Lucas S, Hounnou A, Beaumel A, et al. The pathology of adult HIV infection in Abidjan, Cote D'Ivoire. PoB3751. 21. Lanjewar DN, Wagholikar U. Mycobacteriosis (M.TB) emerging as most common infection in AIDS victims of India. PoB3556. 22. Caligaris S, El-Hamad I, MatteelliA, et al. Prevalence of PPD reactivity and tuberculosis among HIV infected subjects. PoB3072. 23. Chidede L, Latif A. Is tuberculosis a cofactor in HIV immunosuppression? PoA2121. 24. Perriens J, St. Louis M, Prignot J, Piot P. Immunological evaluation of HIV-1 (+) patients with pulmonary tuberculosis in Kinshasa, Zaire. PoB3092. 25. European Tuberculosis Study Group. Tuberculosis (TBC) in HIV infected patients (P): a multicentric, randomized comparative study of three versus a four drug regimen. PoB3077. 26. Matela B, Mundele L, Mosengo M, et al. Survival and outcome in a cohort of 249 HIV (+) mothers followed for 60 month post-partum period in Kinshasa, Zaire.
TuC)566. 27. Pape JW, Jean S, Ho J, Johnson WD Jr. Effect of isoniazid on the natural history of HIV infection in Haiti. PoB3091. 28. Sckell B, Sehvyn PA, Alcabes P, Schoenbaum E, Kein R, Friedland G. High riskof active tuberculosis in HIV-positive anergic drug injectors; effectiveness of isoniazid prophylaxis in tuberculin reactors. TuCO567. 29. Mungal M, Nunn P, Nyamwaya J, et al. The effect ofHIV-1 on the infecfiousness of tuberulsis, Nairobi, Kenya. TuCQ569. 30. Dooley S, Edlin B, Pearson M, et al. Multidrug resistant nosocomial tuberculosis outbreaks in HIV-infected persons. TuC0568. 31. Fischl M, Uttamchandani R, Daikos G, Poblete R, Moreno J, Lai S. Outbreak of multiple drug resistant tuberculosis (MDR-TB) among patients with HIV infection. TuB0534. 32. Mullen M, Soumakis S, Lessnau K, Sanjana V, Davidson M, Talavera W. Multidrug resistant tuberculosis (MDR-TB) in patients infected with HIV. TuB0535. 33. Edlin BR, TokarsJI, Grieco MH, et al. An outbreak of multidrug-resistant tuberculosis among hospitalized patients with the acquired immunodeficiency syndrome. N Engi JMed 1992;326:1514-1521. 34. Feldblum P, Hira S, Godwins, et al. Efficacy of spermicide use and condom use by HIV-discordant couples in Zambia. WeC1O85. 35. Roddy RE, Cordero M, Cordero C, et al. Dosing study of Nonoxynol-p and genital irritation. PoB3783. 36. GervasoniC, LazarinA, MusiccoM, Sa-
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racco A. Contraceptive practices and man-to-woman HIV sexual transmission. PoC4651. 37. Boschl C, Castilho EA, Gulmaraes MP, et al. Association between oral contraceptive use and HIV infection. PoC4355. 38. Hittl J, Walker CK, Nsubuga PSJ, et al. Oral contraceptive use and HIV infection. PoC4309. 39. Pattulo ALS, Plourde P, Ndinga-Achola JO, et al. Prospective study of HIV-1 seroconversion in women with genital ulcers attending an African STD clinic. PoC4326. 40. Kreiss J, Hopkins S. The association between circumcision status and HIV infection among homosexual men. PoC4091. 41. Tyndall M, Agoki E, Malisa W, et al. HIV-1 prevalence and risk of seroconversion among uncircumcised men in Kenya. PoC4308. 42. Massimo M, Angarano A, Saracco A, et al. Antiretrviral therapy reduces the rate ofsexual transmission of HIV-1 from man to woman. WeC1088. 43. Chirianni A, Pema E, Liuzzi G, et al. Absence of anti-HIV seroconversion in heterosexual partners of H1V patients treated with zidovudine. PoC4530. 44. Tross S, Abdul-Quader AS, Silvert HM, Simons P, Des Jarlais DC, Friedman S. Determinants of condom use in female sexual partners (FSPs) of IV drug users in NY City. WeD 1075. 45. Abdul-Quader AS, Tross S, Silvert H, Simons P, Friedman SR, Des Jarlais DC. Peer influence and condom use by female sexual partners of injecting drug users in New York City. PoD 5489. 46. Ramos S, Mantell J, Majidi K, GloverWalton C, Gonzalez V, Brown LS, Jr. Gender Variations in contraceptive and reproductive attitudes, intentions and practices among New York City injecting drug users. PoD 5518. 47. Kline A, VanLandingham M. Determinants ofcondom use among HIV-infected women in New Jersey. PoD 5211. 48. Kelly JA, Sikkema KJ, Winett RA, et al. Outcomes of a 16city randomized field trial of a community-level HIV risk reduction intervention. TuD 0543. 49. Hickson F, Weatherbum P, Davies PM, Hunt AJ, Coxon APM, McManus TJ. Why gay men engage in anal intercourse. PoD 5183. 50. Ekstrand M, Stall R, Marlatt A, Pollack L, McKusick L, Coates T. Frequent and infrequent relapsers need different AIDS prevention programs. PoD 5126. 51. Nieri GN, Lemp GF, Watson RP, Nguyen S, Parisi MK, Clevenger AC. HIV-1 seroprevalence and risk behaviors among young gay and bisexual men in San Francisco. PoC 4092. 52. Ford W, Weber MD, Cheng FK, Hill DA, Kerndt PR. Trends in the prevalence of HIV infection among sexually transmitted disease patients in Los Angeles County, 1988-1991. PoC 4298. 53. Freeman AC, Krepcho M, Hedrich A, et al. Gay, bisexual, and straght men who have sex with men: HIV risk and disclosure. PoC 4099. 54. Hunter J, Rotheram-Borus MJ, Reid H,
Rosario M. Sexual and substance abuse acts that place lesbians at risk for HIV. PoD 5208. 55. Russell MA, Alcober J, McKinley P. The perception of risk for HIV infection among lesbians in New York City. PoD 5217. 56. Holtzman D, Mathis MP, Kann L, Collins J, Kolbe UJ. Trends in HIV-related instruction and behaviors among high school students in the United States, 1989-1991. PoD 5114. 57. Arnold W, Altschuler S. Peer education program reaches teens with HIV/AIDS information. PoD 5018. 58. Melese-d'Hospital I, Strauss AL. Sexual decision-making processes among HIV"savvy" adolescents. PoD 5368. 59. WatersJ, McIntyreG, Hughes K, Karugu A, Robertson J, Schwartz A. HIV prevention in very high risk groups: evaluation research. PoD 5440. 60. St. Lawrence JS, Davis J, Brasfield T, et al. Gender differences relevant to AIDS prevention with Afican-American adolescents. PoD 5449. 61. Battjes R, Pickens R. Trends in HIV infection and AIDS risk behaviors among intravenous drug users in selected US cities. PoC 4247. 62. Martinez R, Colon HM, Robles RR, et al. Factors associated with HIV seropositivity among drug injectors entering treatment in Puerto Rico. PoC 4249. 63. Jones TS, Slutsker L, Frey B, Ward J, Buehler J. AIDS cases associated with injection druguse, United States, 1991. PoC 4693. 64. Friedman SR, Des Jarlais DC, Deren S, Jose B, Neaigus A. HIV seroconversion among street-recruited drug injectors in 14 United States cities. PoC 4251. 65. Watters JK, Cheng YT, Bluthenthal R, Carlson J, Lorvick J. Drug injectors and HIV-1 infection in the San Francisco Bay area. PoC 4700. 66. Avins A, Woods W, Lindan C, HaynesSanstad K, Clark W, Hulley S. High prevalence of HIV risk behavior and infection among alcoholics in treatment. PoC 4688. 67. Woods WJ, Avins A, Lindan C, HaynesSanstad K, Clark W, Hulley S. Alcohol intoxication: associations with HIV risk. PoD 5497. 68. Edlin BR, Irwin KL, Ludwig DD, et al. HIV infection and crack cocaine smoking in street-recruited urban youth, USA. WeC 1028. 69. Wallace JI, Weiner A, Steinberg A, Hoffmann B. Fellatio is a significant risk behavior for acquiring AIDS among New York City streetwalldng prostitutes. PoC 4196. 70. EllerbrockT, Harrington P, BushT, et al. A community-based study of HIV prevalence and risk factors in pregnant women with private, public, and no prenatal care. PoC 4366. 71. El-Bassel N, Schilling R, Gilbert L, et al. Correlates of sex trading among female drug users in Harlem. PoC 4658. 72. Schilling R, Serrano Y, Faruque 5, et al. Predictor variables of trading sex among male drug users in Harlem. PoC 4659. 73. Faruque 5, Serrano Y, El-Bassel N, et al.
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Cumty Sexual risk behavior and risk araisal in male crack users in Harlem. PoD 5491. 74. Dubois-Arber F, Jeannin A, Zeugin P. Evaluation of AIDS prevention in Switzerland: behavioural change in the general population. PoD 5140. 75. Hausser D, Michaud PA. Condom promotion does not increase sexual intercourse among adolescents. TuD 0575. 76. O'Reilly KR, Hi ns DL, Schnell DJ, et al. Stages of behavior change amonghighrisk hard-to-reach groups in the AIDS community demonstration projects. PoD 5088. 77. Bonilla L, Porter J, Mendez S. Condom use in low income island and mainland Puerto Rican populations. PoD 5138. 78. Wooten KG, Jason J. Detenninants of condom use by 18 to 39 year old U.S. adults. PoD 5388. 79. HelquistM, SchneiderA, Francis C, Middlestadt SE, Eustace MA. Policy and controversy in condom marketing campaigns. PoD 5144. 80. Serpeiloni G, Gomma M, Morgante S, Perlato R, Brunelli M, Capra C. Methadone treatment and reduced possibility to acquire HIV infection. PoC 4282. 81. Woody G, Metzger DS, McLellan AT, et al. HIV and HTLV-I/ll infection among IDUs in and out of methadone treatment. PoC 4268. 82. Kerndt PR, Ford WL, Weber MD, Cheng FR Trends in HIVinfeci among heterosexuals in mehade drug treatmentinLos Angeles County, 1981991. PoC 4257. 83. Case P, Tarantola D, Jerath N, Cohen M, MannJ. How many injection drug users in the world?: assessment of epidemic potential. PoC 4291. 84. Drucker E. Addiction treatment and
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AIDS prevention in the US: low enrollment, retention, and therapeutic efficacy limit population impact. PoC 4250.
85. SchoenbaumEE, AlcabesP, McLaughlin S, et al. Participation in a needle exchange program in New York City by injecting drug users (IDU) enrolled in a prospective study of HIV. PoC 4801. 86. Oliver K, Friedman S, Maynard H, Des Jarlais DC, FlemingD. Comparison of behavioral impacts of syringe exchange with bleach/outreach education, and community impacts of an exchange. PoC 4284. 87. Hagan H, Des Jarlais DC, Friedman SR, Purchase D. Multiple outcome measures of the impact of the Tacoma syringe exchange. PoC 4283. 88. Desenclos J, Papaevangelou G. Knowledge of HIV serostatus and preventive behaviours among European injecting drug users. PoC 4281. 89. Coleman JL, Lodico M, Evans P, DiClemente R. Can street-based injection drug users change behavior? PoD 5075. 90. Kelaher M, Ross MW. Dominant determinants of HIV related risk behaviour in injecting drug users. PoD 5362. 91. Rhodes F, Humfleet G, CorbyN. Efficacy of an individual counseling intervention in reducing AIDS risk among injection drug users. PoC 4800. 92. GraberJ, Hershow R, Trowbridge J, et al. HIV counseling and testing and risk reduction among asymptomatic gay men. PoC 4546. 93. Skumick J, Bromberg J, Cordell J, Foley M, Wang W, Louria D. Change in couples' sexual activity after knowledge of HIV discordance: a report from the heterosexual HIV transmission study (HATS). PoC 4170.
94. Ehrhardt AA, Meyer-Bahlburg HFL, Exner TM, et al. Impact of HIV+ serostatus on sexual risk behaviors in IVDU women. PoD 5516. 95. Mitchell JL, Thompson R, Namerow P, Gordon T, Carrington B, Williams S. A comparison of contraceptive usage by HIV infected and non-infected women one year post delivery. PoD 5383. 96. Ostrow DG, Leite MC, Beltran E, Adib SM. Long term effects of HIV serostatus on mental health and sexual behavior. PoC 4350. 97. McKirnan D, Doetsch J, Doll L, Harrison J, Delgado W. Sexual risk and comnunication among HIV tested vs. untested gay men. PoC 4097. 98. Ickovics J, Morril A, Beren S, Walsh R, Rodin J. HIV testing and women: behavioral/psychological consequences. PoC 4787. 99. Centers forDisease Control. Unexplained CD4+ T-lymphocyte depletion in persons without evident HIV infection-United States. MMWR 1992;41:541-543. 100. Centers for Disease Control. Update: CD4+ T-lymphocytopenia in persons without evident HIV infection-United States. MAMR 1992;41:578-579. 101. Cohen J. Mystery virus meets the skeptics. Science. 1992;257:1032-1034. News and Comments. 102. Curran JW. Demographic impact of HIV in the United States. Invited presentation, Session 100. 103. Hellinger FJ. Assessing the medical care costs of the HIV epidemic in the United States: 1992-1995. WeC1O33. 104. World Health Organization (WHO). World AIDS Cases Quarterly Update. WHO Press Release no. 44; 1991.
November 1992, Vol. 82, No. 11
Introduction More than 11 000 researchers, clinical and public health practitioners, and persons with human immunodeficiency virus (HIV) infection convened at the Eighth International Conference on AIDS/Third Sexually Transmitted Disease World Congress, held from July 19 to 24, 1992, in Amsterdam, the Netherlands. Advances in the epidemiology and prevention of HIV infection were reported in the more than 3000 posters and presentations at the meeting. This report summarizes progress made in three selected areas that were highlighted during the meeting's scientific session and a fourth area that received widespread media attention: (1) the epidemiology of HIV infection and acquired immunodeficiency syndrome (AIDS) in heterosexual women; (2) tuberculosis as an increasing opportunistic pathogen in HIV-infected persons; (3) prevention research, practice, and policy; and (4) preliminary reports of severe immunodeficiency in persons without evident HIV infection.
Epidemiology of HWVand AIDS in Women Natural history studies show similarities in the survival of HIV-infected women and HIV-infected men when health care, stage of disease, and zidovudine (AZT) use were controlled for. In one particular US study in which 54% (75) of 139 women were asymptomatic at entry, compared with 37% of 111 men, the gender-specific differences in progression to AIDS and survival were not statistically significant.1 In a study of 254 HIV-infected women and 422 HIV-infected men in Italy for whom seroconversion could be accurately estimated within 2 years, there
were no significant gender differences in progression to AIDS.2 The authors observed that women aged 25 years and older at seroconversion progressed to AIDS more rapidly than did women younger than 25 years, a finding previously reported for HIV-infected men with hemophilia. In a third study, a survival analysis of HIV-infected persons with estimated seroconversion showed no significant difference in disease progression by gender.3 Important risk factors for HIV infection among women who inject drugs were described. In one study of drug-use paraphemalia practices, 74% of 50 HIV-infected women reported recently sharing injection equipment, compared with 34% of 125 HIV-infected men (P < .01).4 Findings from another study offered a possible explanation: among 39 heterosexual couples in a methadone maintenance program, women commonly used injection equipment after men.5 Several reports focused on the prevalence of uterine cervical abnormalities in HIV-infected women. One report compared colposcopic findings in HIV-infected and uninfected women receiving methadone maintenance treatment. Squamous intraepithelial lesions were reported in 25% (28) of 111 HIV-infected women and in 10% (11) of 107 women who were not infected with HIV (P = .005).6 Although no statistically significant differKenneth G. Castro and James W. Curran are with the Office of the Associate Director (HIV) and Ronald 0. Valdiserri is with the National Center for Prevention Services, all at the Centers for Disease Control, Atlanta, Ga. Requests for reprints should be sent to Kenneth G. Castro, MD, Office of the Associate Director (HIV), Centers for Disease Control, 1600 Clifton Rd, NE, Mailstop D-21, Atlanta, GA 30333.
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Commetay ences by HIV status in cervical disease progression or persistence of abnormal cytology were observed after standard gynecologic care of early cervical lesions, most studies followed relatively few women after treatment. The prevalence of cervical dysplasia increased as HIV-related immunodeficiency progressed. For example, in one study the mean CD4+ T-cell count was 264 per microliter in women with abnormal Papanicolaou smears, compared with a mean value of 524 per microliter in women with normal smears.7 In another study, a mean CD4+ T-cell count of less than 213 per microliter was reported in 29 HlV-infected women with grade I, 1, or Ill cervical intraepithelial neoplasia (CIN) cytology, compared with a mean CD4+ T-cell count of less than 436 per microliter in 69 HIVinfected women with normal cytology.8 Several studies reported a significantly higher frequency of candida esophagitis and other mucocutaneous ftngal infections in women than in men.' 9g10 Women with HIV infections were more likely to have a history of vaginitis and to have a positive vaginal culture for Candida albicans as their CD4 T-lymphocyte count declined, particularly as it dropped below 200 per microliter." In summaly, the findings presented at the conference indicate that the progression of HIV infection to AIDS and the survival of HIV-infected persons do not seem to differ significantly between women and men. As previously observed in cohorts of HIV-infected men, age influences HIV disease progression in women. The prevalence of cervical abnormalities is high in HIV-infected women, and the rate rises as HIV-related immunodeficiency increases. Candida esophagitis and other mucocutaneous fungal infections are more common opportunistic pathogens in HIV-infected women than in HIV-infected men.
Tubenuosis and HIVInfection Studies consistently demonstrated a relatively high prevalence of tuberculosis and HIV coinfection. The World Health Organization estimated that approximately 4.4 million persons worldwide are infected with both tuberculosis and HIV; about 110 000 of these reside in North America.12'13 Estimates of the proportion of tuberculosis attributable to HIV ranged from 28% to 43%14-16 The prevalence of HIV infection ranged from 15% among 281 patients hospitalized with tuberculosis in Johannes1466 American Journal of Public HealthN
burg to 90% in 235 patients hospitalized with tuberculosis who were tested for HIV in New York City.17"18 Among patients initially reported with HIV or AIDS, there was extensive variation in the extent of recognized tuberculosis. The prevalence ranged from less than 1% in a cohort of 58 HIV-infected persons who participated in zidovudine treatment trials in New York City19 to 38% of 261 autopsied HIV-infected patients in C6te D'Ivoire.20 The highest rate of tuberculosis (87%) was reported among 15 autopsied AIDS patients in India.21 Patients with HIV infection and clinical tuberculosis showed evidence of substantial inmunodeficiency. Among HIV-infected patients diagnosed with tuberculosis in Italy, 81% had CD4+ T-cell counts of less than 200 per microliter.22 In Zimbabwe, 171 HIV-infected patients hospitaized with tuberculosis had a median CD4+ T-ceil count of 251 per microliter. This median count improved to 389 per microliter after 1 year of therapy (P = .02).23 In 222 HIV-infected patients from Zaire with pulmonary tuberculosis, 33% had CD4+ T-cell counts of less than 200 per microliter, another 38% had CD4+ T-ceil counts in the range of 200 to 500 per microliter, and 29% had CD4+ T-ceil counts higher than 500 per microliter.24 In the same study, 55% of persons with CD4+ T-cell counts lower than 200 per microliter were anergic to tuberculin. Among HIV-infected patients in Italy without symptoms of tuberculosis, 17% of those with CD4+ T-cell counts of less than 200 per microliter reacted to tuberculin, comparedwith 23% of patients with CD4+ T-celi counts higher than 500 per microliter.2 These studies confirm other reports that suggest that in HIV-infected persons, the tuberculin skin test is useful for the diagnosis of latent tuberculosis but loses its utility as HIV disease progresses and C7D4+ T-cell counts decline. In a multicenter European study, no signifcant differences in treatment failures were observed among 567 HIV-infected persons with active tuberculosis who were randomized to receive three (isoniazid, rifampin, pyrazinamide) vs four (three plus ethambutol) antituberculosis drugs.25 In Zaire, relapse was observed among 17.6% of 34 HIV-infected women postpartum after documented completion of treatment for tuberculosis (drug regimen not stated).26 The benefit of antituberculosis prophylaxis in HIV-infected persons was clearly demonstrated in a study from Haiti. Only 5.5% (2 of 36) of tuberculin-positive HIV-infected persons taking isoniazid and vitamin B6 de-
veloped active tuberculosis, compared with 37.5% (6 of 16) of tuberculin-positive WHV-infected persons who took only vitamin B6 over that time period.27 Sckell and colleagues also documented the benefit of isoniazid prophylaxis in preventing tuberculosis among tuberculin-positive HIV-infected drug users in methadone maintenance programs. This benefit may extend to anergic HIV-infected persons in that population.28 One study reported no statistically significant differences in tuberculosis infectiousness by HIV status,29 confirming previous reports. The problem of multidrug-resistant tuberculosis in the United States was also highlighted. Valway, Fischl, and Mullen summarized the nosocomial outbreaks of multidrug-resistant tuberculosis in New York and Florida.30-32 Most cases occurred among HIV-infected patients who had previously been hospitalizd, or who had been seen at the ambulatoxy clinic, within the same institution experiencing the outbreak. Nosocomial transmission was often confirmed by matching restriction fragment length polymorphism, or DNA fingerprint, pattems among Mycbacterim tuberulosis isolates within the institution, affirming the usefulness of combining epidemiologic and molecular genetic data during investigations of outbreaks of multidrug-resistant tuberculoSiS.33 Case-fatality rates exceeded 72%, and the interval from the tuberculosis diagnosis to the time of death ranged between 4 and 16 weeks. Outbreaks of multidrug-resistant tuberculosis in correctional facilities were also reported, and cases occurred among immunosuppressed health care workers and a prison
guard.
Prevention Several studies confirmed that proper and consistent condom use is associated with lower HIV infection rates. But the risks and benefits of spermicide use for preventing HIV infection, including the potential role of spermicide-mediated epithelial disruption in facilitating HIV infection, are not yet clear.3435 Neither an increased nor a decreased risk for HIV infection was noted in women who used oral contraceptives.36-39 Male circumcision was associated with significantly lower rates of HIV infection in a cross-sectional study of gay men in Seattle and in both cross-sectional and prospective studies of heterosexual men with genital ulcer disease in Kenya and New York.40A4l Finally, in Italian studies of disNovember 1992, Vol. 82, No. 11
commutay cordant partners, long-term zidovudine therapy was associated with a significant reduction in HIV transmission to uninfected partners.4'2'43 These different transmission rates remained signiicant after sexual activity, condom use, and stage of disease were controlled for. Investigators continue to add to the knowledge base descnbing the deterninants of high-risk sexual behavior as well as protective behavior. Data from a variety of study settings involving various populations show that adopting and maintaining safer sexual behaviors requires more than the provision of adequate information. For example, among the female sex partners of injecting drug users, self-reported condom use with male partners is significantl associated with peer endorsement of condoms, perceived efficacy of condoms, the perception that condoms are pleasurable, and perceived selfefficacy in using condoms.44"45 Similarly, for women enrolled in methadone maintenance programs, peer support of condom use as a risk reduction practice was significantl associated with clients' selfreported use.46 Among 209 sexually active HIV-infected women from New Jersey, the perception that condoms decrease sexual enjoyment was among the significant factors that decreased condom use and perceived self-efficacy in discussing condoms with a male partner was among the significant factors that increased condom use.47 The adoption of safer sexual practices among gay men was significantly influenced by peer group norms, most notablywhen the social norms were thought to endorse safer sexual practices."8'49 The prevalence of unsafe sexual behavior was shown to be increased for certain populations of younger gay men,50'51 especially for those in racial and ethnic minority groups.52 In a survey of 258 young gay men from San Francisco, 43% of those aged 17 to 19 years reported practicing unprotected anal intercourse.5' Among Black homosexual men receiving services at six public sexually transmitted disease clinics in Los Angeles, the prevalence of HIV infection increased from 23% in October 1988 to 40% in September 1991 (P < .05), while it decreased for White and Hispanic homosexual men.52 These changes may reflect decreased or inappropriate perceptions of risk, skills deficits in the ability to negotiate safer sex, or incomplete identification with or integration into existing gay social networks.53 Attitudinal barriers, including low perceptions ofrisk and negative opinions about barrier November 1992, Vol. 82, No. 11
methods, have been associated with the failure of lesbians to adopt safer sexual practices.54,55 School-based HIV education programs are associated with decreases in risky sexual practices among American high school students. Preliminary findings from the United States National Youth Risk Behavior Survey indicated that the percentage of students in grades 9 through 12 who received HIV instruction in school increased from 54% in 1989 to 83% in 1991, while the percentage of students who reported having had sexual intercourse decreased from 59%0o to 54%. There were also significant declines in the percentages of high school students who reported two or more lifetime partners (40%o in 1989 to 35% in 1991) and four or more lifetime partners (24% in 1989 to 19% in 1991).56 Yet failure to adequately gauge HlV risk and lack of skills needed to negotiate and practice safer sex were shown to be major impedinents to prevention for sexually active adolescents in other studies.57-W The use of contaminated injection equipment remains avery important mode of HIV transmission in the United States.61-65 Of AIDS cases reported in 1991, 34.6% were associated directly or indirectly with injection drug use.63 Fiftysix HIV seroconversions were reported by Friedman and colleagues among a cohort of 4644 HIV-seronegative injecting drug users in 14 US cities. HIV seroconverters were significantly more likely than seronegative injecting drug users to report renting or borrowing used syringes (relative risk = 2.16, 95% CI = 1.08, 1.46)." Evidence that the use of noninjected drugs, including alcohol, is associated with HIV infection continues to accumulate.66"67 Frequent unsafe sexual practices, such as the sale of sex for drugs, increase the risk of HIV infection among crack cocaine users.->73 In the prevention policy arena, information on national condom promotion campaigns and needle exchange programs was highlighted. The consistent and correct use of condoms would substantially reduce the spread of HIV infection and other sexually transmitted diseases, but some have raised the possibility that condom promotion campaigns could result in earlier initiation of sexual activity, more frequent sexual intercourse, or both. Swiss researchers found that their country's public education campaign promoting condom use was associated with an increase in self-reported consistent condom use among persons aged 17 to 30
years from 8% in January 1987 to 52% in October 1991.74 Furthermore, an evaluation of the campaign revealed that it had not increased the proportion of adolescents (aged 16 to 19 years) who engaged in sexual intercourse over a 3-year period.75 To develop effective condom promotion campaigns, it will be necessary to develop messages that are consistent with the audiences' behavioral intentions,76 culturally sensitive,77 and responsive to peergroup norms.78 One group of researchers reported that potential controversies over promoting condom use can be minimized by consensual decision making and policy development.79 Enrolling injecting drug users in treatment has been shown to decrease their risk of acquiring H1V infection.W-82 For example, Woody and colleagues compared 152 injecting drug users enrolled in methadone treatment programs with 103 opiate-using injecting drug users who had not been in treatment during the previous 12 months.81 The cumulative incidence rate of HIV infection was significantly higher for those who were not in methadone treatment (22%) than for those who remained in methadone treatment (3.5%) (P < .005). However, the number of injecting drug users in the United States and worldwide continues to outstrip the supply of available drug treatment services.83,84 Some have advocated needle and syringe exchange programs as a means of decreasing the frequency of sharing injection equipment. Information was provided on such programs in London, Glasgow, Paris, Berlin, Toronto, Montreal, Vancouver, Portland, Tacoma, New Haven, and New York City. Researchers from New York City found that injecting drug users who used the program were more likely to be HIV infected and that there was no difference in injection frequency between injecting drug users who were enrolled in needle and syringe exchange programs and those who were not.85 In Portland, similar needle practice behaviors were noted between exchangeprogram clients and injecting drug users recruited from street outreach, although the former reported lower frequencies of reusing syringes without cleaning and were, understandably, less likely to discard syringes in public places.86 In Tacoma, the HIV seroprevalence rate among 265 exchange-program clients was 2%, compared with a seroprevalence rate of 8% among 93 non-clients.87 Additional scientific evaluations of needle and syringe exchange programs are needed to
American Journal of Public Health 1467
Canmuntai
inform policy decisions and to resolve the controversies surrounding these programs. Results on the behavioral outcomes of publicly funded HIV counseling and testing programs were mixed. Several researchers reported reductions in unsafe drug use88-91 and sexual practices88'89'91-95 following counseling and testing, primarily for those who learned they were seropositive. Other researchers failed to observe a change in behaviors as a result of HV counseling and testing.9-98 These diverse results indicate that although individual knowledge of HIV serostatus can play an important role in the adoption of safer behaviors, it is probably not the only factor; nor does such information have consistent behavioral effects across different groups. Numerous reports from across the country indicate that the programtic response to HV prevention continues to involve a diverse combination ofgovemmental and nongovemmental organizations. In both industiaized and developing countries, community-based organizations are incrasing reconized as integral partners in HIV prevention programs.
Opportnist Infections and Assoaed CD4+
T-lymphoytopeni in Pe mons wtout Evidn HlVInfection Preliminary press reports and discussions among scientists at the meeting regarding persons with persistently low CD4+ T-cell counts and AIDS-like illnesses stirred much interest in Amsterdam. The Centers for Disease Control established a national surveillance system to determine the prevalence and distnbution of this condition and published preliminary reports.99.100 Additional information about HIV-negative persons with severe immunodeficiency was discussed at a follow-up meeting in Atlanta.101 By the time of the follow-up meeting, 30 US casepatients with CD4+ T-cell counts persistently below 300 per microliter and no evident HIV infection had been reported to the Centers for Disease Control. Of these, 13 had AIDS-defining illnesses, 12 were symptomatic with non-AIDS-defining illnesses, and 5 were asymptomatic. Absolute CD4+ T-cell levels ranged between 17 and 296 per microliter. There was no geographic clustering of these case-patients; many are persons at risk for HIV infection. Dates of CD4+ 1468 American Journal of Public Health
T-cell tests were available for 27 casepatients; 6 had their first lowest CD4+ T-cell count documented during the period from 1983 to 1987, 8 during 1988 to 1990, and 13 during 1991 to 1992. These case-patients resided in 15 states and ranged in age from 18 to 70 years. The observed high proportion of persons at risk for HIV infection probably reflects an ascertainment bias because these persons are likely to have lymphocyte subset determinations as part of their medical evaluations. The heterogeneous epidemiologic profile suggests that these cases represent an apparently unusual disorder, different disease entities, or both. Preliminary laboratory investigations descnbed intracistemal viral particles and reverse transcriptase activity in a few of these case-patients, but no convincng evidence was presented of the existence of a virus associated with the syndrome. The significance of these findings remains unclear. Additional epidemiologic and laboratory investigations are in progress to help clarify these observations.
Conclusion The Eighth International AIDS Symposium in Amsterdam provided updated scientific and programmatic information to thousands of interested participants working in the fields of HIV and AIDS throughout the world. As in other scientific areas, the amount of information presented in epidemiology and prevention was overwhelming; however, the scientific progress made was steady but incremental. Meanwhile, the national and international public health burden of the HIV epidemic increases each year. In the United States, between 415 000 and 535 000 cases of AIDS will have been diagnosed by the end of 1994, and well over a quarter of a million persons will be living with severe HIV disease at that time.102 Direct health care costs in the United States for persons with HIV infection or AIDS are projected to reach $13.5 billion in 1994.103 The future course of the worldwide HIV epidemic cannot be accurately predicted, but the forecasts that a minimum of 30 to 40 million people will be infected by the end of this decade are sobering.104 To stem transmission worldwide, a safe and effective vaccine is urgently needed. Currently, in the absence of such a vaccine, it is crucial for all of the world's communities to apply the best science-based prevention methods available. O
References Except for citations from published reports, the referenced materials were presented at the Eighth Intemational Conference on AIDS, July 19-24,1992, Amsterdam, the Netherlands. The numbers provided correspond to the session in which the information was presented or to numbers published in the program oforal and poster abstracts. 1. Szabo S, Miller LHI, Sacks HS, et al. Gender differences in the natural history of HIV infection. MoCO030. 2. Dorrucci M. Italian seroconversion study: age accelerates progression from HIVseroconversion to AIDS in women.
MoCO033. 3. Brettle RP, Richardson AM, Bums SM, Fielding K, Leen CLS. Survival analysis by gender and risk group for HIV in Edinburgh. MoCO066. 4. Hindin R, Bigelow C, Vickers-Lahti M, Lewis B, McCuskerJ. Genderdifferences in sharing behavior among intravenous drug users (IVDUs). PoC4254. 5. Clark LL, Calsyn DA, Saxon AJ, Jackson TR, Wrede IAF. HIV risk behaviors of heterosexual couples in methadone maintenance. PoC4656. 6. Klein RS, Adachi A, Fleming I, Ho GYF, Burk R. A prospective study of genital neoplasia and human papillomavirus (HPV) in HIV infected women. TuB0527. 7. Regevik N, Sen P, Raska K, et al. Cervical human papillomavirus (HPV) in women infected with human imnmunodeficiency virus (HIV) and its correlation with immune status and Papanicolaou smear abnormalities. TuBQ528. 8. Anastos K, Denenberg R, Solomon L, Rein S. Relationship of CD4 cell counts to cervical cytologic abnormalities and gynecologic infections in 150 HIV-infected women. TuB0532. 9. Benson C, Sha B, Urbanski P, Pottage J, Kessler H. Women with HIV disease: clinical progression and survival in a cohort followed at a university medical center. MoCX034. 10. MayerK,JesdaleB, FlaniganT, etal.The prevalence of specific illnesses in HIVinfected US women with associated CD4 counts. PoC4371. 11. DuerrA. Gynecologic conditions in HIVinfected women in Brooklyn, New York. PoB3051. 12. Valdespino JL. Epidemiology of tuberculosis. Session 64 presentation. 13. Curran JW. Public policy implications of the tuberculosis/HIV epidemics. Session 64 presentation. 14. Chintu C, Bhat GJ, Luo C, Kabika M, Raviglione MC, O'Brien RJ. Fatal skin reactions in children treated for tuberculosis in Zambia. PoB3859. 15. Aisu T, Raviglione MC, Narain JP, et al.
Monitoring HlV-associated tuberculosis in Uganda: seroprevalence and clinical features. PoC4023. 16. BroekJvd, Borgdorff MW, PakkerNG, et al. Risk of HIV infection for developing active tuberculosis. PoC4417. 17. Martin DJ, SimJGM, SoleG, Shalekoff S, Rymer L. CD4+ lymphocyte counts in
African tuberculosis patients with and without HIV superinfection. PoB3097.
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Conmeutai 18. Agins B, Felder H, Osten W, Burke G, DiFerdinando G. HIV seroprevalence in hospitalized patients with tuberculosis. PoC4665. 19. BaileyE, DiamondG, Simberkoff M. Frequency of recurrent TB and positive skin test in a cohort of ARC earlyvs late AZT treatment in a cooperative trial. PoB3070. 20. Lucas S, Hounnou A, Beaumel A, et al. The pathology of adult HIV infection in Abidjan, Cote D'Ivoire. PoB3751. 21. Lanjewar DN, Wagholikar U. Mycobacteriosis (M.TB) emerging as most common infection in AIDS victims of India. PoB3556. 22. Caligaris S, El-Hamad I, MatteelliA, et al. Prevalence of PPD reactivity and tuberculosis among HIV infected subjects. PoB3072. 23. Chidede L, Latif A. Is tuberculosis a cofactor in HIV immunosuppression? PoA2121. 24. Perriens J, St. Louis M, Prignot J, Piot P. Immunological evaluation of HIV-1 (+) patients with pulmonary tuberculosis in Kinshasa, Zaire. PoB3092. 25. European Tuberculosis Study Group. Tuberculosis (TBC) in HIV infected patients (P): a multicentric, randomized comparative study of three versus a four drug regimen. PoB3077. 26. Matela B, Mundele L, Mosengo M, et al. Survival and outcome in a cohort of 249 HIV (+) mothers followed for 60 month post-partum period in Kinshasa, Zaire.
TuC)566. 27. Pape JW, Jean S, Ho J, Johnson WD Jr. Effect of isoniazid on the natural history of HIV infection in Haiti. PoB3091. 28. Sckell B, Sehvyn PA, Alcabes P, Schoenbaum E, Kein R, Friedland G. High riskof active tuberculosis in HIV-positive anergic drug injectors; effectiveness of isoniazid prophylaxis in tuberculin reactors. TuCO567. 29. Mungal M, Nunn P, Nyamwaya J, et al. The effect ofHIV-1 on the infecfiousness of tuberulsis, Nairobi, Kenya. TuCQ569. 30. Dooley S, Edlin B, Pearson M, et al. Multidrug resistant nosocomial tuberculosis outbreaks in HIV-infected persons. TuC0568. 31. Fischl M, Uttamchandani R, Daikos G, Poblete R, Moreno J, Lai S. Outbreak of multiple drug resistant tuberculosis (MDR-TB) among patients with HIV infection. TuB0534. 32. Mullen M, Soumakis S, Lessnau K, Sanjana V, Davidson M, Talavera W. Multidrug resistant tuberculosis (MDR-TB) in patients infected with HIV. TuB0535. 33. Edlin BR, TokarsJI, Grieco MH, et al. An outbreak of multidrug-resistant tuberculosis among hospitalized patients with the acquired immunodeficiency syndrome. N Engi JMed 1992;326:1514-1521. 34. Feldblum P, Hira S, Godwins, et al. Efficacy of spermicide use and condom use by HIV-discordant couples in Zambia. WeC1O85. 35. Roddy RE, Cordero M, Cordero C, et al. Dosing study of Nonoxynol-p and genital irritation. PoB3783. 36. GervasoniC, LazarinA, MusiccoM, Sa-
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racco A. Contraceptive practices and man-to-woman HIV sexual transmission. PoC4651. 37. Boschl C, Castilho EA, Gulmaraes MP, et al. Association between oral contraceptive use and HIV infection. PoC4355. 38. Hittl J, Walker CK, Nsubuga PSJ, et al. Oral contraceptive use and HIV infection. PoC4309. 39. Pattulo ALS, Plourde P, Ndinga-Achola JO, et al. Prospective study of HIV-1 seroconversion in women with genital ulcers attending an African STD clinic. PoC4326. 40. Kreiss J, Hopkins S. The association between circumcision status and HIV infection among homosexual men. PoC4091. 41. Tyndall M, Agoki E, Malisa W, et al. HIV-1 prevalence and risk of seroconversion among uncircumcised men in Kenya. PoC4308. 42. Massimo M, Angarano A, Saracco A, et al. Antiretrviral therapy reduces the rate ofsexual transmission of HIV-1 from man to woman. WeC1088. 43. Chirianni A, Pema E, Liuzzi G, et al. Absence of anti-HIV seroconversion in heterosexual partners of H1V patients treated with zidovudine. PoC4530. 44. Tross S, Abdul-Quader AS, Silvert HM, Simons P, Des Jarlais DC, Friedman S. Determinants of condom use in female sexual partners (FSPs) of IV drug users in NY City. WeD 1075. 45. Abdul-Quader AS, Tross S, Silvert H, Simons P, Friedman SR, Des Jarlais DC. Peer influence and condom use by female sexual partners of injecting drug users in New York City. PoD 5489. 46. Ramos S, Mantell J, Majidi K, GloverWalton C, Gonzalez V, Brown LS, Jr. Gender Variations in contraceptive and reproductive attitudes, intentions and practices among New York City injecting drug users. PoD 5518. 47. Kline A, VanLandingham M. Determinants ofcondom use among HIV-infected women in New Jersey. PoD 5211. 48. Kelly JA, Sikkema KJ, Winett RA, et al. Outcomes of a 16city randomized field trial of a community-level HIV risk reduction intervention. TuD 0543. 49. Hickson F, Weatherbum P, Davies PM, Hunt AJ, Coxon APM, McManus TJ. Why gay men engage in anal intercourse. PoD 5183. 50. Ekstrand M, Stall R, Marlatt A, Pollack L, McKusick L, Coates T. Frequent and infrequent relapsers need different AIDS prevention programs. PoD 5126. 51. Nieri GN, Lemp GF, Watson RP, Nguyen S, Parisi MK, Clevenger AC. HIV-1 seroprevalence and risk behaviors among young gay and bisexual men in San Francisco. PoC 4092. 52. Ford W, Weber MD, Cheng FK, Hill DA, Kerndt PR. Trends in the prevalence of HIV infection among sexually transmitted disease patients in Los Angeles County, 1988-1991. PoC 4298. 53. Freeman AC, Krepcho M, Hedrich A, et al. Gay, bisexual, and straght men who have sex with men: HIV risk and disclosure. PoC 4099. 54. Hunter J, Rotheram-Borus MJ, Reid H,
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