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EPIDEMIOLOGY, PREVENTION, AND PUBLIC HEALTH
TRACK 'C' HIGHLIGHTS

Mother-to-Child Transmission, Links Between HIV and Drug Use, TB, and STDs, Effects of War and Migration, and Evaluation of Global Prevention Efforts to Be Focus of 12^th World AIDS Conference

ENGLISH    FRENCH

(GENEVA, SWITZERLAND) - Thursday, 2 July, 1998- Following a Conference opening Plenary that focuses on the state of the art in prevention: vaccines, mother-to-child transmission, and targeted interventions, Conference track C of the 12^th World AIDS Conference includes a number of presentations examining and evaluating the effectiveness of HIV prevention efforts in different parts of the world. As with the other Conference tracks, Track C, the Epidemiology, Prevention, and Public Health track, will include important scientific presentations from all parts of the world - - so as to provide an overview of HIV as a truly global epidemic, and HIV prevention, diagnosis, and treatment as global responsibilities.

"We have learned that HIV prevention is far more complex than simply making the appropriate information available," noted Track C Chair Dr. Jean-Baptiste Brunet, of the European Centre for the Epidemiological Monitoring of AIDS, Paris. "One of the most important things we can accomplish at the 12^th World AIDS Conference is to bring together prevention researchers and advocates from around the world to take a hard look at where we are succeeding or failing in HIV prevention. What policies and interventions are useful in creating environments that help individuals control their risk of HIV infection? These are the most important questions we will ask in Track C, and may indeed be some of the most important public health questions of the end of this century".

Track C sessions will also focus on links between HIV, tuberculosis (TB), and sexually transmitted disease (STDs), new information on mother-to-child transmission, IV drug use, voluntary HIV testing and counselling, the explosion of HIV in Eastern Europe, the public health impact of new therapies on AIDS-related morbidity and mortality at population level, and HIV risks and prevention for youth.

Mother-to-Child Transmission

Mother-to-child or vertical transmission of HIV, is increasing dramatically in many parts of the world. Vertical transmission may occur during pregnancy, birth, or as a result of breast feeding by a woman infected with HIV. While vertical transmission of HIV is on the rise, recent clinical trials have indicated that interventions that are shorter and cost less than previously believed can significantly reduce the risk of mother-to-child HIV transmission.

While several Track C sessions address the many issues associated with mother-to-child transmission, these important issues are also threaded through sessions in Tracks A, B and D.

Educational, and medical issues associated with vertical transmission are addressed in session C 12 "Mother-to-Child HIV Transmission: Latest Research" (Monday, 11.00-12.30, Hall VI) which includes the research presentation, "Randomised Placebo-Controlled Trial of Short-Course Oral ZDV

to Reduce Perinatal HIV Transmission, Thailand" and other papers, including several Late Breaker studies, on efforts to reduce mother-to-child transmission, particularly in resource-poor countries.

Session C 37 "Mother-to-Child HIV Transmission: New Findings" (Wednesday, 15.00-17.00, Hall V) includes the presentation "Late Postnatal Mother-to-Child Transmission of HIV-1: International Multicentre Pooled Analysis", an international study that provides new data demonstrating that HIV transmission through breast-feeding can occur as late as sixth months after birth. This finding re-emphasises the need to minimise breast feeding by HIV-positive women, but also illustrates that prevention education after birth could still reduce HIV infections among infants. Other data presented in this session will examine including the safety and efficacy of combination therapies for pregnant HIV-positive women in the North.

A Late Breaker, titled "A Randomised Trial of Vitamin Supplements in Relation to Pregnancy Outcomes and T Cell Counts Among HIV-Infected Women in Tanzania" (Monday, 08.30-10.30, Hall VI) presents data on multivitamin supplements as a low-cost option for reducing adverse pregnancy outcomes and increasing T cell counts among pregnant women.

While the effects of zidovudine in pregnant HIV-infected women have been thoroughly evaluated, little data has been available on the effects of more advanced treatment regimens. An additional Late Breaker, "Safety of Combined Antiretroviral Therapies With or Without Protease Inhibitors in Pregnant HIV-Infected Women and Their Offspring" (Friday, 08.30-10.30, Arena) presents one of the first evaluations of the safety of these regimens on pregnant women and neonates.

Issues surrounding breastfeeding and its impact on mother-to-child HIV transmission will be considered in Bridging Session C15 "Mother-to-Child HIV Transmission: Research into Policy and Practice" (Monday, 13.00-14.30, Hall VI) and will be the focus of an entire Track D session, D25 "Mother-to-Child Transmission: Infant Feeding" (Tuesday, 15.00-17.00,  Hall I).

In addition, the determinants of mother-to-child transmission will be considered by basic scientists in session A23 "Mother-to-Child Transmission: Biological Determinants" (Tuesday, 3.00-14.30, Hall III). Treatment of those infants and children with HIV will be addressed in session B43 "HIV Infection in Children" (Thursday, 11.00-12.30, Arena).

STD Diagnosis and Treatment

Research indicates that sexually transmitted diseases and HIV are frequently linked, and that HIV treatment and prevention strategies must take into account the high degree of likelihood of co-infection with other STDs. Conference Session C 14, "Access to STD Diagnosis and Treatment" (Monday, 13.00-14.30, Hall V) includes "The Value of Risk Assessment in the Detection of Gonococcal/Chlamydial Cervical Infections at a Ugandan STD Clinic", as well as a number of other studies that focus on improving diagnosis and treatment of STDs in developing countries. The Ugandan study, one of many Conference presentations that evaluate methods of improving health care delivery in resource-poor countries, evaluates the use of behavioural data together with simple clinical assessment to diagnose and treat STD infection in the absence of access to definitive laboratory tests.

Conference Session C 42 "STD/HIV Interaction" (Thursday, 11.00-12.30, Hall VI), includes two papers from Rakai, Uganda, the site of one of the most comprehensive ongoing HIV prevention research initiatives in Africa. Among the issues and approaches examined in Rakai is the routine treatment of all pregnant women with antibiotics for STDs. Data from Rakai show a decrease in morbidity and mortality among both women and children, while the systematic prescription of antibiotics raises a number of additional concerns.

Another Rakai study, included as a Late Breaker (Friday, 08.30-10.30, Arena), is titled "The Rakai Randomised, Community-Based Trial of STD Control for AIDS Prevention: No Effect on HIV Incidence Despite Reductions in STDs." As the title of this paper suggests, this randomised, controlled, community trial found that STD control efforts created significant differentials in STD rates between study arms, but did not lead to any observable effect on HIV incidence in the study population or in key subgroups. This study suggests that, in a mature epidemic, control of STDs does not impact upon HIV prevention efforts.

HIV and Tuberculosis

For many people with HIV/AIDS, particularly in the developing world, death is actually caused by tuberculosis. The link between the HIV and TB epidemics is explored in Session C 47 "Tuberculosis and HIV in Developing Countries" (Thursday, 15.00-17.00, Hall IV). While the challenge of combating HIV and TB may seem insurmountable, particularly in resource-poor areas, one presentation in this session, "The Impact of HIV-Infection on Tuberculosis Control: A Prospective Cohort Study of African Patients" demonstrates the success of a TB and HIV prevention programme aimed at South African gold miners, a population at high risk for both diseases.

A Late Breaker paper, "Significant Reduction in Mortality Attributable to Cotrimoxazole Prophylaxis Among HIV-Infected Tuberculosis Patients in Abidjan, Côte d’Ivoire," (Friday, 08.30-10.30, Arena) finds that cotrimoxazole prophylaxis significantly reduces morbidity and mortality in HIV-infected tuberculosis (TB) patients -- findings that the authors state may have important implications for enhancing the clinical management of HIV-infected tuberculosis patients in Africa.

HIV Prevention and Evaluation

A number of Conference sessions will focus on HIV prevention and evaluation:

• Prevention programmes aimed at young people in many cultures will be the focus of Session C13, "Prevention Programmes for Youth" (Monday, 11.00-12.30, Satellite Hall 2000) co-chaired by U.S. Surgeon General Dr. David Satcher. The programme contains research presentations evaluating programmes aimed at reducing HIV risk behaviour among youth in Brazil, the United States, South Africa, Zimbabwe, and Peru.

• Post-exposure prophylaxis, sometimes erroneously referred to "morning after pills", has been the source of increasing speculation and study. Conference Session C26 "Post-Exposure Prophylaxis", (Tuesday, 13.00-14.30, Satellite Hall 2000) includes preliminary data from several studies evaluating the effectiveness and tolerability of post-exposure prophylaxis for both sexual and occupational exposures to HIV.

• "Male and Female Condoms" will be the subject of Session C38 (Wednesday, 15.00-17.00, Hall VI) One of the research presentations here, titled "Free Condoms/Sold Condoms: Which is Actually Used?" examines assumptions and reality about free condoms versus those sold through "social marketing" programmes in Uganda.

• A Late Breaker relating to these issues is titled "Protection against STDs by Granting Sex Workers the Choice of Using the Male or the Female Condom: Results from a Randomised Controlled Trial" (Friday, 08.30-10.30, Arena). This study, conducted in 34 sex establishments in four Thai cities, provides new data on the willingness of sex workers and their partners to use male or female condoms, and on reductions in unprotected sex and STDs associated with the use of each. In cases where sex workers were given the option of using male or female condoms, rates of protected sex were higher and STDs lower than in situations where only male condoms were available.

• With one new HIV infection every five seconds, the need for effective HIV prevention is critical. Questions of how to evaluate the effectiveness of prevention interventions become critical. Conference Session C45, "Model-Based Evaluation of HIV Prevention Programmes" includes studies evaluating diverse prevention efforts in Europe, the United States, and several African nations.

• One of these studies, "HIV Counselling and Testing in Tanzania and Kenya is Cost Effective: Results from the Voluntary HIV Counselling and Testing Study" includes a cost-efficiency analysis of HIV prevention that shows infections can be averted at a very small cost per life saved, and raises questions about whether it is most effective to direct scarce HIV prevention resources to those who are already HIV-positive.

Counselling and Testing

The effectiveness of voluntary HIV counselling and testing is explored in Session C17, "Counselling and Testing" (Monday, 15.00-17.00, Hall V), with presentations from the United States, Europe, and Africa.

A Late Breaker paper, (Monday, 11.00-12.30, Hall VI ) "HIV Testing of Pregnant Women and Prevention of Vertical Transmission in Africa," presents data from a large HIV counselling and testing program designed to reduce vertical transmission of HIV in a number of African cities. The study finds that the uptake of HIV testing has increased among pregnant women in Africa. Yet, the acceptability of testing was lower among more highly educated women, and women infected with HIV were three times less likely to return for test results.

Risks for Gay Men

While HIV transmission patterns have shifted in both developed and developing worlds, gay men remain at particular risk for HIV in many parts of the world. Session C11 "Gay Men: Risks and Community Response" examines risk behaviours and prevention interventions, the effects of multiple loss on gay communities, and the particular risk for HIV infection associated with young gay men. Session C35 "Culture and Community: Men Who Have Sex With Men" (Wednesday, 13.00-14.30, Hall VI) reviews a number of important studies on innovative programmes to prevent HIV transmission among gay men and other men who have sex with men in the developing world. This has long been an under-addressed area of significant concern in the transmission of HIV in the South.

Local Policies and Their Implications for the Global HIV Epidemic

The HIV epidemic does not exist in a social or political vacuum. Other social and political pressures, including war and social upheaval, economic disruptions, and changes in government affect HIV transmission, prevention, diagnosis, and treatment, and can dramatically shift the global epidemic.

Session C 32 "Local Policies, National Issues, Global Impact" (Wednesday, 11.00-12.30, Hall VI) examines several of these issues. One of the papers presented here, "Medical Supply for HIV/AIDS in Developing Countries: Thailand Experience" looks at the Asian economic crisis in terms of its effect on HIV education and treatment in one of the Asian countries most affected by HIV/AIDS.

War, Migration, and the HIV Epidemic

Many parts of the world that are most affected by HIV/AIDS are also those facing war, displacement, and mass migration. Conference Session C 25 "Migration and HIV" (Tuesday, 13.00-14.30, Hall VI) examines what happens to HIV prevention, diagnosis and treatment efforts in populations in crisis. How these programmes are designed and implemented, and the effectiveness of HIV outreach on different categories of displaced persons will be examined in research presentations that focus on sub-Saharan Africa, India, and Bosnia and Herzegovina.

Harm Reduction for Injecting Drug Users

Needle exchanges, and other programmes aimed at harm reduction rather than abstinence from drugs, remain controversial in most of the world. Conference Session C36 "Harm Reduction Programmes for IDUs", (Wednesday, 13.00-14.30, Satellite Hall 2000), examines needle exchanges and other HIV prevention interventions targeted to active injection drug users in Eastern Europe, the United States, Bangladesh, and Brazil.

Epidemiological Trends

Conference Session C41, "Trends and Patterns of HIV Epidemics" (Thursday, 11.00-12.30, Hall V) focuses on trends in HIV infection and AIDS diagnosis in different parts of the world, including Thailand, the Philippines, Sub-Saharan Africa, and Eastern Europe. One of the session presentations, "The HIV/AIDS Epidemic in Europe: Changing Trends and New Challenges" examines the gap between Eastern and Western Europe in new HIV infections.

A Late Breaker study (Friday, 08.30-10.30, Arena), titled "How Suitable are Antenatal Clinic Attendees as a Sentinel Population to Estimate HIV Prevalence in Rwanda?", found that this anonymised measure of HIV infection is imprecise -- overestimating infection in urban areas while underestimating infection rates in rural ones. However, the authors conclude that, while inexact at sub-population levels, this method is still useful to monitor overall national trends in HIV infections.

While AIDS incidence is declining in much of Western Europe, mainly as a result of better treatments, and HIV infection there has largely stabilised, countries of the former Soviet Union, which until 1995 had virtually no HIV epidemics, have experienced large outbreaks of HIV infections over the past two years. Studies presented here indicate that this part of the world, which was previously virtually untouched by HIV, may experience the next explosion in AIDS diagnoses.