Signs of Progress Emerge in Worldwide AIDS Battle

There were no breakthroughs announced here last week against the deadly AIDS virus at the International Conference on AIDS, nor were any expected. But emerging from the often bewildering array of about 950 oral presentations and written research statements were signs of slow but concrete progress in the fight against the virus.

These signs of progress--in understanding the biology of the virus and how it spreads, and in detecting the virus in blood and steps toward a possible vaccine--were tempered by a sober realization that this global health problem is likely to become profoundly more serious in the years ahead.

“The world is five years into a new epidemic but just beginning to recognize it and focus a barely adequate level of attention on it,” said Dr. Michael S. Gottlieb of the UCLA Medical Center, one of the first physicians to identify the unusual illnesses that are collectively known as acquired immune deficiency syndrome.

At this second international conference, attended by about 3,000 health care workers and journalists, there was an undeniable sense of gloom created by the predictions of an increasing number of AIDS cases for the foreseeable future and the bewildering number of diseases associated with the virus.

“It is profoundly depressing that every time you think you’ve heard of the last new complication of AIDS, you hear about something else,” said Dr. Harry Hollander, the chief physician for AIDS patients at the UC Medical Center, San Francisco.

Many public health officials, believing that the AIDS threat has been underestimated to date, were careful not to hold out high hopes when no breakthrough appears on the horizon.

“One has to be struck with the crisis proportions that exist now and certainly are predicted without overstating the case,” said Dr. Mervyn Silverman, former director of the San Francisco Department of Public Health and currently a coordinator of AIDS programs for the Robert Wood Johnson Foundation, one of the leading private groups supporting medical projects in the United States.

“As public health officials, we try to be somewhere between ‘Chicken Little, the sky is falling’ and apathy,” Silverman said. “But if we do the apathy bit on AIDS, (we will be faced with) Chicken Little in two years.”

But from interviews with dozens of participants seeking to make sense out of the three days of intense scientific discussions, a series of concrete steps forward--mostly achieved in the last year--stood out.

Understanding the Virus

Dr. Robert C. Gallo of the National Cancer Institute, a discoverer of the AIDS virus, said “spectacular progress” has been made in understanding the virus itself. This has included the discovery in recent months of a key viral gene whose removal stops the virus from reproducing.

He predicted that almost all the “very fundamental information” about the virus and its effects on the human immune system will be known within a year, when the third international conference is set for Washington next spring.

While most reports on drug therapy against the virus were pessimistic or too premature for results to be reported, some participants were heartened by the quickening pace of research on an AIDS vaccine, even though the ultimate success of these efforts is uncertain.

Researchers from Genentech in South San Francisco and Oncogen in Seattle, as well as a West German group, announced progress in using genetic engineering techniques to manufacture trial vaccines.

Some leading researchers, such as Harvard Medical School’s Dr. William Haseltine and Dr. Jay Levy of the UC Medical Center, San Francisco, expressed skepticism about the chances for success with a vaccine. This is because of the apparent ability of the AIDS virus to hide inside cells and thus escape detection by the body’s immune system.

It will be impossible to resolve this uncertainty until vaccine test results from monkeys and chimpanzees are available. The first such results may be announced by the end of the year.

Progress was also evident in understanding the epidemiology of the AIDS virus and how it spreads. The virus is transmitted by heterosexual or homosexual contact that involves the exchange of body fluids such as semen, through contaminated blood or needles and from mother to newborn, according to many presentations here. There is no evidence that the AIDS virus is spread by casual contact, insects or poor sanitary conditions.

The virus attacks the immune system, particularly a key cell called the T-4 lymphocyte, leaving the victim vulnerable to a variety of infections and tumors. The virus appears equally contagious in different parts of the world, although individuals who have additional illnesses, such as a venereal disease, may more easily transmit the disease to others by sexual contact.

Concentrates in Blood Cells

The AIDS virus concentrates in the infection-fighting white blood cells, which are produced in large amounts in the genital organs in response to diseases such as gonorrhea. Some researchers suggested that this factor may explain why AIDS seems more easily spread by heterosexual contact in places such as Haiti and Africa, where venereal illnesses are more likely to go untreated than in the United States.

By comparison, physicians remain perplexed by the growing list of illnesses related to AIDS and the marked variation in the extent of these illnesses in different parts of the world and between patients in different risk groups. These yet-to-be-explained variations make it more difficult to develop treatments for patients.

For example, pneumonia caused by the Pneumocystis carinii microbe is the leading infection in AIDS patients in the United States, but not in Africa, where the common AIDS infections are the Cryptococcus fungus and the toxoplasma protozoa. And the tumor Kaposi’s sarcoma is found in Africa and in homosexual men in the United States, but is unusual in intravenous drug users, another high-risk group.

Equally perplexing are the recently recognized brain diseases that appear to be directly caused by the AIDS virus. The most feared brain complication is encephalopathy. It leaves its victims confused and often unable to care for themselves.

At the UC Medical Center, San Francisco, encephalopathy is a major problem for about 30% of AIDS patients, according to Hollander, who said, “We are not close to understanding what it is and how to treat it.”

With a better realization of the complexities of the AIDS virus, the focus of disease control efforts has broadened to include not just patients with the fatal disorder, but also patients who are infected with the virus but have no symptoms. Up to 30% of such individuals may develop AIDS within five years of becoming infected and others will develop related diseases, according to several presentations here.

The 100,000 AIDS cases that are estimated to have developed in the world to date are just the “tip of the iceberg,” Dr. James W. Curran of the federal Centers for Disease Control said. In addition, 5 million to 15 million people may be infected with the AIDS virus. In the United States, there have been about 22,000 cases of AIDS, and about 1 million to 1.5 million people may be infected with the virus.

Detecting Virus in Blood

The most practical benefit of AIDS laboratory research has been the rapidly improving techniques for detecting the virus in the blood. These tests complement efforts to screen out blood donors in AIDS risk groups.

Indeed, Dr. Harvey J. Alter of the National Institutes of Health predicted the “total elimination” of new cases of blood transfusion-related AIDS virus infections in the United States by the end of next year, even though one such “very rare” case developed recently.

All of these developments will facilitate the establishment of public health programs to prevent transmission of the AIDS virus, according to Dr. Jonathan M. Mann, the newly appointed coordinator of the World Health Organization’s AIDS control program.

In the absence of effective therapy or a vaccine against this fatal disease, prevention of infection is the only way to halt its spread, many experts said at the meeting. “Effective and frank prevention messages are all we have,” UCLA’s Gottlieb said.

In developing countries, these programs will be needed if unnecessary blood transfusions and injections with unsterile needles, common means of transmitting the virus, are to be eliminated. The availability of simpler, less expensive AIDS blood tests will also help.

In all countries, educational programs to change behavior will be stressed. One of the few concrete examples of success, albeit only partial, in controlling the spread of the disease was provided by Dr. Warren Winkelstein of the University of California, Berkeley. Because of changed sexual practices in response to intensive educational programs, he reported that the rate of new AIDS virus infections has slowed considerably among homosexual men in San Francisco over the past four years. Nevertheless, about 50% of the homosexuals in the city are estimated to be viral carriers.

Heterosexuals and AIDS

In the United States, an increasing concern is preventing the transmission of AIDS between heterosexuals. To this point, these cases, which occur in both men and women, mostly result from heterosexual contact with a bisexual man or an intravenous drug user.

“We need to get our prevention act together real fast to stop this infection from becoming self-sustaining in the heterosexual population (as it is in Africa),” said Dr. Don Des Jarlais of the New York Division of Substance Abuse Services.

As the basic scientific understandings of the AIDS virus are nailed down, researchers hope that additional practical benefits will be realized. But until then, as the AIDS death toll continues to mount, many are sustained by their faith in science and the spirit of international collaboration that was evident here despite some widely publicized feuding in the past between French and American researchers.

“It was an inspirational meeting to have colleagues share this sense of commitment that overtakes everyone who works on AIDS,” said the World Health Organization’s Mann. “Once you get into this, you are driven by the sense of urgency and the need to contribute your part.”