Dying in stages

Dying in stages

twenty years ago, the world received a major jolt when reports about the existence of the acquired immune deficiency syndrome (aids) virus was confirmed. It has spread so fiercely over the years that it now rivals history's deadliest epidemics -- plague and influenza. aids has gradually moved towards becoming the top five leading causes of death the world over. So far, it has killed as many people as malaria has and is second only to tuberculosis.

Reports suggest that about 5.6 million people were infected and 2.3 million people killed in 1997. And it is spreading. Especially in the developing countries. Of the 30 million people infected with the aids -causing human immunodeficiency virus ( hiv), about 90 per cent live in developing nations. If the trend continues, experts predict that 40 million people around the world could harbour hiv by the year 2000 .

Just before the 12th World aids Conference concluded in Geneva, Switzerland, recently, the United Nations (un) issued a grim report on the aids epidemic. According to this report, people in Africa have been the worst affected. In Botswana and Zimbabwe, one in every four adults is an aids patient. One-third of the adults and about 70 per cent of women in some major African cities are infected by the virus. Many infected women pass the virus on to their babies.

In 13 African nations, hiv has infected at least 10 per cent of adults while countries south of the Sahara has reported the highest rates of infection among adults aged 15-49, the most sexually active segment of the popula tion. According to health officials, South Africa, Namibia and other countries could soon reach a 25 per cent adult infection rate unless these countries initiate strong prevention programmes similar to those in Senegal and Uganda.

Today, the average hiv infection rate is about one per cent among adults the world over. The rate is 0.76 per cent in the us and 0.33 per cent in Canada, according to a United Nations aids Programme report .

Peter Piot, head of the unaids Programme, says the new report provides evidence that aids rivals the greatest epidemics of history. Plague and influenza can kill in days, but death from untreated aids can take even up to a decade. aids is a silent epidemic, Piot says, because the massive, long-term mortality from aids has less of a visible impact on society than the sudden deaths due to plague or influenza. He says the problems could multiply in the future unless various countries take strong action to prevent transmission or an anti- aids vaccine is discovered.

In 1997, death from aids left 1.6 million children with a single parent. During 1981-1998, 8.2 million children lost their mothers to aids . In east Africa, 40 per cent of children (15 or younger) have lost their mother or both parents.

The unaids has cited four reasons for the high infection rate in Africa:

• More women of the child-bearing age are infected with hiv in Africa than elsewhere.

• African women beget more children than mothers elsewhere. Hence the chances of infecting more number of children are higher.

• Nearly all children are breast-fed. Breast-feeding also accounts for hiv transmission from mother to a child.

• Non availability of new drugs.

In the us , aids is spreading largely among the black community. Blacks comprise 13 per cent of the us population but account for about 57 per cent of hiv cases, according to the us Centre for Disease Control and Prevention. Among people aged 13-24, the estimate based on data collected from 25 states from January 1994 to June 1997, is a staggering 63 per cent. And while the death rate from aids is on the decline the world over, the disease is still the leading cause of deaths among black people between the age of 25 and 44.

Figures for Asia, where hiv is a latecomer, are less reliable because only a few Asian countries have developed sophisticated methods for monitoring the spread of the virus. India has the largest number of hiv -infected people -- four million -- in the world.

Seeking solutions
The 12th World aids Conference focused on the problems in Africa. Health officials called on the world community to fight the killer disease. They stressed the need to provide treatment to the worst-hit regions of the world and called on governments to become more active in fighting the deadly disease.

A global plan was proposed to hasten the development of the aids vaccine. The International aids Vaccine Initiative (iavi), an independent non-profit scientific organisation, released a "scientific blueprint" designed to advance progress in preventive vaccines against the hiv virus and also to experiment them in developing countries where they are needed the most.

"Only a vaccine has a chance of ending this global epidemic. However, the world is not on track to meet the goal of a safe and effective aids vaccine in the next decade," says Seth Berkley, president of iavi. The purpose of this programme is to put vaccine development on a fast track. "This is our best hope of stopping the epidemic that has continued to gallop along with the current 16,000 newly-infected persons each day," Berkley says.

iavi plans to identify gaps in scientific development, provide technical assistance to poorer nations and encourage public and private collaboration in vaccine research. It has also proposed the creation of up to six international product development teams to identity promising vaccines and get them into trials as soon as possible.

Also, the first widescale testing of an anti- aids vaccine on humans is underway in Thailand and the us. "Aidsvax" targets the hiv virus in a bid to prevent widespread infection in Australia, South Asia, the us and western Europe.

Ray of hope
Researchers are optimistic that a drug will someday be found which may be able to eliminate the aids virus from the body or reduce it to a point where the immune system can successfully control it. "Eradication of hiv is not a myth," says Roberto Siliciano of John Hopkins University, usa . The goal, he says, is to find the spots in the body where the virus lingers and then kill it.

Combination drug therapies with medicines called protease inhibitors can reduce the level of the hiv virus in the blood stream so much that they cannot be readily measured. However, tests show that the so-called memory cd 4 cells in the lymph tissues continue to harbour the virus. After a person has spent years on anti- aids treatment, the immune responses that have been damaged by the aids virus rebound and grow more powerful. Some scientists believe that at this point it may sometimes be possible for the immune system to control the lingering infection even if the virus is not wiped out entirely.

During the Geneva conference, researchers unveiled a surprisingly powerful and easy-to-use combination drug therapy that may change the way hiv infections are treated. The new therapy slashes the prescribed number of pills -- from 10 to three a day. The therapy's relatively simple dosing regimen makes it the first potent combination of anti- aids drugs with the potential to be widely used in poorer areas, where taking many medicines each day is impractical. But the relatively high cost and the fact that the drugs will still need to be taken every day makes it impossible to reach the 27 million hiv -infected people in Africa, Asia and South America. It is important for scientists, doctors, activists, policymakers and those infected by the disease to ensure that advances in understanding, prevention and treatment are relevant to the vast majority of people living with hiv/aids .