To win a War against any dreaded disease of epidemic proportions, one needs the appropriate armaments, such as adequate skills to tackle the problem, workable strategies, needed drugs, including suitable diagnostic, prophylactic and therapeutic products and resources in terms of infrastructure and finance. Where does the World stand with respect to each of these components, which will make it possible to control, if not eradicate this disease in all its manifestations?
No other disease has attracted so much attention as AIDS, in the history of human ailments. The issues that the disease has raised at the Global level are related to needed versus available resources, current status of treatment options, compulsions to change certain life styles and prospects for discovery and development of appropriate drugs and vaccines.
Recognised for the first time in 1981 by the US-based Centre for Disease Control (CDC), initially it was considered a disease restricted to homosexual men (the original name given to the disease was Gay Related Immuno Deficiency - GRID). Within a couple of years it became apparent that it affected other populations as well, including users of hypodermic needles, transfused blood and intravenous drugs, regardless of whether they are homo or heterosexual men or women.
It is remarkable that within two years of the recognition of the disease as a new entity, two groups led by Robert Gallo at the National Cancer Institute and Luc Montagnier of the Institute Pasteur clearly established the aetiology of the disease to a new virus, now commonly referred to as HIV, even though, the controversy over the priority for this discovery is still unsettled. By 1985, a diagnostic method was developed which is capable of detecting antibodies against the virus. Due to the relatively high mortality from the disease in a short time and partly due to many opportunistic diseases which emerged as a result of the infection based on a virus, the disciplines of immunology and virology in relation to their relevance to HIV infection and AIDS got major support from public funded agencies, most notably in the United States.
Incidence of AIDS
According to the estimates by UNAID reported in 2002 at Barcelona, 40 million people including 3 million children were living with HIV/AIDS, there were 3 million deaths and 5 million got newly infected in 2001. Geographically, the number of adults and children estimated to be living with HIV/AIDS at the end of 2001 were around 1 million in N America, 1.5 million in Latin America, 400,000 in the Caribbean, 28.5 million in Sub-Saharan Africa, 500,000 in Western Europe, 1 million in Eastern Europe and 1 million in East Asia and the Pacific. Africa, particularly Sub Saharan Africa is the worst affected with the number increasing every year at double-digit growth rates. There are however some unexplained pockets, even within Africa, where decrease in incidence has been reported. Thu, for example, in Uganda, Cote d'Ivore and Senegal there has been reduction in incidence, not due to administration of retroviral drugs, but perhaps due to creation of better awareness and prevention strategies. In India, the National Aids Control Organisation (NACO), estimates the number at 3.31 million HIV infected people in 2001, which, if a 20% variability due to underestimates are taken into account, would rise to around 4 million, up from 2.25 million in 1995. NACO has also reported that there was a marginal decrease in new cases in 2001, for example, 0.11 million in 2001 against 0.16 million in 2000. NACO predicts that if this trend continues and if the States and the Union Territories in India fully implement the planned programmes, the burden of new infections will decrease in the next five years.
In a more recent report (Feb 2003), the U.N. estimates that by 2050, the population of nations hit hardest by AIDS will be fewer by 480 million people because of AIDS as against 300 million predicted two years back. India alone will account for 47 million of these deaths and China for 40 million. Most of the 53 nations hit most by AIDS are in Sub Saharan Africa, where, in Botswana, Lesotho, Namibia, South Africa, Swaziland, Zambia and Zimbabwe, the report says more than 20% of their population are infected with HIV. In Botswana, in particular, one third of all adults are infected. Life expectancy in the country, which was 65 years in 1995 has plunged to 56.3 in 2000 due to AIDS. In the next 10 years, life expectancy in Botswana is expected to drop to 39.7, unless new strategies and effective treatment modalities are in place.
As far as U.S., a country which claims to have been successful in arresting the spread of the disease is concerned, much of it has been achieved by creating better awareness among the high-risk groups and access to retroviral drugs. The programme systematically promoted by the CDC consisted of strategies for prevention among individuals identified as high-risk cases and improved linkages to treatment and care. CDC's surveillance programmes have tracked the course of the infection since the first cases were reported twenty or more years back. As a result of these interventions, it was possible to reduce mother to child infection from an estimated 1000 -2000 per year, in the mid fifties to 300-400 in 2001.
Since the first case was identified in the U.S. as AIDS in 1981, there have been 774,467 cases reported and around 450,000 Americans have died from AIDS and consequent opportunistic infections. The peak for new infections was in the mid eighties, around 150,000 in a year, which came down to 40,000 by the mid nineties. Today around 500,000 - 600,000 live with HIV infection in the U.S., with another 280,000, as another report suggests, infected, but not diagnosed. The sharp decline in AIDS in the U.S., since 1996 led to the number of cases leveling off by 1999. However, an indication that there is no room for complacency became obvious from a recent report (Feb 2003) that in 25 States in the U.S., AIDS cases actually increased by over 8% between1999 and 2001. Data is still not available for the other States, some of them known to have high incidence.
Do the Numbers Lie?
There has been some criticism that the numbers estimated by various agencies, of HIV prevalence and incidence is much too high and consequently, the hysteria generated is not justified. For example the Governments of India and South Africa had openly expressed reservations about the figures quoted by many sources for their countries. In India after the visit of Bill Gates in 2002 and his announcement of aid for combating AIDS to the tune of $ 100 million, the Government questioned the high figures quoted for HIV/AIDS cases in India, notwithstanding the extensive data provided by NACO from its epidemiological studies, more or less justifies the numbers.
President Mbeki of South Africa contended that the problem in that country is not so much AIDS, but poverty. The increased deaths from Tuberculosis and Pneumonia were not due to AIDS infection, according to him, but were merely independent infections. In Dec 2002, as per the Nelson Mandela-initiated project based on a well conducted field survey in South Africa, HIV infection in the 15-49 age group, the most vulnerable for infection, projected figures were brought down from 20 to 15.6 %. Overall the report claimed that there are 4.5 million infected people (around 11% of the population) in the country. Even though these figures are marginally lower than the earlier estimates, President Mbeki's playing down the problem does not appear to be vindicated. The Government stand on not heeding the real numbers could also have been partly motivated by the demand on the Government from the patients and activists to provide retroviral drugs at affordable prices to the people of the country who are in dire need.
Conclusion
There is no unequivocal evidence to establish that there is a decline in HIV infections around the World, or for that matter even in countries, such as U.S., Thailand, Uganda and a few others where, based on limited data it has been suggested that a certain degree of control has been effected. The multi-aetiological nature of the disease, the ability of the organism(s) to rapidly mutate, absence of vaccines, inadequacy and poor efficacy of available drugs to cure the disease, unacceptable adverse reactions triggered by present-day approved drugs, lack of access to even the available therapeutic agents, failure of preventive methods, including promotion of safer sex, non-reuse of hypodermic needles, quality control of blood used in transfusions and a host of other related factors have made the fight against the disease almost a losing battle.
The predictions for the future, made by various organizations have assumed that breakthroughs particularly for prevention of the disease with vaccines or cure with effective and safe drugs are unlikely to be achieved in the very near future. Hopefully this assumption will turn out to be wrong. National Governments and International agencies are seized of the problem and major R&D efforts are under way in many laboratories around the World. How soon one sees light at the end of the tunnel will depend on our ability to harness all available resources, and utilize them to better understand the disease, the organism and aspects of host immunity. Concurrently, preventive approaches including life style changes would be required if the targets set by the consortium of interested groups to reduce this menace to manageable levels are to be achieved.
-- The author is a top research scientist & industry observer