GUEST ARTICLE AIDS: Invest Now or Pay More Later SETH BERKLEY, PETER PIOT, AND DORIS SCHOPPER human immunodeficiency virus (HIV). Since greater because it mainly affects productive S DEVELOPING coun- the beginning of the epidemic, over 14 million young adults, and the resultant illnesses lead persons have probably been infected and over to demands for costly care. tries seek the most cost- 2 million have died. There are cost-effective interventions to effective ways to control The HIV epidemic is still growing—unlike slow the epidemic, yet current annual world- fil many other relatively stable diseases such as wide expenditure on AIDS prevention is only the spread of AIDS, the malaria—and holds the potential to become about $1.5 billion a year, with perhaps less World Development Report 1993 one of the most costly and debilitating epi- than $200 million of this spent in developing argues that no country is demics for developing countries. While HIV is countries. Among them, Thailand spends the still less common than diseases such as most ($45 million in 1992, 75 percent of which immune. Delaying action will malaria, its economic impact per case is far was from government funds), whereas total sharply raise the cost of spending throughout Sub-Saharan Africa was only double this amount, a mere 10 percent of intervening and increase the Developing countries bear the which came from government funds. heaviest burden threat the epidemic poses to A recent WHO study suggests that compre- Estimated distribution of HIV prevalence hensive services to prevent AIDS and sexually development. Without a cure, in adults, late 1993 transmitted disease (STD) in all developing prevention holds the key, along (millions) countries would cost $1.5 billion to $2.9 billion a year. While this would be a substantial with research on vaccines and Sub-Saharan Africa 7.00+ increase in current spending, WHO estimates South and Southeast Asia 2.00 that the number of new adult HIV infections treatments Latin America and the Caribbean 1.00+ North America .80 averted could be as high as 9.5 million over the Western Europe .40 next decade. This article looks at the most Although the first cases of AIDS were not North Africa and Middle East .08 cost-effective ways to fight the spread of identified until 1981, the virus has now spread Eastern Europe and Central Asia .05 East Asia and Pacific .03 AIDS, drawing heavily upon the studies worldwide, with cases reported in 173 coun- Australasia .02 undertaken for the World Bank's World tries. The World Health Organization (WHO) Development Report 1993. estimates that, currently, over 12 million per- Global total 11-12 sons—90 percent of whom live in developing Source: World Health Organization. Why a special case? countries (see table)—are infected with the For developing countries, a key question 40 Finance & Development / June 1994 ©International Monetary Fund. Not for Redistribution these days is how much of limited gov- Moreover, the effects of losing an adult ernment funds should be spent on Chart 1 persist into the next generation as chil- The shifting trend among regions dren are withdrawn from school to help fighting AIDS, especially given that (estimated global annual AIDS incidence) there are other diseases that currently at home. exact a higher toll. The WDR 1993 Preventing AIDS prevents argues that the spread of HIV and other key transmissible diseases. AIDS merits special and immediate Efforts to slow the spread of HIV attention for several reasons: will also reduce the magnitude of the The HIV epidemic is bad and STD and tuberculosis (TB) epidemics. getting worse. The HTV virus is STDs are extremely common (over 250 spread in three ways: through sexual million new infections worldwide contact, through contact with contami- per year), are harder to treat in nated blood or blood products, and HIV-infected individuals, and have from mother to child during the perina- severe, often irreversible consequences tal period with an additional risk dur- that disproportionately compromise ing breast-feeding. In developing women. Besides their enormous bur- countries, HIV is ostensibly an STD, den, STDs increase by three- to fivefold with over 85 percent of infections the transmission and acquisition of occurring through heterosexual inter- HIV. course. Source: World Health Organization. For individuals previously infected Available evidence suggests that all with the tuberculosis bacillus, infection HTV-infected individuals will ulti- with HIV is one of the most important mately suffer from AIDS and that all factors promoting the development of AIDS patients will die within a few years. care giver for those infants not infected will active tuberculosis. There are estimated to be Because, on average, it takes six to ten years contribute to a reversal of the long-term down- more than four million persons dually for an HIV-infected adult to develop AIDS, ward trend in child mortality. In these heavily infected. TB is already the first and second regardless of future changes in HIV transmis- affected countries, population growth rates ranked cause of disease burden in young and sion, there will be an increasing number of will decline substantially, although due to the middle-aged males. In females, it ranks second AIDS cases over the next few years. Already, high fertility rates, growth will still be posi- and third in the same age groups. Increasing the estimated 12 million infected individuals tive. But it is in Asia where the virus is numbers of active TB infections will lead to constitute about 2.4 percent of the world's spreading fastest (Chart 1). In Thailand, 2 per- further spread in both the HTV and non-HIV global burden of disease—the present value of cent of the adult population is already infected populations. future streams of disability-adjusted life years infected, and India is in the midst of an explo- The cost-effectiveness of the avail- (DALYs) lost as a result of death, disease, or sive epidemic. able interventions rapidly declines as injury. This measure attempts to gauge the AIDS is an especially costly disease. the epidemic spreads. Since there is no full loss of healthy life. At the macro level, AIDS poses a threat to eco- vaccine or cure for AIDS, primary prevention But even these figures obscure the true nomic growth in many countries already in is the only current method of fighting the magnitude of the epidemic. In young adults in distress. Indeed, World Bank simulations indi- epidemic. Without it, AIDS spreads rapidly developing countries, HIV/AIDS is already the cate an annual slowing of growth of income in the transmission, or "core," groups—those greatest cause of disease burden in males and per capita by an average 0.6 percentage point particularly vulnerable to acquiring and the fourth greatest cause in females. per country in the ten worst affected countries transmitting infection due to high-risk activi- Conservative projections indicate that the in Sub-Saharan Africa. ties—followed by a slower and then accelerat- number of persons infected with HIV will The powerful negative impact of AIDS on ing spread in the general population (Chart 2). increase to more than 26 million in the year households, productive enterprises, and coun- Thus, early and effective targeting of HIV 2000, with 1.8 million deaths that year alone, tries stems partly from the high costs of treat- interventions is critical because the cost-effec- contributing about 3.3 percent to the global ment, which divert resources from productive tiveness of these interventions diminishes as burden of disease. Given the short time it investments, and mostly from the fact that the infection moves out of the high transmis- takes infection rates to double in many devel- AIDS primarily affects people during their sion groups into the general population. oping countries and the recent spread to coun- economically productive adult years, when Studies in nine developing and seven high- tries with low infection levels, total figures in they are typically responsible for the support income countries suggest that preventing one 2000 could even be two or three times higher. and care of others. case of AIDS saves, on average, about twice Of course, there are large differences in One study in a rural African community the GNP per capita in discounted lifetime infection rates among regions and within has shown that 89 percent of the deaths in the costs of medical care. In some urban areas, the regions. For a long time, Africa, where it is population of those 25-34 years can be savings may be as much as five times GNP estimated that HIV accounts for 6.3 percent of attributed to HTV infection (an excess mortal- per capita. Moreover, indirect costs are an esti- the burden of disease, had to contend with the ity of 13/1,000). These adult deaths can tip mated five to ten times higher. In Thailand, for most rapid spread of the virus. In some vulnerable households into poverty. Even in example, calculations suggest that if we could African populations, 1 in 40 adults is already Tanzania, where the government pays a large slow transmission rates by just 20 percent, infected, whereas in certain capital cities, the share of health costs, a Bank study shows that discounted savings in medical costs by the prevalence of infection is as high as 1 in 3 sex- affected rural households in 1991 spent year 2000 would be $1,250 per currently ually active women. The deaths of their $60—roughly the equivalent of annual rural infected person, or a potential total of $560 infected offspring as well as the loss of the income per capita—on treatment and funerals.