AIDS around the World

Just as clearly, experience shows that the right approaches, applied quickly enough with courage and resolve, can and do result in lower HIV infection rates and less suffering for those affected by the epidemic. An ever-growing AIDS epidemic is not inevitable; yet, unless action against the epidemic is scaled up drastically, the damage already done will seem minor compared with what lies ahead. This may sound dramatic, but it is hard to play down the effects of a disease that stands to kill more than half of the young adults in the countries where it has its firmest hold.

Already, 18.8 million people around the world have died of AIDS, 3.8 million of them children. Nearly twice that many - 34.3 million - are now living with HIV, the virus that causes AIDS, and most of these are likely to die over the next decade or so. The most recent UNAIDS/WHO estimates show that, in 1999 alone, 5.4 million people were newly infected with HIV.

Africa: the enormous challenges of a long-lasting epidemic

The African countries south of the Sahara have some of the best HIV surveillance systems in the world. They show that in most sub-Saharan countries, adults and children are acquiring HIV at a higher rate than ever before: the number of new infections in the region during 1999 was 4 million. This acceleration effect is yet another challenge posed by long-standing epidemics. As the rate of HIV infection in the general population rises, the same patterns of sexual risk result in more new infections simply because the chances of encountering an infected partner become higher.

Altogether, there are now 16 countries in Africa in which more than one-tenth of the adult population aged 15-49 is infected with HIV. In seven countries, all in the southern cone of the continent, at least one adult in five is living with the virus. In Botswana, a shocking 35.8% of adults are now infected with HIV, while in South Africa, 19.9% are infected, up from 12.9% just two years ago. With a total of 4.2 million infected people, South Africa has the largest number of people living with HIV/AIDS in the world.

Whilst West Africa is relatively less affected by HIV infection, the prevalence rates in some large countries are creeping up. Cط£ئ’ط¦â€™ط£â€ أ¢â‚¬â„¢ط£ئ’أ¢â‚¬ع‘ط£â€ڑط¢آ´te d'Ivoire is already among the 15 worst affected countries in the world; in Nigeria over 5% of adults have HIV but the prevalence rate in other West African countries remains below 3%.

Infection rates in East Africa, once the highest on the continent, hover above those in the West of the continent but have been exceeded by the rates now being seen in the southern cone. The prevalence rate among adults in Ethiopia and Kenya has reached double-digit figures and continues to rise.

These rises are not inevitable. Uganda has brought its estimated prevalence rate down to around 8% from a peak of close to 14% in the early 1990s with strong prevention campaigns, and there are encouraging signs that Zambia's epidemic may be following the course charted by Uganda. Yet, even in these countries, the suffering generated by HIV infections acquired years ago continues to grow.

Asia holds HIV at bay - but for how long?

In comparison with the rates of HIV infection in Africa, those in the general populations of Asia are low. The prevalence among 15-49-year-olds exceeds 1% in only three countries - Cambodia, Myanmar and Thailand. In other countries the prevalence rate is overall far lower. In Indonesia, fewer than 5 people in 10,000 are living with HIV. In the Philippines, the rate of HIV infection is only slightly higher, at 7 per 10,000.

These figures do not tell the whole story, however. Within the largest Asian nations, some geographic regions have far more inhabitants than most African countries and have HIV prevalence rates far greater than the national average. In Asian countries in which the epidemic is concentrated in certain groups, such as injecting drug users, it is misleading to focus solely on the prevalence in the general population.

China and India between them account for around 36% of the world's population. With such huge populations, even low HIV prevalence rates mean that huge numbers of people live with the virus. Indeed, in India, where only 7 adults in 1,000 are infected with HIV, 3.7 million people were living with HIV/AIDS by the end of 1999 - more than in any other country in the world except South Africa. India's epidemic is highly diverse: whilst some states show almost no HIV infection, others have reached adult HIV prevalence rates of 2% and above.

In parts of north-east India, widespread injecting drug use provided an easy early entry-point for HIV. In Manipur, the prevalence of HIV infection among injecting drug users shot up from virtually nothing in 1988 to over 70% just four years later, and it has remained at these high levels ever since. Predictably, since almost all injecting drug users in the state are men, HIV then spread to their wives and girlfriends through unprotected sex. Around 2.2% of pregnant women in Manipur tested positive for HIV in 1999. In other states, even higher levels of HIV have been recorded among pregnant women. Most cases of infection appear to have been acquired from husbands who had been infected in turn by sex workers, themselves part of a longer chain of transmission. By the mid-1990s, a quarter or more of sex workers in cities such as New Delhi, Hyderabad, Madurai, Pune, Tirupati and Vellore tested positive for HIV. In Mumbai, the prevalence of HIV infection among sex workers reached 71% in 1997.

The Indian Government and individual state governments have launched prevention programmes to reduce high-risk sex, and there is evidence that in some states these programmes are resulting in safer behaviour. If current prevention efforts can be scaled up and sustained, India may be able to bring down the rates of HIV infection in particularly exposed groups and avert a widespread heterosexual epidemic.

Latin America: an epidemic with many faces

The HIV epidemic in Latin America is highly diverse. Most transmission in Central American countries and countries on the Caribbean coast occurs through sex between men and women. Brazil, too, is experiencing a major heterosexual epidemic, but there are also very high rates of infection among men who have sex with men and injecting drug users. In Mexico, Argentina and Colombia, HIV infection is also confined largely to these sub-populations. The Andean countries are currently among those least affected by HIV infection, although risky behaviour has been recorded in many groups.

The countries with the highest prevalence rates in the region tend to be found on the Caribbean side of the continent. Over 7% of pregnant women in urban Guyana tested positive for HIV in 1996. Studies of sex workers in the capital, Georgetown, showed that 46% of street and brothel-based women were infected with HIV, and over a third of the women said they never used condoms with clients.

In Honduras, Guatemala and Belize there is also a fast-growing heterosexual epidemic, with HIV prevalence rates among adults in the general population between 1 and 2%. In 1994, less than 1% of pregnant women using antenatal services in Belize District tested positive for HIV, while one year later the prevalence had risen to 2.5%, the rate in one health centre, in Port Loyola, hitting 4.8%. In the Honduran city of San Pedro Sula, the rate of HIV infection among pregnant women has fluctuated between 2% and 5% for several years. Much of the problem is concentrated in teenagers, suggesting that the worst is still to come.

Heterosexual transmission of HIV is rarer in other countries of Central America. In Costa Rica, for example, HIV is transmitted mainly during unprotected sex between men. In this country, as in many other parts of Latin America, there is little systematic surveillance for HIV among groups with high-risk behaviour, but studies among men who have sex with men in Costa Rica showed infection rates of 10-16% as long ago as 1993.

In Mexico, too, HIV has affected mainly men who have sex with men, more than 14% of whom are currently infected. HIV rates among pregnant women, however, are extremely low. Data from a programme to reduce the transmission of HIV from mothers to infants suggest that fewer than 1 in every 1,000 women of childbearing age is infected. Even among female sex workers in Mexico, the prevalence rate is well under 1%.

HIV in the Caribbean: small islands, large epidemic

HIV is ravaging the populations of several Caribbean island states. Indeed, some have worse epidemics than any other country in the world outside of sub-Saharan Africa. In Haiti, over 5% of adults are living with HIV, and in the Bahamas the adult prevalence rate is over 4%. In the Dominican Republic, 1 adult in 40 is HIV-infected, while in Trinidad and Tobago the rate exceeds 1 adult in 100.

At the other end of the spectrum lie Saint Lucia, the Cayman Islands and the British Virgin Islands, where fewer than 1 pregnant woman in 500 tested positive for HIV in recent surveillance studies. In most of the worst-affected countries of the Caribbean, the spread of HIV infection is driven by unprotected sex between men and women, although infections associated with injecting drug use are common in some places, such as Puerto Rico. High rates have also been recorded among small populations of men who have sex with men in a number of islands, including Haiti and Jamaica.

Haiti is the worst-affected nation in the region. In some areas, 13% of anonymously tested pregnant women were found to be HIV-positive in 1996. Overall, around 8% of adults in urban areas and 4% in rural areas are infected. HIV transmission in Haiti is overwhelmingly heterosexual, and both infection and death are concentrated in young adults. It is estimated that nearly 75,000 Haitian children had lost their mothers to AIDS by the end of 1999.

The Dominican Republic also has a substantial heterosexual epidemic. The HIV prevalence rate among new mothers in the capital, Santo Domingo, more than doubled over a seven-year period reaching 1.9% in 1997, while the average rate in sex workers and patients with sexually transmitted infections was around 6-8%.

The heterosexual epidemics of HIV infection in the Caribbean are driven by the deadly combination of early sexual activity and frequent partner exchange by young people. In Saint Vincent and the Grenadines, where the prevalence of sexually transmitted infections such as syphilis is high for the region, a quarter of men and women in a national survey said they had started having sex before the age of 14, and half of both men and women were sexually active at the age of 16.

Eastern Europe and Central Asia: drug injecting is still the main risk

In the countries of the former Soviet Union, the HIV epidemic continues to be concentrated heavily in injecting drug users. The absolute number of cases has remained small in many countries so far, but overall the growth has been rapid.

In Ukraine, the number of diagnosed HIV infections jumped from virtually zero before 1995 to around 20,000 a year from 1996 onwards, about 80% of them in injecting drug users. As HIV spreads and new infections occur, the total number of people living with HIV continues to grow, reaching an estimated 240,000 at the end of 1999, compared with 110,000 two years earlier.

In any country with unsafe drug-injecting practices, a fresh outbreak of HIV is liable to occur at any time. This is especially true of the countries in Eastern Europe where the HIV epidemics are still young and have so far spared some cities and sub-populations. In the Russian Federation, a new outbreak of HIV among injecting drug users in the Moscow region in 1999 resulted in the reporting of more than three times as many new cases in that year than in all previous years combined. Whilst about 130,000 Russians are thought to be already infected with HIV, recent estimates of the number of injecting drug users in the country range between 1 and 2.5 million. Obviously, many more infections may still occur in this group, apart from the risk of further spread of HIV into other parts of the population.

High-income countries: long survival but more risk behaviour

In high-income nations, HIV infections are concentrated principally among injecting drug users and gay men. The available data suggest that there are very low HIV infection rates among heterosexuals in the general population. In Germany in the mid-1990s, fewer than 3 out of 10,000 women of childbearing age were infected. Similarly low rates have been recorded elsewhere. Very early in the epidemic, once information and services for prevention had been made available to most of the population, the level of unprotected sex fell in many countries and the demand rose for reproductive health services, HIV counselling and testing and other preventive services.

The situation is very different among injecting drug users. Some communities and countries have initiated aggressive HIV prevention efforts in this group, containing the HIV prevalence rate to below 5%. In many places, however, the political cost of implementing needle-exchange and other prevention programmes has been considered too high for such programmes to be started or maintained. As a result, there are continuing high prevalence rates among injecting drug users in many high-income countries. In Canada, nearly half of all new HIV infections occur in this group. In Spain, a study in Barcelona found a prevalence rate of 51% among injecting drug users.

Among gay men the virus had spread widely before it was even identified and had established a firm grip on the population by the early 1980s. With massive early prevention campaigns targeted at gay communities, risk behaviour was substantially reduced and the rate of new infection dropped significantly during the mid and late 1980s. Recent information suggests, however, that the frequency of risk behaviour may be increasing again in some communities. This and the effects of therapies that keep infected people alive for longer have added up to slowly rising numbers of people living with AIDS.

Credits:

Global Youth Alliance...

This article is taken, with adaptations, from the "Report on the Global HIV/AIDS epidemic June 2000" published by UNAIDS and AVERT