HIV epidemiology and the effects of antiviral therapy on long-term consequences

Abstract

Twenty-seven years have now elapsed since the first description of AIDS in homosexual men in San Francisco, USA. Since those early reports in 1981, millions of people have died from this disease and millions are living with HIV infection worldwide. The rate of new cases of HIV infection has stabilized in some parts of the developed world, but in other areas of the world, especially in Africa, south-east Asia and eastern Europe, the number of newly infected individuals continues to rise alarmingly. Despite international commitment, there is still much to be done to improve access to antiretroviral drugs in areas of greatest need, especially sub-Saharan Africa. The availability of antiretroviral drugs is a key factor in limiting the pandemic and prolonging the lives of those infected, but a more universal, targeted approach, incorporating prevention, early diagnosis, counselling and treatment, will only succeed in stemming the spread of the virus. In the face of the apparent inability to control the increasing rate of new infections there are some positive signs in the battle against HIV/AIDS. In developed countries, the introduction of antiretroviral drugs has resulted in a significant reduction in AIDS-related mortality and improved survival. As access to antiretroviral drugs in the developing world improves, it is hoped that these trends will begin to be reflected worldwide. As HIV/AIDS shifts from a fatal to a chronic disease, however, a new range of health complications and threats to mortality are beginning to arise.

Fig. 1. Impact of HIV on life expectancy in Africa

Botswana; South Africa; Swaziland; Zambia; Zimbabwe. Reproduced with kind permission of UNAIDS [1].

Fig. 2

Cumulative proportion of patients surviving by months after the first diagnosis of an AIDS-defining opportunist infection 1997–2004 [6].

Fig. 3. Decline in registered AIDS-related mortality in age groups with implementation of antiretroviral therapy in Botswana

■ On antiretroviral treatment; 0–4 years; ● 5–24 years; ◆ 25–54 years; ▲ 55+ years. ART, Antiretroviral therapy [8].

Fig. 4. Estimated number of AIDS patients and deaths among adults and adolescents with AIDS (United States and dependent areas) 1985–2005.^a

▲ AIDS; ◆ deaths. ^aData have been adjusted for reporting delays [22].