The deadly interaction: HIV/AIDS and other diseases
The interaction of HIV/AIDS with other infectious diseases is an increasing public health concern. In sub-Saharan Africa, for example, malaria, bacterial infections and tuberculosis (TB) have been identified as the leading causes of HIV-related morbidity (22). HIV infection increases both the incidence and severity of clinical malaria in adults (23). In some parts of Africa, falciparum malaria and HIV infection represent the two most important health problems.
The pandemic has brought about devastating changes in the epidemiology of TB, especially in Africa where about one-third of the population is infected with TB but does not necessarily have the disease (it is dormant). However, by the end of 2000 around 17 million people in Africa and 4.5 million people in south-east Asia were infected with both TB and HIV (24). A high proportion of these people can be expected to develop active TB unless they receive treatment (25), because HIV, by weakening the immune system, greatly increases the likelihood of people becoming ill with TB.
In African countries with high rates of HIV infection, including those with well-organized control programmes, case-notification rates of TB have risen more than fourfold since the mid-1980s, reaching more than 200 cases per 100 000 population in 2002 (25). In the USA, 16% of TB cases have been attributed to the virus.
In parts of Asia and eastern Europe, the number of people coinfected with multidrug-resistant TB and HIV is also likely to increase. In India, for example, where an estimated 1.7 million adults in 2000 were coinfected with TB and HIV, there is a multidrug resistance rate of up to 3% of previously untreated TB patients.