HIV in low- and middle-income countries

Abstract The HIV pandemic has disproportionately affected people in low- and middle-income countries. In many countries in sub-Saharan Africa, HIV infection is established in the general population: in southern Africa, which is particularly severely affected, adult HIV prevalence has reached 30% in some areas. Local epidemiology depends on the balance between incidence (due to sexual contact, mother-to-child transmission, or exposure to blood or blood products) and mortality, and the effect of antiretroviral therapy on both mortality and transmission. The main route of transmission is sex between men and women. The manifestations of HIV disease vary by geographical region, reflecting increased frequency of exposure in low- and middle-income countries to common pathogens such as tuberculosis, non-typhoid salmonellae, and Streptococcus pneumoniae. People with advanced immunosuppression are also at risk of disease due to geographically restricted opportunistic pathogens (e.g. leishmania and Tarolomyces marneffei).