Global HIV epidemiology: specific patterns of the epidemic in the North and South.

Thirty years after the identification of the first cases of AIDS, it was estimated that 34 million of people were living with HIV worldwide in 2011. The incidence is declining but remains high, with 2.5 million of new HIV infections per year. Africa is the region of the world most heavily affected, accounting for three-quarters of the global burden of HIV infection and the same proportion for new infections. The incidence declines in most parts of the world while heterosexual transmission remains the dominant mode of HIV acquisition followed by homosexual transmission. Intravenous drug use continues to drive the epidemic in Eastern Europe and parts of Asia. Condom use remains the cornerstone of prevention of sexual transmission. Male medical circumcision has now been proven an effective public health intervention to prevent sexual transmission. Antiretroviral treatment may reduce sexual transmission at population level while improving the conditions of life and survival of those harbouring the virus. Harm-reduction together with blood safety prevent blood transmission. The prevention of mother-to-child transmission is now moving its global objective to elimination by the end of 2015. At least 20 years will be necessary for achieving HIV control at the worldwide level with currently available interventions.