Developments in STD/HIV interactions: The intertwining epidemics of HIV and HSV-2

More than 75 million people worldwide have been infected with HIV over the past 2 decades despite ambitious global prevention programs. Currently 40 million people are living with HIV and over 35 million have died from AIDS. The spread of HIV has been primarily through sexual intercourse with a lesser proportion of cases attributable to intravenous drug use and contaminated blood transfusions. The alarming numbers camouflage the fact that the HIV virus is spread inefficiently through sexual intercourse, perhaps as infrequently as 1 out of 1000 sexual exposures. Sexually transmitted diseases, particularly ulcerative genital diseases, increase infectiousness and susceptibility to HIV infections. Data from international and domestic studies point increasingly to the role of herpes simplex virus type 2 (HSV-2) as a primary cofactor in facilitating the spread of HIV infection. This article reviews the recent developments in this important interaction and the potential impact of different intervention strategies targeting HSV-2.