Vaccine and Infectious Disease Division

Herpes may predict HIV epidemics

Unlike sub-Saharan Africa, North Africa and the Middle East have relatively low rates of HIV, but epidemiological data in these areas are sparse.  Assessing those who may be at high risk for HIV infection has proved difficult, in part because of the conservative nature of many countries in this region.  Recently, VIDD affiliate investigator Dr. Laith Abu-Raddad and colleagues conducted more extensive risk behavior surveys in these areas among populations generally at higher risk of HIV infection, including sex workers, men who have sex with men, and drug users, and found that while infection rates remain low even in these groups, high risk behavior does exist in these areas.  These results implied that North Africa and the Middle East may be in danger of future HIV epidemics.

Infection with the sexually transmitted herpes simplex virus-2 (HSV-2) often goes hand in hand with HIV infection, as HSV-2 infection increases HIV acquisition and transmission rates, and both are more common in areas with higher levels of sexual risk taking.  Some scientists believe that an HSV-2 epidemic may have paved the way for the HIV epidemic in sub-Saharan Africa.  Abu-Raddad and colleagues, including VIDD research associate Dr. Joshua Schiffer and affiliate investigator Dr. Rhoda Morrow, used mathematical modeling to ask whether population data on HSV-2 infection can predict future HIV epidemics.  While data on HSV-2 infection rates are also limited in North Africa and the Middle East, the researchers’ model predicted that if HSV-2 infection levels are low, as is currently seen in these areas, large-scale HIV epidemics are unlikely, but increased HSV-2 infection rates past 20 percent predict risk of a significant HIV outbreak.  Using additional corroborating predictions of HIV infection such as HSV-2 infection may help researchers get a better picture of sexual behavior and HIV likelihood in areas with limited epidemiological information, such as North Africa and the Middle East.

Abu-Raddad LJ, Schiffer JT, Ashley R, Mumtaz G, Alsallaq RA, Ayodeji Akala F, Semini I, Riedner G, Wilson D.  HSV-2 serology can be predictive of HIV epidemic potential and hidden sexual risk behavior in the Middle East and North Africa, Epidemics (2010).