Kaposi’s sarcoma-associated herpesvirus (KSHV) is the ninth known human herpesvirus; its formal name according to the International Committee on Taxonomy of Viruses (ICTV) is Human gammaherpesvirus 8, or HHV-8 in short.
This virus causes Kaposi’s sarcoma, a cancer commonly occurring in AIDS patients, as well as primary effusion lymphoma, HHV-8-associated multicentric Castleman’s disease and KSHV inflammatory cytokine syndrome. It is one of seven currently known human cancer viruses, or oncoviruses. Even after so many years of discovery of KSHV/HHV8, there is no known cure for KSHV associated tumorigenesis.
The seroprevalence of HHV-8 varies significantly geographically and infection rates in northern European, southeast Asian, and Caribbean countries are between 2-4%, in Mediterranean countries at approximately 10%, and in sub-Saharan African countries at approximately 40%. In South America, infection rates are low in general but are high among Amerindians.
Even within individual countries, significant variation can be observed across different regions, with infection rates of about 19.2% in Xinjiang compared to about 9.5% in Hubei, China. Although seroprevalence has been consistently shown to increase with age in a linear manner, countries with high infection rates may see higher seroprevalence in younger age groups. Educational level has shown an inverse correlation with infection rates. Individuals infected with HIV-1 or genital warts are generally more likely to be co-infected with HHV-8.