Human herpesvirus 8 epidemiology: what we do and do not know.

Abstract

Human herpesvirus 8 (HHV-8), also known as ‘Kapo-si’s sarcoma-associated herpesvirus’ (KSHV), was firstidentified in 1994 [1]. Its discovery is a good exampleof how epidemiological and molecular-biological datacan be combined to evaluate causality for a putativeagent [2]. In fact, before the discovery of HHV-8,the analysis of surveillance data had suggested that, inHIV-infected individuals, there existed an infectiousco-factor other than HIV that was critical to thedevelopment of Kaposi’s sarcoma (KS), leading to theidentification of HHV-8 in KS tissues [3].HHV-8 is now considered to be the necessary cause ofall variants of KS, including AIDS KS, classic KS,endemic KS and iatrogenic KS, and is a determinant ofother rare diseases, such as primary effusion lymphoma,or body cavity-based lymphoma and multicentric Cas-tleman’s disease [4,5]. However, various aspects of theepidemiology of HHV-8 infection still need to beclearly defined: in particular, the evolution of theHHV-8 epidemic, the appropriate serological assaysand their application, the distinct distribution featuresof HHV-8 in relation to KS, transmission modalities,and the natural history of infection. In the present text,we provide a synopsis of what we do and do not knowabout the epidemiology of HHV-8 infection, especiallywith regard to Africa. It is therefore not intended toprovide an exhaustive review but to highlight thecurrent thinking about HHV-8, as guided by thepioneering research performed to date.