EPIDEMIOLOGY OF INFECTION WITH EPSTEIN-BARR-VIRUS TYPE-1 AND TYPE-2 -LESSONS FROM THE STUDY OF A T-CELL-IMMUNOCOMPROMISED HEMOPHILIC COHORT

In apparent contrast to earlier work on Epstein Barr virus (EBV) carri age in the general Caucasian population, in vitro virus isolations fro m human immunodeficiency virus (HIV)-positive male homosexual cohorts have shown frequent examples of multiple EBV infection and an overall prevalence of type 2 EBV strains exceeding 30%, Here we ask to what ex tent these findings might hold true in another T-cell-immunocompromise d cohort, HIV-positive hemophilic patients. Resident EBV strains were rescued within lymphoblastoid cell lines derived from the blood and th roat washings of 39 such individuals, using the same in vitro protocol s of virus isolation as for the homosexual cohort. A mean of 19 indepe ndent cell lines was made per patient, and in each case the resident v irus was characterized by PCR-based viral genomic analysis and by immu noblotting to reveal the viral ''EBNAprint.'' By these criteria a sign ificant proportion (14 of 39) of the hemophilic cohort carried more th an one EBV strain, suggesting that T-cell impairment does indeed sensi tize virus carriers to reinfection with new strains of exogenously tra nsmitted virus. However, the overall incidence of type 2 EBV infection was 10%, which is close to that observed in the earlier work with hea lthy carriers and substantially lower than that seen in HIV-positive h omosexuals. We infer that type 2 EBV is relatively rare in the general Caucasian population but has become endemic in the homosexual communi ty.