Comparison of seroprevalences of human herpesvirus-6 and -7 in healthy blood donors from nine countries.

BACKGROUND AND OBJECTIVES: The purpose of the study was to register antibody prevalences of HHV-7 in various locations of the world in comparison to the closely related HHV-6. MATERIALS AND METHODS: Sera of healthy blood donors from nine countries in five continents were titered by indirect immunofluorescent assays using HHV-6 infected HSB2 and HHV-7 infected SupT1 cells. RESULTS: Antibody prevalence for HHV-7 is high (75-98%) in practically all countries except for Northern Japan (44%), with no simple correlation to elevated HHV-6 antibody titers. There were regions of low, intermediate and high mean antibody titers against HHV-7 such as 78.5-91.3 for Belgium, Israel, Japan, USA and Australia, 175.4-182.6 for Mexico and Cologne/Germany, and 389.2 for South Africa for which geographic characteristics may be responsible. CONCLUSION: HHV-7, similar to HHV-6, is a widespread human herpesvirus with elevated antibody titers in the healthy human population essentially everywhere. The data warrant further studies to evaluate its possible pathologic potential, preferentially in persons with defective immune responses.

[Prevalence of human herpesvirus 7 in Mexican blood donors]. / Prevalencia del virus humano herpes 7 en donadores de sangre Mexicanos.

The human herpes virus 7 (HHV-7) has been recently isolated from CD4 cells of healthy persons. The present study describes the antibody prevalence of this virus in a healthy Mexican population. Two hundred blood samples from candidates for blood donation at the Hospital General de Mexico were studied with the indirect immunofluorescence test (IFA) in HHV-7 infected SupT1 cells. The testing was done in the University of Cologne, Germany; 167 were males and 33 female; the donors came from 12 of the 31 states in the Mexican republican, predominantly from Mexico City (60.5%) and the State of Mexico (28%). Their mean age was 29.2 years. All but three samples were positive to the HHV-7 (98.5% positivity). Nearly 85% had high titers (> or = 1:80). Other serology testing in the samples revealed 1% positive tests to hepatitis B, 2% to syphilis, and 0.5% to brucella. Hepatitis C and the HIV test were negative in all. The high prevalence of HHV-7 in our donor population should be further studied in order to determine titers indicative of an active infection and of their association with illnesses.