ABSTRACT
We conducted seroepidemiological studies on antibody prevalence to hepatitis E virus (HEV) in 5,233 sera from 11 countries to ascertain the present state of HEV infection on a global basis. The prevalence of anti-HEV IgG increased with age in these tested countries, but the rate of antibody positivity was over 20% in the 16-30 year-old group in most of the participating countries, except for Japan, the USA, and Spain. Of patients with acute hepatitis of unknown etiology from Nepal, 56% (14/25) were positive for the IgM class of anti-HEV antibody. In addition, HEV RNAs in the serum from 3 Nepali patients who had the IgM antibody were detected by nested PCR and all of the HEV genes isolated belonged to genotype 1. Our results indicate that HEV is spreading worldwide, not only in developing countries, but also in more industrialized countries than previously thought.
Subject(s)
Adolescent , Adult , Age Distribution , Aged , Aged, 80 and over , Asia/epidemiology , Bolivia/epidemiology , Child , Child, Preschool , Egypt/epidemiology , Europe/epidemiology , Female , Health Surveys , Hepatitis Antibodies/blood , Hepatitis E/epidemiology , Humans , Infant , Infant, Newborn , International Cooperation , Male , Middle Aged , Seroepidemiologic Studies , United States/epidemiology , Global HealthABSTRACT
The seroprevalence of human herpesvirus 8 (HHV-8) infection in the Thai population was investigated. Sera from 1,018 human immunodeficiency virus 1 (HIV-1)-negative and 436 HIV-1-positive individuals were tested for antibodies to latent and lytic HHV-8 antigens by indirect immunofluorescence assay (IFA) and an enzyme-linked immunosorbent assay (ELISA) using mixed recombinant orf HHV-8 proteins. The positive sera were further tested with recombinant HHV-8 protein expressed 293T cells by IFA. The seroprevalence of HHV-8 infection was determined by the concordant reactivity of sera among antibody testing assays. The results showed a low rate of HHV-8 seropositivity in both HIV-1-negative healthy individuals (0.6%) and HIV-1-infected patients (0.7%). These results are consistent with the fact that a small number of patients with AIDS-associated KS have been reported in Thailand and that HHV-8 is an uncommon pathogen in this country. Interestingly, we found that sera from the general population living in the north, but not other regions of Thailand, had antibodies to HHV-8.