Subject(s)
Antibodies, Viral/blood , Herpesviridae Infections/epidemiology , Herpesvirus 8, Human/immunology , Viral Proteins , Adolescent , Adult , Africa/ethnology , Antigens, Viral/immunology , Comorbidity , Denmark/epidemiology , Female , Glycoproteins/immunology , Gonorrhea/epidemiology , Greece/ethnology , Herpesviridae Infections/ethnology , Herpesviridae Infections/virology , Humans , Israel/ethnology , Italy/ethnology , Male , Odds Ratio , Prevalence , Seroepidemiologic StudiesABSTRACT
Epidemiologic studies of infection with the oncogenic human herpesvirus 8 (HHV-8) depend on serologic methods to diagnose infection. However, optimal strategies for identifying HHV-8 infection remain undefined. We therefore evaluated four enzyme-linked immunoassays (EIAs) and one immunofluorescence assay (IFA) using sera from 87 individuals with the prototype HHV-8 disease, Kaposi's sarcoma (KS), and 210 participants in a hemophilia study (who were presumed not to be infected with HHV-8). Assays performed reasonably well in distinguishing between infected and uninfected persons, with receiver operator curve areas between 0.86 and 0.96. Nonetheless, IFA had only 86% sensitivity and 88% specificity, and no EIA simultaneously had sensitivity and specificity above 90% for any of the optical density (OD) cutpoints used to define seropositivity. Some assays were markedly less sensitive with diluted KS sera, suggesting that they poorly identify low-titer antibodies present in asymptomatic infection. We also developed a classification tree that categorized individuals as seropositive if they had OD > 2.00 on recombinant K8.1 protein EIA or if they had both K8.1 OD between 0.51 and 2.00 and positive IFA results; this strategy had between 80% and 90% sensitivity and 95% and 100% specificity. Overall, assays performed adequately for use in most epidemiologic investigations, but wider applications will require improved tests.
Subject(s)
Antibodies, Viral/blood , Fluorescent Antibody Technique, Indirect , Herpesvirus 8, Human/immunology , Immunoenzyme Techniques , Sarcoma, Kaposi/diagnosis , AIDS-Related Opportunistic Infections/diagnosis , AIDS-Related Opportunistic Infections/virology , Adult , Aged , Evaluation Studies as Topic , Female , Hemophilia A , Humans , Male , ROC Curve , Sarcoma, Kaposi/virology , Sensitivity and SpecificityABSTRACT
During the last interglacial, Antarctic climate changed before that of the Northern Hemisphere. Large local changes in precession forcing could have produced this pattern if there were a rectified response in sea ice cover. Results from a coupled sea ice-ocean general circulation model supported this hypothesis when it was tested for three intervals around the last interglacial. Such a mechanism may play an important role in contributing to phase offsets between Northern and Southern Hemisphere climate change for other time intervals.
