Evaluation of immunological markers in serum, filter-paper blood spots, and saliva for dengue diagnosis and epidemiological studies

BackgroundNumerous immunological approaches exist to diagnose dengue or detect dengue virus (DENV) infections.ObjectivesTo determine the best immunological markers and specimen types for dengue diagnosis and for measuring incidence of DENV infection in community-based studies.Study DesignIn one study, acute- and convalescent-phase samples were collected from hospitalized suspected pediatric dengue cases in Managua, Nicaragua, from September 2003 to February 2004. A second study examined specimens collected in a community setting in Managua before and after the 2003–2004 dengue season to measure incidence of DENV infection. In both studies, detection of anti-DENV IgM, IgA, and IgG in serum, filter-paper blood spots, and saliva was compared to a gold standard performed on serum samples.ResultsFor dengue diagnosis, the highest sensitivity and specificity was obtained by measuring IgM or IgA in serum or filter-paper blood spots; intermediate and poor results were obtained in saliva for IgM and IgA, respectively. Detection of IgG alone in serum, filter-paper blood spots, or saliva functioned best for measuring DENV infection.ConclusionsDetection of IgM and IgA in serum and filter-paper blood spots yielded optimal results for diagnosis of dengue cases, whereas IgG was the best marker for measuring incidence of DENV infection.