Diagnosis and surveillance of dengue virus infections: gold standards and new directions.

The dengue viruses belong to the family Flaviviridae, named after the prototype yellow fever virus, which has played a leading role in the development of the science of medical virology. Other important viruses in this family are the Japanese encephalitis virus, St. Louis encephalitis virus and tick-borne encephalitis virus. All these viruses are arthropod-borne viruses and are important causes of human disease. The most important breakthrough in laboratory diagnosis of arboviruses was the development of the haemagglutination test which detected the presence of virus antigen.'32 The detection of antibody to viral haemagglutinin was now possible using a haemagglutination inhibition test with haemagglutinins prepared from the sera of infected monkeys, and thus began the tradition of the haemagglutination inhibition (HI) test. The much cited work of Clarke and Casals on HI test methods made it possible to make confirmatory laboratory diagnoses of many arbovirus infections by demonstrating seroconversions in paired sera, and this has since been the "gold standard" of arbovirus serology . This paper will discuss currently used methods of diagnosis of dengue virus infection and will review critically the many recently published variations of methods used for the determination of anti-dengue IgM. We will then take a brief look at future trends and needs in the development of tools for the diagnosis and surveillance of dengue virus infections.