The test panel included sera from patients with primary EBV infection, immunocompromised patients with recent cytomegalovirus infection, healthy persons (blood donors), and EBV-seronegative persons. Among the tests for EBV-specific antibodies the sensitivity was good, with only small differences between the different assays. However, there was a greater variation in specificity, which varied between 100% (Enzygnost) and 86% (Biotest). Tests for detection of heterophile antibodies based on purified or selected antigen (Avitex, Alexon, Clearview IM, and Cards؎OS Mono) were more sensitive than the Paul-Bunnell-Davidsohn and Monosticon tests.The diagnosis of infectious mononucleosis is usually based on typical clinical and hematologic findings and confirmed with a positive test for heterophile antibodies. However, in some cases there is a need for analysis of Epstein-Barr virus (EBV)-specific antibodies, especially when there are atypical symptoms or in the absence of heterophile antibodies. This is often observed with specimens from children, who also may have an unusual EBV antibody pattern. Tests used for the virological diagnosis of mononucleosis should have both high sensitivity and high specificity.In Norway, tests for detection of both EBV-specific and heterophile antibodies are performed at the majority of the microbiological laboratories. Our regular quality assessment system has revealed the need for better control with the use of commercial tests. Also, over the past few years, some newly developed tests have been introduced. Together with nine other microbiological laboratories, the Department of Virology at the National Institute of Public Health (NIPH) in Oslo, Norway, conducted an evaluation of a total of 12 commercial tests for detection of EBV-specific and heterophile antibodies.
MATERIALS AND METHODSParticipants in the study. The microbiological departments in the following counties in Norway participated in the study: Aust-and Vest-Agder, Akershus, Bergen, Nordland, Oslo (NIPH, the National Hospital, and Ullevål Hospital), Rogaland, Sogn and Fjordane, and Vestfold.Tests evaluated. Table 1 gives information on the EBV serological tests evaluated, including manufacturers, antigens, test principle, and mode of detection. All enzyme-linked immunosorbent assay (ELISA) tests were based on microwell enzyme immunoassay (EIA). Table 2 gives similar information on tests for heterophile antibodies.Test panel. A test panel consisting of 248 and 241 serum specimens for the EBV antibody and heterophile antibody evaluations, respectively, was selected on the basis of both clinical diagnosis and results of laboratory investigations. Before distribution to the sites, the sera received code numbers. Specimens were assigned to the following groups.(i) Group A. Group A consisted of specimens from patients with recent primary EBV infection. The diagnosis was confirmed by a positive test for heterophile antibodies and an EBV antibody pattern compatible with recent primary infection. A total of 139 and 140 serum specime...