title: Reactivity of serum samples from patients with a flavivirus infection measured by immunofluorescence assay and ELISA.
abstract: Flavivirus infections are a significant public health problem, since several members of the Flaviviridae family are highly pathogenic to humans. Accurate diagnosis and differentiation of the infecting virus is important, especially in areas where many flaviviruses are circulating. In this study we evaluated a newly developed commercially available immunofluorescence assay (IFA) (INDX, Baltimore, MD, USA) for the detection of IgM and IgG antibodies against dengue virus, yellow fever virus, Japanese encephalitis virus and West Nile virus. IFA was compared with standard diagnostic enzyme immunoassays (EIAs) specific for the detection of IgM and IgG antibodies against these viruses. Forty-seven serum samples from patients with a defined flavivirus infection were tested. As controls, serum samples from individuals with antibodies against tick-borne encephalitis virus and hepatitis C virus as well as healthy individuals were included. The results obtained from this study indicate that IFA showed a significantly better discrimination for flavivirus specific IgM antibodies than did the standard IgM specific EIAs (the overall cross-reactivity varied between 4 and 10% by IFA and 30-44% by EIA for the respective viruses). In contrast, the detection of flavivirus specific IgG antibodies showed high cross-reactions in both IFA and EIAs (overall cross-reactivity 16-71 and 62-84%, respectively). This study clearly stated the complexity of flavivirus diagnosis, showing that one cannot rely on one assay or search for one virus only. The flavivirus IFA is a useful tool for the identification of flavivirus infections during the acute stage of disease. In particular, IFA can be an important diagnostic tool for testing samples from travellers who have been accidentally exposed to these viruses.
authors.affiliation: Laboratory for Exotic Viral Infections, Institute of Virology, Erasmus Medical Centre, Dr Molenwaterplein 40 3015GD, Rotterdam, The Netherlands.
authors.forename: Penelopie
authors.initials: P
authors.lastname: Koraka
authors.forename: Herve
authors.initials: H
authors.lastname: Zeller
authors.forename: Matthias
authors.initials: M
authors.lastname: Niedrig
authors.forename: Albert D M E
authors.initials: AD
authors.lastname: Osterhaus
authors.forename: Jan
authors.initials: J
authors.lastname: Groen
mesh_terms: D000914:Antibodies, Viral / Q000097:blood*; D003429:Cross Reactions / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D005416:Flavivirus / Q000276:immunology / Q000302:isolation & purification*; D018177:Flavivirus Infections / Q000097:blood / Q000276:immunology* / Q000821:virology; D005455:Fluorescent Antibody Technique; D006801:Humans; D007118:Immunoassay; D007074:Immunoglobulin G / Q000276:immunology; D007075:Immunoglobulin M / Q000276:immunology; D011933:Reagent Kits, Diagnostic; D012680:Sensitivity and Specificity
chemical_list: D000914:Antibodies, Viral; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D011933:Reagent Kits, Diagnostic