Quality control assessment for the serological diagnosis of tick borne encephalitis virus infections.
BACKGROUND
The diagnosis of tick borne encephalitis (TBE) is mainly based on the demonstration of specific antibodies in serum when neurological disease is manifested. Improving diagnostics is the most important step in detecting and dealing with these pathogens. Quality control measures are essential for TBE diagnosis.


OBJECTIVE
To assess an external quality assurance (EQA) program for the serologic diagnosis of TBE infections.


METHODS
A panel of 12 serum samples was sent out to be tested for the presence of TBE virus-specific IgM and IgG. This panel contained seven TBE-positive samples for IgM and/or IgG; three negative samples; two samples positive either for West Nile virus (WNV) or Dengue virus (DENV).


RESULTS
Fourty-two laboratories from 25 European and 2 non-European countries participated in this EQA. The correct answer by each laboratory for all samples ranked between 58 and 96% and sera with IgM antibody positive for TBE were correctly recognized by 46-88% of the laboratories. Sera with IgG antibody positive for TBE were correctly recognized by 83-95% of the laboratories. False TBE-positive results were obtained with DENV, WNV or negative sera only for IgG-based assays.


CONCLUSIONS
Correct results for at least 90% of the samples were obtained by 33 of 40 participating laboratories for IgM and for 16 of 42 laboratories for IgG.
Niedrig
Matthias
M
Robert Koch-Institut, Nordufer 20, 13353 Berlin, Germany. niedrigm@rki.de
Avsic
Tatjana
T
Aberle
Stephan W
SW
Ferenczi
Emöke
E
Labuda
Milan
M
Rozentale
Baiba
B
Donoso Mantke
Oliver
O
D000914:Antibodies, Viral / Q000097:blood*; D004669:Encephalitis Viruses, Tick-Borne / Q000276:immunology*; D004675:Encephalitis, Tick-Borne / Q000097:blood* / Q000276:immunology; D005455:Fluorescent Antibody Technique / Q000379:methods; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology; D007075:Immunoglobulin M / Q000097:blood / Q000276:immunology; D011786:Quality Control; D012698:Serologic Tests / Q000379:methods / Q000592:standards
D000914:Antibodies, Viral; D007074:Immunoglobulin G; D007075:Immunoglobulin M