Does proficiency testing improve the quality of hantavirus serodiagnostics? Experiences with INSTAND EQA schemes.
Hantavirus infections in Germany appear periodically with peak numbers every 2-3 years. The reported cases in the years 2007, 2010 and 2012 exceeded many times over those in the years in-between. In order to reveal faults of certain in vitro diagnostic assays (IVDs), to harmonize the performances of the individual assays and to improve the users' competence in interpreting the results, the National Consiliary Laboratory for Hantaviruses and INSTAND e.V. (Society for Promoting Quality Assurance in Medical Laboratories e.V.) established an external quality assessment (EQA) scheme for proficiency testing of hantavirus serodiagnostics. The first EQA scheme (pilot study) started in March 2009 with 58 participating laboratories from Germany and neighboring countries. Twice a year four serum samples were sent out to the participants to investigate whether the sample reflects an acute or past infection and to distinguish between infections with the hantavirus types Puumala virus (PUUV) and Dobrava-Belgrade virus (DOBV), both endemic in Central Europe. In addition, samples negative for anti-hantavirus antibodies were tested in order to examine the specificity of the IVDs applied in the participating laboratories. An increasing number of laboratories participated, with a maximum of 92 in March 2014. When summarizing in total 2592 test results, the laboratories reached an overall specificity of 96.7% and a sensitivity of 95% in their detection of a hantavirus infection. A correct distinction between acute and past infections was forwarded in 90-96% of replies of laboratories. Exact serotyping (PUUV vs. DOBV) of the infection was reported in 81-96% of replies with the lowest accuracy for past DOBV infections; cross-reactivities between diagnostic antigens of the two viruses as well as persistent IgM titers in humans may interfere with exact testing. The EQAs revealed acceptable results for the serodiagnostic of hantavirus infection including serotyping but further improvement is still needed.
National Consultant Laboratory for Hantaviruses, Institute of Medical Virology, Helmut-Ruska-Haus, Charité-University Medicine, Charitéplatz 1, 10117 Berlin, Germany. Electronic address: joerg.hofmann@charite.de.
Jörg
J
Hofmann
GBD Gesellschaft für Biotechnologische Diagnostik mbH, Potsdamer Chaussee 80, 14129 Berlin, Germany.
Hans-Peter
HP
Grunert
INSTAND e.V., Society for Promoting Quality Assurance in Medical Laboratories, Ubierstrasse 20, 40223 Düsseldorf, Germany.
Oliver
O
Donoso-Mantke
INSTAND e.V., Society for Promoting Quality Assurance in Medical Laboratories, Ubierstrasse 20, 40223 Düsseldorf, Germany; Institute of Virology, Campus Benjamin Franklin, Charité-University Medicine, Hindenburgdamm 27, 12203 Berlin, Germany.
Heinz
H
Zeichhardt
National Consultant Laboratory for Hantaviruses, Institute of Medical Virology, Helmut-Ruska-Haus, Charité-University Medicine, Charitéplatz 1, 10117 Berlin, Germany.
Detlev H
DH
Kruger
D005060:Europe; D018778:Hantavirus Infections / Q000175:diagnosis*; D006302:Health Services Research; D006801:Humans; D059021:Laboratory Proficiency Testing / Q000379:methods* / Q000458:organization & administration*; D012680:Sensitivity and Specificity; D012698:Serologic Tests / Q000379:methods*
Dobrava-Belgrade virus; Hantavirus; Proficiency testing; Puumala virus