1. Institute for Laboratory Medicine, Microbiology & Infection Control, Northwest Medical Centre, Academic Teaching Hospital, Medical Faculty, Goethe University Frankfurt, Steinbacher Hohl 2-26, D-60488 Frankfurt am Main, Germany
2. INSTAND e.V., Gesellschaft zur Förderung der Qualitätssicherung in medizinischen Laboratorien e.V., Ubierstraße 20, D-40223 Düsseldorf, Germany
3. Institute for Medical Microbiology & Infection Control, University Hospital Frankfurt, Goethe University Frankfurt, Paul-Ehrlich Str. 40, D-60596 Frankfurt am Main, Germany
4. W. Harry Feinstone Department of Molecular Microbiology & Immunology, Bloomberg School of Public Health, Johns Hopkins University, 615 N Wolfe St, Baltimore, MD 21205, USA