1. Institute for Veterinary Medical Research, Centre for Agricultural Research, Hungarian Academy of Sciences, H-1581 Budapest, P.O. Box 18, Hungary
2. National Food Chain Safety Office, Veterinary Diagnostic Directorate, Tábornok u. 2, H-1143 Budapest
3. Center for Biologics Evaluation and Research, Food and Drug Administration, 10903 New Hampshire Avenue, Silver Spring, MD 20993