1. Molecular Virology Unit, Advanced Biotechnology Center,1
2. Department of Communications Computer and System Sciences2 and
3. Department of Internal Medicine3 and
4. School of Medicine, University of Genoa, Genoa, and Virology Section, “Laboratorio Dott. Pignatelli,”Lecce,4 Italy, and
5. Division of Infectious Diseases, Mount Sinai Medical School, New York, New York5
6. Department of Surgery, Anesthesiology, Organ Transplantation and Microbiology, Section of Microbiology C. A. Romanzi,6