1. Special Care Dentistry Center, Division of Oral and Maxillofacial Pathology, Department of Stomatology, School of Dentistry, University of Sao Paulo, Sao Paulo, SP, Brazil
2. Division of General Pathology, Department of Stomatology, School of Dentistry, University of Sao Paulo, Sao Paulo, SP, Brazil
3. Laboratory of Virology, Institute of Tropical Medicine of Sao Paulo, University of Sao Paulo, Sao Paulo, SP, Brazil