1. Department of Infectious Diseases and Microbiology, University of Pittsburgh, Pittsburgh, Pennsylvania.
2. Department of Cell Biology and Physiology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania.
3. Division of Infectious Diseases, Department of Medicine, Miriam Hospital/Alpert Medical School, Brown University, Providence, Rhode Island.
4. Division of Infectious Diseases, Department of Obstetrics and Gynecology, Miriam Hospital/Alpert Medical School, Brown University, Providence, Rhode Island.