1. NeuroAIDS SNRP, University of Puerto Rico, Medical Sciences Campus, San Juan, Puerto Rico.
2. Neurology Section, Department of Internal Medicine, University of Puerto Rico, Medical Sciences Campus, San Juan, Puerto Rico.
3. Department of Orthopedic Surgery, Johns Hopkins University, Baltimore, Maryland.
4. Neurology Department, Johns Hopkins University, Baltimore, Maryland.
5. Center of Sexually Transmitted Diseases, San Juan, Puerto Rico.
6. Maternal Infant Studies Center, University of Puerto Rico, Medical Sciences Campus, San Juan, Puerto Rico.