[1] Columbia Univ, Med Ctr, Dept Internal Med, Div Infect Dis, New York, NY 10027 USA
[2] Columbia Univ, Med Ctr, Dept Pediat, Div Infect Dis, New York, NY 10027 USA
[3] New York Presbyterian Hosp, Comprehens Hlth Ctr, HIV Prevent Program, New York, NY USA
[4] Columbia Univ, Med Ctr, Dept Pathol & Cell Biol, New York, NY USA