Funding for this research was provided by:
Centers for Disease Control and Prevention (IU62PS003959-01/13-20643-02)
First Online: 7 February 2017
Compliance with Ethical Standards
: All authors, no potential conflict of interest.
: All procedures were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. Full committee IRB approval was obtained from the Philadelphia Department of Public Health. Data were collected as part of routine HIV surveillance activities.