[1] Los Angeles Cty STD Program, Los Angeles, CA 90007 USA
[2] Ctr Dis Control & Prevent, Natl Ctr HIV STD & TB Prevent, Div STD Prevent, Atlanta, GA USA
[3] Los Angeles Cty Publ Hlth Lab, Los Angeles, CA USA
[4] Ctr Dis Control & Prevent, Natl Ctr HIV STD & TB Prevent, Div HIV AIDS Prevent, Atlanta, GA USA
[5] San Francisco Dept Publ Hlth, San Francisco STD Control Program, San Francisco, CA USA