[1] Univ Calif San Francisco, Sch Nursing, San Francisco, CA 94143 USA
[2] Calif Dept Publ Hlth, Occupat Hlth Branch, Richmond, CA USA
[3] Calif Dept Publ Hlth, Healthcare Associated Infect Program, Richmond, CA USA
[4] Ctr Dis Control & Prevent, Natl Ctr Immunizat & Resp Dis, Immunizat Serv Div, Atlanta, GA USA