[1] Ctr Infect Dis Res Zambia, Plot 34620,Off Alick Nkhata Rd,POB 34681, Lusaka 10101, Zambia
[2] Amer Inst Res, Lusaka, Zambia
[3] Univ Alabama Birmingham, Sch Med, Birmingham, AL USA
[4] Univ Zambia, Sch Med, Lusaka, Zambia
[5] Johns Hopkins Univ, Sch Med, Baltimore, MD USA
[6] Univ North Carolina Chapel Hill, Gillings Sch Global Publ Hlth, Chapel Hill, NC USA