[1] Univ Iowa, Dept Geog & Sustainabil Sci, 303 Jessup Hall, Iowa City, IA 52245 USA
[2] Univ Iowa, Dept Epidemiol, Iowa City, IA 52245 USA
[3] Univ N Carolina, Dept Geog, CB3220,Carolina Hall, Chapel Hill, NC USA
[4] Univ N Carolina, Dept Biostat, CB7420,McGavran Greenberg Hall, Chapel Hill, NC USA
[5] Univ N Carolina, Dept Epidemiol, CB7435,McGavran Greenberg Hall, Chapel Hill, NC USA
[6] Natl AIDS Control Program PNLS, Kinshasa, DEM REP CONGO
[7] Univ Kinshasa, Fac Med, Ecole Sante Publ, Kinshasa, DEM REP CONGO