[1] Univ North Carolina Chapel Hill, Dept Epidemiol, Chapel Hill, NC USA
[2] Univ Iowa, Dept Geog & Sustainabil Sci, Iowa City, IA USA
[3] Univ North Carolina Chapel Hill, Dept Geog, Chapel Hill, NC USA
[4] Univ Kinshasa, Fac Med, Ecole Sante Publ, Kinshasa, DEM REP CONGO
[5] Univ North Carolina Chapel Hill, Sch Med, Div Infect Dis, Chapel Hill, NC USA