[1] Univ Valle Guatemala, Ctr Estudios Salud, Guatemala City, Guatemala
[2] CDCP, Div Foodborne Waterborne & Environm Dis, Atlanta, GA USA
[3] US PHS, Bethesda, MD USA
[4] CDCP, Epidem Intelligence Serv, Atlanta, GA USA
[5] Washington State Univ, Paul G Allen Sch Global Hlth, Pullman, WA USA
[6] Univ Valle Guatemala, 2 305,18 Ave 11-95 Zona 15 Vista Hermosa III, Guatemala City 01015, Guatemala