[1] Med Univ Vienna, Inst Hyg & Appl Immunol, Water Hyg, Kinderspitalgasse 15, A-1090 Vienna, Austria
[2] Interuniv Cooperat Ctr Water & Hlth, Vienna, Austria
[3] Med Univ Vienna, Inst Specif Prophylaxis & Trop Med, Kinderspitalgasse 15, A-1090 Vienna, Austria
[4] Tech Univ Dresden, Inst Med Microbiol & Hyg, Med Fac Carl Gustav Canis, Helmholtzstr 10, D-01069 Dresden, Germany
[5] Karl Landsteiner Univ Hlth Sci, Div Water Qual & Hlth, Dr Karl Dorrekstr 30, A-3400 Krems, Austria