Harvy Joy Liwanag1, Kaspar Wyss2. 1. Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland; Ateneo School of Medicine and Public Health, Ateneo de Manila University, Metro Manila, Philippines. Electronic address: harvy.liwanag@unibas.ch. 2. Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland. Electronic address: kaspar.wyss@unibas.ch.