“…In most studies one environmental variable and one statistical method at a time (either correlation or regression analysis) were used (Table 1.1). All identified studies positively correlated precipitation and pathogen concentrations (Funari et al, 2012b, Abia et al, 2015, Vermeulen and Hofstra, 2013, Martinez et al, 2014, Isobe et al, 2004 and waterborne diseases (Seidu et al, 2013, Thomas et al, 2006, Chou et al, 2010. Most of these studies that are conducted in the temperate regions, reported a negative correlation with water temperature (Shibata et al, 2004, Walters et al, 2011, Olyphant and Whitman, 2004, Vermeulen and Hofstra, 2013, while most tropical studies reported a positive correlation (Koirala et al, 2008, Kelly-Hope et al, 2007, Huang et al, 2008.…”