Table 1. Information on sampling sites.

				Clinically diagnosed human cases positive by IS2404 PCR
Communities	Water body	Activities	Population size	2008 (%)	2009 (%)	2010 (%)	2011 (%)
Ananekrom	Egyaah River upper and lower, Betom River	Fishing, recreation, pathway for humans and animals, *domestic activities	1951	28 (1.44)	31 (1.59)	39 (2.00)	33 (1.69)
Nshyieso	Esuo-Efi River (stagnant water)	*Domestic activities	1429	8 (0.56)	10 (0.70)	5 (0.35)	17 (1.19)
Serebouso	Onwamtifi River	*Domestic activities	1275	7 (0.55)	16 (1.25)	11 (0.86)	6 (0.47)
Dukusen	Onwam River	*Domestic activities	675	4 (0.59)	2 (0.30)	7 (1.04)	2 (0.30)
Bebuso	Pupunasoe River (stagnant water)	*Domestic activities, human and animal crossing, fishing	966	6 (0.62)	4 (0.41)	5 (0.52)	4 (0.41)
Mageda	Abena Supuni River	Market traders drink from it	773	0 (0)	0 (0)	0 (0)	0 (0)
Pataban	Pataban River	Drinking	1421	0 (0)	0 (0)	0 (0)	0 (0)

*Domestic activities: bathing, washing, cooking and sometimes drinking.