Table 1. The study sites.

	Zimbabwe	Zanzibar, Tanzania	Kolkata, India
Area under consideration	Whole country	Unguja and Pemba	Ward 29, 30
Cholera endemicity	epidemic	endemic	endemic
Population	13,4 million	1,182,804	57,099
Annualized cholera incidence	-	0.5 per 1000	1.6 per 1000
Attack rate	7.39/1000	-	-
Laboratory confirmation	First cases only	First cases only	all