Table 1. STEC prevalence in four cohort studies in Peruvian children.

Study	No. patients	Age range (months)	Year of study	Prevalence in diarrhoea group (n/N) (%)	Prevalence in control group (n/N) (%)
Huaraz, Ancash	485	0–36	1987	4/733 (0.5)	2/467 (0.4)
Villa el Salvador, Lima	313	6–18	2004	4/556 (0.7)	nd
Chorrillos, Lima	1034	2–24	2007–2008	4/1129 (0.4)	7/767 (0.9)
Independencia, Lima	380	12–24	2008–2009	2/801 (0.2)	6/1461 (0.4)
All four studies	2212	0–36	–	14/3219 (0.4)	15/2695 (0.6)

nd, Not determined: control samples were not collected in this study.