Table 2.

Inclusion Criteria for Cases

1. Child is 0–59 mo of age

2. Child belongs to the demographic surveillance system population at the site

3. Child is not currently enrolled as a case (meaning previously enrolled and pending 60-day visit)a

4. Child meets case definition of diarrhea (≥3 abnormally loose stools in the previous 24 h)

5. Diarrhea episode is:  • Acute (onset within 7 d of study enrollment) and  • Represents a new episode (onset after ≥7 diarrhea-free days) [23, 24]

6. Diarrhea is moderate-to-severe, meaning that the child met at least 1 of the following criteria: • Sunken eyes, confirmed by parent/primary caretaker as more than normal • Loss of skin turgor (determined by abdominal skin pinch (slow return [≤2 s] or very slow return [>2 s]) • Intravenous rehydration administered or prescribed • Dysentery (visible blood in a loose stool) • Hospitalized with diarrhea or dysentery

^a A child was eligible to be enrolled as a case irrespective of whether he or she had been included as a case or as a control previously; whereas cases were eligible for reenrollment only after the 60-day follow-up visit had been completed, controls could be enrolled as a case at any time they met the criteria.