TABLE 3.

Classification of disease outcome

Outcome	Definition	Scale	Source
Diarrhea severity	Divided into 4 categories: (i) no diarrhea; (ii) mild (2 or 3 grade 3–5 stools and <400 g of grade 3–5 stools in 24 h); (iii) moderate (4 or 5 grade 3–5 stools or 400–800 g of grade 3–5 stools in 24 h); (iv) severe: (≥6 grade 3–5 stools or >800 g of grade 3–5 stools in 24 h)	Binary outcome: volunteers were placed in 1 of 2 categories: (i) those with no or mild diarrhea; (ii) those with moderate or severe diarrhea	Defined per protocol (this study)
Dysentery	A grade 3–5 stool with gross blood on at least 2 occasions with reportable constitutional/enteric symptoms	Binary outcome: volunteers were grouped by whether they received a dysentery diagnosis during the study	Defined per protocol (this study)
Disease severity score	Volunteers are assigned scores across the following categories depending on severity and frequency: (i) objective symptoms (gross blood, oral temperature, vomiting); (ii) subjective symptoms (constitutional/enteric symptoms); (iii) grade 3–5 stool output per 24 h	Ordinal outcome: volunteers’ scores across three categories are added to for a score between 0 and 9	12
Shigellosis	One of three definitions must be met: (i) severe diarrhea; (ii) moderate diarrhea with fever ≥38.0°C or ≥1 moderate constitutional/enteric symptom or ≥2 episodes of vomiting in 24 h; (iii) dysentery with fever ≥38.0°C or ≥1 moderate constitutional/enteric symptom or ≥2 episodes of vomiting in 24 h	Binary outcome: volunteers grouped by whether they received a shigellosis diagnosis during the study	9