Fig. 3

Standardized RD and 95% CI for the association between illness and human-associated Bacteroides markers among swimmers. Standardized risk differences (black circles) and 95% confidence intervals (bars) for the association between illness and human-associated Bacteroides markers among body immersion swimmers in all beaches (top), freshwater beaches (middle), and marine (bottom) beaches. Arrows show intervals that extend beyond field of vision of diagram. Risk differences compare marker presence (detected in ≥2 samples/day) to absence (detected in 0–1 sample/day) estimated using model-based standardization. *Models for this outcome adjusted for beach, age, mean bathers, sand, rainfall (3 pm the previous day to 8 am present day), and water temperature. †Models for this outcome adjusted for beach, age, mean bathers, sand, and rainfall (3 pm the previous day to 8 am present day). CI, confidence interval; GI, gastrointestinal illness; RD, risk difference