Prognostic Factors Related to Recovery from Diarrhea among U.S. Students with Diarrhea in Mexico

Background: Medical charts of subjects treated with placebo from five double-blinded placebo-controlled clinical trials were reviewed to determine pre-enrollment prognostic factors related to later recovery from diarrhea. Method: Recovery or time from initiation of a placebo until passage of the last unformed stool after being declared well was calculated for each subject. Results: A longer duration of diarrhea was associated with presence of fever (rate ratio = 0.34; 95% CI = 0.2-0.9), presence of an invasive pathogen in the stool (rate ratio = 0.35; 95% CI = 0.2-0.7) or a noninvasive pathogen in stool (rate ratio = 0.7; 95% CI = 0.6-1.0), severe abdominal pain or cramps (rate ratio = 0.5; 95% CI = 0.3-0.9), passage of more than five watery stools per 24 hours (rate ratio = 0.58; 95% CI = 0.4-0.8). Severe vomiting predicted a shorter duration of post-enrollment diarrhea (rate ratio = 2.43; 95% CI = 1.1-5.6). Conclusion: A number of clinical and microbiologic factors found in travelers with diarrhea in the present study predicted duration of untreated diarrhea. The authors suggest the use of antimicrobial therapy in travelers with predictors of a long duration of diarrhea. Data developed in the present study may be used to create a historical control for clinical trials of antidiarrheal compounds using the same study criteria.