Background: Few epidemiological studies have shown that enteric infections are associated with exacerbations of ulcerative colitis (UC). Patients with active UC have higher frequency of parasitic stool pathogens. The aim of this study was to evaluate the frequency of stool pathogens including: parasites, organisms grown in stool cultures and presence of Clostridium difficile in Mexican patients with UC, and clinical outcomes related to the presence of pathogens.
Methods: We studied 303 with diagnosis confirmed UC patients from the IBD Clinic from the period of january 2014 and december 2015. Disease extension, severity, medical treatment, extra-intestinal manifestations, hospitalizations, length of hospital stay, and stool tests were analyzed. Statistical analysis was performed by SPSS v.21 program. A P value <0.05 was considered significant.
Results: A total of 303 UC patients were evaluated from 2007 to 2016. We evaluated 160 men and 143 women, with a mean age of 46.6±14.2 years-old. 35 active and 368 remission patients were found. 46.5% of patients had pancolitis. 247 of 303 patients had stool tests performed. 61.4% of active patients had a positive stool test. A positive parasite test (51.6% of active patients) was associated to: current activity (p=0.002) and severity (p=0.006); number of parasites isolated in test had a trending association to UC extension (p=0.051). Most isolated parasite was Blastocystis hominis in 15.8%. A positive stool culture was found in 13.2% of patients, most isolated pathogen was Clostridium difficile in 4.6% of patients. Having any positive stool test was associated to current activity (p=0.001) and severity (p=0.003), and with a trend in need for hospitalization caused by exacerbation (p=0.056). We found 85 steroid-dependent patients, of which 38 had a positive stool test (p=0.14), and 29 had a positive parasite stool test (p=0.35), with no association. Negative stool test and negative parasite stool test were significantly associated to clinical (p<0.001 & p=0.001), biochemical (p=0.001 & p=0.003) and endoscopic remission (p=0.025 & p=0.018), but not with histological remission.
Conclusions: A high frequency of 61.4% of positive stool tests were found in active UC patients. Presence of stool pathogens was associated to several important clinical outcomes such as activity and severity of UC as well as hospitalizations related to this disease.