Symptom profiling for infectious intestinal disease (IID): a secondary data analysis of the IID2 study

Less than half of stool samples from people symptomatic with infectious intestinal disease (IID) will identify a causative organism. A secondary data analysis was undertaken to explore whether symptomology alone could be used to make inferences about causative organisms. Data were utilised from the Second Study of Infectious Intestinal Disease in the Community. A total of 844 cases were analysed. Few symptoms differentiated individual pathogens, but grouping pathogens together showed that viral IID was more likely when symptom onset was in winter (odds ratio (OR) 2.08, 95% confidence interval (CI) 1.16-3.75) or spring (OR 1.92, 95% CI 1.11-3.33), the patient was aged under 5 years (OR 3.63, 95% CI 2.24-6.03) and there was loss of appetite (OR 2.19, 95% CI 1.29-3.72). The odds of bacterial IID were higher with diarrhoea in the absence of vomiting (OR 3.54, 95% CI 2.37-5.32), diarrhoea which persisted for >3 days (OR 2.69, 95% CI 1.82-3.99), bloody diarrhoea (OR 4.17, 95% CI 1.63-11.83) and fever (OR 1.67, 95% CI 1.11-2.53). Symptom profiles could be of value to help guide clinicians and public health professionals in the management of IID, in the absence of microbiological confirmation.