Epidemiological Investigation of an Outbreak of Acute Diarrheal Disease: A Shoe Leather Epidemiology

BACKGROUND: Health care problems faced by migrant construction workers are always neglected. Fifteen patients were admitted with the complaints of loose motion and pain in the abdomen from a labor settlement at a construction site near our city. Three stool samples revealed darting motility. OBJECTIVES: To find out more number of cases, the source of infection and to recommend necessary actions to control the outbreak. STUDY DESIGN: A cross-sectional epidemiological study. MATERIALS AND METHODS: Pre-tested, pre-designed epidemiological case sheet was used. Sanitary survey and assessment of ecological correlation was also done. Stool samples of all the admitted patients and seven water samples from the site were collected for laboratory analysis. RESULTS: Out of 99 inhabitants, 69 were suffering from the same complaints. Male sufferers were more in number. The age groups affected prominently were 1–4 years and 15–44 years. Peculiar epidemic curve with one peak was noted down. There was a history of heavy rains 2 days before the complaints had started. The construction site was situated on the plateau. The source of the water – dug well – was situated on a slope. The water from the site while moving along the slope was getting mixed into the well. Considering the person, time, place distribution and the peculiar symptoms, presumptive diagnosis of outbreak (point source) of acute gastroenteritis was made. The well water was thought to be the source of infection. Three stool samples and three water samples including the sample from drinking well water grew Vibrio cholerae O1. These results support an earlier hypothesis. The timely interventions were done. CONCLUSION: The impending outbreak can be brought under control with the rapid and simple field epidemiological investigation (shoe leather epidemiology).