Epidemiological Investigations of Acute Watery Diarrhea Outbreak During July-August 2017 in Amarpura, Rawalpindi - Pakistan

Abstract

Background: On July 24, 2017, two cases suspected of acute watery diarrhea (AWD) were reported from tertiary care hospital, Rawalpindi. District health authorities directed to conduct outbreak investigation, identified risk factors and recommend control measures. Methods: A descriptive followed by age-sex matched case control study (1:3) was done from Jul 27 to Aug 02, 2017. Case definition was "sudden onset of loose watery stools (? 3 in past 24hrs) with any of symptoms i.e. vomiting, nausea, abdominal cramps or fever in residents of Amar Pura from July 19 to August 02, 2017". Active and passive case finding technique were done in addtion to hosptial record review. Total 02 stool and 03 water samples were collected for microbiological testing. Odd ratios computed on 95% confidence interval and P value <0.05. Results: Total 18 cases were identified (mean age: 16 year; range: 02 m-55yrs), predominate were male 2.6:1. Overall attack rate (AR) was 7.2/1000 and preponderate affected age group was 15-24 years (AR: 10/1000). Significantly associated risk factors were; use of untreated municipal water (OR:15, CI: 4.00-73.96) and use of untreated well water (OR:14.52, CI: 3.98-59.99). Use of water from filtration plant was found protective association (OR: 0.12, CI: 0.005-0.750). Laboratory found Vibrio Cholera Serotype Inaba in stool samples and coliforms in water samples. Conclusion: Consumption of contaminated water was most probable cause of outbreak. Use of filtered water was found to be a protective measure. Chlorination of water sources and health awareness sessions on water sanitation and hygiene were done in community.