Salāmat-i ijtimā̒ī (Nov 2018)
Diarrhea Outbreak Associated with Drinking Water in Pardis city, Tehran 2014
Abstract
Background and Objective: Diarrhea outbreaks caused by contaminated water or food result in 1.8 million deaths worldwilde every year. This study aimed to identify factors associated with diarrhea outbreaks in Pardis city in 2014. Materials and Methods: This case-control study was conducted with participation of residents of Phase One to Four of Pardis city in Tehran province in 2014. Of 5075 people with diarrhea, 250 were selected as cases. For each case, a control from the neighbors who was healthy and did not have diarrhea at the onset of the outbreak was selected. Data were collected by interviewing participants and using the standard questionnaire for water and food borne diseases outbreak designed by the Ministry of Health of Iran. Blood and stool samples were collected for laboratory tests. Data were analyzed using SPSS-21 software, and Chi-Square and Kruskal-Wallis tests were used to analyze the data. Results: Among all participants, 144 (57.7%) were women, and 106 (42.3%) were men. The mean (SD) age in the case and control group was 25.8 (2.1) and 29.8 (1.8) years respectively. Most participants who were affected by the diarrhea outbreak lived in Phase Three of Pardis city. They reported that diarrhea symptoms appeared on December 26th 2016 between 18:00 and 24:00. Drinking tap water instead of bottled water, (OR=5.94, 95% CI=3.45-10.21) and drinking of tap water at home after water supply reconnection (OR=4.20, 95% CI=1.56-11.30) had an impact on the incidence of diarrhea outbreaks among cases compared with controls at the time of outbreak (P<0.05). Laboratory samples were also reported positive for Norwalk and E.coli serotypes. Conclusion: The diarrheal outbreak in Pardis city was due to bacterial and viral pollution of water following water pipe fractures in the water distribution system of the city.
