An epidemiological investigation of foodborne and waterborne disease outbreaks in Fars Province in Iran from 2020 to 2023

Objective: To examine the incidence of foodbome and waterborne diseases as well as the relationship between the sources of outbreaks and the method of drinking water supply with the initial symptoms of the disease in Fars province of Iran from 2020 to 2023. Methods: This cross-sectional study analyzed 630 confirmed outbreaks reported to health centers within the jurisdiction of Shiraz University of Medical Sciences from March 2020 to March 2023. Data analysis was performed using SPSS software, version 22. Results: Totally 630 outbreaks were reported, affecting 2 363 primary cases with 190 hospitalizations from 2020 to 2023. The highest incidence of the outbreaks by year and month was reported in 2022 ( n =266, 42.2%) and in April ( n =77, 12.2%). The main source of infection in the outbreak was food with 426 (67.6%) cases, with food poisoning syndrome being the most common symptom observed ( n =435, 69.0%). Besides, the causative agent of 461 (73.1%) outbreaks was unknown and 56 (8.9%) was salmonellosis. Additionally, relationship between source of outbreak and the method of drinking water supply with primary symptoms of the disease was statistically significant ( P <0.001). Conclusions: This study found that the cause of most outbreaks is unknown, with transmission occurring through food, which leads to the hospitalization of many individuals. The findings can help officials and the public increase awareness, implement stricter monitoring of water and food safety, and ultimately reduce the burden of disease.