Prevalence of Salmonella contamination in consumed eggs in Iran: A systematic review and meta-analysis study on published studies from 1996 to 2018

BACKGROUND AND AIM: Food poisoning caused by Salmonella is among the most common gastrointestinal discomfort resulted from egg consumption which can produce various syndromes. The present study is a systematic review and meta-analysis investigation on the published studies about the prevalence of Salmonella contamination in the consumed eggs in Iran. MATERIALS AND METHODS: The data were collected and analyzed from four international search databases, including PubMed, Scopus, Science Direct, and Google Scholar and four Iranian databases comprising SID, MagIran, Civilica, and IranDoc. After searching all the databases, 303 articles were found, from which 31 articles were included in the final analysis. RESULTS: According to the data analysis, the highest rate of contamination was belonged to the industrial eggs (7.49%), however, the prevalence rate was reported 13.61% in the eggshell part. The overall prevalence of Salmonella contamination in consumed eggs of Iran using culture of microbial, molecular, molecular-serological, culture-molecular, culture-serological, and culture -molecular-serological methods was obtained 11.33%, 5.52%, 0.37%, 1.91%, 5.52%, and 0.73%, respectively. Prevalence in the 21 geographical areas, where studies have been conducted, ranged from 0% (Zahedan) to 29.06% (Tabriz). The studies have also showed that eight different serotypes were among the major cause of Salmonella contamination in eggs. The most common Salmonella serotype was Salmonella Enteritidis and the highest diversity in Salmonella contaminant serotypes was recorded in Talesh (including S. Enteritidis, Salmonella Gallinarum, Salmonella Virchow, and Salmonella Newport). CONCLUSION: Results of this study revealed the high prevalence of Salmonella contamination in eggs, in Iran. Therefore, disinfection and cleaning bed, cleaning of equipment and supplies, and proper maintenance temperature and humidity of the eggs are recommended. In addition, proper personal hygiene and prohibition of consuming raw egg products are essential.