Quantitative Salmonella enterica serovar Enteritidis risk assessment from consumption of hard-boiled eggs, half-boiled eggs and raw eggs among Malaysians

High occurrences of Salmonella enterica serovar Enteritidis outbreak from table eggs have been reported worldwide over the past two decades. Consumptions of hard-boiled and half-boiled eggs are popular among Malaysians. However, there is a lack of study in the risk assessment of salmonellosis associated with different egg consumption patterns. The purpose of this study was to determine the survival rate of S. enterica ser. Enteritidis in different methods for cooking eggs (hard-boiled, half-boiled and a minimally cooked egg with hot cocoa drink) using the simulation model of consumers eating habits and the risk associated with different egg consumptions patterns. In this study, S. enterica ser. Enteritidis was not detected in the hard-boiled egg samples. However, the survival rate of S. enterica ser. Enteritidis in both the half-boiled and the raw egg samples were 3.15 log CFU/mL and 7.01 log CFU/mL, respectively. The Monte Carlo Simulation applying quantitative microbial risk assessments (QMRA) was carried out using 10,000 iterations to access the risk of acquiring salmonellosis by consuming eggs cooked under different heat treatments. The total dosage of S. enterica ser. Enteritidis ingested per serving meal in the hard-boiled, half-boiled and minimally cooked eggs were 0.00 CFU/g, 7.526× 10⁴ CFU/ mL and 5.433× 10⁸ CFU/mL, respectively. The consumptions of half-boiled and minimally cooked eggs were above infectious dosage level (10² to 10⁴ CFU/mL). The annual risk for the three feature of methods were 0.00, 1.00 and 1.00, respectively. In this study, it was indicated that there was a high probability of acquiring salmonellosis through the consumption of half-boiled and minimally cooked eggs. Thus, the fully cooked eggs should be taken instead of the undercooked eggs to avoid consuming S. enterica ser. Enteritidis.