Quantitative Exposure Assessment to Vibrio cholerae through Consumption of Fresh Fish in Lusaka Province of Zambia

Fresh fish is one of the widely consumed sources of proteins in Zambia. Consumption of contaminated fresh fish has been linked to zoonotic transmission of diseases in humans as fresh fish harbors several spoilage bacteria and pathogens including V. cholerae which cause cholera in humans. This study aimed to conduct a quantitative exposure assessment to Vibrio cholerae through consumption of fresh fish in Lusaka Province of Zambia. We used Swift Quantitative Microbial Risk Assessment (sQMRA) model to estimate the risk of exposure. We obtained data from reviews of scientific literature, government reports, questionnaire survey, and expert opinions. We categorized fish consumers using three risk pathways; restaurants, households with low socioeconomic status, and households with high socio-economic status. Results revealed that at a serving portion of 100g in households with low socioeconomic status, a concentration of 50 cfu/g, and infectious dose 50 (ID50) of 106 cells, one person out of 2,251,898 population at risk would get ill, representing a probability of 4.4x10-7. At a serving portion of 200g in households with high socioeconomic status, a concentration of 330 cfu/g, and ID50 of 106 cells, 13 people out of 2,251,898 would get ill, representing a probability of 5.7x10-6. At an average serving portion of 200g in restaurants, a concentration of 50 cfu/g, and ID50 of 106 cells, 47 people would get ill, translating to a probability density of 2.02 x 10-5. These results indicate that the risk of exposure to Vibrio cholerae through the consumption of fresh fish among the population at risk in Lusaka Province of Zambia is extremely low through all risk pathways. Cross-contamination during preparation and consumption is the main source of exposure to the Vibrio cholerae. Therefore, improvement in good food safety handling and processing would further minimize the occurrence of foodborne illnesses.