Assessing the impact of market practices on E. coli and V. cholerae contamination on tomatoes in Kampala

Abstract

Tomatoes are the most consumed vegetable in Uganda. Its production and consumption have increased rapidly in the recent years however this vegetable is very susceptible to microbial contamination. Uganda’s markets have also changed over the time most importantly with the MATIP program which saw construction of modern markets. This increased variation in organization from peri-urban and traditional markets which should translate into a variation in microbial levels in these markets categories. This study was carried out in Wandegeya, Owino and Kalerwe markets as representatives from each market category. 150 tomatoes collected from 30 vendors and questionnaires administered to the same. Microbial work was carried out in PMB laboratory to isolate E. coli and V. cholerae and data analysis done using various software packages to find their mean concentration and possible human practices responsible for the observed levels. The results showed that samples from all markets were found positive of E. coli and V. cholerae, Mean E. coli contamination was statistically significant between the three markets [ANOVA, F (2,42) = 11.89, P-value<0.001]. Kalerwe market had the highest mean level of E. coli of all 3 markets. Kalerwe and Owino markets had statistically similar mean level of V. cholerae. Wandegeya market had the lowest mean level of both E. coli and V. cholerae of all 3 markets. Unhygienic selling areas, contaminated farm produce and lack of hand and fruit washing programs were the major cause of the observed E. coli and V. cholerae levels in Kalerwe and Owino markets.