Assessment of parasitic contamination of lettuce and cabbages sold in selected markets in Maputo city, Mozambique

Abstract

Background: In Mozambique, vegetables are the main source of nutrients and they are consumed raw or cooked. Their consumption, especially in their raw form, might be a source of contamination, which may take place during production and/or transportation as well as in the markets. In this study we aimed to assess the profile and frequency of parasites in lettuces and cabbages sold in some selected markets in Maputo city, the capital of Mozambique.Methods: A cross sectional study was conducted between February and March 2018, in 10 selected markets from Maputo City. A total of 100 combined samples of lettuces and cabbages were analyzed using a spontaneous sedimentation method. Data such as gender and age of the vendors and about handling of vegetables at the point of sale were also collected.Results: Out of the samples, 84 (84%) were contaminated with parasites (86% of lettuces and 82% of cabbages). The analyses performed revealed the presence of E. coli (66%), S. stercoralis (40%), E. histolytica (20%), A. duodenalis (6%), S. haematobium (4%), A. lumbricoides (2%), S. mansoni (2%) and T. trichiura (1%). Two markets, Janete and Fajardo showed contamination in all samples. A Chi square analysis revealed a significant association between the contaminated cabbages and the market where they were obtained. The majority of vendors (57%) do not wash their hands before handling vegetables. Most of the vendors had tables to place vegetables (72%) and those tables are cleaned before display (86%). None of the differences observed in each risk factor studied were statistically significant.Conclusion: The present study highlights that contamination of raw vegetables with pathogenic parasites in markets might represent a vector for transmission of intestinal and water- borne parasites to consumers. Future studies should investigate the extent of vegetable contaminationat each stage of the supply chain from the farm to consumers, as well as its relationship to human parasitic infection and its consequences. Good hygienic practices of farmers, vendors and consumers should be enforced to break the contamination chain. Whenever possible, hydroponic cultivation should be encouraged to avoid the influence of highly contaminated soils.