The prevalence of foodborne parasites in raw vegetables in Iran: a comprehensive systematic review and meta-analysis

Fresh Leafy Vegetables and Parasitic Contamination: Practical Solutions

This study aimed at investigating the parasitic contamination of fresh leafy vegetables in Tehran, Iran, during 2020-2021. A cross-sectional study was conducted and 180 fresh leafy vegetables (including leek, watercress, mint, spring onion, radish, basil, parsley, lettuce, and spinach) were collected randomly in the five regions of Tehran, Iran. Each 200-g sample was soaked with tap water containing detergent, and the obtained sediment was centrifuged and examined for parasitic stages using a light microscope. The overall rate of parasitic contamination was 19.4%, with Trichostrongylus and Toxocara eggs being the most prevalent parasites (3.9%) and the highest rate of parasitic contamination was observed in spinach (40%), whereas no contamination was found in spring onions. Except for radish, other vegetable samples had multiple parasitic infections. Due to the contamination of vegetables, it is necessary to have a suitable method to reduce the parasites. Consequently, policymakers should safeguard public health by consistently monitoring contaminants in food and prioritizing education and research on methods to mitigate their presence in the food chain.

Exploring genetic variability of Giardia duodenalis and Enterocytozoon bieneusi in raw vegetables and fruits: implications for food safety and public health in Mozambique

Giardia duodenalis and Enterocytozoon bieneusi are etiological agents of enteric diseases characterized by diarrhea that can progress to chronicity in humans, especially in children and in immunocompromised patients. This study aims to assess the genetic pattern of G. duodenalis and E. bieneusi detected in vegetables and fruits commercialized in Maputo markets, Mozambique and determine their public health importance. Eight study points were sampled: a farmer zone, a wholesale, four retail markets, and two supermarkets in Maputo city, where eight types of horticultural products were purchased. Using nested-PCR methods, 2.8% (9/321) and 1.3% (4/321) of samples monitored were positive for G. duodenalis and E. bieneusi, respectively. Based on the analysis of the β-giardin and ITS rRNA sequences of G. duodenalis and E. bieneusi detected, respectively, four different sequences of G. duodenalis (three novel sequences: BgMZ1, BgMZ2, and BgMZ3, and one known sequence) all from assemblage B and three genotypes of E. bieneusi (two novel sequences: EbMZ4 and EbMZ5, and one known sequence: KIN-1) from group 1. These microorganisms were found and characterized for the first time in horticultural products in Maputo markets. All identified G. duodenalis and E. bieneusi display high genetic similarity within their β-giardin and ITS rRNA sequences, respectively, having been clustered into assemblages and genotypes with high zoonotic transmission potential. Our study may represent a relevant step in the understanding of these intestinal pathogens in association with fresh vegetables and fruits for human consumption, for a better and broader "One Health" approach.

From fox to fork? Toxocara contamination of spinach grown in the south of England, UK

BACKGROUND

Toxocara canis and Toxocara cati are intestinal parasites of dogs, cats and foxes, with infected animals shedding eggs of the parasite in their faeces. If humans accidentally ingest embryonated Toxocara spp. eggs from the environment, severe clinical consequences, including blindness and brain damage, can occur. Previous work has demonstrated the presence of Toxocara spp. eggs on vegetable produce grown in the UK, but only in small-scale community gardens. The aim of this study was to determine whether Toxocara spp. eggs are also present on vegetables grown on commercial farms in the UK, which supply produce to a greater number of people.

METHODS

A total of 120 samples (300 g each) of spinach (Spinacia oleracea) were collected across four farms in the south of England, UK. The samples were processed using a sieving approach followed by multiplex quantitative polymerase chain reaction analysis.

RESULTS

Overall, 23.0% of samples were positive for T. canis (28/120; 95% confidence interval 16.7-31.7%) and 1.7% for T. cati (2/120; 95% confidence interval 0.5-5.9%). There was a statistically significant difference in the number of positive samples between farms (P = 0.0064). To our knowledge, this is the first report of the isolation of Toxocara spp. from vegetables grown on commercial farms in the UK.

CONCLUSIONS

The results of this study highlight the requirement for the thorough washing of vegetables prior to their consumption, especially those such as spinach which may be eaten without first peeling or cooking, and effective farm biosecurity measures to minimise access to farmland by definitive host species of Toxocara spp.