Prevalence of Some Human Enteroparasites in Commonly Consumed Raw Vegetables in Tabuk, Saudi Arabia

Abstract

The problem of parasitic contamination of food, especially fresh vegetables, is not limited to personal hygiene during food preparation but is also widely dependent on the source of the food and the handling it undergoes before it gets to the consumer. The objective of the present study was to evaluate parasitic contamination in eight common raw vegetables in Tabuk, Kingdom of Saudi Arabia. A total of 400 samples of raw vegetables obtained from wholesale and retail markets were examined for helminth eggs and larvae and for cysts of different parasites, using standard methods. The prevalence of the parasites was 20.65% in cucumber, 15.76% in cabbage, 14.67% in pea, 14.13% in cress, 13.04% in lettuce, 10.33% in carrot, 8.70% in green onion, and 2.72% in tomato. Statistical analysis showed a significant difference (P < 0.05) for Entamoeba spp. cysts, Ascaris lumbricoides eggs, Entamoeba coli cysts, and unknown isolated parasite cysts. Parasites are common in vegetables that are frequently eaten raw and, for this reason, may pose a health risk for consumers in Tabuk.

Detection of human intestinal protozoan parasites in vegetables and fruits: a review

“…A portion (usually 50-250 g) of each vegetable or fruit sample is washed separately in a container containing some chemical solutions. The most widely used solutions are normal saline [14,[17][18][19][20] and phosphate-buffered saline [12,[21][22][23][24]. The commonly used solutions are glycine [11,25], sodium dodecyl sulfate [26], Alconox ® [27], and Tween 80 [28].…”

“…More than one smear slide is usually prepared for each specimen to allow its precise detection [12,26]. Oocysts or cysts can be detected microscopically based on their morphological features [14,17,20,29], using Lugol's iodine [12,14,29] or modified Ziehl-Neelsen staining (or any other staining technique) [14,19,26]. The extraction of the parasitic DNA from the sediment, followed by the PCR amplification of specific genes, is also efficiently used for the protozoan detection in vegetable and fruit samples [22,24].…”

“…Giardia duodenalis cysts can be detected with light microscopy based on their morphological features [19,42,43], and staining with typical Lugol's iodine is universally used for the detection of G. duodenalis cysts [12,14,17,18,29]. However, an immunofluorescence assay is usually applied for the detection of Giardia cysts in food items with more sensitivity [7].…”

“…Entamoeba spp. infections are significantly associated with the consumption of contaminated vegetables and fruits [17,41,51,52].…”

Investigation of parasitic contamination of salad vegetables sold by street vendors in city markets in Damascus, Syria

“…Studies over the world have shown that many species of enteric helminthes and protozoa can infect humans who consume contaminated, improperly washed fruits and vegetables ( Al-Shawa and Mwafy, 2007 ; Adanir and Tasci, 2013 ; Ismail, 2016 ). Vegetables become contaminated with different parasitic phases (cyst, oocyst, ova, larvae) during irrigation by waste water or by direct contamination from animals and humans during harvesting, packing, transport processing, distribution, and marketing ( Amoah et al, 2007 ; Gabre and Shakir, 2016 ). Many countries around the world have realized the importance of evaluating the role of raw vegetables in the transmission of intestinal parasites ( Abougrain et al, 2010 ; Omowaye and Audu, 2012 ; Chau et al, 2014 ; Khan et al, 2017 ).…”