Prevalence and Distribution of Protozoan Parasite Contamination in Fresh Vegetables from Bang Khla District, Chachoengsao Province, Thailand
DOI:
https://doi.org/10.69650/ahstr.2026.4621Keywords:
protozoan contamination, fresh vegetables, food safety, irrigation contamination, water spinachAbstract
Intestinal protozoan infections pose a significant public health concern, particularly for children and the elderly. This cross-sectional study investigated the prevalence and distribution of protozoan cysts and oocysts in fresh vegetables grown in Bang Khla District, Thailand. The analysis employed the sedimentation technique and modified acid-fast staining method to analyze a total of 369 samples encompassing nine commonly consumed vegetable types collected from cultivation plots. The prevalence of four protozoan species was detected: Cryptosporidium spp. (11.9%), Entamoeba histolytica/E. dispar (7.6%), Blastocystis sp. (3.5%), and Giardia spp. (1.9%). Notably, there was a statistically significant variation in contamination rates across different types of fresh vegetables (p < 0.05). Among the nine vegetable types, water spinach exhibited the highest contamination rate (70.7%), followed by coriander (36.6%), lettuce (34.1%), celery and kale (each at 22.0%), hoary basil and sweet basil (each at 12.2%), spring onion (9.8%), and yardlong bean (4.9%). The high contamination observed in water spinach, a semi-aquatic plant, suggests a potential role of irrigation water as an important source of protozoan contamination. The consumption of raw vegetables, particularly water spinach, may therefore pose a significant risk for the transmission of protozoan infections. These findings underscore the importance of food safety practices, including proper washing and cooking, as well as improved management of irrigation water and cultivation environments. This study provides important evidence supporting the need for strengthened environmental sanitation, targeted public health interventions, and further research on contamination pathways in agricultural systems.
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