Occurrence of enteroparasites in vegetables commercialized in Sao Paulo, Brazil

Parasitic diseases constitute an important public health problem. Their transmission can occur by ingestion of water contaminated with human feces and/or parasitized animals, and by poorly washed fruits and vegetables. Considering the scarcity of national studies reporting the degree of contamination of vegetables, the present study investigated and compared the contamination of enteroparasites in 32 samples of each of the types: lettuce (Lactuca sativa) of the smooth and curly variety and watercress (Nasturtium officinale), commercialized in the city of Sao Paulo. For this purpose, the samples were washed with distilled water. The product of the washings was decanted in conical sedimentation vessels for 24 hours by the spontaneous sedimentation method, and the sediment was analyzed under an optical microscope. The results showed that of the 96 samples analyzed, 78 (82%) presented some parasitic form. Vegetables purchased from supermarkets and street markets showed a contamination rate of 80% (48/60) and 83% (30/36), respectively. The parasitic forms found were: 42% Ancylostoma sp larvae, 15.94% Ancylostoma sp eggs, 7.24% Ascaris sp eggs, 8.69% Enterobius sp eggs, 8.69 % Strongyloides sp larvae, 7.24% Hymenolepis sp eggs, 5.79% Taenia sp eggs and 4.34% Entamoeba sp cysts. These results demonstrate the need to develop a more efficient health education program aimed at horticulturists and vegetable handlers, with the intention of preventing the occurrence of these parasites, and further contamination of the population.