Evaluation of two analytical methods of detection for intestinal parasites in curly lettuce sold in food stalls

Abstract This study aimed to investigate the occurrence of parasitic structures in curly lettuce (Lactuca sativa L.) sold in food stalls open markets in Cuiabá city, in the Brazilian state of Mato Grosso (MT). For this purpose, 50 samples were evaluated using spontaneous sedimentation and centrifugal flotation methods. These techniques showed positivity in 96% (48/50) and 78% (39/50) of the samples, respectively. The sedimentation method was statistically (p ≤ 0.05) more effective in detecting parasitic structures of the pathogens as Entamoeba histolytica, Ascaris spp., Strongyloides spp., Larvae and Hookworm eggs, when comparing both methods. However, these methods did not differ significantly for the detection of Giardia lamblia. Ascaris spp and Entamoeba coli occurred in 64% (32/50) and 46% (23/50) of the positive samples, respectively, with the highest percentages observed. The occurrence of Blastocystis spp., Fasciola spp., Dipylidium caninum and Ascaris lumbricoides revealed detection exclusively by the spontaneous sedimentation method, while Iodamoeba butschlii and Enterobius vermicularis were detected by centrifugal– flotation procedure. These results could reinforce the need to use methods based on sedimentation and the fluctuation of parasite structures in the analysis of lettuce. The presence of parasites in lettuce by fecal origin, with recognized pathogenicity, represents a risk to consumer health and demonstrates a deficit in good agricultural practices in the production, distribution and commercialization of lettuce. Resumo Este estudo objetivou averiguar a ocorrência de estruturas parasitárias nas alfaces crespas (Lactuca sativa), comercializadas em feiras livres e permanentes da cidade de Cuiabá-MT. Para tanto, 50 amostras foram avaliadas pelos métodos de sedimentação espontânea e centrífugo-flutuação, que revelaram positividade em 96% (48/50) e 78% (39/50) das amostras, respectivamente. O método de sedimentação foi mais eficaz na detecção de estruturas parasitárias dos patógenos Entamoeba histolytica, Ascaris spp., Strongyloides spp. e de larvas e ovos de Ancilostomídeo, quando comparado ao método centrífugo-flutuação, com diferença estatisticamente significativa (p ≤ 0,05). Contudo, estes métodos não diferiram significativamente na verificação de Giardia lamblia nas amostras. Ascaris spp. e Entamoeba coli ocorreram em 64% (32/50) e 46% (23/50) das amostras positivas, respectivamente, com os maiores percentuais observados. A ocorrência de