Analysis of the parasitological quality of lettuce sold in open-air markets in the city of São Luís, Maranhão; 2025

Abstract

Objective: The study aimed to evaluate the parasitological profile of lettuces sold at markets in the city of São Luís, Maranhão, between December 2024 and May 2025. Methods: One lettuce was collected from each stall at the markets in the selected neighborhoods. These samples were sent for analysis to the Human Parasitology Laboratory at the State University of Maranhão. After washing with distilled water and Triton X 100 soap, the vegetables were centrifuged at 3500 revolutions per minute for approximately five minutes. After that, the supernatant was discarded, and the sediment was collected with the help of a Pasteur pipette and stored in Falcon tubes until microscope analysis. Results: A total of 44 lettuces were collected at the markets. The analyzed samples were found to have 70.4% (31/44) contamination with some form of parasite, with Ancylostoma spp. (12/44) and Hymenolepis spp. (12/44) being the most frequent helminths. Additionally, other organisms were detected, such as Strongyloides spp. (1/44), Enterobius vermicularis (3/44), Habronema spp. (1/44), Toxocara canis (1/44), and Taenia spp. (3/44). The protozoan Eimeria spp. was also found, along with other biological contaminants such as insects, mites, and unidentified parasite eggs. Conclusion: Consuming contaminated vegetables poses a health risk to consumers due to the possibility of transmitting infectious agents and parasites. Therefore, the implementation of hygienic and sanitary practices is effective in minimizing the presence of these pathogens. The markets evaluated in this study need to implement and/or improve these practices to ensure food safety for consumers.