FREQUENCY OF PARASITES ON LETTUCE (Lactuca sativa) FROM SELF-SERVICE RESTAURANTS OF PORTO ALEGRE CITY, BRAZIL

Abstract

Eating contaminated food is a known route of infection for intestinal parasitosis and many studies describe fresh vegetables carrying human parasites. This study evaluates the presence of parasitic organisms and dirt on lettuce as well as the hygienic procedures employed by self-service restaurants in Porto Alegre, Brazil. Ninety samples of lettuce (45 before and 45 after hygiene) were collected from fifteen restaurants. Each sample, consisting of 20 to 25 large leaves of lettuce, was separated and packed in first use plastic bags by employees in each establishment. Parasitological analysis was carried out using the Lutz sedimentation method and the hygiene procedures were evaluated by an epidemiological questionnaire. On uncleaned samples free living nematodes (21/45) and insects (17/45) were observed. On samples ready for consumption insects (7/45) and unsporulated oocysts (3/45) were found. Chlorine products were the most frequent disinfectant used (10/15 restaurants), while three restaurants used only running water. Despite no pathogenic parasitic organisms being found, the hygiene procedures employed were considered inefficient as 20% (9/45) of the disinfected samples were proven to still be contaminated.