The intestinal parasites are an important healthy problem to human population
worldwide. The consumption of vegetables is one of the major routes of transmission
of this pathogens. This study aimed to determine the frequency and diversity of
intestinal parasites transmitted by vegetables sold in the metropolitan region of
Belém-PA and its relation to the seasonal climate of the region. It was used 252
samples of three species of vegetables, of which 84 were of lettuce (Lactuca sativacurly
variety), 84 were watercress (Nasturtium officinale) and 84 were coriander
(Coriandrum sativum) purchased in open markets, gardens and in a supermarket,
from November of 2008 to December of 2009. Each samples was washed with
500ml of PBS, permitting the spontaneous sedimentation and centrifuging 30 ml of
the final sediment. The final sediment was analyzed in an optical microscope. The
levels of contamination of the three species of vegetables were obtained by the
monthly average of intestinal parasite structures identified in each vegetable and by
the total number of parasites identified in the samples of each open market, garden
and supermarket. In the results obtained in the microscopic analysis of samples were
applied the Chi-square and Fisher's Exact Test to determine the existence or not of
significant differences between these results. It was used the significance level α ≤
0.05. This microscopic analysis showed a contamination of 100% of the samples at
open markets, gardens and supermarket included in the study, there isn’t statistical
difference in overall frequency of parasites among them. Strongyloides stercoralis
was the most prevalent parasite, followed by complex Entamoeba histolytic / dispar
and the hookworms, both in samples from the gardens, as in samples of the open
markets and the supermarket. The cress and lettuce had higher rates of parasitic
contamination that coriander. It had been characterized seasonal influence on the
intensity of parasites in vegetables investigated because there was statistical
difference between the results obtained with a higher prevalence of parasites in
samples of summer, for the samples of winter. There wasn’t also statistically
significant difference between the monthly averages of contamination of vegetables
sold in open markets, gardens and supermarket, indicating that the hygienic
conditions under which the vegetables are sold, although important to keep their
flavors, have less influence on levels of parasitic contamination, which seems to be
associated with the place and growing conditions these plants. These datas permit a
good level of comparison to future studies.
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