Parasitos intestinais em escolares de área rural e urbana na Amazônia Central

Abstract

Intestinal parasites are a serious public health problem in many regions of the world, especially in developing countries where rapid urban growth not keeping pace with demand for sanitation. The diagnostic tests used for detection of intestinal parasites have accuracy less than 100%, leading to diagnostic errors with false-negative results. Rarely discusses the optimal amount of readings for each stool sample to be examined by the method of sedimentation. Thus, this study aims to estimate the prevalence of intestinal parasites evaluating the strategy of increasing the sampling to detect parasites and establish possible correlations between parasites and environmental conditions. A group of 101 school students from the urban area of Manaus and 100 students of rural Rio Pardo, municipality of Presidente Figueiredo - Amazonas - Brazil were selected after sample calculation. Stool samples were collected and analyzed by the method of sedimentation using three stool samples and a total of nine readings blades. The prevalence of intestinal parasites was higher in urban areas with 90.10 %. The multiparasitism was 62.68 %. The common parasite that has been identified from both populations was Entamoeba coli rate of 34.49 % followed by 18.36 % Giardia intestinalis with statistical difference between two intestinal parasites proportion of urban and rural areas were : Giardia intestinalis (p - value = 0.0030 , OR 3.10 , CI 1.70 to 5.67) , Endolimax nana (p - value = 0.0000 , OR 37.44 , CI 13.92 to 100.71) , Ancylostoma spp. ( p - value = 0.0065 , OR 3.93 , CI 1.39 to 11.12) , Iodamoeba butschlii (p - value = 0.0007 , OR 7.01 , CI 2.00 to 24.64) , Hymenolepis nana (p - value = 0.0181 , OR 5.99 CI 1.29 to 27.76). There was no sex predominance in both populations. Only the rural statistical significance for variables 1-2 bedrooms (p - value = 0.0243), treatment of drinking water (p = 0.0227) and sewage disposal in the stream (p = 0.0447) . With the increased number of stool samples and reads blades there was also a considerable increase in positivity of most analyzes parasitological stool tests. The Wilcoxon test to determine the proportion of positive aspects of the readings of the blades had statistical significance in almost all intestinal parasites, except Endolimax nana (p - value = 0.059) and Hymenolepis nana (p - value = 0.317). From the fourth blade, the positive samples had an increased cumulative frequency ranging from 21% to five times coming. Procedures sedimentation increasing the number of samples and readings blades showed high ability to detect intestinal parasites.