Prevalence and distribution of soil‐transmitted helminth (STH) infections in urban and indigenous schoolchildren in Ortigueira, State of Paranà, Brasil: implications for control

Abstract

SummarySoil-transmitted helminth (STH) infections represent a major public health problem in poor and developing countries. During the period September-October 1998 we conducted an epidemiological survey of STH infections in schoolchildren of an urban area (group A) and an indigenous reserve (group B), in the Municipality of Ortigueira, State of Paranà, Brazil, to assess potential benefits of mass treatment. Stool samples were examined for helminth eggs by quantitative (Kato-Katz) technique to determine the prevalence and intensity of intestinal parasitic infection. Moreover, we examined the relationship between prevalence and intensity of STH infections and housing/hygienic factors (by means of a 7-item questionnaire). 236 schoolchildren aged 5-15 years were enrolled, 136 in group A and 100 in group B. The prevalence of STH infections was significantly higher in group B (93%) than in group A (22%) (P Ͻ 0.001). Detected parasites were: A. lumbricoides (16.1% prevalence in group A, 88% in group B, P Ͻ 0.001), hookworms (5.8% in group A, 52% in group B, P Ͻ 0.001) and T. trichiura (5.1% in group A, 2% in group B, P ϭ 0.2). Heavy infections were detected in 2.9% and 23% of the children in group A and B, respectively (P Ͻ 0.001). Housing/hygienic indicators were significantly poorer in group B. A statistically significant correlation was observed between total prevalence of STH infections and prevalence of high-intensity infections with most housing/hygienic variables. On the basis of these results, mass treatment and educational interventions were suggested for the indigenous community, whereas target treatment and educational interventions were suggested for the urban community. Even in a geographically homogeneous area different epidemiological realities can be found, which in turn can influence infection levels and control programmes. keywords soil-transmitted helminthiasis, epidemiologic survey, control, schoolchildren, Brazil correspondence Dr

Prevalence and intensity of soil-transmitted helminthiasis in the city of Portoviejo (Ecuador)

“…Among the few studies reported from South America are the recent epidemiological surveys conducted by Scolari et al (2000) and Rocha et al (2000) in addition to earlier studies performed in Chile and Brazil in the late seventies (Puga et al1980, Dias 1981, Schenone et al 1981. The only data from the Andean countries are derived from a school based control program in an indigenous rural community of northern Ecuador (San Sebastian & Santi 2000).…”

Avaliação de atividades de controle para enteroparasitos em uma aldeia Kaingáng do Paraná

“…With regard to the intensity of infection by geohelminths, an epidemiological survey among schoolchildren aged five to 15 years in the Queimadas indigenous territory in 1998 (when there was still no sanitation) recorded rates that were higher than those found in the present study. 15 The "ideal" prevalence of high-intensity infections in a community is close to zero, as seen in Faxinal, with a range from 0.4% to 1.8%. If the prevalence reaches 10% or more of the population, intervention measures appropriate to this category of community (level I) should be adopted, such as universal treatment repeated periodically, along with sanitation improvements and health education.…”

“…a For example, among the Kaingáng schoolchildren in the Queimadas indigenous territory (Paraná), the prevalence observed was 2.0%. 15 However, high rates of this helminth were recorded among different ethnic groups in Amazonas, ranging from 43.3% among the Yanomami a to 91% in an unspecified ethnic group. 10 E. coli, E. nana and I. butschlii occurred at rates ranging from 22.2% to 66.0%.…”

“…Over the next five days, the researchers visited these individuals' homes twice a day (morning and afternoon) to collect the material. The reliability of the results was checked using the EpiInfo software (version 3.3.2), using the parameter of an expected frequency of infection with enteroparasites of 93% 15 among the population of 447 people, thus obtaining a confidence level that ranged from 99% to 99.9%.…”

“…15 To combat and prevent health problems among indigenous populations, primary healthcare actions need to consider the epidemiological profile of these populations and the particular features of their way of life. The aim of the present study was to analyze the parasitological state of families in an indigenous community after institution of control measures against enteroparasites.…”