MATERIAL AND METHODS

This is a cross-sectional, descriptive study with a quantitative approach and non-probabilistic convenience sample conducted in five quilombola communities (Angelim DISA, Córrego do Alexandre, Córrego do Macuco, Nova Vista and São Jorge), located in the municipalities of São Mateus and Conceição da Barra, Northern region of Espírito Santo, Brazil. The population of the municipality of São Mateus is estimated at 109,028 inhabitants, distributed in an area of 2,338.727 Km2, with a population density of 46.62 inhabitants/Km2, and a Human Develop Index (HDI) of 0,735. The municipality of Conceição da Barra has a population of 28,449 inhabitants, distributed in 1,184.908 Km2, with a population density of 24.01 in-habitants/Km2 and HDI of 0.681 ²⁴.

Socioeconomic data and fecal samples were collected between December 2015 and June 2016. A total of 500 residents of quilombola communities were contacted to participate in the study. Of these, only 150 (30%) accepted to participate, and gave stool samples and answered the questionnaire. Parasitological analyses were per-formed using qualitative spontaneous sedimentation methods proposed by Hoffman, Pons and Janer (HPJ), and the Kato-Katz semi-quantitative method, in triplicate and duplicate, respectively ^25-27. A single faecal sample was collected from an individual subject. The results of the parasitological examinations were given to each participant or legal guardian. The data obtained, systematized in a Microsoft Excel 2007 spreadsheet and typed twice, were analyzed using the software STATA, version 12.0. Univariate and multivariate analyses were performed using the Pearson chi-square test, Fisher's exact test and Poisson regression analysis, respectively. The dependent variable chosen for this study was "Parasitosis". The independent variables were chosen among other socioeconomic and demographic variables included in the National household sample survey questionnaire ²⁸, and those that presented statistical significance (p<0.20) in the Pearson chi-square test and Fisher's exact test were included in the Poisson regression model. The Prevalence Ratio was obtained and a confidence interval of 95% (p<0.05) was adopted in the final model. The questionnaire presents questions related to socioeconomic, demographic and health variables such as gender, skin color, age, what kind of material predominates on the roof of the houses, how many rooms are in the house, whether the residence has piped water, how the garbage family is income, and whether residents have access to health care.

RESULTS

From a total of 150 stool specimens analyzed, considering the methods of Spontaneous Sedimentation and Kato-Katz, 48.0% (n=72) were positive for intestinal parasites, out of them 75.0% (n=54) monoparasite and 25.0% (n=18) biparasite/polyparasite, presenting two or more species of parasites. Among the positive samples, protozoa were found in 72.2% (n=52) and helminths in 41.6% (n=30). On the other hand 13.8% (n=10) of the samples had parasites of both groups.

The commensal Entamoeba coli was the most frequent among the samples (55.6%, n=40), followed by Ascaris lumbricoides and by the commensal ENDOLIMAX nana, present in 19.4% (n=14) and 16.7% (n=12), respectively. The complete prevalence of parasitic species is described in (Table 1).

The Kato-Katz method allowed the identification of six kinds of intestinal parasites in 19 positive samples, some of which biparasite. When comparing the methods of spontaneous sedimentation and Kato-Katz it was observed that the Kato-Katz method was more specific for most of the helminths identified in the study (Table 2).

Once the number of infected individuais was established, the number of parasites eggs per gram of feces (epg) per individual sample was determined, with values ranging from 24 to 14,808 epg. Of all infected individuais, 14 (73.68%) had low parasite load (up to 100 epg), none had intermediate parasite load (>100 and <400 epg) and 5 (26.32%) had high parasite load (above 400 epg) ²⁹ (Table 3).

It was observed that intestinal parasites were more frequent in males (52.8%), black-skinned (76.4%) aged between 21 and 60 years old (50%). Regarding the socioeconomic conditions of the studied population, 95.3% have piped water, of which 76% come from a well or spring, 97.3% have a bathroom at home, 85.4% have a toilet drain made in a rudimentary septic tank and 59.3% reported having litter buried or burned. In addition, 40.7% report having a family income between two and three minimum wages and 80.7% report having access to the public health service (Table 4).

When comparing socioeconomic and demographic variables between positive and negative samples for parasitosis, using the Pearson chi-square test or Fisher's exact test when necessary, a value of p<0.20 can be observed for the variables skin color, age group, toilet drain, waste management, family income and access to health services. Subsequently, these variables were applied to the Poisson regression model, and a significant association with the parasitological results was obtained only for the variable access to the health services, with gross prevalence ratio (PR) of 2.9 (95% CI: 0.37-1.02) and prevalence ratio (PR) adjusted by the model of 1.59 (95% CI: 1.092.66, p<0.05), showing that individuals who do not have access to health services have an increase of 1.59 in the prevalence of parasitosis, when compared to those who have access to these services.

DISCUSSION

The study showed a high prevalence of intestinal parasites, as observed in other epidemiological studies conducted by Damazio et al. ³⁰ and Mendes et al. ³¹, who identified, respectively, frequencies of 42.7% and 40.6% of intestinal parasites; both studies were also conducted in quilombola communities of Espírito Santo.

It is worth noting that intestinal parasites are a public health problem common to quilombola communities in several states and regions of Brazil, as can be observed in parasitological surveys conducted by Andrade et al. ¹⁴ and Amorim et al. ³², who identified, respectively, a prevalence of 63.8% parasitosis in quilombola communities in the state of Minas Gerais and 35.4% in communities in the state of Bahia.

The use of two parasitological techniques (Spontaneous Sedimentation and Kato-Katz) allows obtaining more accurate results, as described by Mendes et al. ³³ and Carvalho et al. ³⁴ who reported that the laboratory routine should use more than one parasitological method for detecting parasitic forms of protozoa and helminths, especially in samples with low parasite load ^35,36, as observed in the present study.

Although not posing a health risk, the prevalence of commensal, non-pathogenic parasites, such as E. coli and E. nana, suggests poor hygiene and basic sanitation, since they indicate fecal-oral contamination, thus facilitating the transmission of other pathogenic parasites with a similar contamination pathway ^9,37.

Unlike protozoa E. coli and E. nana, E. histolytica/dispar, present in 11.1% (n=8) of the positive samples, may pose a public health risk. E. histolytica and E. dispar are morphologically identical, but biochemically, physio-logically and genetically distinct, which makes E. dispar non pathogenic and E. histolytica, the etiological agent of intra-intestinal amoebiasis and, in the most severe cases, extra-intestinal invasion, with clinical manifestations ranging from asymptomatic infections to death. Species differentiation can be done through ELISA, indirect immunofluorescence, radioimmunoassay, among others, and the parasitological methods used in this study are insufficient to distinguish them ^30,37,38.

In addition to protozoa, helminth species with a high degree of pathogenicity were identified in quilombola communities, such as Taenia sp., hookworms and A. lumbricoides, besides other species that manifest themselves with milder symptoms, such as E. vermicularis, H. nana and T. trichiura. However, not only does the severity of parasitic infections depend on virulence, but also on parasite load and host characteristics, such as age, nutritional status and immunological status ^38,39.

The children, aged 0-10 years, were the most affected by intestinal parasites, which is in agreement with studies that relate the age of the children with being more prone to parasitic infections, once the immune response to parasites is still under development, personal hygiene care is being learned, many are dependent on parents and/or caregivers, in addition to a change in dietary patterns, with the introduction of raw foods in the diet, besides a greater contact with the soil, domestic animals and other children ^40-42.

The high prevalence of intestinal parasites is often related to the precarious conditions of infrastructure and basic sanitation, favoring the transmission and maintenance of parasitosis in the populations. The high prevalence of A. lumbricoides, Ancylostomidae, E. histolytica/dispar, H. nana, T. trichiura, E. vermicularis, Taenia sp. parasites and the commensals E. coli and E. nana, indicating the need for effective interventions through educational actions, improved access to health services, implementation of parasite control programs, expansion and improvement of basic sanitation services offered to the community, in order to reduce the prevalence of intestinal parasites and to ensure better conditions and quality of life to the residents.

Considering that basic sanitation involves services of water supply, sewage and solid waste management, and that the population must be assisted in these three aspects to have a quality service, the results of this study indicate precarious conditions of basic sanitation, which makes the population vulnerable to diseases, posing a risk to public health ^18,43.

The water supply comes mainly from wells or springs, without prior treatment or quality control, and may be unfit for human consumption, acting as a vehicle in the transmission of parasitic, bacterial and/or viral diseases. In addition, the burning and burial of the solid waste generated contributes negatively to population health, favoring air pollution, increasing the probability of respiratory problems, among others, besides the contamination of soil and groundwater, compromising the agricultural production of these populations. Some studies associate the poor conditions of basic sanitation and home infrastructure in quilombola communities to geographic isolation, making it difficult to increase services and improve the living conditions of this population ^18,44.

However, in spite of the precarious socioeconomic condition, a statistically significant association between socioeconomic and demographic variables with the prevalence of parasitosis was not observed in this study, except for the variable access to the public health service, which presented an inversely proportional relation, acting as a protection factor, which may have occurred due to the number of participants in this study. Other studies with the same theme are suggested, covering a quilombola population that is representative of the state of Espírito Santo ♣