From the sixteenth century, black populations arrived in Brazil on expeditions brought from the African continent in the holds of slave ships, in the condition of slaves. Blacks were treated as inferior beings and subjected to poor living conditions, various forms of violence and overwork, factors that triggered episodes of resistance and struggle against the slave rule 1,2.
The history of slaves is characterized by innumerable social movements and actions that were based on the intense search for freedom, regardless of the means used to achieve it: escape, negotiation with lords, donation and, in some extreme cases, suicide and abortion as well were practiced. The escape was seen by the slaves as the main form of survival, and it culminated in the formation of quilombos which, according to their Bantu etymology, are defined as fortified camps in the forest 1,3-6.
With the abolition of slavery, they came to be known as quilombola communities or quilombo remnant com-munities, which present "a historical trajectory of their own, endowed with specific territorial relations and with black ancestry related to the resistance to the historical oppression suffered" 6,7.
After Africa, Brazil is considered the country with the largest contingent of black population, and this prominent presence has led to a change in the State's attitude towards the racial issue. Many researchers consider the Federal Constitution of 1988 as an important landmark for the social changes that occurred in the country, since it instituted the criminalization of racism and all forms of discrimination, besides recognizing the lands of quilombola communities as definitive property 1,8,9.
Since then, many laws, programs, operational strategies, actions and public policies have been instituted to protect the black population and reduce racial inequality in the country, guaranteeing the black population and residents of quilombola communities access to health, improvements in environmental protection, basic sanitation, comprehensive health care, food and nutritional security 10.
However, it is still possible to observe in these communities a scenario marked by socioeconomic marginalization and precarious living and health conditions; quilombola dwellers deal with high poverty rates that are reflected in several ways, among them, difficulty in accessing health services, lower life expectancy and higher infant mortality 1,11,12. It is observed that the legal rights of quilombola communities do not correspond to their effectiveness, and this is often due to the scarcity of studies that are not only demographic, but also epidemiological, which help in a suitable formulation, institution and execution. On the other hand, some researchers have identified this need and have carried out research in quilombola communities, in order to collect socioeconomic data and health indicators of these populations 1,13.
Socioeconomic assessment can illustrate the conditions and quality of life of a population. Quilombola com-munities are usually referred to as vulnerable in relation to the disease/health process, since they have precarious health and infrastructure conditions, where the vast majority do not have adequate homes, treated water and sanitary sewage 14,15.
In fact, this socioeconomic reality is directly related to the transmission of intestinal parasites, since low sanitary conditions, associated with inadequate domestic and personal hygiene practices, are determining factors in the development and propagation of parasitic diseases 16-18.
Parasitic diseases are infections caused by the presence of protozoa or helminths in the intestinal tract, who-se transmission mainly occurs via the fecal-oral route, through the ingestion of contaminated food or water and inadequate hygiene practices. Brazil has several endemic areas with a high prevalence of parasitic diseases, constituting a serious public health problem 19-21.
Besides the association with socioeconomic conditions, researchers relate the high frequency of parasitosis with the ease of transmission, the resistance of the infecting forms, and the possibility of triggering reinfection cycles. The clinical manifestations of parasitic diseases can increase morbidity rates and, in more severe situations, lead to the death of infected individuals, which makes the knowledge of this reality relevant in different population groups 16,18,22,23.
In this context and considering that quilombola com-munities are constantly associated with poor basic sanitation conditions 1,11,14,15, this study aimed to evaluate socioeconomic and parasitological aspects in quilombola communities located in the Northern region of Espírito Santo.
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.
Ethics statement
The study was initially evaluated and approved by the Research Ethics Committee of Federal University of Espírito Santo, under N° CAAE: 47999915.1.0000.5063. The participants of the research were oriented on the objectives of the study and, through the agreement, they signed an Informed Consent Term (TCLE). The participants were adults and minors and for the minors the parents or guardians provided consent on behalf of all child participants.
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).
Parasites | N | %* |
---|---|---|
Ascaris lumbricoides | 14 | 19.4 |
Hookworm | 7 | 9.7 |
Entamoeba coli | 40 | 55.6 |
Entamoeba histolytica/dispar | 8 | 11.1 |
Endolimax nana | 12 | 16.7 |
Enterobius vermicularis | 2 | 2.8 |
Hymenolepis nana | 3 | 4.2 |
Trichuris trichiura | 3 | 4.2 |
Taenia sp. | 2 | 2.8 |
n=72 |
* The total % of the table is more than 100%. Some of the samples had co-infection and involved in more than one parasite infection percentage.
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).
Parasites | Spontaneous sedimentation method | Kato-Katz method | ||
---|---|---|---|---|
N | % | N | % | |
A. lumbricoides | 1 | 1.4 | 13 | 18.1 |
Hookworm | 3 | 4.2 | 4 | 5.6 |
Entamoeba coli | 40 | 55.6 | 0 | 0 |
Entamoeba histolytica/dispar | 8 | 11.1 | 0 | 0 |
Endolimax nana | 12 | 16.7 | 0 | 0 |
Enterobius vermicularis | 2 | 2.8 | 0 | 0 |
Hymenolepis nana | 2 | 2.8 | 1 | 1.4 |
Trichuris trichiura | 1 | 1.4 | 2 | 2.8 |
Taenia sp. | 0 | 0 | 2 | 2.8 |
n=72 |
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).
a | Parasites | epg (feces) |
---|---|---|
1 | Hookworm | 24 |
Ascaris lumbricoides | 24 | |
2 | Ascaris lumbricoides | 24 |
3 | Hymenolepis nana | 24 |
4 | Trichuris trichiura | 72 |
5 | Ascaris lumbricoides | 48 |
Taenia sp. | 48 | |
6 | Ascaris lumbricoides | 24 |
7 | Ascaris lumbricoides | 8.7 |
8 | Hookworm | 24 |
9 | Hookworm | 24 |
10 | Taenia sp. | 24 |
11 | Ascaris lumbricoides | 24 |
12 | Ascaris lumbricoides | 1.5 |
13 | Hookworm | 24 |
14 | Ascaris lumbricoides | 11.1 |
Trichuris trichiura | 72 | |
15 | Ascaris lumbricoides | 14.8 |
16 | Ascaris lumbricoides | 2.1 |
17 | Ascaris lumbricoides | 9.2 |
18 | Enterobius vermicularis | 24 |
19 | Ascaris lumbricoides | 48 |
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).
General Sample (n1) | Negative Sample (n2) | Positive Sample (n3) | p | ||||
---|---|---|---|---|---|---|---|
Gender | n | % | n | % | N | % | 0.76 |
Female | 79 | 52.7 | 45 | 57.7 | 34 | 47.2 | |
Male | 71 | 47.3 | 33 | 42.3 | 38 | 52.8 | |
Skin color | |||||||
Yellow | 1 | 0.7 | 0 | 0 | 1 | 1.4 | 0.008* |
White | 7 | 4.7 | 5 | 6.4 | 2 | 2.8 | |
Black | 103 | 68.6 | 48 | 61.6 | 55 | 76.4 | |
Pardo | 39 | 26.0 | 25 | 32.0 | 14 | 19.4 | |
Age group | |||||||
0-10 years old | 27 | 18.0 | 10 | 12.8 | 17 | 23.6 | 0.01* |
11-20 years old | 15 | 10.0 | 10 | 12.8 | 5 | 6.9 | |
21-60 years old | 75 | 50.0 | 39 | 50.0 | 36 | 50.0 | |
Above 60 years old | 33 | 22.0 | 19 | 24.4 | 14 | 19.5 | |
Wall Material | |||||||
Masonry | 148 | 98.7 | 78 | 100 | 70 | 97.2 | 0.25 |
Plywood | 2 | 1.3 | 0 | 0 | 2 | 2.8 | |
Roof material | |||||||
Asbestos | 123 | 82.0 | 64 | 82.1 | 59 | 81.9 | 0.22 |
Concrete | 3 | 2.0 | 2 | 2.6 | 1 | 1.4 | |
Roof tile | 20 | 13.3 | 9 | 11.5 | 11 | 15.3 | |
Wood | 4 | 2.7 | 3 | 3.8 | 1 | 1.4 | |
Number of rooms | |||||||
Up to three | 2 | 1.3 | 2 | 2.6 | 0 | 0 | 0.39 |
Four or more | 148 | 98.7 | 76 | 97.4 | 72 | 100 | |
Number of bedrooms | |||||||
Up to two | 56 | 37.3 | 32 | 41 | 24 | 33.3 | 0.55 |
Three or more | 94 | 62.7 | 46 | 59 | 48 | 66.7 | |
Piped water | |||||||
Yes | 143 | 95.3 | 76 | 97.4 | 67 | 93.1 | 0.35 |
No | 7 | 4.7 | 2 | 2.6 | 5 | 6.9 | |
Origin of water | |||||||
Well or spring | 114 | 76.0 | 58 | 74.4 | 56 | 77.8 | 0.33 |
General distribution network | 35 | 23.3 | 20 | 25.6 | 15 | 20.8 | |
Rain or transported | 1 | 0.7 | 0 | 0 | 1 | 1.4 | |
Bathrooms | |||||||
Yes | 146 | 97.3 | 77 | 98.7 | 69 | 95.8 | 0.53 |
No | 4 | 2.7 | 1 | 1.3 | 3 | 4.2 | |
Toilet drain | |||||||
Rudimentary septic tank | 128 | 85.4 | 68 | 87.2 | 60 | 83.3 | 0.04* |
Septic tank | 20 | 13.3 | 10 | 12.8 | 10 | 13.9 | |
Sewerage system | 2 | 1.3 | 0 | 0 | 2 | 2.8 | |
Use of bathroom | |||||||
Exclusive to the household | 147 | 98.0 | 77 | 98.7 | 70 | 97.2 | 0.82 |
Common to other households | 3 | 2.0 | 1 | 1.3 | 2 | 2.8 | |
Waste management | |||||||
Burned or buried | 89 | 59.3 | 45 | 57.7 | 44 | 61.1 | 0.16* |
Collected | 61 | 40.7 | 33 | 42.3 | 28 | 38.9 | |
Family income | |||||||
Less than 1 minimum wage | 29 | 19.3 | 23 | 29.5 | 6 | 8.3 | 0.04* |
1 minimum wage | 57 | 38.0 | 24 | 30.8 | 33 | 45.8 | |
2 to 3 minimum wages | 61 | 40.7 | 29 | 37.2 | 32 | 44.5 | |
Between 3 and 5 minimum wages | 1 | 0.7 | 1 | 1.3 | 0 | 0 | |
Above 10 minimum wages | 2 | 1.3 | 1 | 1.3 | 1 | 1.4 | |
Access to health services | |||||||
Yes | 121 | 80.7 | 69 | 88.5 | 52 | 72.2 | 0.001* |
No | 29 | 19.3 | 9 | 11.5 | 20 | 27.8 |
n1=150; n2=78; n3=72 *p<0.20: significant result.
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 ♣