Enteroparasitosis in patients attended by the health public service : epidemiology and spatial distribution

Aims: This research aims to determine the epidemiology and the spatial distribution of intestinal parasitosis in the city of Teresina, Brazil. Methods: A cross-sectional study was carried out based on the data of parasitological fecal exams performed in the Laboratory Raul Bacelar between January, 2014 and July, 2017. In addition to the prevalence of intestinal parasitosis and polyparasitism, we verified the association of these diseases with gender, zone and period of the year by means of the chi-squared test, whereas the relation with age was analyzed by the Mann-Kendall tests and multiple comparisons of age classes. The spatial distribution was performed using the QGIS georeferencing software. Results: The prevalence of enteroparasitosis in Teresina was 17.8% with Ascaris lumbricoides being the most common species. The prevalence of individuals with polyparasitism was 3.1%, in which an association between the species Entamoeba coli and Entamoeba histolytica/dispar was found. There was no relation between intestinal parasitosis with gender, but we verified that individuals in rural areas were more susceptible to these diseases. The species Ascaris lumbricoides and Entamoeba histolytica/dispar occured more frequently in the first and second semester, respectively. We observed that there was an apparent tendency to increase cases of Entamoeba histolytica/dispar and reduction of cases of Giardia sp. according to aging. Mapping intestinal parasitosis showed us that there was a prevalence between 1 and 20% in most of Teresina’s neighborhoods, and Ascariasis embodies at least 40% of cases of enteroparasitosis in these neighborhoods. Conclusions: Investments in basic sanitation and new epidemiological investigations must be carried out to control intestinal parasitosis in Teresina, emphasizing that children and the elderly should be considered priority groups in these programs.


INTRODUCTION
Intestinal parasitosis are a group of diseases caused by protozoa and helminths that affect the gastrointestinal tract, transmitted through contact with contaminated soil or through ingestion of contaminated food or water [1,2]. The symptomatology provoked by intestinal parasitosis is varied and not very specific, including diarrhea, nausea, vomiting, and abdominal pain [3]. Individuals with high parasitic load or compromised immune system present more severe manifestations, such as intestinal obstruction and abscesses, which may culminate in the death of the host [3,4].
Children and elderly people are more susceptible to the appearance of inherent complications in parasitosis. We emphasize that the consequences in children and teenagers are not limited to gastrointestinal symptoms, impairing cognitive and physical development [5]. Patients suffering from diseases that suppress the immune system, such as acquired immunodeficiency syndrome and cancer, also demand attention because of the increased mortality risk [6].
Despite having a wide knowledge about harms generated to the health of those affected, as well as harms on the economy, enteroparasitosis are considered neglected diseases [7]. The shortage of data makes it difficult to plan policies to reduce the number of infected individuals and makes it impossible to monitor the effects of actions taken [8]. In this sense, public initiatives must be oriented for specific groups in population.
The prevalence rates of intestinal parasitosis change according to the region of the country and are related to the health of local citizens in Brazil [9]. Basic sanitation, housing conditions and hygiene habits are factors associated with the incidence of intestinal parasitosis [10]. Therefore, we can comprehend that the environment influences on the appearance of these diseases since such aspects are determinants of the health of populations [11]. In this context, epidemiology contributes significantly to the understanding of the health-disease process dynamics by making it possible to identify the most affected groups and a disease spatial distribution [2,12].
Considering the importance and the shortage of data on the subject, this study aims to determine the prevalence, epidemiological characteristics and spatial distribution of intestinal parasitosis in patients attended by health public service of Teresina, in the state of Piauí, Brazil.

Study Area
Teresina is the capital of the state of Piauí, which is located in the Northeast of Brazil. The city is located at 05º05'21'' S and 42º48'07'' W and has a total area of 1,392 km 2 . The climate of the city is characterized by the concentration of rainfall in the first four months of the year, so that the relative humidity of the air remains high during the first semester and suffers an intense reduction in

Data Collection
The present work consists of an observational and transversal study, developed through the analysis of data from parasitological fecal exams performed by

Statistical Analysis
The data were organized and submitted to statistical tests with the help of LibreOffice suite and Giardia sp. also stood out as common parasites ( Table 1). in the samples showed a higher correlation and an association between the species was verified by the chi-square test ( Table 2).    which immunological tests are more reliable for differential diagnosis [21]. Another reason which explains the association could be intrinsic factors that need to be identified in future investigations.
There was no association between the positivity of parasitological tests and gender, so that the predominance of cases of intestinal parasitosis in female subjects is related to the profile of the study population, composed mainly of women.
The area where patients reside, in turn, was associated with the frequency of these diseases.
As observed in this research, rural inhabitants are more likely to acquire enteroparasitosis when compared to individuals living in the urban area, due to the absence or precariousness of basic sewage services, water supply and garbage collection, which makes such environment more conducive to the spread of these diseases [10]. and Endolimax nana did not show any tendency according to age. We highlight the unrestricted distribution of Ascaris lumbricoides by age groups in the investigated population, a feature that contributes to this enteroparasite being the most prevalent in the city. The apparent tendency to reduce the frequency of giardiasis with the increasing age, also observed in study carried out with patients in tertiary care hospital in India [24], results from the immunity acquired by individuals previously exposed to Giardia sp., which induces the production of specific antibodies and CD4 + T memory cells [25]. As a result, children become more susceptible to Giardia sp. and have a significantly higher prevalence when compared to other age groups.
The most frequent enteroparasitosis among the elderly were concordant with another study carried out in Piauí in which protozoa, including Entamoeba histolytica/dispar, are the most prevalent [17].

Notes Funding
This study did not receive financial support from external sources

Conflicts of interest disclosure
The authors declare no competing interests relevant to the content of this study.

Authors' contributions.
All the authors declare to have made substantial contributions to the conception, or design, or acquisition, or analysis, or interpretation of data; and drafting the work or revising it critically for important intellectual content; and to approve the version to be published.

Availability of data and responsibility for the results
All the authors declare to have had full access to the available data and they assume full responsibility for the integrity of these results.