[Prevalence and epidemiological aspects of enteroparasites in the population of São José da Bela Vista, São Paulo]

Prevalence of helmintic infections in Brazilian Maxakali indigenous: a repeated cross-sectional design

BACKGROUND

The prevalence of intestinal parasites is known to be high among Amerindian populations; further, there are serious problems in the healthcare of these populations in Brazil. The Maxakali, located in the northeastern region of Minas Gerais, Brazil, is an indigenous group that still preserves many of its cultural aspects. This study aimed to compare the positivity rate of schistosomiasis and soil-transmitted helminths in this ethnic group in epidemiological surveys conducted in 1972 and 2014.

METHODS

Stool parasitological examinations were performed by the Kato-Katz technique during both periods in this population. In 2014, the parasitological diagnosis was also realized with the TF-Test® technique.

RESULTS

In 1972, 270 inhabitants were examined. The positivity rates were 67.4% for Schistosoma mansoni, 72.9% for hookworms, 43.7% for Ascaris lumbricoides, and 23.7% for Trichuris trichiura. In 2014, 545 individuals were examined, and the positivity rates obtained were 45.7% for S. mansoni, 22.8% for hookworms, 0.6% for A. lumbricoides, and 2.8% for T. trichiura.

CONCLUSIONS

The comparison of the parasitological surveys conducted in 1972 and 2014, indicates that the indigenous Maxakali remained neglected by the health and indigenous protection authorities during these four decades. The infection rate observed in 2014 for schistosomiasis and hookworm remains high, considering the current epidemiological view of these diseases in the Brazilian population.

Enterobius vermicularis in Brazil: An integrative review

Enterobius vermicularis, an intestinal helminth, is transmitted through the ingestion of eggs found in food, water, dust, or other fomites, including infected individuals. This review aimed to examine the frequency and distribution of E. vermicularis infections in Brazil between 1991 and 2022. The conducted bibliographic survey revealed that the frequency of E. vermicularis infections in Brazil ranged from 0.1 to 26.1%, depending on factors such as population ethnicity, individual age group, geographic area, time frame, and diagnostic method. However, these findings were based on a limited number of publications, suggesting that the actual prevalence rates of E. vermicularis infection may still be unknown and potentially underestimated.

Diversity, geographical distribution, and prevalence of Entamoeba spp. in Brazil: a systematic review and meta-analysis

The genus Entamoeba includes a variety of widely distributed species adapted to live in the digestive tracts of humans and a large variety of animals of different classes. The objective of this study was to investigate the prevalence, distribution, and molecular epidemiology of Entamoeba spp. in different classes of hosts in Brazil. Studies that analyzed hosts from several classes, including humans and domestic, wild, or captive animals, were considered. The pooled prevalence of Entamoeba spp. was calculated using the random-effects model. A total of 166 studies on humans and 16 on animals were included. The prevalence of Entamoeba spp. in the Brazilian population was 22% (95% CI: 21–24). The state with the highest prevalence was Paraiba with 72%, followed by Federal District with 53%, and Rondonia with 50%. In immunocompromized patients, the prevalence was 18%, and cancer (36%) was the most prevalent cause of immunosuppression. The prevalence of Entamoeba spp. in animal hosts was 12% (95% CI: 7–17). Captive wild animals and domestic farm animals showed the highest prevalence, with 16% and 15%, respectively. The species found more often were E. coli (86.5%), E. dispar (7.9%), and E. histolytica (3.1%). In conclusion, a high prevalence (22%) of Entamoeba spp. was found in the Brazilian population, with a prevalence of up to 50% mainly in the northern, northeastern, and central-western regions. The pathogenic species E. histolytica is distributed in most Brazilian regions, with significant prevalence percentages. Among animals, unidentified Entamoeba species were most prevalent in mammals.

Canine visceral leishmaniasis in the metropolitan area of São Paulo: Pintomyia fischeri as potential vector of Leishmania infantum

American visceral leishmaniasis is a zoonosis caused by Leishmania infantum and transmitted mainly by Lutzomyia longipalpis. However, canine cases have been reported in the absence of this species in the Greater São Paulo region, where Pintomyia fischeri and Migonemyia migonei are the predominant species. This raises the suspicion that they could be acting as vectors. Therefore, this study sought to investigate specific vector capacity parameters of these species and to compare them with those of Lu. longipalpis s.l. Among these parameters the blood feeding rate, the survival, and the susceptibility to the development of Le. infantum were evaluated for the three species, and the attractiveness of dogs to Pi. fischeri and Mg. migonei was evaluated. The estimated interval between blood meals was shorter for Lu. longipalpis s.l, followed by Pi. fischeri and Mg. migonei. The infection rate with Le. infantum flagellates in Lu. longipalpis was 9.8%, in Pi. fischeri 4.8%, and in Mg. migonei nil. The respective infective life expectancies (days) of Lu. longipalpis, Mg. migonei, and Pi. fischeri were 2.4, 1.94, and 1.68. Both Pi. fischeri and Mg. migonei were captured in the kennel with a predominance (95%) of Pi. fischeri. Considering the great attractiveness of dogs to Pi. fischeri, its susceptibility to infection by Le. infantum, infective life expectancies, and predominance in Greater São Paulo, this study presents evidence of Pi. fischeri as a potential vector of this parasite in the region.

Leishmania infantum Genetic Diversity and Lutzomyia longipalpis Mitochondrial Haplotypes in Brazil

Leishmania infantum is the etiological agent of visceral leishmaniasis (VL) in the Americas with domestic dogs being its major reservoir hosts. The main VL vector is the sandfly Lutzomyia longipalpis, while other Lutzomyia species may play a role in disease transmission. Although the genetic structure of L. infantum populations has been widely evaluated, only a few studies have addressed this subject coupled to the genetic structure of the respective sandfly vectors. In this study, we analyzed the population structure of L. infantum in three major VL endemic areas in Brazil and associated it with Lutzomyia longipalpis geographic structure.

Prevalence and predictors associated with intestinal infections by protozoa and helminths in southern Brazil

Approximately 2 billion people are infected with soil-transmitted helminths worldwide, mainly in tropical and subtropical areas. This research aimed to investigate the prevalence and predictors associated with parasitic infections in primary health care. A cross-sectional study was performed with a large random sample to identify the prevalence and predictors associated with parasitic infections in primary health care in Marialva, southern Brazil, from April 2011 to September 2013. Stool samples from 775 individuals were analyzed for the presence of protozoan cysts, helminth eggs, and larvae. The overall prevalence of intestinal parasites was 13.94 %, and the prevalence of protozoa and helminths was 15.1 and 2.9 %, respectively. The predictor variables that were associated with intestinal parasites were male gender odds ratio (OR) 1.60, 95 % confidence interval (CI 1.10-2.40) and the absence of a kitchen garden (OR 2.28, 95 % CI, 1.08-4.85). Positive associations were found between Giardia duodenalis and individuals aged ≤18 with high risk (OR 19.0, 95 % CI 2.16-167.52), between Endolimax nana and the absence of a kitchen garden (p < 0.01), and between Trichuris trichiura and the presence of a kitchen garden (p = 0.014). Polyparasitism was present in 27.27 % of infected individuals. Our findings confirmed a relatively low prevalence in primary care, compared to international standards, despite the rare publications in the area. As variables, male gender and the absence of a kitchen garden stood out as important predictors. It is highly relevant that the health conditions of the population comply with consistent standards.

Spatial analysis of schistosomiasis human cases in the horticultural community of Zona da Mata of Pernambuco state, Brazil

The objective of this study was to describe the spatial distribution of schistosomiasis in horticultural community of Natuba, district of Vitória de Santo Antão, Pernambuco state. It was conducted a parasitological survey, examined the fecal material of 310 community residents. The cases positive for Schistosoma mansoni were geocoded and included in the computerized template of the community, generating maps of spatial distribution with kernel estimators. The results showed a high prevalence of schistosomiasis, with 28.4% of the parasites. Other parasites were found in 25.8% of the population. The use of GIS tools to map and understand the possible distribution of cases of schistosomiasis in the space occupied by the community highlighting and listing locations of lower elevation (able to flooding), with a higher frequency of human cases. Studies like this provide information to the local health services, may intervene and bring about change for individuals living in areas with low housing conditions to minimize their exposure to risk of contracting schistosomiasis.

[Study of the association between socio-environmental factors and the prevalence of intestinal parasitosis in the suburbs of the city of Manaus in the state of Amazonas, Brazil]

This study assesses the association between socio-environmental factors and urban sanitation conditions with the prevalence of intestinal parasitosis in a community on the periphery of the city of Manaus. The study comprised a socio-environmental survey and a parasitological inquiry. A heterogeneous community was revealed with some socio-economic and environmental differences between the micro-areas evaluated, even though the urban sanitation conditions were found to be predominantly precarious. The prevalence of intestinal parasitosis was 44.2%. There was no significant difference between the micro-areas that could explain the occurrence of intestinal parasitosis. An association was found between intestinal parasitosis and residential building types, age bracket and the quality of the water used for personal hygiene and consumption in the home. Open air sewage was a risk factor associated with intestinal parasitosis (OR=6.72; p=0.034) and also with intestinal protozoa (OR=21.87; p=0.004). In terms of the presence of protozoa, two risk factors were verified: the dumping of sewage directly into the river system (OR=12.98; p=0.011) and the use of rudimentary cesspits (OR=9.54; p=0.019).

Parasitoses intestinais se associam a menores índices de peso e estatura em escolares de baixo estrato socioeconômico

OBJETIVO: Avaliar a prevalência de parasitoses intestinais, correlacionando-as com os fatores socioeconômicos e ambientais, peso, estatura e hemoglobina, em crianças de dois estratos socioeconômicos, no município de Osasco (SP). MÉTODOS: Estudo transversal, comparando 84 crianças de seis a dez anos, residentes em área sem saneamento básico e moradia precária, com 35 crianças de escola particular no mesmo município, que possuíam boas condições socioeconômicas e de moradia. Excluíram-se aquelas com diarreia há menos de 30 dias ou doença grave. Utilizou-se questionário padronizado para avaliar as condições socioambientais. A avaliação nutricional foi realizada mediante escores Z de peso para idade, estatura para idade e índice de massa corpórea. A determinação da hemoglobina em amostra de sangue capilar foi realizada pelo método Hemocue® e a pesquisa de parasitas intestinais, pelos métodos de Hoffman, Ritchie, Kinyoun e swab anal. RESULTADOS: Parasitose intestinal ocorreu em 60,7% das crianças da favela e em 5,9% das crianças da escola particular (p<0,001; OR 24,7). A média dos escores Z de peso para idade, estatura para idade e índice de massa corpórea foi menor nas crianças parasitadas (-0,78±0,84; +0,50±0,90; -0,76±0,96) em relação àquelas não parasitadas (-0,18±1,18; +0,03±1,10; -0,28±1,16), sendo as diferenças estatisticamente significantes (p<0,05). Não houve diferença nos valores médios de hemoglobina entre as crianças parasitadas e não parasitadas do grupo da favela (12,6±1,1g/dL e 12,8±1,2g/dL); p=0,58. CONCLUSÕES: A parasitose intestinal foi mais prevalente em crianças da favela e se associou a menores índices de peso e de estatura.

Epidemiological aspects of strongyloidiasis in Brazil

The objective of this review was to outline an epidemiological profile of Strongyloides stercoralis by parasitological and serological diagnosis in inhabitants, and to associate this profile with different immunosupression situations, in Brazil, over 20 years (1990-2009). The occurrence of S. stercoralis using parasitological methods was 5·5%, being 4·8% in rural and 5·0% in urban areas, characterizing the country as hyperendemic. There was a diversity of techniques used as a diagnostic tool and only 39·1% of the studies presented results based on at least 1 specific method. The occurrence increased with age, being 12·1%, for those over 60 that suggests an epidemiological condition of concern for the elderly population. Of the seroepidemiological studies in the general population the mean positivity in serum samples was 21·7% and 29·2%, using an immunofluorescence antibody test and enzyme-linked immunosorbent assay (ELISA), respectively. The occurrence of strongyloidiasis in immunosuppressed individuals was 11·8% by parasitological methods and 19·5% using immunological methods. Considering that Brazil is a tropical country and that the character of chronicity and autoinfection of the parasite that can result in severe forms of hyperinfection or dissemination makes strongyloidiasis an important medically and socially neglected problem.

Prevalence of intestinal parasites in preschool children in the region of Uberlândia, State of Minas Gerais, Brazil

INTRODUCTION

Children are an important high-risk group for helminth and protozoa infections. Daycare centers are environments where children have proven to be more susceptible to acquiring intestinal parasites. Thus, the purpose of this study was to verify the prevalence of intestinal parasites in children who attended the two daycare centers maintained by the local government of Uberlândia, State of Minas Gerais, Brazil.

METHODS

Fecal samples were collected from 133 children (73 children at the Public Preschool for Early Childhood Education, PPECE A, and 60 at the PPECE B) following identification according to sex and age and agreement to participate by parents or guardians who signed the free, informed consent form. The samples were examined by the Lutz method.

RESULTS

Coproparasitological tests performed on 133 children showed that 29.3% of them were parasitized for enteroparasites or commensals, 6.7% of the children presented polyparasitism. Among the protozoa, Giardia lamblia were the most prevalent and Hymenolepis nana were the most frequent among the helminths.

CONCLUSIONS

Thus, analysis of the results showed that intestinal parasites still represent a public health problem, especially among children and in areas where the socioeconomic and educational conditions are less favorable.

[Prevalence of enteroparasitosis in the population of Maria Helena, Paraná State]

The epidemiological study on intestinal parasites has the purpose of determining the main diseases and their respective etiologic agents, which are endemically or epidemically spread worldwide. The aim of this study was to evaluate the enteroparasitosis infection prevalence, in which age group they prevail, relating the infection with age, gender, and the region in which the person lives, in the city of Maria Helena - PR. Data collection was performed from June of 2004 to May of 2006. 431 samples of feces were analyzed through the spontaneous sedimentation and centrifugal fluctuation methods. The enteroparasitosis prevalence was of 16%, being the most frequent enteroparasitosis: Endolimax nana (6.5%), Entamoeba coli (3.5%), Giardia lamblia (6.3%), Ascaris lumbricoides (1.4%), Strongyloides stercoralis (0.7%), Entrobius vermicularis (0.7%), Anchylostomiasis (0.2%), Entamoeba hystolitica and Taenia sp (0.2%). Poly-parasitism was found in 3.2% of the samples. The age group from 0 to 9 years presented the highest prevalence, however there was no statistical difference among the analyzed factors since p>0.05. From these results, it was possible to conclude that the city presents similar characteristics both in rural and urban zones.

Intestinal parasites inside public restrooms and buses from the city of Uberlândia, Minas Gerais, Brazil

The objective of this study was to describe the occurrence of intestinal parasites inside public restrooms and buses from a Brazilian city. Sample material was obtained using a transparent adhesive tape. Thirty two public restrooms were investigated and two (6.25%) were contaminated with helminth eggs (Ascaris lumbricoides and Enterobius vermicularis). Of the sixteen different bus lines, three (18.7%) were found to harbor eggs of E. vermicularis. Public restrooms and buses can be an important source of parasite transmission and sanitary education could be improved by using these points.

[Observations on Blastocystis hominis and Cyclospora cayetanensis in routine parasitological examinations]

We report some observations made from routine parasitological examinations on feces. The methods of Faust et al. and of spontaneous sedimentation in water are not enough to identify Blastocystis hominis. Significant percentage presence of this protozoan was found, especially when staining with iron hematoxylin was performed. Cyclospora cayetanensis was found in 0.7% of the cases, which suggests that this parasite should also routinely be investigated by appropriate techniques.

Occurrence of enteroparasites in day care centers in Botucatu (São Paulo State, Brazil) with emphasis on Cryptosporidium sp., Giardia duodenalis and Enterobius vermicularis

The occurrence of the enteroparasites was verified in 279 children (0 to 6 years) of four municipal day cares of Botucatu/SP. Three samples of each child's feces were collected and processed by the methods of Hoffman-Pons-Janner, Faust and Ritchie and subsequent coloration of the fecal smear by the methods of Auramina-O and Ziehl-Neelsen modified for diagnosis of Cryptosporidium sp. and Graham method for diagnosis of Enterobius vermicularis. Of the analyzed children we verified a prevalence of intestinal parasitism in 53.40%, and the most frequent parasite was Giardia duodenalis (26.88%). Significant association was verified among enteroparasitosis, family income, maternal education and age; the lowest enteroparasite frequency occurred in children of families with larger income and higher education. It was observed that G. duodenalis is more prevalent in children from 0 to 4 years and E. vermicularis is more frequent in children between three and four years old. The high enteroparasite prevalence in day cares suggests complex structure in its epidemiology, where factors beyond sanitation should be considered.

Enzyme-linked immunosorbent assay (ELISA) immunoassaying versus microscopy: advantages and drawbacks for diagnosing giardiasis

CONTEXT AND OBJECTIVE

Giardiasis is common in Brazil. For laboratory diagnosis, the method most utilized is microscopic examination of fecal samples, but the immunoenzymatic method is also available. The aim of this work was to verify the advantages and drawbacks of immunoassaying versus microscopy for diagnosing Giardia lamblia, when a single fecal sample is analyzed.

DESIGN AND SETTING

Prospective, double-blind study at the parasitology laboratory of Faculdade de Medicina da Fundação ABC.

METHODS

Samples were prepared according to the traditional sedimentation (Hoffman, Pons and Janer) and Faust methods. Results were deemed positive when Giardia lamblia was found by one or both methods. The Prospect ELISA kit was used for detecting Giardia lamblia-specific antigen, in accordance with the manufacturer's instructions. Results were expressed on a visual scale as negative or positive (+, ++, +++ or ++++).

RESULTS

The ELISA test was positive even when a significant proportion of corresponding samples examined by microscopy were negative. This trend was statistically significant (p < 0.001). The overall concordance of results between the ELISA test and microscopic examination of single samples was only moderate (0.50 by kappa test).

CONCLUSION

The ELISA test is useful when just searching for Giardia lamblia, because of its high sensitivity. For daily practice, we recommend microscopy, which is much cheaper and can also detect other parasites. The low positivity of single samples in this method can be overcome by using three samples, as recommended by most authors.

[Some socioeconomic aspects related to intestinal parasitosis and evaluation of an educational intervention in scholars from Estiva Gerbi, SP]

Among the students attended by the City Education Secretary of Estiva Gerbi, 11.5% presented enteroparasites. This prevalence could be related to socioeconomic aspects. Accordingly we conducted a workshop on intestinal parasites with the objective of informing and discussing related aspects in combination with medical treatment. Students were evaluated from the Alaíde R. Batista School, which attends children up to 4 years old and had the highest (23.5%) level of parasitism. Reevaluation two years after the workshop showed that the prevalence of enteroparasites in the treated students had decreased to 6.6%, but considering the school as a whole the prevalence was still 23.3%, due to the enrolling of new students. It was concluded that educational programs are only effective when integrated to a complete and continuous process of education, control and eradication of enteroparasitosis.

[Determination of Entamoeba histolytica infection in patients from Greater Metropolitan Belém, Para, Brazil, by enzyme-linked immunosorbent assay (ELISA) for antigen detection]

The epidemiological status of amebiasis has been reevaluated since Entamoeba histolytica (pathogenic) was considered a distinct species from Entamoeba dispar (non-pathogenic). We investigated E. histolytica antigens in stool samples from residents of Belém, Para State, Brazil, with commercially available enzyme-linked immunosorbent assay (E. histolytica Test, TechLab Inc., Blacksburg, USA). A total of 845 samples were analyzed, of which 248 were positive (29.35%). E. histolytica infection was more frequent in the over-14-year age group (30.36%) than in the 0-14-year group (28.28%), but the difference was not statistically significant (p < 0.05). Of all the samples, 334 were also submitted to parasitological methods (direct, Hoffman, and Faust et al.). There were discordant results between ELISA and parasitological methods in 83 samples (24.85%), with more positive results using ELISA. Our results thus suggest that intestinal amebiasis is an important public health problem in Greater Metropolitan Belém.

[Basic sanitary conditions in Iporanga, São Paulo State, Brazil]

OBJECTIVE

To assess the pollution of water bodies by domestic sewage and to evaluate the basic sanitation conditions of residences and the knowledge of the local population concerning intestinal parasitic diseases and the hazards they present to public health.

METHODS

Thirteen water samples were collected from each of four sites in different water bodies of the Bairro da Serra region, in Iporanga, São Paulo State. Rates of total and fecal coliforms were measured and median values were presented so as to show domestic sewage contamination in the area. Questionnaires were administered to 50% of local households in order to obtain information on water supply and disposal of domestic sewage and solid waste, and to evaluate knowledge of the transmission, health hazards, and prevention of intestinal parasitic diseases among the local population.

RESULTS

The Betari river showed microbiological indexes indicative of pollution by domestic sewage. Higher levels were verified both upstream and downstream from the Bairro da Serra. Median values were even higher in two of the river's tributary streams, indicating strong pollution by domestic sewage and lack of conformity with current legislation. In 91% of the households investigated, sewage disposal was done by means of septic tanks, most of which were rudimentary and contributed to the contamination of the environment. The knowledge of 62% of interviewed subjects concerning the transmission of helminthic diseases was considered as poor.

CONCLUSIONS

Our results indicate a risk of proliferation of intestinal parasitoses and of other water-transmitted diseases, an issue which is aggravated by increases in population caused by the region's vocation for ecotourism.

Elevada porcentagem de blastocistose em escolares de São Paulo, SP

Em exame parasitológico de fezes de 227 alunos de escola pública de São Paulo (SP), encontramos 87 (38,3%) positivas para Blastocystis hominis. A blastocistose ainda suscita controvérsias e indefinições, merecedoras de esclarecimentos sobretudo para evitar contratempos no âmbito da saúde pública e das atenções médico-assistenciais.

[Influence of specific treatment of intestinal parasites and schistosomiasis on prevalence in students in Barra de Santo Antônio, AL]

From a total of 1,020 students examined, 983 (92%) showed positive results for at least one species of parasite. Six months after treatment, a sample of 383 students (37.5%) was reevaluated and 347 (90.6%) presented positive results. There was no significant change in prevalence before and after treatment, although the number of individuals that had multiple parasitism was significantly lower in the second sample.

[Risk factors for multiple intestinal parasites in an indigenous community of the State of Pernambuco, Brazil]

An investigation into the ethno-epidemiological profile of the Pankararu indigenous group in the State of Pernambuco, Brazil, identified multiple intestinal parasites in nearly all members of the community. To detect possible environmental risk factors, we used the data base from a previous survey to test relations between daily living conditions (housing, sanitation, water supply and treatment, and garbage disposal) and the number of different parasite species found in the same household. The sample consisted of 84 families from the original sample of 112. Selection was based on the number of stool tests performed in the family. The mean number of parasite species was 5.0 per family, for a mean family size of 6.1 members. This number was greater for wattle-and-daub houses (mean 6.0 parasite species vs. 4.9 for brick houses; p < 0.03) and when water used in the household was not treated (mean 5.1 parasite species, vs. 4.5 for treated water; p < 0.05). Other household characteristics and hygienic habits did not significantly influence this number. We concluded that multiple intestinal parasitism in the Pernambuco Pankararu community is frequent, to the point of being the rule, and that it relates essentially to water source and treatment.