Introduction: The present study aimed to determine the prevalence and factors associated with Giardia intestinalis infection, verifying its impact on the nutritional status of children in northeastern Brazil. Methodology: A cross-sectional study was conducted to obtain parasitological, sociodemographic, and anthropometric data in two municipalities in the states of Piauí and Ceará, northeastern Brazil. Results: Prevalence of giardiasis was 55/511 (10.8%). G. intestinalis was more frequent in people living in poverty (30/209 [14.4%], p = 0.041), performing open evacuation (26/173 [15%], p = 0.034), and drinking rainwater stored in cisterns (9/56 [16.1%], p = 0.005). The proportion of stunting and being underweight in children infected with G. intestinalis was significantly higher than that in uninfected children (5/23 [21.7%] vs. 10/179 [5.6%], p = 0.017, OR = 4.69, 95% confidence interval [CI] = 1.44–15.25 and 5/23 [21.7%] vs. 13/179 [7.3%], p = 0.038, OR = 3.54, 95% CI = 1.13–11.09, respectively). Infection with G. intestinalis remained significantly associated with stunting and being underweight after adjustment for poverty, municipality, sex, and age in a logistic regression multivariate model. Conclusions: In rural areas in northeastern Brazil, giardiasis has acquired great public health importance in the soil-transmitted helminths control era, impacting the nutritional status of children and requiring new approaches to diagnosis and treatment and translational research that could generate applicable solutions at the community level.

Introduction. The drought in the Brazilian semiarid region has affected the quality of water. This study assessed the relationships between enteric parasitoses, water management, and water quality, correlating them with pluviometric seasonality.Methods. Cross-sectional surveys were carried out in four rural communities at the beginning of the dry season (n=151), at the end of the dry season (n=184), and in the rainy season (n=199), in order to collect sociodemographic data, human fecal samples, and samples of the water used for human consumption for physicochemical and microbiological analyses. In 2015, water filters were provided to 30 households under study.Results. There was an increasing trend in detection rates of commensal protozoa and theEntamoeba histolytica/Entamoeba disparcomplex at the beginning of the rainy season, with detection rates of 6% in 2014 and 21.6% in 2016.Giardia intestinalisandAscaris lumbricoidespresented distinct temporal distributions, which peaked in 2015: 20.1% and 30%, respectively. The proportion of inhabitants drinking inadequate water was 55% at the beginning of the dry season and 28.8% at the end of the dry season, reaching 70.9% at the beginning of the rainy season. The presence of filters reduced this proportion among those who received the hollow ceramic candle filter.Conclusions. Data suggest that the strategies to increase water supply in the Brazilian semiarid region can be ameliorated in order to improve the quality of drinking water.

Background: Entamoeba species harbored by humans have different degrees of pathogenicity. The present study explores the intra- and interspecific diversity, phylogenetic relationships, prevalence and distribution of tetra- and octonucleated cyst-producing Entamoeba in different Brazilian regions. Methods: Cross-sectional studies were performed to collect fecal samples (n = 1728) and sociodemographic data in communities located in four Brazilian biomes: Atlantic Forest, Caatinga, Cerrado, and Amazon. Fecal samples were subjected to molecular analysis by partial small subunit ribosomal DNA sequencing (SSU rDNA) and phylogenetic analysis. Results: Light microscopy analysis revealed that tetranucleated cysts were found in all the studied biomes. The highest positivity rates were observed in the age group 6–10 years (23.21%). For octonucleated cysts, positivity rates ranged from 1 to 55.1%. Sixty SSU rDNA Entamoeba sequences were obtained, and four different species were identified: the octonucleated E. coli, and the tetranucleated E. histolytica, E. dispar, and E. hartmanni. Novel haplotypes (n = 32) were characterized; however, new ribosomal lineages were not identified. The Entamoeba coli ST1 subtype predominated in Atlantic Forest and Caatinga, and the ST2 subtype was predominant in the Amazon biome. E. histolytica was detected only in the Amazon biome. In phylogenetic trees, sequences were grouped in two groups, the first containing uni- and tetranucleated and the second containing uni- and octonucleated cyst-producing Entamoeba species. Molecular diversity indexes revealed a high interspecific diversity for tetra- and octonucleated Entamoeba spp. (H ± SD = 0.9625 ± 0.0126). The intraspecific diversity varied according to species or subtype: E. dispar and E. histolytica showed lower diversity than E. coli subtypes ST1 and ST2 and E. hartmanni. Conclusions: Tetra- and octonucleated cyst-producing Entamoeba are endemic in the studied communities; E. histolytica was found in a low proportion and only in the Amazon biome. With regard to E. coli, subtype ST2 was predominant in the Amazon biome. The molecular epidemiology of Entamoeba spp. is a field to be further explored and provides information with important implications for public health. Graphical

This study aims to assess the prevalence, distribution, and etiological profile of intestinal parasitism in children living in periurban areas in Cachoeiras de Macacu, Rio de Janeiro, Brazil. A community-based cross-sectional survey (n = 479) was carried out. Prevalence of infection with G. duodenalis and E. histolytica/E. dispar was 8.6% (n = 41) and 13.4% (n = 64), respectively. Infection with G. duodenalis was significantly more frequent among children living in poor families (24/187 (12.8%) vs. 16/272 (5.9%); prevalence ratio (PR) = 2.18; 95% confidence interval (CI) = 1.19–3.99; p=0.011). This difference was also significant for infection with any pathogenic parasite (43/187 (23%) vs. 40/272 (14/7%); PR = 1.56; 95% CI = 1.06–2.30; p=0.026). In addition, people residing in houses with more than four inhabitants showed significantly higher positivity for infections with G. duodenalis and with E. histolytica/E. dispar (22/138 (15.9%) vs. 16/311 (5.1%); PR = 3.09; 95% CI = 1.68–5.71; p<0.001 for G. duodenalis and 32/138 (23.2%) vs. 30/311 (9.6%); PR = 2.40; 95% CI = 1.52–3.79; p<0.001 for E. histolytica/E. dispar). Laboratory diagnosis of protozoan enteric infections and effective drugs for their treatment are unmet goals in the primary health care system. Therefore, giardiasis and amebiasis are neglected conditions.

Background: This study assessed the interactions between income, nutritional status and intestinal parasitism in children in Brazil. Methods: A cross-sectional study (n = 421 children aged 1 to 14 years living in the states of Piauí (rural communities in the city of Teresina) and Rio de Janeiro (rural and periurban communities in the city of Cachoeiras de Macacu) was performed in order to obtain income and anthropometric data, as well as fecal samples for parasitological analyses through the Ritchie technique. Results: Children infected with Ascaris lumbricoides had significantly lower means of height-for-age z scores (− 1.36 ± 0.75 vs. − 0.11 ± 1.02; p < 0.001), weight-for-age z scores (− 1.23 ± 0.74 vs. 0.09 ± 1.15; p = 0.001), and weight-for-height z scores (− 0.68 ± 0.44 vs. 0.23 ± 1.25; p = 0.006) when compared with uninfected children. Infection with hookworm was also associated with lower means of height-for-age z scores (− 1.08 ± 1.17 vs. − 0.12 ± 1.02; p = 0.015) and weight-for-age z scores (− 1.03 ± 1.13 vs. 0.08 ± 1.15; p = 0.012). Children infected with Entamoeba coli presented significantly lower means of height-for-age z scores (− 0.54 ± 1.02 vs. − 0.09 ± 1.02; p = 0.005) and weight-for-age z scores (− 0.44 ± 1.15 vs. 0.12 ± 1.15; p = 0.002). The multivariate multiple linear regression analysis showed that height-for-age z scores are independently influenced by monthly per capita family income (β = 0.145; p = 0.003), female gender (β = 0.117; p = 0.015), and infections with A. lumbricoides (β = − 0.141; p = 0.006) and Entamoeba coli (β = − 0.100; p = 0.043). Weight-for-age z scores are influenced by monthly per capita family income (β = 0.175; p < 0.001), female gender (β = 0.123; p = 0.010), and infections with A. lumbricoides (β = − 0.127; p = 0.012), and Entamoeba coli (β = − 0.101; p = 0.039). Monthly per capita family income (β = 0.102; p = 0.039) and female gender (β = 0.134; p = 0.007) positively influences mid upper arm circumpherence. Conclusions: Intestinal parasitism and low family income negatively influence the physical development of children in low-income communities in different Brazilian regions.