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Soil-transmitted helminths (STHs) are a group of parasites that are globally distributed and are the most prevalent neglected disease (NTD) in Latin America and the Caribbean (LAC); their presence is associated with health and development problems. In Argentina, their distribution is heterogenous, and there are highly endemic areas in the north of the country. The World Health Organization (WHO) recommends the mass deworming of children as a first-line strategy for the prevention and control of STHs and recently also encourage the development of more sensitive diagnostic tests. The aim of this study was to determine the prevalence of STHs in Tartagal (Salta, Argentina) after four years of deworming interruption with albendazole and ivermectin. A total of 437 fecal samples were analyzed using standard coprological techniques, a subset of which were selected to molecularly typify protozoan parasites; 257 blood samples were analyzed for the presence of specific antibodies to the STH Strongyloides stercoralis. The most prevalent protozoan species were G. intestinalis (19.6–49.2%) and B. hominis (19.1–38.5%). Molecular characterization allowed us to evidence possible zoonotic or human-to-human transmission pathways for Giardia intestinalis or Blastocystis spp., while serology for S. stercoralis proved to be a useful screening tool for monitoring this parasite after treatment. In general, a decrease in the prevalence of STHs was observed in the area, from 60% to 2.9–20% for hookworms and from 51% to 1–9.3% for S. stercoralis four years after treatment, demonstrating the effectiveness and duration of anthelmintic treatment with these two drugs. [ABSTRACT FROM AUTHOR]

Brownian ratchets have recently been considered as models to describe the ability of certain systems to locate very specific states in multidimensional configuration spaces. This directional process has particularly been proposed as an alternative explanation for the protein folding problem, in which the polypeptide is driven toward the native state by a multidimensional Brownian ratchet. Recognizing the relevance of robustness in biological systems, in this work we analyze such a property of Brownian ratchets by pushing to the limits all the properties considered essential to produce directed transport. Based on the results presented here, we can state that Brownian ratchets are able to deliver current and locate funnel structures under a wide range of conditions. As a result, they represent a simple model that solves the Levinthal's paradox with great robustness and flexibility and without requiring any ad hoc biased transition probability. The behavior of Brownian ratchets shown in this article considerably enhances the plausibility of the model for at least part of the structural mechanism behind protein folding process. [ABSTRACT FROM AUTHOR]

We propose a model for protein folding in vivo based on a Brownian ratchet mechanism in the multidimensional energy landscape space. The device is able to produce directed transport taking advantage of the assumed intrinsic asymmetric properties of the proteins and employing the consumption of energy provided by an external source. Through such a directed transport phenomenon, the polypeptide finds the native state starting from any initial state in the energy landscape with great efficacy and robustness, even in the presence of different types of obstacles. This model solves Levinthal’s paradox without requiring biased transition probabilities but at the expense of opening the system to an external field. [ABSTRACT FROM AUTHOR]

Background: Soil-transmitted helminths (STHs) are widely distributed throughout the world. Various factors, including the environment, socioeconomic characteristics, and access to water and sanitation, play an important role in the spread and persistence of these parasites within communities. They, in turn, affect the growth and development of members of the community, especially children. Studies in the northern provinces of Argentina have shown variable prevalence of STHs, but the factors associated with their presence have not been completely elucidated., Objective: This cross-sectional study aimed to identify the socioeconomic and environmental factors related to STH infection in indigenous villages located in Puerto Iguazú (Misiones), Argentina., Methods: Between 2018 and 2019, stool samples were collected from individuals ≥1 year residing in 3 villages: Mini-Marangatú, Yriapú, and Fortín Mbororé. Standard parasitological methods were used to determine STH prevalence. Standardized questionnaires were used to assess participants' habits, customs, and household characteristics, and environmental data were obtained through satellite imagery. Multilinear regression with Akaike information criterion stepwise variables was used to explore relevant associations., Results: A total of 342 individuals from the 3 villages participated in this study. The prevalence of STHs varied across villages: 89.6% (43/48), in Mini-Marangatú, 80.8% (101/125) in Yriapú, and 68.5% (115/169) in Fortín Mbororé. Notably, there was a significant difference in hookworm infection among the villages (P=.02). The analysis highlighted the significant influence of specific environmental factors on STH presence and spatial distribution, particularly in relation to hookworm infection. Vegetation patterns represented by the Vegetation Heterogeneity Index, created ad hoc for this study, emerged as a critical factor, with 2 significant predictors related to it (P=.002 and P=.004) alongside impervious surface density with a significant predictor (P<.001). The multilinear regression model yielded a high F test score (F 108 =4.75, P<.001), indicating a strong fit (R 2 =0.5465). Furthermore, socioeconomic factors, including walking barefoot in houses with dirt floors and overcrowding, were significantly correlated with hookworm infection intensity (P<.001 and P=.001, respectively). We also used the multilinear regression model to calculate hookworm infection intensity (F 110 =21.15, P<.001; R 2 =0.4971)., Conclusions: Our study underscores the complexity of STH transmission, as villages with similar living conditions and environmental characteristics displayed varied STH prevalence and spatial distribution. Specific environmental factors, such as vegetation pattern and impervious surface density, played major roles in STH presence, demonstrating the crucial relationship between environmental factors and hookworm infection distribution. Moreover, our findings emphasize the significant influence of socioeconomic factors on hookworm infection intensity. By gaining insights into this complex interplay, our research contributes to a better understanding of STH transmission characteristics, thereby informing targeted public health interventions for effective control., (©Ernesto Candela, Carolina Goizueta, Leonardo Sandon, Carla Muñoz-Antoli, Maria Victoria Periago. Originally published in JMIR Public Health and Surveillance (https://publichealth.jmir.org), 07.11.2023.)