Background: Intestinal parasites (IPs) are widely distributed worldwide and are one of the major contributors to gastrointestinal disease. Their prevalence is associated with poor access to water, sanitation and hygiene (WASH). The objective of this study was to identify the prevalence of IPs, including soil-transmitted helminths (STH), and their relation to socioeconomic characteristics, as well as a first approach to molecularly characterize the types ofGiardia intestinalis,Blastocystisspp. andEntamoeba histolyticapresent in an indigenous community from Puerto Iguazú, Misiones, Argentina.Methods: A cross-sectional study was conducted in the rural settlement of Fortin Mbororé between January and March 2018. Socioeconomic variables, household characteristics, and stool and blood samples were collected. Standard coprological techniques were used to analyze stool samples, and a complete hemogram was performed on the blood samples.Giardia intestinalismicroscopy-positive samples were genetically typed by the β-giardin (bg) gene. Molecular identification ofBlastocystisspp. subtypes andE. histolyticawere carried out by amplification and sequencing of a partial fragment of the small subunit ribosomal RNA gene (SSU rDNA).Results: The overall prevalence of IPs was 92.7%, with 72.0% specifically for hookworm. IPs were significantly more prevalent in preschool- and school-age children (P < 0.05). No formal education (P = 0.035), the presence of unimproved floors (P = 0.001) and overcrowding (P = 0.005) were significantly associated with IP infection. Hookworm was associated with anemia (P = 0.019). Molecular characterization revealed the presence ofE. histolyticasub-assemblages AII (12.5%), AIII (87.5%) and BIV (100%); one case of sub-assemblage D forG. intestinalis; and the presence of subtypes ST1 (14.8%), ST2 (14.8%) and ST3 (70.4%) ofBlastocystisspp.Conclusions: Protozoans detected in this study are transmitted mainly through water contaminated with fecal matter, evidencing the need to improve the quality of water and sanitation for the inhabitants of Fortín Mbororé. Molecular characterization showed that domestic animals can be implicated in the zoonotic transmission ofG. intestinalisandBlastocystisspp. to humans. A hyperendemic area for STH was found, with hookworm prevalence greater than 50%. Therefore, improvements in WASH as well as mass deworming programs need to be implemented in this area to control and decrease the prevalence of IPs in general and STH in particular.Graphical

: There is narrow evidence on which strategies are most effective for disseminating information on dengue prevention. This is particularly relevant because social habits have a great prevention capacity for dengue. We investigated how effective are children as health educators, and how much they learn as they teach. We recruited 142 children and 97 parents in Argentina’s tropical area for two cluster randomized parallel trials. In Study 1, we compared the dynamics of dengue knowledge of 10-year-old children who—after receiving a dengue talk—1) listened to an unrelated topic; 2) read a booklet with information about dengue, 3) taught their parents about dengue, or 4) taught their parents about dengue, using the booklet. In Study 2, we assessed whether the parents’ dengue knowledge changed after interacting with their children, in comparison with parents learning about dengue from an expert or about an unrelated topic. Children that taught their parents what they learned, using a booklet, showed 2.53 more correct responses (95% CI [0.20, 4.85]; P = 0.027) than children who listened to an unrelated topic. This style of teaching also serves to effectively propagate knowledge: parents learned from their children the same as from an expert; and significantly more than parents who learned about an unrelated topic. Parents learned from their children even if they were taught with booklets (1.49, 95% CI [0.01, 2.96]; P = 0.048) or without (1.94, 95% CI [0.44, 3.44]; P = 0.006). Specifically, after being taught by their children, parents showed on average 1.49 (if they were taught with a booklet) and 1.94 (without booklet) more correct responses than parents that learned about an unrelated topic. The simple action of prompting children to teach consolidated their own knowledge and broadcasted it effectively to their parents. This strategy is a potential low to no-cost method for sharing information about dengue prevention.

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 (F108=4.75, P<.001), indicating a strong fit (R2=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 (F110=21.15, P<.001; R2=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.

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 (F108=4.75, P<.001), indicating a strong fit (R2=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 (F110=21.15, P<.001; R2=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.

Background: Strongyloides stercoralis is frequently underdiagnosed due to the limited sensitivity of stool-based methods. Serology improves detection, but venous blood collection and cold-chain requirements complicate field implementation. Dried blood spots (DBS) offer a practical alternative for large-scale surveys. This study aimed to evaluate the diagnostic accuracy of DBS-based serology and compare its performance with conventional ELISA. Methods: A cross-sectional study was conducted in peri-urban communities of Puerto Iguazú, Misiones, Argentina. Stool samples were examined using sedimentation–concentration and Baermann techniques. Venous blood on DBS was analyzed using a commercial ELISA (cELISA) and an in-house NIE-ELISA. Diagnostic accuracy was assessed using a primary reference standard. Agreement between serum and DBS was evaluated using kappa statistics, and ROC curves were generated for paired samples. Results: DBS cELISA showed the highest sensitivity (89.1%), followed by serum cELISA (81.1%) and in-house NIE-ELISA (71.7%). Concordance between sera vs DBS was substantial for cELISA (κ = 0.68) and fair for NIE-ELISA (κ = 0.21). ROC analysis showed comparable AUCs for cELISA using sera (0.85) and DBS (0.83), whereas in-house NIE-ELISA performance declined with DBS (AUC = 0.61). Conclusion: DBS-based cELISA demonstrated high diagnostic accuracy and strong agreement with sera, supporting its use as a field-adapted tool for strongyloidiasis surveillance. DBS serology represents a feasible and reliable alternative for epidemiological studies in resource-limited settings.

Dengue represents a growing challenge for public health in Argentina, where entomological surveillance is essential to Aedes aegypti control interventions. However, low community participation in surveillance activities constitutes a major obstacle to these interventions. In this mixed-methods (quantitative–qualitative) study, we analyzed the reasons for reluctance to undergo household inspections in Tartagal and Puerto Iguazú between March and December 2021. A total of 9065 responses were recorded, among which the most frequent reason was the perception that inspection was unnecessary (64.2%). Four additional categories of reluctance were identified: impossibility or restriction of access to the housing unit, lack of interest in the visit, safety concerns, and other causes. Analysis using the Shannon diversity index showed homogeneity of responses in Tartagal (H′ = 0.77) and greater diversity in Puerto Iguazú (H′ = 1.59). Although most respondents reported knowing what dengue is and where the vector mosquito breeds, lack of interest in identifying breeding sites predominated in Tartagal, whereas greater willingness to collaborate was observed in Puerto Iguazú. The findings suggest that risk perception, overlap of activities, institutional recognition, and safety concerns influence community participation. Understanding these factors is key to adjusting surveillance strategies and increasing the effectiveness of vector control programs.