Malnutrition and intestinal parasitosis: Current prevalences and risk factors among schoolchildren in Misiones (Argentina).

OBJECTIVES: To assess the current prevalences of nutritional status and intestinal parasites, and their potential association with socio-environmental conditions among schoolchildren in Aristóbulo del Valle, Misiones. METHODS: We measured body weight and height in 444 schoolchildren aged 3-14 years and evaluated their nutritional status following WHO criteria. We examined fecal samples and anal swabs from 234 schoolchildren and collected socio-environmental data through questionnaires. RESULTS: The prevalence of undernutrition was 4.5% and excess of weight was 24.1%. The prevalence of stunting and of being overweight reached 2.3% and 12.4%, respectively. About 42% of the schoolchildren were infected with at least one of the 12 species identified. The most prevalent species were Blastocystis sp., Enterobius vermicularis, and Giardia lamblia. Entamoeba dispar was recorded for the first time in the locality. The multiple correspondence analysis identified peri-urban, urban, and rural groups. Underweight, stunting and obesity were highest in the peri-urban group, while overweight, wasting and parasitism rates were highest in the rural group. The urban group showed the lowest parasitic prevalences. Bed-sharing, mother's education, and animal husbandry were associated with parasitic infections. CONCLUSIONS: The study highlights a decrease in undernutrition but a rise in overweight and obesity, indicating an ongoing nutritional transition. The association between socio-environmental risk factors and parasitic infections underscore the need for comprehensive interventions addressing both nutritional and socio-environmental conditions to improve the population's life quality.

Glyphosate-environmental variables interaction: How does it affect the parasite Chordodes nobilii?

The worldwide used herbicide Glyphosate can interact with environmental variables, but there is limited information on the influence of environmental stressors on its toxicity. Environmental changes could modify glyphosate effects on non-target organisms, including parasites such as gordiids. The freshwater microscopic larvae of the gordiid Chordodes nobilii are sensitive to several pollutants and environmental variables, but their combined effect has not been evaluated yet. The aim of this study was to evaluate the impact of temperature, pH and exposure time on the toxicity of Glyphosate to C. nobilii larvae. A protocol was followed to evaluate the infectivity of larvae treated with factorial combinations of concentration (0 and 0.067 mg/L), exposure time (24 and 48 h), temperature (18, 23 and 28 °C), and pH (7, 8 and 9). The reference values were 23 °C, pH 8 and 48 h. The interaction effect on the infectivity of gordiid larvae was assessed post-exposure using Aedes aegyptii larvae as host. Results were evaluated using GLMM, which does not require data transformation. The modeling results revealed three highly significant triple interactions. Glyphosate toxicity varied depending on the combination of variables, with a decrease being observed after 24 h-exposure at pH 7 and 23 °C. Glyphosate and 28 °C combination led to slightly reduced infectivity compared to temperature alone. This study is the first to report the combined effects of glyphosate, temperature, pH and time on a freshwater animal. It demonstrates that a specific combination of factors determines the effect of glyphosate on a non-target organism. The potential use of C. nobilli as a bioindicator is discussed. In the context of global warming and considering that the behavioral manipulation of terrestrial hosts by gordiids can shape community structure and the energy flow through food webs, our results raise concerns about possible negative effects of climate change on host-parasite dynamics.

Long-term prevalence of the protists Crithidia bombi and Apicystis bombi and detection of the microsporidium Nosema bombi in invasive bumble bees.

An initial survey in 2009 carried out at a site in northwestern Patagonia region, Argentina, revealed for the first time in South America the presence of the flagellate Crithidia bombi and the neogregarine Apicystis bombi, two pathogens associated with the Palaearctic invasive bumble bee Bombus terrestris. In order to determine the long-term persistence and dynamics of this microparasite complex, four additional collections at the same site (San Carlos de Bariloche) were conducted along the following seven years. Both protists were detected in all collections: prevalence was 2%-21.6% for C. bombi and 1.2%-14% for A. bombi. In addition, the microsporidium Nosema bombi was recorded for the first time in the country in the last two collections, at prevalences of 12.4% and 2.4% and unusually high infection intensities (Average = 6.56 × 107 spores per individual). Due to the exceptional dispersal ability of the exotic B. terrestris, these three multihost pathogens should be considered as potential threats to South American native bumble bees.