Intestinal parasitism and nutritional status among indigenous children from the Argentinian Atlantic Forest: Determinants of enteroparasites infections in minority populations

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.

The Relationship Between Soil-Transmitted Helminth Infections and Environmental Factors in Puerto Iguazú, Argentina: Cross-Sectional Study

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.

Prevalence of Enterobius vermicularis among children in Iran: A comprehensive systematic review and meta-analysis

Background

Parasitic infections are among the most common diseases worldwide, and enterobiasis is a well-known type of parasitic infection in children. Given the existence of several reports on the prevalence of Enterobius vermicularis in different provinces of Iran and the heterogeneity of the reported prevalence data, this study aims to investigate the overall prevalence of Enterobius vermicularis among children in Iran through a systematic review and meta-analysis.

Methods

This systematic review and meta-analysis study involved a comprehensive search of several databases, including PubMed, ScienceDirect, SID, and Google Scholar, focusing on cross-sectional studies that examined the prevalence of Enterobius vermicularis infection in Iranian children. The identified studies were entered into the EndNote software for review. The quality of observational studies was evaluated using the STROBE checklist. The information extracted from the studies was entered into the Comprehensive Meta-analysis (CMA, Version 2) software. Heterogeneity among the studies was analyzed using the I² test, and publication bias was assessed using the Egger test and funnel plot.

Results

A total of 51 studies, with a sample size of 46,070 children, were included in the review. Using the random effects method, the overall prevalence of Enterobius vermicularis among children in Iran was determined to be 6.7% (95%CI: 5.2-8.6). The review of the factors affecting study heterogeneity and sample size indicated that as sample size increased, the prevalence of Enterobius vermicularis among children in Iran also increased (p = 0.578). Additionally, with an increase in the year of conducting the studies, the prevalence of Enterobius vermicularis among children in Iran decreased (p < 0.05).

Conclusion

The findings of this study show a relatively high prevalence of Enterobius vermicularis among children in Iran. We recommend health policymakers recognize the significance of this issue and take necessary measures to reduce the incidence of this infectious agent in children, implementing more effective preventive measures through mass media and educational campaigns.

Effect of Deworming on Health Outcomes among Children Aged 12-59 Months in Tanzania: A Multilevel Mixed Effects Analysis

Introduction

Mass deworming of preschool children is a strategy suggested to prevent soil-transmitted helminth infections in most developing countries. Nonetheless, there is a scarcity of data showing the contribution of mass deworming to a child's nutritional status. The purpose of this study was to assess the effect of deworming on nutritional health outcomes (stunting, underweight, and anemia) in children aged 12 to 59 months.

Methods

A secondary analysis of data extracted from the Tanzania Demographic and Health Survey (TDHS) 2015-16 data was carried out. A total of 7,962 children were included in this study. A multilevel logistic regression was used at a 5% level of significance to determine the individual- and community-level determinants of deworming on health outcomes among children.

Results

The prevalence of underweight (62.6%), stunting (61.0%), and anemia (61.8%) was higher in children who were not dewormed than those who were dewormed. Female children were more likely to suffer from poor health outcomes (OR = 1.01 and 95% CI = 0.95-1.07) than male children. Children aged 24-35 months and 36-47 months were significantly less likely to suffer from poor health outcomes (OR = 0.89; 95% CI = 0.82-0.97 and OR = 0.88; 96% CI = 0.81-0.96, respectively; p < 0.01). Children from households with unimproved toilets (OR = 1.38 and 95% CI = 1.25-1.52), unimproved water sources (OR = 1.08 and 95% CI = 1.01-1.16), and living in rural areas (OR = 1.02 and 95% CI = 0.91-1.14) had higher odds for poor health outcomes.

Conclusion

Deworming may be an effective technique for preventing poor health outcomes in children and the risks associated with them, such as poor growth and development.

Intestinal parasitic infections in a community from Pampa del Indio, Chaco (Argentina) and their association with socioeconomic and environmental factors

Neglected tropical diseases are a group of 20 disabling diseases, which, in particular, are the most common chronic infections in the most vulnerable people. This study aimed to characterize the infection by intestinal parasites (IPs) in dwellings from a peri-urban neighborhood in Pampa del Indio, Chaco (Argentina), and its association with socioeconomic and environmental variables. Single stool samples were collected from all individuals older than 1 year through household visits and processed using coprological sedimentation and flotation techniques. Standardized questionnaires were used at the household level to collect socio-economic information. Environmental variables were obtained from the Planetscope image, Landsat 8 images and remote sensors, while land-use layers were obtained through the use of a maximum likelihood algorithm. Stool samples were provided by 314 individuals. The prevalence of IPs found was 30.6% (n = 96), with a predominance of Giardia lamblia (12.7%, n = 40) and Hymenolepis nana (7.6%, n = 24). The only soil-transmitted helminth found was Strongyloides stercoralis with a 2.5% prevalence (n = 8). Individuals of adult age (> 18 years) were 0.65 times less likely to present parasitic infections with respect to children and adolescents. The only environmental variable that was closely associated with the presence of IPs, was the Normalized Difference Water Index (NDWI), a measure of humidity; being higher around houses with positive individuals. Most of the IPs found in this study were of water-borne transmission and those transmitted directly from person-to-person, therefore fecal contamination is present. We believe that the low prevalence of STH in this area, which requires a passage through the soil, is related to the environmental characteristics, which are unsuitable for the development/permanence of the infective stages of these parasites. The geospatial data and tools used herein proved to be useful for the study of the relationship between the different factors that influence the presence of IPs in a community, from an eco-health approach.

Prevalence and factors associated with stunting and thinness among school age children in rural primary schools, East Dembia District, Northwest Ethiopia

Purpose

To assess the prevalence and factors associated with stunting and thinness among school-age children in rural primary schools in the East Dembia District, Northwest Ethiopia.

Methods

An institution-based cross-sectional study was conducted using a systematic random sampling procedure to select 840 school-aged children. A structured interviewer-administered questionnaire was used to collect the data. Height and weight measurements were taken, and a combined wet mount and concentration technique was used. Epi Data 3.1 was used to enter data, which was then exported to SPSS version 20 for analysis. Bi-variable and multivariable logistic regression analyses were done. Variables with a p-value of less than 0.05 were considered significantly associated with stunting and thinness.

Results

The prevalence of stunting and thinness was 25.5 and 13.0%, respectively. Being infected with an intestinal parasite (AOR =4.34; 95% CI: 2.52, 12.27), being in the age group 11–14 years (AOR =3.73; 95% CI: 2.19, 6.34), having the lowest dietary diversity practice (AOR =4.61; 95% CI: 1.73, 12.27), unimproved water sources (AOR =1.76; 95% CI: 1.07, 2.91), not practicing good hygiene practice (AOR =1.71; 95% CI: 1.04, 2.804) and having an unimproved latrine type (AOR =1.72; 95% CI: 1.03, 2.89) were significantly associated with stunting. On the other hand, unsecured food (AOR =1.74; 95% CI: 1.08, 2.81), eating less than 3 meals per day (AOR = 2.67; 95% CI: 1.11, 6.46), and untreated water (AOR =1.72; 95% CI: 1.08, 2.75) were factors associated significantly with thinness.

Conclusion

Stunting and thinness are predominant public health problems in the study area, provided that the prevalence of stunting is slightly higher than that of a national survey on health and nutrition in schoolchildren, whereas the prevalence of thinness is lower when compared to the same national survey. In this study, the primary factor that was significantly associated with stunting was dietary diversity; the primary factor that was associated with thinness was eating fewer than 3 meals per day. So, an integrated strategy is important to alleviate undernutrition among school-aged children in the current study area.

Association between Intestinal Parasite Infections and Proxies for Body Composition: A Scoping Review

It has long been recognized that intestinal parasite infections and undernutrition are closely linked. However, little is known about the role of intestinal parasite infections (IPIs), or parasite clearance, in these processes. The aim of this scoping review was to summarize published evidence on the association between IPIs and body composition. PRISMA guidelines, PubMed/MEDLINE, EMBASE and Cochrane Library databases were searched up until June 2021. Studies reporting on IPIs in relation to (proxies for) body composition were eligible. Study quality and risk of bias were assessed using Joanna Briggs Institute (JBI) critical appraisal tools. Twenty-four studies were included, two Randomized Control Trials (RCTs) and 22 observational. Most observational studies showed IPIs to be associated with lower Body Mass Index (BMI) or being underweight as proxies for body composition. One RCT showed no effect of antiparasitic treatment on body composition, while the other one showed a significant post-treatment increase in body fat, as measured by BMI z-scores and skinfolds. This review lends support to distinct associations between IPIs and body composition. More longitudinal studies are needed using direct measures of body composition to investigate whether weight gained after antiparasitic treatment concerns an increase in body fat or healthy weight gain.

Nutritional status, intestinal parasitic infections, and socio-environmental conditions in Mbyá-guaraní children: The current situation in communities in central Misiones, Argentina

OBJECTIVES

Our previous research in Mbyá-guaraní communities of central Misiones showed high levels of growth stunting and intestinal parasites in children, as well as associations between these variables and deficient sanitary conditions. New studies were necessary to update the present health status of the previously studied Mbyá populations after around two decades. Therefore, we evaluated the current nutritional status, intestinal parasites, and socio-environmental conditions among Mbyá-guaraní children from these communities.

METHODS

Body weight and height of 102 individuals (aged 2-14) were measured and nutritional status was estimated according to the World Health Organization criteria. Serial fecal samples and anal swabs were analyzed from 75 children (aged 1-14). Socio-environmental data were obtained from questionnaires.

RESULTS

The prevalence of undernutrition was 31.4% and excess of weight was 10.8%. The prevalence of stunting and of overweight reached 30.4% and 8.8%, respectively. About 85% of the children were infected with at least one of the 14 species identified, and around 44% had multiple parasite infections. The most prevalent species were Enterobius vermicularis and hookworms. Among undernourished children, 88.2% were parasitized by at least one of the potentially pathogenic species detected. Most of the families lived in overcrowded conditions in precarious houses, defecated in latrines, and consumed well water. A higher risk of parasitosis was associated with the source of drinking water.

CONCLUSIONS

Although the prevalence of undernutrition and intestinal parasites decreased compared with our previous studies, we still observed the coexistence of stunting, excess weight, and parasitic infections, in a context of socio-environmental vulnerability.

Enterobiasis and its risk factors in urban, rural and indigenous children of subtropical Argentina

A cross-sectional survey to assess the prevalence of Enterobius vermicularis infection and its associated factors among the child population of infant, preschool and school age in the urban, rural and indigenous population of Iguazú city, in subtropical Argentina was presented. Additionally, the status of enterobiasis at country level was reviewed and analysed. Enterobius vermicularis presence was assessed employing an oviscopic serial sampling technique. Statistical analysis of socio-demographic determinants was performed by generalized linear mixed models at individual, household and community levels. Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines were used to gather national information about E. vermicularis prevalence spanning the decade 2010–2020. A total of 916 children from 470 families participated. Overall prevalence was 29.8%, with 25.3, 30.7 and 34.2% detected for children inhabiting urban, rural and indigenous villages, respectively. The multi-level analysis showed that the presence of E. vermicularis was mostly determined by individual (e.g. age, playing habits, previous pinworm infection) and household-level factors (e.g. family size, overcrowding conditions). Interestingly, WASH variables, such as waste disposal, analysed at community level were also important. Data were analysed to provide eco-epidemiological features of enterobiasis in a heterogeneous subtropical child population in the same territory but with different socio-sanitary realities. The importance of promoting multi-level actions against the determinants identified, to control this public health problem integratively was evidenced. The scoping review of national data updated the state of knowledge of this parasitosis, identifying risk determinants and gaps in knowledge at country level.

Prevalence of intestinal parasites and molecular characterization of Giardia intestinalis, Blastocystis spp. and Entamoeba histolytica in the village of Fortín Mbororé (Puerto Iguazú, Misiones, Argentina)

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 of Giardia intestinalis, Blastocystis spp. and Entamoeba histolytica present 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 intestinalis microscopy-positive samples were genetically typed by the β-giardin (bg) gene. Molecular identification of Blastocystis spp. subtypes and E. histolytica were 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 of E. histolytica sub-assemblages AII (12.5%), AIII (87.5%) and BIV (100%); one case of sub-assemblage D for G. intestinalis; and the presence of subtypes ST1 (14.8%), ST2 (14.8%) and ST3 (70.4%) of Blastocystis spp.

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 of G. intestinalis and Blastocystis spp. 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 Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13071-021-04968-z.

Parasitic risk factors in migrant horticultural families from Bolivia settled in the rural area of La Plata, Buenos Aires, Argentina

Objective

The aims were to diagnose intestinal parasites in migrant horticultural families in the rural area of La Plata, and assess factors that increase the risk of parasitic infection.

Materials and methods

Serial stool samples and anal swabs of 350 individuals were processed using sedimentation and flotation techniques. Socio-sanitary and environmental characteristics were surveyed using a semi-structured questionnaire. A generalized linear model was used to assess the change in parasitic prevalence with different predictor variables.

Results

Of all examined individuals, 79.1% were parasitized, and 12 parasites were identified. Blastocystis sp. (58.9%), Entamoeba coli (26.3%), Enterobius vermicularis (26.0%), and Giardia lamblia (24.0%) were the most prevalent species. Risk factors were age group (<12 years), sampling site, and a basic education of parents.

Conclusion

The high prevalence of intestinal parasites in horticultural families is associated with inadequate environmental sanitation, a limited access to education, and insufficient hygienic habits. An increase in parasitological references in integrated studies (human, animal and environmental health) would result in an understanding of the parasitic etiology, and the development of effective actions for the control of intestinal parasites.

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La Plata Horticultural area is the most important region for vegetable production in Argentina.

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79.1% of analyzed farming population was parasitized and the species found indicate an inadequate environmental sanitation.

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An increase in parasitological references in integrated studies could mitigate the effect of intestinal parasitoses.

Toxicological risk factors in the burden of malnutrition: The case of nutrition (and risk) transition in sub-Saharan Africa

Toxicant exposures may worsen the micronutrient status, especially during the womb-to-childhood development, impairing organism programming and increasing the risk for health disorders in adulthood. Growing evidence calls for an integrated risk analysis of the interplay of environment, behavior and lifestyle, where a) imbalanced diet and micronutrient deficiencies may increase the vulnerability to toxicants and alter body defence systems and b) intake of antinutrients and contaminants may increase nutritional requirements. Such scenarios are especially evident in communities undergoing a fast nutrition transition, such as in many countries of sub-Saharan Africa. Specific challenges of toxicological risk analysis in sub-Saharan Africa still need a thorough assessment, including: rapid changes of lifestyle and consumers' preferences; dumping of foods and consumer' products; risk management under weak or non-existent awareness, legislation enforcement and infrastructures. The significant and growing literature from Africa-led scientific research should be used to build quality-controlled data repositories supporting regulatory top-down actions. Meanwhile, bottom-up actions (eg consumer's empowerment) could exploit social and economic drivers toward a qualified African presence in the global and local markets. A science-based combination of top-down and bottom-up actions on preventable toxicological risk factors will contribute fighting the new forms of malnutrition and prevent multi-factorial diseases. Exposures to toxicants should be included in the integrated approach proposed by WHO to address the urgent health challenge of simultaneously reduce the risk or burden of both malnutrition (ie deficiency of one or more essential nutrients) and overweight, obesity, and diet-related NCDs.

A holistic approach is needed to control the perpetual burden of soil-transmitted helminth infections among indigenous schoolchildren in Malaysia

A cross-sectional survey was conducted among 1,142 Orang Ali schoolchildren in six states of Peninsular Malaysia to investigate the current prevalence and risk factors of STH infections. Faecal samples were examined using direct smear, formalin-ether sedimentation, Kato-Katz, and Harada-Mori methods. A pre-tested questionnaire was used to collect information on the demographic, socioeconomic, personal hygiene, and health status of the participants. Overall, 70.1% (95% CI = 67.4, 72.7) of the participants were infected with at least one of the STH species. The prevalence of Ascaris lumbricoides, Trichuris trichiura, and hookworm infections was 63.1%, 61.8% and 11.5%, respectively. Moderate-to-heavy STH infections accounted for 61.3% of the total infections. Univariate and logistic regression analyses revealed different sets of risk factors, with age (> 10 years) being the significant risk factor of all three STH species. Moreover, other species-specific risk factors were identified including being a member of the Senoi tribe, family size (≥ 7 members), school size (150-250 pupils), maternal unemployment, unimproved source of drinking water, lacking improved toilet in the house, inadequate WASH facilities at school, not washing hands before eating, and not washing fruits before eating; presence of domestic animals, and not wearing shoes when outside. The high prevalence of STH infections found in the study population exceeds the WHO policy intervention threshold (20% prevalence). Thus, an innovative holistic approach should be adopted to control STH infections among these children as part of the efforts to improve the quality of life of the entire Orang Asli population. .

Substantial reduction in child stunting is differentially associated to geographical and socioeconomic disparities in Misiones Province, Argentina

OBJECTIVE

To estimate trends in the prevalence of child stunting in the population of children under 5 years of age covered by public health programmes, between 2009 and 2014 in Misiones, Argentina.

METHODS

Using Bayesian model-based geostatistics, we evaluated 724 872 anthropometric measurements corresponding to 110 633 children. In order to identify disparities at local scale, we evaluated the hypotheses of a differential reduction of stunting according to the geographical location (at two-level spatial resolution) and to the socioeconomic level in a rural or urban environment.

RESULTS

The prevalence of stunting had fallen significantly in the province overall. Sex and age defined gender disparities at individual level, and there were regional disparities with higher prevalence values in the north and northeast regions. In these areas, stunting decreased to a greater degree during the studied period, although the spatial pattern remained smoother. Stunting increased in peripheral urban and dispersed rural areas that are socioeconomically vulnerable.

CONCLUSIONS

The spatial multi-level geostatistical estimates of child undernutrition provide a precision public health tool to target public policies to those populations with the greatest need, in order to reduce health disparities.