Prevalence of Anemia in Children from Latin America and the Caribbean and Effectiveness of Nutritional Interventions: Systematic Review and Meta⁻Analysis

Variations in the Prevalence of Childhood Anemia by Ethnicity Before and During the COVID-19 Pandemic in Peru

We aimed to determine the variations in the prevalence of childhood anemia according to the ethnic group before and during the COVID-19 pandemic in Peru. Secondary analysis of the Demographic and Family Health Survey during 2016-2021. The outcome variable was anemia, and the exposure variable was maternal ethnicity. Also, we included sociodemographic and clinical confounding variables. We constructed generalized linear models of the Poisson family with a logarithmic link function. We evaluated 85,905 records; 30.34% had anemia, 50.83% were mestizo, 25.98% were Quechua, and 2% were Aymara. Compared with mestizos, Quechua children (PR: 1.11; 95% CI: 1.07-1.15; p < 0.001), Aymara (PR: 1.35; 95% CI: 1.27-1 .44; p < 0.001), natives of the Amazon (PR: 1.20; 95% CI: 1.12-1.28; p < 0.001) and those who belonged to other indigenous peoples (PR: 1.29; 95% CI: 1.05-1.57; p = 0.013) had a higher prevalence of childhood anemia. On the contrary, compared to mestizos, white children had a lower prevalence of anemia (PR: 0.93; 95% CI: 0.89-0.99; p = 0.019). During the COVID-19 pandemic, compared to mestizos, only Quechua (PR: 1.15; 95% CI: 1.08-1.23; p < 0.001) and Aymara (PR: 1.38; 95% CI: 1.23-1.55; p < 0.001) had a higher prevalence of childhood anemia. Except for Afro-descendants, children from 6 to 59 months of age who belong to an ethnic minority had a higher probability of having childhood anemia than mestizos. However, only Quechua and Aymara children had higher odds of anemia during the COVID-19 pandemic than mestizos.

Evaluation of dietary composition between hemoglobin categories, total body iron content and adherence to multi-micronutrients in preschooler residents of the highlands of Puno, Peru

BACKGROUND

The anemia prevalence is higher in highlands populations. It is assumed that iron deficiency anemia (IDA) in children is mainly due to low dietary intake. However, other suggest that high prevalence of anemia is due to an inappropriate hemoglobin (Hb) adjustment for altitude.

MATERIALS AND METHODS

Cross-sectional study conducted in 338 preschoolers (PSC) from Puno-Peru. Hb was measured in whole blood, and ferritin, Soluble transferrin receptor, and Interleukin 6 in serum.The dietary iron intake was assessed by 24-h dietary recall, using NutriCap Software. Hb concentration was assessed as adjusted or unadjusted for altitude.

RESULTS

With unadjusted Hb, the anemia prevalence was 4.7%, whereas after Hb correction, the prevalence raised-up to 65.6% (p < 0.001). Reciprocally, erythrocytosis proportion decreased from 20.35 to 0.30% (p < 0.001). Total Body Iron (TBI) showed that 7.44% had ID and 0.32% had IDA. PSC with normal unadjusted Hb levels have more protein and micronutrients intake than anemic ones. PSC with erythrocytosis consumed less fat, and more niacin and ascorbic acid than anemics. Total iron intake was lower in anemic than the other groups, but without statistical significance due to the standard deviation of the data in a small number of anemic PSC (n = 16). TBI, unadjusted Hb, and adjusted Hb were not different between groups consuming or not multimicronutrients.

CONCLUSIONS

The consumption of iron and iron status in children who live at high altitude is adequate, and that anemia could be due to other micronutrient deficiencies and/or that the adjustment of Hb by altitude is inappropriate.

Anaemia among school children of different socioeconomical status in a city of Southern Brazil

Background: Iron deficiency is one of the leading causes of anaemia, with those most affected being children and women of childbearing age, in Brazil there is a scarcity of studies involving the local prevalence of anaemia. Aim: To evaluate anaemia and associated factors in schoolchildren in Santa Cruz do Sul through the analysis of biochemical and haematological markers and parasitological examination of faeces. Subjects and methods: School children from 10 to 12 years of age were evaluated through complete blood count, serum ferritin, C-reactive protein and stool parasitological examination, as well as socio-demographic characteristics and prophylaxis with ferrous sulphate in childhood. Results: It was found that 13.0% of the population was anaemic, girls were very slightly overrepresented among the anaemic children. Only 5.3% had altered haematocrit levels; 26.6% had low Mean Corpuscular Volume levels; 18.4% had low ferritin levels; 2.4% had increased C-reactive protein levels, and 21.7% had altered eosinophils. As for the socioeconomic level, classes A2 and D presented lower haemoglobin levels, as well as class D presenting lower ferritin levels, although without statistical significance. Only 6.0% of the population presented iron-deficiency anaemia and 46.0% of the schoolchildren had used ferrous sulphate supplementation in childhood. Conclusion: The prevalence of anaemia in the studied municipality is low, probably due to the high municipal human development index. Epidemiological studies are essential to characterise the population in a systematic form, to prevent future problems.

Prevalence of anemia and its associated factors among children aged 6-23 months, in Ethiopia: a systematic review and meta analysis

INTRODUCTION

Despite several strategies exist for anemia prevention and control, it has been the major public health important problem in the world. Numerous immediate and long-term health issues were reported in children who have history of anemia including decreased work productivity in adult hood period. Although analyzing data on burden and risk factors of anemia are the recommended action areas of World Health Organization framework for accelerating anemia reduction, the aggregated national burden and contributors of anemia in Ethiopia has not been determined so far. There for, this systematic and meta-analysis study is aimed to assess the pooled prevalence and associated factors of anemia among children aged 6-23 months in Ethiopia.

METHODS

The electronic databases including PubMed, Scopus, EMBASE, Web of Science, Science Direct, Google scholar and institutional repositories were searched using search terms. The studies that reported the prevalence and/or risk factors of anemia in children 6-23 months of age were included. The JBI quality assessment tool was used to evaluate the quality of each study. The data was extracted with Microsoft Excel, 2019 and analyzed with STATA 17.0 statistical software. A random effect model was used to estimate the pooled prevalence of anemia and its associated factors. The Cochrane Q-test statistics and I2 test were used to measure heterogeneity between the included studies. Furthermore, publication bias was examined using the funnel plot graph and statistical tests (Egger's and begg tests). Outliers also visualized using Galbraith plot. When necessary, sensitivity analysis was also employed to detect small study effect.

RESULT

Ten studies with a total population of 14, 733 were included for analysis. The pooled prevalence of anemia among children aged 6-23 months of age in Ethiopia was found to be 57.76% (95%CI; 51.61-63.91; I2 = 97.192%; p < 0.001). Having history of diarrhea AOR = 2.44 (95%CI: 1.03-3.85), being stunted AOR = 2.00 (95%CI: 1.38-2.61), living in food insecure house hold AOR = 2.08 (95%CI: 1.10-3.07), consuming less diversified food AOR = 2.73 (95%CI: 2.06-3.39) and being 6-11 months of age AOR = 1.59 (95%CI: 1.23-1.95) were associated with anemia.

CONCLUSION AND RECOMMENDATION

The prevalence of anemia is in the range of severe public health problem among children aged 6-23 months in Ethiopia. Diarrhea, stunting, house hold food insecurity, dietary diversity, and age were the predictors of anemia. Further, prospective cohort and random controlled trial studies are recommended. Further, random controlled trial especially effectiveness of nutritional education interventions trial is important. To reduce prevalence of anemia, strengthening diarrhea reduction program, securing household food insecurity, preventing stunting, giving special attention for infants age 6-11 months and encouraging food diversification are important.

Anemia prevalence and its predictors among children under-five years in Ghana. A multilevel analysis of the cross-sectional 2019 Ghana Malaria Indicator Survey

Background and Aims

Despite the implementation of anemia control interventions in Ghana, anemia prevalence is still high in children under-fives. Reducing the prevalence of anemia requires identifying and targeting associated critical risk factors. This study seeks to identify predictors of anemia among children under-fives in Ghana.

Methods

Nationally representative data from the 2019 Ghana Malaria Indicator Survey was used in this study. Both fixed and random effects (multilevel) logistic regression models were applied to 2434 children to identify critical factors associated with anemia.

Results

In this study, 54% (95% confidence interval [CI] 52.0-57.0) of children under-5 years were anemic. Infants were more likely to be anemic (66.7%) compared with other children below 5 years. In the multivariable multilevel model, the risk of anemia was found to be higher in younger children especially 6-11 months old (adjusted odds ratio [aOR] = 3.59, CI: 2.54-5.08) and 12-23 months old (aOR = 2.97, CI: 2.08-4.23), children who had malaria (aOR = 1.53, CI: 1.13-2.06), children whose mothers were not registered but not covered with health insurance (aOR = 1.45, CI: 1.21-1.74) or were not even registered for insurance (aOR = 1.49, CI: 1.15-1.93), children born to adolescent mothers (aOR = 2.21, CI: 1.36-3.57), children born to non-Christian mothers (Islam [aOR = 1.53, CI: 1.17-2.00]), children born to families of poorer households (poorest [aOR = 3.01, CI: 1.64-5.51]; poorer [aOR = 2.56, CI: 1.65-3.98]); middle (aOR = 2.03, CI: 1.32-3.11) and richer (aOR = 1.78, CI: 1.19-2.64), and children who lived in either Upper East (aOR = 2.03, CI: 1.26-3.26) or Central (aOR = 2.52, CI: 1.42-4.47) regions. Significant unobserved community-level differences in anemia prevalence were observed.

Conclusion

The probability of anemia in children under-fives differs substantially from one community to another, and the prevalence remains high. The identified critical risk factors should be addressed. Multifaceted and targeted approaches are needed to help reduce the anemia prevalence in this setting to achieve the multiple United Nation's Sustainable Development Goals, which are related to risk and prevalence of anemia by 2030.

Prevalence of and factors associated with childhood anaemia in remote villages of the Peruvian Amazon: a cross-sectional study and geospatial analysis

BACKGROUND

Anaemia is a public health problem in Peru. In the Loreto region of the Amazon, ≥50% of children may be anaemic, although insufficient information exists for rural villages.

METHODS

To generate more data about childhood anaemia in the Peruvian Amazon, haemoglobin was measured as part of a trachoma survey in 21 randomly selected villages. All children 1-9 y of age from 30 randomly selected households per village were recruited. Anaemia was classified according to the World Health Organization guidelines and a socio-economic status (SES) index was created for each household using principal component analysis. Spatial autocorrelation was determined using Moran's I and Ripley's K function.

RESULTS

Of 678 children with complete haemoglobin data, 25.4% (95% confidence interval [CI] 21.2 to 30.1) had mild-or-worse anaemia and 22.1% (95% CI 15.6 to 30.3) had moderate-or-worse anaemia. Mild-or-worse anaemia was more common among children whose primary source of drinking water was surface water (prevalence ratio [PR] 1.26 [95% CI 1.14 to 1.40], p<0.001) and who were in the lowest SES tercile (PR 1.16 [95% CI 1.02 to 1.32], p=0.021). Moderate-or-worse anaemia was more common among boys (PR 1.32 [95% CI 1.09 to 1.60], p=0.005). No evidence of geospatial clustering was found.

CONCLUSIONS

Remote villages of the Amazon would benefit from interventions for childhood anaemia and the poorest households would have the most to gain. Integrating anaemia screening into neglected tropical diseases surveys is an opportunity to use public health resources more efficiently.

Gender differences in vision health-seeking behavior and vision health outcomes among rural Chinese schoolchildren by birth order and family size

BACKGROUND

The gender gap remains a major impediment in the path toward equality, and it is especially wide in low-income countries. Gender differences in health-seeking behaviors may be a factor. Family size and childbirth order are two critical factors affecting family resource allocation. This study examines gender differences in healthcare-seeking behaviors among children with visual impairment in rural China across different family structures (birth order and family size).

METHODS

We draw on a dataset containing 19,934 observations constructed by combining data from 252 different school-level surveys spanning two provinces. The surveys were all conducted in 2012 using uniform survey instruments and data collection protocols in randomly selected schools across western provinces in rural China. The sample children range in grades from 4 to 5. Our analysis compares rural girls with rural boys regarding vision health outcome and behavior (vision examination and correction).

RESULTS

The findings revealed that girls have worse vision than boys. Regarding vision health behaviors, girls have a lower overall vision examination rate than boys. There is no gender difference when the sample student is the only child or the youngest child in the family, but there is still a gender difference when the sample student is the oldest child in the family or the middle child in the birth order. When it comes to vision correction behavior, boys are more likely to own eyeglasses than girls are for groups of students with mild visual impairment, even when the sample student is the only child in the family. However, when the sample student has another brother or sister (the sample student is the youngest, the oldest child in the family, or the middle child in the birth order), the gender difference disappears.

CONCLUSIONS

Gender differences in vision health outcomes are correlated with gender differences in vision health-seeking behaviors among rural children. Depending on the birth order and family size, gender disparities in visual health practices vary. In the future, consideration should be given to providing medical subsidies to reduce the cost of vision health behaviors and to provide information interventions to change gender inequality in households and promote equality in children's vision health behaviors.

TRIAL REGISTRATION

The trial was approved by the Stanford University Institutional Review Board (Protocol No. ISRCTN03252665). Permission was received from local Boards of Education in each region and the principals of all schools. The principles of the Declaration of Helsinki were followed throughout. Written informed consent was obtained from at least one parent for all child participants.

Childhood Obesity and Plasma Micronutrient Deficit of Chilean Children between 4 and 14 Years Old

Objective: To analyze the nutritional status and plasma levels of vitamins and minerals in a cohort of Chilean children between 4 and 14 years old from three cities in Chile (Santiago, Antofagasta, and Concepcion). Design: This is a descriptive analysis of micronutrient levels in Chilean children as it relates to obesity and food consumption. Setting: This study included 1235 children from schools in Santiago (central area), Antofagasta (northern area), and Concepcion (southern area) in Chile. Results: Plasma levels of micronutrients revealed deficiencies in children from all these cities. Copper (26.4%) and calcium (33.0%) deficiencies were found in the children from Antofagasta, whereas iron (26.7%) and zinc (20.8%) deficiencies were found in the children from Concepcion and Santiago, respectively. The percentage of children with vitamin D deficiencies was exceptionally high in all cities (over 78%). The analysis of micronutrients and nutritional status revealed that vitamin D deficiencies were significantly higher (p = 0.02) in overweight children, particularly in Antofagasta. In the analysis of the nutritional status of children and their food consumption habits, the proportion of overweight and obesity was significantly higher (p = 0.001) in children that skipped breakfast compared to children that did not. Finally, children from low socioeconomic levels were significantly more overweight and obese compared to children from high socioeconomic levels (p < 0.05). Conclusions: this is the first study to describe plasma levels of micronutrients in Chilean children and adolescents. High percentages of obesity, overweight, and vitamin D deficiency were detected in children. These results are of significant relevance to future public health policies in Chile.

Inequalities in anemia among Peruvian children aged 6–59 months: A decomposition analysis

Objective

To quantify the inequalities of anemia in Peruvian children aged 6–59 months and uncover its contributing factors.

Materials and methods

We conducted a cross-sectional study based on the secondary data analysis of the 2021 Peruvian Demographic and Health Survey (DHS). Our sample included Peruvian children aged 6–59 months with complete data for the variables of interest. Anemia was defined as having a hemoglobin level of less than 11 g/dL, adjusted by altitude. Erreygers Concentration Index (ECI) and concentration curves were computed to estimate the socio-economic inequality in anemia among Peruvian children. Moreover, ECI was decomposed to figure out the contributing factors to the inequality of anemia and the residual variation.

Results

Nationwide, the prevalence of anemia in Peruvian children was 29.47%. We found a pro-poor inequality regarding anemia at the national level (ECI = −0.1848). The determinants included in the model explained 81.85% of the overall socio-economic inequality in anemia. The largest contribution to inequality was from household- and community-related factors. Having a higher mother’s education level (26.26%) and being from the highlands (24.91%) were the major significant contributors to the overall health inequality.

Conclusion

Almost one-third of Peruvian children have anemia. A pro-poor inequality of anemia in Peruvian children was found. Public policies ought to address the major contributing factors of anemia inequality.

Prevalence of anemia and associated factors in a Moroccan population from the Northwestern region of Morocco (M'diq-Fnideq-Martil Prefecture)

Introduction

anemia remains a major public health challenge worldwide, frequently having multifactorial causes and wide-ranging, largely underestimated repercussions. The purpose of this paper is to assess the prevalence of anemia and identify associated factors in a group of children, adults, and pregnant women.

Methods

our sample consisted of a total of 1360 volunteers (group I: 410 school-aged children aged 5-11 years; group II: 533 adults aged 16 to 65 years; group III: 417 pregnant women aged 17 to 45 years) randomly selected from different towns of the M'diq-Fnideq prefecture, Morocco from March 2018 to September 2018. Data on socio-demographic, anthropometric, and dietary status were collected from a questionnaire survey. A complete blood count was performed using a hematology analyzer, Sysmex KX21N® (Sysmex Corporation, Kobe, Japan), in the hematology laboratory of the Mohamed VI Hospital of M'diq.

Results

anemia was found in 31% of children, 52.4% of adults, and 22.5% of pregnant women. Microcytic hypochromic anemia was the most dominant type of anemia in children, adults, and pregnant women with percentages of 40.6%, 48.7%, and 43.5%, respectively. Mild anemia was much more common than moderate and severe anemia in all groups. Furthermore, anemia was associated with low socioeconomic and educational levels in adults (22.8% versus 27.9%) and pregnant women (18.1% versus 16.8%). Schoolchildren with illiterate parents and low socioeconomic levels are the most affected by anemia, with a prevalence of 75% and 69.44%, respectively. Also, children with insufficient stature are at a high risk for anemia compared to children of normal stature (p<0.001). As for weight for age, the odds ratio (OR) was 4.32. A significant difference between underweight and anemia was revealed (p<0.001). A frequency of meat product, vegetables, and fruit consumption lower than 1.5 times per week increases the risk of anemia in schoolchildren.

Conclusion

these findings showed a significant prevalence of anemia in all study groups associated with socioeconomic, anthropometric, and nutritional factors. However, further studies are needed to focus on interventions and etiologies in order to limit potential complications, especially in schoolchildren and pregnant women.

Factors associated with anaemia among preschool- age children in underprivileged neighbourhoods in Antananarivo, Madagascar

BACKGROUND

Anaemia occurs in children when the haemoglobin level in the blood is less than the normal (11 g/dL), the consequence is the decrease of oxygen quantity in the tissues. It is a prevalent public health problem in many low-income countries, including Madagascar, and data on risk factors are lacking. We used existing data collected within the pathophysiology of environmental enteric dysfunction (EED) in Madagascar and the Central African Republic project (AFRIBIOTA project) conducted in underprivileged neighbourhoods of Antananarivo to investigate the factors associated with anaemia in children 24 to 59 months of age.

METHODS

Children included in the AFRIBIOTA project in Antananarivo for whom data on haemoglobin and ferritin concentrations were available were included in the study. Logistic regression modelling was performed to identify factors associated with anaemia.

RESULTS

Of the 414 children included in this data analysis, 24.4% were found to suffer from anaemia. We found that older children (adjusted OR: 0.95; 95% CI: 0.93-0.98) were less likely to have anaemia. Those with iron deficiency (adjusted OR: 6.1; 95% CI: 3.4-11.1) and those with a high level of faecal calprotectin (adjusted OR: 2.5; 95% CI: 1.4-4.4) were more likely to have anaemia than controls.

CONCLUSIONS

To reduce anaemia in the children in this underprivileged area, more emphasis should be given to national strategies that improve children's dietary quality and micronutrient intake. Furthermore, existing measures should be broadened to include measures to reduce infectious disease burden.

Multilevel Analysis of the Nutritional and Health Status among Children and Adolescents in Eastern China

We aimed to identify multiple nutritional health problems and the relevant factors among children and adolescents aged 7–17 years. This study was part of the China Nutrition and Health Surveillance of Children and Lactating Mothers in 2016–2017, conducted in Jiangsu Province in eastern China. After sampling, 3025 school-age children and adolescents were enrolled into this study. Demographic information collections and anthropometric measurements were conducted by trained local Center for Disease Control and Prevention (CDC) staff. Venous blood in the amount of 6 mL was drawn from each participant in the morning and used for testing biochemical and nutritional indicators. Multivariate logistic regression analysis and Poisson regression analysis were used for overnutrition- and undernutrition-related disorders to test relevant personal, parental, and household factors. The prevalence of wasting, overweight, and obesity was 5.5%, 14.8%, and 12.7%, respectively. Metabolic syndrome (MetS) was prevalent among 5.1% of participants. Among the study participants, 29.5% had hyperuricemia. The overall prevalence of high low-density lipoprotein (LDL) and high total cholesterol (TC) of all participants was 4.8% and 7.4%, respectively. 0.9% of the participants had vitamin A deficiency (VAD) and 14.6% had marginal vitamin A deficiency; 25.1% had vitamin D deficiency (VDD) and 54.5% had inadequate vitamin D levels. Anemia was present in 4.0% of all participants. The prevalence of zinc deficiency was 4.8%. Demographic characteristics, behavioral characteristics, parents’ characteristics, and family characteristics were associated with these multiple malnutrition disorders. The double burdens of malnutrition, which includes overnutrition- and undernutrition-related diseases, were prevalent among the school-age children and adolescents in Jiangsu Province in eastern China. There were various factors related to different nutritional problems. Thus, health education focusing on behavior intervention and nutrition education are necessary in containing nutritional problems among children.

Nutrition-specific interventions for preventing and controlling anaemia throughout the life cycle: an overview of systematic reviews

BACKGROUND

Anaemia is a prevalent health problem worldwide. Some types are preventable or controllable with iron supplementation (pills or drops), fortification (sprinkles or powders containing iron added to food) or improvements to dietary diversity and quality (e.g. education or counselling).

OBJECTIVES

To summarise the evidence from systematic reviews regarding the benefits or harms of nutrition-specific interventions for preventing and controlling anaemia in anaemic or non-anaemic, apparently healthy populations throughout the life cycle.

METHODS

In August 2020, we searched MEDLINE, Embase and 10 other databases for systematic reviews of randomised controlled trials (RCTs) in anaemic or non-anaemic, apparently healthy populations. We followed standard Cochrane methodology, extracting GRADE ratings where provided. The primary outcomes were haemoglobin (Hb) concentration, anaemia, and iron deficiency anaemia (IDA); secondary outcomes were iron deficiency (ID), severe anaemia and adverse effects (e.g. diarrhoea, vomiting).

MAIN RESULTS

We included 75 systematic reviews, 33 of which provided GRADE assessments; these varied between high and very low. Infants (6 to 23 months; 13 reviews) Iron supplementation increased Hb levels and reduced the risk of anaemia and IDA in two reviews. Iron fortification of milk or cereals, multiple-micronutrient powder (MMNP), home fortification of complementary foods, and supplementary feeding increased Hb levels and reduced the risk of anaemia in six reviews. In one review, lipid-based nutrient supplementation (LNS) reduced the risk of anaemia. In another, caterpillar cereal increased Hb levels and IDA prevalence. Food-based strategies (red meat and fortified cow's milk, beef) showed no evidence of a difference (1 review). Preschool and school-aged children (2 to 10 years; 8 reviews) Daily or intermittent iron supplementation increased Hb levels and reduced the risk of anaemia and ID in two reviews. One review found no evidence of difference in Hb levels, but an increased risk of anaemia and ID for the intermittent regime. All suggested that zinc plus iron supplementation versus zinc alone, multiple-micronutrient (MMN)-fortified beverage versus control, and point-of-use fortification of food with iron-containing micronutrient powder (MNP) versus placebo or no intervention may increase Hb levels and reduce the risk of anaemia and ID. Fortified dairy products and cereal food showed no evidence of a difference on the incidence of anaemia (1 review). Adolescent children (11 to 18 years; 4 reviews) Compared with no supplementation or placebo, five types of iron supplementation may increase Hb levels and reduce the risk of anaemia (3 reviews). One review on prevention found no evidence of a difference in anaemia incidence on iron supplementation with or without folic acid, but Hb levels increased. Another suggested that nutritional supplementation and counselling reduced IDA. One review comparing MMN fortification with no fortification observed no evidence of a difference in Hb levels. Non-pregnant women of reproductive age (19 to 49 years; 5 reviews) Two reviews suggested that iron therapy (oral, intravenous (IV), intramuscular (IM)) increased Hb levels; one showed that iron folic acid supplementation reduced anaemia incidence; and another that daily iron supplementation with or without folic acid or vitamin C increased Hb levels and reduced the risk of anaemia and ID. No review reported interventions related to fortification or dietary diversity and quality. Pregnant women of reproductive age (15 to 49 years; 23 reviews) One review apiece suggested that: daily iron supplementation with or without folic acid increased Hb levels in the third trimester or at delivery and in the postpartum period, and reduced the risk of anaemia, IDA and ID in the third trimester or at delivery; intermittent iron supplementation had no effect on Hb levels and IDA, but increased the risk of anaemia at or near term and ID, and reduced the risk of side effects; vitamin A supplementation alone versus placebo, no intervention or other micronutrient might increase maternal Hb levels and reduce the risk of maternal anaemia; MMN with iron and folic acid versus placebo reduced the risk of anaemia; supplementation with oral bovine lactoferrin versus oral ferrous iron preparations increased Hb levels and reduced gastrointestinal side effects; MNP for point-of-use fortification of food versus iron and folic acid supplementation might decrease Hb levels at 32 weeks' gestation and increase the risk of anaemia; and LNS versus iron or folic acid and MMN increased the risk of anaemia. Mixed population (all ages; 22 reviews) Iron supplementation versus placebo or control increased Hb levels in healthy children, adults, and elderly people (4 reviews). Hb levels appeared to increase and risk of anaemia and ID decrease in two reviews investigating MMN fortification versus placebo or no treatment, iron fortified flour versus control, double fortified salt versus iodine only fortified salt, and rice fortification with iron alone or in combination with other micronutrients versus unfortified rice or no intervention. Each review suggested that fortified versus non-fortified condiments or noodles, fortified (sodium iron ethylenediaminetetraacetate; NaFeEDTA) versus non-fortified soy sauce, and double-fortified salt versus control salt may increase Hb concentration and reduce the risk of anaemia. One review indicated that Hb levels increased for children who were anaemic or had IDA and received iron supplementation, and decreased for those who received dietary interventions. Another assessed the effects of foods prepared in iron pots, and found higher Hb levels in children with low-risk malaria status in two trials, but no difference when comparing food prepared in non-cast iron pots in a high-risk malaria endemicity mixed population. There was no evidence of a difference for adverse effects. Anaemia and malaria prevalence were rarely reported. No review focused on women aged 50 to 65 years plus or men (19 to 65 years plus).

AUTHORS' CONCLUSIONS

Compared to no treatment, daily iron supplementation may increase Hb levels and reduce the risk of anaemia and IDA in infants, preschool and school-aged children and pregnant and non-pregnant women. Iron fortification of foods in infants and use of iron pots with children may have prophylactic benefits for malaria endemicity low-risk populations. In any age group, only a limited number of reviews assessed interventions to improve dietary diversity and quality. Future trials should assess the effects of these types of interventions, and consider the requirements of different populations.

Prevalence of childhood anaemia in Brazil: still a serious health problem: a systematic review and meta-analysis

OBJECTIVE

To estimate the prevalence of anaemia in Brazilian children up to 83·9 months old.

DESIGN

Systematic review and meta-analysis, using databases PubMed, Scopus, SciELO, Lilacs, Google Scholar, Periódicos Capes, Arca, Biblioteca Virtual em Saúde, Microsoft Academic Search and Cochrane Library using search terms: anaemia, prevalence, child and Brazil. PROSPERO Registration number: CRD42020208818.

SETTING

Cross-sectional, cohort, case-control and intervention studies published between 2007 and 2020 were searched, excluding those who assessed children with an illness or chronic condition. The main outcome was anaemia prevalence. Random effects models based on the inverse variance method were used to estimate pooled prevalence measures. Sensitivity analyses removed studies with high contribution to overall heterogeneity.

PARTICIPANTS

From 6790 first screened, 134 eligible studies were included, totalling 46 978 children aged zero to 83·9 months analysed, with adequate regions representativeness.

RESULTS

Pooled prevalence of anaemia was 33 % (95 % CI 30, 35). Sensitivity analyses showed that withdrawal of studies that contributed to high heterogeneity did not influence national average prevalence.

CONCLUSIONS

Childhood anaemia is still a serious public health problem in Brazil, exposing 33 % of Brazilian children to the anaemia repercussions. The main limitation of the study is the estimation of national prevalence based on local surveys, but a large number of studies were included, with representation in all regions of the country, giving strength to the results. In Brazil, more public policies are needed to promote supplementation, fortification and access to healthy eating to reduce the high level of anaemia among children.

Regional Differences in the Prevalence of Anaemia and Associated Risk Factors among Infants Aged 0-23 Months in China: China Nutrition and Health Surveillance

Infantile anaemia has been a severe public health problem in China for decades. However, it is unclear whether there are regional differences in the prevalence of anaemia. In this study, we used data from the China Nutrition and Health Surveillance (CNHS) to assess the prevalence of anaemia and the risk factors associated with its prevalence in different regions. We included 9596 infants aged 0–23 months from the CNHS 2013 database. An infant was diagnosed with anaemia if he/she had a haemoglobin concentration of <110 g/L. We used multivariate logistic regression to investigate the potential risk factors associated with the development of anaemia. We found that anaemia was present in 2126 (22.15%) of the infants assessed. Approximately 95% of these cases were classified as mild anaemia. Based on the guidelines laid out by the World Health Organization, 5.5% and 43.6% of the surveillance sites were categorized as having severe and moderate epidemic levels of anaemia, respectively. The prevalence of infantile anaemia in Eastern, Central and Western China was 16.67%, 22.25% and 27.44%, respectively. Premature birth, low birth weight, breastfeeding and residence in Western China were significantly associated with higher odds of developing anaemia. Female sex and having mothers with high levels of education and maternal birth age >25 years were associated with lower odds of developing anaemia. In conclusion, we observed significant regional disparities in the prevalence of infantile anaemia in China. Western China had the highest prevalence of infantile anaemia, and rural regions showed a higher prevalence of anaemia than urban regions.

Differences in factors associated with anemia in Haitian children from urban and rural areas

BACKGROUND

In Haiti, differences in the prevalence of anemia between urban and rural areas have been observed.

OBJECTIVE

To identify moderating factors that may help explain the difference in the prevalence of anemia in children from poor urban vs. rural areas of Haiti.

METHODS

This cross-sectional study used secondary data from urban and rural school-based trials that assessed the effectiveness of a nutrition intervention. The study was registered at ClinicalTrials.gov as NCT02747524. A total of 300 rural- and 981 urban- children between 2.5-13 years of age were included in this analysis. Effect modification in a binary logistic generalized linear mixed model was conducted using sample weights in SPSS® version 26. Models were adjusted for age and income. School cluster was included as random effect.

RESULTS

In rural areas, stunting was more prevalent in children with anemia vs. no anemia, (16.6%, and 6.3%, P = 0.008), respectively. Also, rural children with anemia lived with fewer adults vs. rural children with no anemia, ([Formula: see text] = 2.83±1.29, and 3.30±1.54, P = 0.005), respectively. In poor urban areas, helminth morbidities were more frequent in children with anemia vs. no anemia, (21.9% vs. 13.9, P = 0.011), respectively. In the combined sample, stunting, [AOR = 2.05; 95%CI (1.32-3.18)], age [AOR = 0.89; 95%CI (0.85-0.93)], and households with more adults [AOR = 0.77; 95%CI (0.67-0.87)] were associated with anemia. Effect modification by place of residence was observed in households with more adults (t = 3.83, P<0.001). No other nutritional, dietary, sanitation or morbidity factors or effect modifiers were observed.

CONCLUSIONS

In this sample, factors associated with anemia differed in poor urban and rural children from Haiti including family structure and helminth morbidities. Stunting and lower age increased the odds of anemia in the combined sample. Family structure appears to have an important role in anemia, and further research understanding the influence of family structures in anemia is needed.

Spatial variations and determinants of anemia among under-five children in Ethiopia, EDHS 2005-2016

Background

Anemia has severe public health significance in sub-Saharan Africa. In Ethiopia, anemia has been increasing in the last two decades, reaching the highest national level in 2016, however, the geospatial distribution and determinants of anemia in children weren’t well explored at a national level.

Methods

We used the Ethiopian Demographic and Health Survey(EDHS) data from 2005–2016. The data consists of samples of households (HHs) obtained through a two-stage stratified sampling procedure. Our analysis included 19,699 children. Descriptive statistics, geospatial analysis, and Generalized Linear Mixed Model (GLMMs) were used.

Results

The overall prevalence of anemia was 51.5%; the spatial distribution of anemia significantly different across clusters in each survey. Children from 6 to 11 months had higher odds of anemia compared to 24–59 months (Adjusted Odds ratio (AOR) = 3.4, 95%Confidence level (CI): 2.99–3.76). Children with the first and second birth order were less likely to be anemic compared to fifth and above (AOR = 0.60, 95%CI: 0.38–0.95, and AOR = 0.83, 95%C: 0.73–0.93) respectively. Mothers’ age 15 to 24 years was associated with higher odds of anemia compared to 35 to 49 years (AOR = 1.37, 95%CI: 1.20–1.55). Children from HHs with the poorest and poorer wealth category showed a higher odds of anemia compared to the richest (AOR = 1.67, 95%CI: 1.45–1.93, and AOR = 1.25, 95%CI: 1.08–1.45) respectively. Moreover, children from HHs with one to two under-five children were less likely to be anemic compared to those three and more (AOR = 0.83, 95%CI: 0.76–0.91).

Conclusions

The geospatial distribution of anemia among children varies in Ethiopia; it was highest in the East, Northeast, and Western regions of the country. Several factors were associated with anemia; therefore, interventions targeting the hotspots areas and specific determinant factors should be implemented by the concerned bodies to reduce the consequences of anemia on the generation.

Factors Associated with Schistosoma mansoni Infestation in Northeast Brazil: A Need to Revisit Individual and Community Risk Factors

In Brazil, schistosomiasis continues to be an important health issue. The aim of this study was to identify factors associated with Schistosoma mansoni infestation. A cross-sectional study was performed to assess factors associated with S. mansoni endemicity in a municipality in Northeast Brazil with a history of reporting schistosomiasis. Participants were divided into four groups: 1) new S. mansoni cases (n = 44), 2) past history of S. mansoni treatment (n = 78), 3) immediate neighbors (n = 158), and 4) nearby controls (n = 35). Multiple comparisons analysis was performed. Subjects had a mean of 6.6 ± 3.9 years of education, and no difference was observed regarding family income (one-way ANOVA, P = 0.215). A total of 95.9% of the individuals had rudimentary cesspit as sanitary wastewater. The mean body mass index was 28.3 ± 5.1, with 41.0% and 24.1% overweight and obesity, respectively. Of note, 28.9% of adults had hypertension. Hemoglobin, mean corpuscular volume, and mean corpuscular hemoglobin were higher in the recent S. mansoni treated group (Wilks' lambda, P < 0.001). Male gender was more prevalent in new S. mansoni cases (likelihood ratio, P < 0.001), close proximity to water collections was a risk for S. mansoni infestation (likelihood ratio, P < 0.001), and a better hematological status was observed in individuals recently treated with praziquantel. This study indicates the need to maintain surveillance for S. mansoni in low-transmission areas and the need to establish community-based interventions to control transmission.

Sudden Sensorineural Hearing Loss Associated with Nutritional Anemia: A Nested Case-Control Study Using a National Health Screening Cohort

Previous studies have suggested an association of anemia with hearing loss. The aim of this study was to investigate the association of nutritional anemia with sudden sensorineural hearing loss (SSNHL), as previous studies in this aspect are lacking. We analyzed data from the Korean National Health Insurance Service-Health Screening Cohort 2002-2015. Patients with SSNHL (n = 9393) were paired with 37,572 age-, sex-, income-, and region of residence-matched controls. Both groups were assessed for a history of nutritional anemia. Conditional logistic regression analyses were performed to calculate the odds ratios (ORs) (95% confidence interval, CI) for a previous diagnosis of nutritional anemia and for the hemoglobin level in patients with SSNHL. Subgroup analyses were conducted for age and sex. Age, sex, income, and region of residence were stratified. Obesity, smoking, drinking alcohol, systolic/diastolic blood pressure, fasting blood glucose, total cholesterol, and the Charlson Comorbidity Index were considered in the regression models. Nutritional anemia was present in 4.8% (449/9393) of patients with SSNHL and 4.0% (1494/37,572) of controls (p < 0.001). The SSNHL group demonstrated 1.20-fold higher odds for nutritional anemia (95% CI = 1.08-1.34, p = 0.001). Hemoglobin levels were not associated with SSNHL. In subgroups <60 years old, there was a consistent positive association of nutritional anemia with SSNHL (adjusted OR = 1.55, 95% CI = 1.11-2.15, p = 0.010 for men <60 years old, and adjusted OR = 1.22, 95% CI = 1.02-1.45, p = 0.028 for women <60 years old). Nutritional anemia, but not hemoglobin level, was associated with an increased risk of SSNHL.

Anemia prevalence, severity and associated factors among children aged 6-71 months in rural Hunan Province, China: a community-based cross-sectional study

Background

In recent 10 years, with the rapid socioeconomic development and the extensive implementation of children nutrition improvement projects, the previous epidemiological data cannot reflect the actual level of anemia among children in China, especially in rural areas. Therefore, this study analyzed the prevalence, severity and associated factors of anemia among children aged 6–71 months in rural Hunan Province.

Methods

A community-based cross-sectional study was conducted. Through multistage stratified cluster sampling, 5229 children aged 6 to 71 months and their caregivers were randomly selected from 72 villages across 24 towns in 12 counties from rural Hunan. The demographic characteristics of children and their caregivers, feeding practice, nutritional status of children, caregivers’ anemia-related feeding knowledge, and gestational conditions of mothers were acquired by using a unified questionnaire. Peripheral blood from the left-hand middle fingertip was sampled from each child, and hemoglobin concentration was measured using a HemoCue301 portable hemoglobin analyzer (Sweden). Associated factors analyses involving overall anemia and anemia severities were conducted on multivariate logistic regression models.

Results

The overall anemia prevalence was 8.8%, and the prevalence of mild, moderate and severe anemia was 6.3, 2.5 and 0.1%, respectively. Children age groups of 6–11 months, 12–23 months and 36–47 months, exclusive breast-feeding within 6 months after birth, and maternal moderate/severe anemia were significantly associated with an increased risk of overall anemia in children. Children age groups of 6–11 months and 12–23 months were significantly associated with an increased risk of mild anemia in children. Children age groups of 6–11 months, 12–23 months and 36–47 months, low caregivers’ anemia-related feeding knowledge level, and maternal moderate/severe anemia were significantly associated with an increased risk of moderate/severe anemia in children. Children who underwent regular physical examination were less likely to have moderate/severe anemia. The common protective factor for overall, mild and moderate/severe anemia in children was high family income.

Conclusions

The anemia status of preschool children in rural Hunan Province was a mild public health problem and associated with children age group, feeding practice, regular physical examination, family income, caregivers’ anemia-related feeding knowledge level, and maternal moderate/severe anemia.

Prevalence of anaemia in Brazilian children in different epidemiological scenarios: an updated meta-analysis

OBJECTIVE

To update the estimation of the prevalence of anaemia in Brazilian children according to four different epidemiological scenarios.

DESIGN

A new systematic review was conducted with a meta-analysis of the results published between 2007 and May 2019. Literature search was carried out in the PubMed and LILACS databases using keywords anaemia, child and Brazil. A total of thirty-seven articles (17 741 children) were selected and categorised according to the origin of their respective samples: childcare centres (Childcare; n 13 studies/2697 individuals), health services (Services; n 4/755), populations with social inequities (Inequities, n 7/6798) and population-based studies (Populations; n 13/7491). Assuming a prevalence of 20·9 % as reference (Health National Survey; n 3455), the combined prevalence ratios (PR) were calculated. A random-effects model was used.

PARTICIPANTS

Brazilian children 6-60 months of age.

RESULTS

The prevalence of anaemia, by scenario, was: Childcare 24·8 % (PR 1·06; 95 % CI 0·81, 1·40); Services 39·9 % (PR 1·76, 95 % CI 1·33, 2·35); Inequities 51·6 % (PR 2·02, 95 % CI 1·87, 2·18); and Populations 35·8 % (PR 1·42, 95 % CI 1·23, 1·64). Therefore, the values were all higher than the national prevalence; the Inequities had the highest prevalence, and only Childcare did not reach statistical significance. Concerning the previous meta-analysis, there was a reduction in anaemia prevalence in all scenarios: -52·3, -33·7, -22·4 and -10·7 %, respectively.

CONCLUSIONS

Compared to the situation revealed in the previous meta-analysis, anaemia, although observed to a lesser extent, remains an important public health problem in the different scenarios analysed, especially for children living in Inequities. Access to Childcare mitigates the risk for this condition.

Anemia and its associated factors among Adolescents in Kuwait

We estimated the prevalence of anemia among school children and investigated factors associated with this problem in Kuwait. A cross-sectional study was conducted on 1415 adolescents randomly selected from middle schools in Kuwait. Hemoglobin, iron, ferritin, folate and vitamin B₁₂, in addition to many other laboratory indicators, were measured in a venous blood sample. Data on risk factors for anemia were collected from parents and adolescents. Multiple logistic regression was used to investigate factors associated with anemia. The prevalence of anemia was 8.06% (95% CI: 6.69-9.60%), which was significantly higher among females compared to males (10.96% vs. 5.04%; p < 0.001). Mean (SD) Hb level was 133.7 (9.89) g/L and 130.00 (10.48) g/L among males and females, respectively (p < 0.001). The prevalence of mild, moderate and severe anemia was 5.94%, 1.91% and 0.21%, respectively. Gender, age, iron concentration and ferritin were associated with anemia in multivariable analysis. These data indicate that anemia among school children in Kuwait is of mild public health significance. Further reduction in anemia in school girls should focus on correcting iron deficiency. Surveillance systems for anemia may consider using a cut-off point that is specific for the method of blood sampling and the method of Hb measurement.

Household food insecurity and its association with anaemia in Mexican children: National Health and Nutrition Survey 2012

OBJECTIVES

To assess the association between household food insecurity (FI) and the presence of anaemia among Mexican children who were between 12 and 59 months old, and to determine whether this association differs by geographical regions.

METHODS

We analysed 7468 children of ages between 12 and 59 months, based on data from the 2012 National Health and Nutrition Survey (ENSANUT 2012). Haemoglobin was measured in capillary blood. Household FI levels were defined according to the Latin American and Caribbean Food Security Scale. An ordinal logistic regression model was developed to assess the relationship between FI and anaemia. The interaction between geographical regions and FI was determined.

RESULTS

The highest proportion of anaemia occurred in children with severe household FI (24.3%), compared to those from households with food security (21.2%). Children from severe FI households have a higher adjusted prevalence of anaemia than those from households with food security. FI and anaemia were associated mainly among children residing in the southern region of Mexico.

CONCLUSIONS

Our findings can contribute to a better understanding of FI and anaemia in children and to strengthen interventions to address these problems.

Anemia epidemiology, pathophysiology, and etiology in low- and middle-income countries

Anemia affects a third of the world's population and contributes to increased morbidity and mortality, decreased work productivity, and impaired neurological development. Understanding anemia's varied and complex etiology is crucial for developing effective interventions that address the context-specific causes of anemia and for monitoring anemia control programs. We outline definitions and classifications of anemia, describe the biological mechanisms through which anemia develops, and review the variety of conditions that contribute to anemia development. We emphasize the risk factors most prevalent in low- and middle-income countries, including nutritional deficiencies, infection/inflammation, and genetic hemoglobin disorders. Recent work has furthered our understanding of anemia's complex etiology, including the proportion of anemia caused by iron deficiency (ID) and the role of inflammation and infection. Accumulating evidence indicates that the proportion of anemia due to ID differs by population group, geographical setting, infectious disease burden, and the prevalence of other anemia causes. Further research is needed to explore the role of additional nutritional deficiencies, the contribution of infectious and chronic disease, as well as the importance of genetic hemoglobin disorders in certain populations.