Research findings reveal that although soil-transmitted helminth (STH) infections have declined significantly worldwide, anemia prevalence among children under five and women of reproductive age continues to fluctuate. After adjusting for socioeconomic factors, STH was no longer found to have a significant effect on anemia. Instead, anemia among children under five was primarily associated with the Human Development Index (HDI), while anemia among women of reproductive age was linked to access to safe drinking water and universal health coverage. These findings support a shift in anemia prevention strategies from relying solely on deworming programs to adopting broader, multisectoral interventions.


Anemia and neglected tropical diseases (NTDs), such as soil-transmitted helminth infections, have long been considered closely interconnected because they share similar geographic distributions and risk factors, particularly in low- and middle-income countries. A study entitled Impact of Soil-Transmitted Helminths Infections on Anemia Burden: A Global Analysis of Children Under Five and Reproductive-Age Women, published in BMC Public Health (2025) by Rahayu Lubis, Fauzi Budi Satria, Rasmaliah, Jemadi, and Siti Khadijah Nasution from the Faculty of Public Health, Universitas Sumatera Utara (USU), in collaboration with Rafdzah Ahmad Zaki from the University of Malaya, re-examined this assumption on a global scale using data from 187 countries collected between 2015 and 2019.


In many developing countries, anemia and helminth infections are often regarded as inseparable health problems that are expected to improve simultaneously through mass deworming programs. However, anemia remains a major global health challenge, affecting approximately 1.62 billion people worldwide. Among children under five and pregnant women, anemia can result in long-term consequences, including impaired cognitive development and an increased risk of mortality. Children under five require higher iron intake to support growth and development, while women of reproductive age have greater iron requirements due to menstruation and pregnancy. Both groups are therefore highly vulnerable to anemia and remain key targets of the World Health Organization’s NTD Roadmap 2030.

To better understand why these two conditions sometimes overlap and sometimes diverge at the population level, the researchers applied the SYSRA framework, which is commonly used to examine interactions between infectious disease programs and broader health systems. Four potential confounding factors were incorporated into the analysis: the Universal Health Coverage (UHC) Service Coverage Index, safe water and sanitation indicators under SDGs 6.1 and 6.2, Government Effectiveness, and the Human Development Index (HDI). The rationale was straightforward—both helminth infections and anemia are more prevalent in areas with poor sanitation, limited healthcare access, and weak governance. Without accounting for these structural factors, any observed relationship between STH and anemia could be misleading.


Methodologically, the research employed an ecological study design, meaning that the unit of analysis was countries rather than individuals. Data on STH prevalence and anemia burden were obtained from the Global Burden of Disease (GBD) database, while UHC, water and sanitation, government effectiveness, and HDI data were sourced respectively from the World Health Organization (WHO), the World Bank’s Worldwide Governance Indicators, and the United Nations Development Programme (UNDP). Countries were categorized into high- and low-prevalence groups using the Receiver Operating Characteristic (ROC) Clustering approach. Statistical analyses included paired t-tests to assess annual trends, chi-square tests to examine associations between variables, and multiple logistic regression to identify independent determinants of anemia after controlling for confounding variables.

The first major finding showed that the prevalence of STH infections declined significantly every year between 2015 and 2019 among both children under five and women of reproductive age, indicating that global interventions such as mass deworming and improved sanitation have been effective. However, anemia did not exhibit the same pattern. Its prevalence fluctuated throughout the study period without showing a consistent downward trend. Numerically, STH prevalence among children under five (87.37 per 100,000 population) was much lower than among women of reproductive age (10,140.04 per 100,000 population). In contrast, anemia prevalence was significantly higher among children under five (248.29 per 100,000 population) than among women of reproductive age (104.37 per 100,000 population).


Among the 187 countries analyzed, 52.94% were classified as having relatively low anemia prevalence, while 47.06% experienced high anemia prevalence. Countries with the greatest anemia burden consistently shared similar characteristics, including low HDI, weak government effectiveness, inadequate water and sanitation infrastructure, and limited UHC coverage, illustrating a pattern of overlapping structural vulnerabilities.

The study’s most significant finding emerged from the multivariate logistic regression analysis. In the initial bivariate analysis using chi-square tests, STH appeared to be significantly associated with anemia among children under five, suggesting that helminth infections contributed to childhood anemia. However, after simultaneously controlling for HDI, government effectiveness, water and sanitation, and UHC, the association disappeared. STH was no longer a statistically significant determinant of anemia among either children under five (OR = 1.62; p = 0.59) or women of reproductive age (OR = 0.59; p = 0.21).

Instead, the analysis identified HDI as the strongest determinant of anemia among children under five. Countries with low HDI were 14.17 times more likely to experience high childhood anemia prevalence (p < 0.05). Among women of reproductive age, the significant determinants were limited access to safe drinking water under SDG 6.1 (OR = 3.98; p < 0.05) and low UHC coverage (OR = 4.09; p < 0.05), indicating substantially higher risks of anemia in countries lacking these essential services.


These findings differ from many previous studies that consistently reported positive associations between STH infections and anemia in both children and women of reproductive age. The discrepancy is likely attributable to the ecological nature of the study, which captures patterns at the national rather than individual level. Consequently, structural determinants such as human development and healthcare access appear more influential than the direct biological effects of helminth infections on hemoglobin levels. Differences in national deworming program coverage may also help explain the divergence from earlier research.


The implications are substantial. The study suggests that efforts to reduce anemia among children under five and women of reproductive age should no longer rely exclusively on deworming initiatives, important though they remain within the global NTD agenda. Instead, broader interventions are needed, including comprehensive human development policies for children, expanded access to safe drinking water, and stronger universal health coverage for women of reproductive age. Poverty reduction, clean water infrastructure, and strengthened health systems should complement conventional public health programs rather than serve merely as supporting measures.

Ultimately, the study demonstrates that although soil-transmitted helminth infections are declining globally due to successful deworming programs and improved sanitation, anemia persists because its underlying causes are far more complex, rooted in inequalities in development, limited access to clean water, and gaps within health systems. The researchers emphasize that, because of the ecological study design, the findings cannot establish causal relationships at the individual level. They therefore recommend future research using individual-level data while considering co-infections such as malaria and HIV to strengthen the evidence base and support more targeted interventions.

Research Highlights

  • Ecological study covering 187 countries (2015–2019) examining the relationship between STH infections and anemia burden among children under five and women aged 15–49 years using Global Burden of Disease data.
  • STH prevalence declined significantly each year (p < 0.05) among children under five (87.37/100,000) and women of reproductive age (10,140.04/100,000), whereas anemia prevalence fluctuated without a consistent decline.
  • Anemia prevalence among children under five (248.29/100,000) was significantly higher than among women of reproductive age (104.37/100,000) (p < 0.05).
  • 52.94% of countries had low average anemia prevalence, while 47.06% had high prevalence.
  • Multivariate analysis showed that STH was not a significant determinant of anemia among children under five (OR = 1.62; p = 0.59) or women of reproductive age (OR = 0.59; p = 0.21).
  • Low HDI increased the risk of high childhood anemia prevalence by 14.17 times (95% CI: 4.25–44.66).
  • Limited access to safe drinking water (SDG 6.1) increased the risk of anemia among women of reproductive age by 3.98 times (95% CI: 1.35–11.78).
  • Low UHC coverage increased the risk of anemia among women of reproductive age by 4.09 times (95% CI: 1.06–15.69).

Paper Details

  • Journal: BMC Public Health, Vol. 25, Article 1356 (2025)
  • Title: Impact of Soil-Transmitted Helminths Infections on Anemia Burden: A Global Analysis of Children Under Five and Reproductive-Age Women
  • Authors: Rahayu Lubis, Fauzi Budi Satria, Rasmaliah, Jemadi, Siti Khadijah Nasution, and Rafdzah Ahmad Zaki
  • Affiliations: Faculty of Public Health, Universitas Sumatera Utara; Doctoral Program in Medical Science & Department of Community Medicine, Faculty of Medicine, Universitas Sumatera Utara; Regional Collaborating Centre USU–SingHealth Duke-NUS Global Health Institute, Medan; Centre for Epidemiology and Evidence-Based Practice, Faculty of Medicine, University of Malaya, Kuala Lumpur
  • DOI: https://doi.org/10.1186/s12889-025-22572-z