In 2024, the World Health Organization (WHO) revised the hemoglobin cutoff values to improve the detection and classification of anemia in children. For infants aged less than 2 years, the threshold for mild anemia was lowered from 11 g/dL to < 10.5 g/dL.

The change in the hemoglobin cutoff, first studied in Peru and now confirmed in Argentina, led to a significant drop in the prevalence of anemia among young children in both countries.

With rates falling below 40%, childhood anemia may lose its classification as a severe public health problem in Latin American countries. However, continued vigilance and targeted interventions are essential to address this ongoing health burden in the country.

Argentina and Peru Data

Speaking with Medscape’s Spanish edition, Ana María Varea, biochemist and human nutrition specialist at the Instituto de Desarrollo e Investigaciones Pediátricas (IDIP), La Plata, Argentina, said, “The WHO’s proposal to lower the cutoff for defining anemia in infants under 2 years led us to ask how this new definition would affect our population, to quantify the change, and to analyze its implications for clinical diagnosis and prevention strategies.”

The research Varea participated in, published in Archivos Argentinos de Pediatría, analyzed 1843 infants aged less than 2 years (median age, 6.74 months; 47.7% girls) who attended the IDIP during 2017-2024.

The results showed that the prevalence of childhood anemia dropped from 46.9% to 25.8% over this period. Approximately 74.4% of infants were aged 6-12 months, the group most affected by mild anemia, which increased from 76.3% of cases in 2011 to 82.2% in 2024. Importantly, no cases of severe anemia (hemoglobin level < 7 g/dL) were recorded. Despite this decline, anemia remains a significant public health issue, affecting 1 in 4 young children in this region.

Varea noted that lowering the cutoff was expected to reduce childhood anemia prevalence in this population. However, she cautioned that even with values below 40%, the condition would still be classified as a moderate public health problem rather than severe, according to the WHO criteria.

“There is a risk that changing the classification will minimize the need for interventions. That 1 in 4 healthy infants under 2 years old, with access to healthcare, still has anemia is a situation requiring immediate action,” she cautioned.

Similar findings have been reported in Peru. Gustavo Gonzales, MD, dean of the Faculty of Health Sciences at Universidad San Ignacio de Loyola, Lima, Peru, and president of the National Academy of Medicine of Peru, was not part of the team that conducted the study in Argentina. However, he described the study as a valuable and timely contribution.

He highlighted the importance of understanding how the epidemiology of childhood anemia may change depending on the definition used.

In collaboration with another author, Gonzales previously published data from a similar study in Revista Médica Herediana in 2024, focusing on Lima. Their analysis of data from 2012 to 2017 showed that the prevalence of anemia in the metropolitan population declined from 45.4% to 25.5% under the updated WHO thresholds. He noted, “This change should not be interpreted as a health victory but as an opportunity to redefine and improve diagnostic criteria without losing sight of the central goal: protecting neurological, physical, and cognitive development in infants.”

Gonzales also noted that, despite government investments in iron supplementation and food fortification, statistics from Peru and other Latin American countries show only modest progress in controlling childhood anemia in recent decades.

He emphasized that Peru must maintain a critical, evidence-based approach, informed by broader epidemiological evidence, to determine how to respond to the new international thresholds.

“This shift in how we diagnose anemia shows that relying on iron supplementation is no longer the most effective approach. Resources should not be cut but redirected toward improving diagnosis and, most importantly, understanding the underlying causes,” Gonzales added.

Broader Context

Approximately 24.3% of the global population has anemia, with the heaviest burden among pregnant women and infants aged less than 5; iron deficiency accounts for 60% of cases.

Varea urged to strengthen the implementation of proven measures such as early infant iron supplementation, antenatal supplementation, diet diversification, and food fortification, as well as to raise awareness by engaging healthcare professionals and families to improve coverage and adherence.

Varea warned that falling prevalence could reduce vigilance. She stated that this could result in inadequate iron intake among children. She urged a multifactorial response that addresses socioeconomic conditions, maternal health, dietary quality, infections, and other micronutrients rather than focusing exclusively on iron.

Gonzales is concerned that children who do not need iron supplements are receiving them, putting them at risk for iron overload and related complications. He noted that the WHO’s revised thresholds may help reduce this risk.

In his article, he questioned whether, with childhood anemia no longer considered a serious public health problem, routine iron should be administered to infants as young as 4 months or to infants aged 6-59 months without anemia, as required by regulations in some countries.

Gonzales cited data showing that supplementation programs have had only a modest impact despite longstanding government support and highlighted scientific concerns about the potential harm from excess dietary iron.

Gonzales and colleagues noted that “the lack or modest response to iron intervention indicates that iron deficiency is not the primary cause of anemia. The World Health Organization recommends a comprehensive assessment for anemia management. In many low- and middle-income countries, inflammatory anemia is a major contributor.”

Both experts agreed that anemia in infants under 2 years of age remains a serious public health concern and must remain a priority in health policy.

“The decrease in prevalence, with the new cutoff point proposed by the World Health Organization, does not mean that anemia has ceased to be a significant problem,” Varea concluded.

SOURCE: Medscape