Anemia is a condition characterized by a lower than normal concentration of hemoglobin or a reduced number of healthy red blood cells. Hemoglobin transports oxygen from the lungs to the body’s tissues, and a deficit impairs this process, leading to symptoms like fatigue and weakness. The World Health Organization (WHO) defines anemia as a serious global public health concern, particularly affecting vulnerable groups worldwide. Globally, the condition affects an estimated 40% of children aged 6–59 months, 37% of pregnant women, and 30% of women of reproductive age.
Anemia is not a single disease but rather a sign of an underlying problem, often caused by nutritional deficiencies, such as iron, folate, or vitamin B12, or by infectious diseases and chronic inflammation. The WHO establishes global health standards for prevention, diagnosis, and management, and has set a target to achieve a 50% reduction in the prevalence of anemia among women of reproductive age by 2025.
WHO Prevention Guidelines for Vulnerable Groups
Preventative action, known as prophylaxis, focuses on fortifying nutrient stores in populations most susceptible to anemia, such as women and young children. For women of reproductive age, the WHO recommends iron and folic acid (IFA) supplementation, especially where anemia prevalence is 20% or higher. This strategy addresses iron loss through menstruation and dietary deficiencies.
Pregnant women have high iron requirements due to the developing fetus and the expansion of maternal blood volume. The guideline specifies a daily dose of 30–60 mg of elemental iron, combined with 400 µg of folic acid, throughout the pregnancy. This regimen prevents iron deficiency and reduces the risk of low birth weight and preterm delivery.
For non-pregnant women and adolescent girls, the WHO permits intermittent supplementation, involving taking the IFA dose once, twice, or three times a week on non-consecutive days. This approach improves iron status and hemoglobin levels while often increasing adherence compared to a daily regimen. Intermittent dosing is a practical measure to manage side effects like gastrointestinal discomfort.
Infants and young children between 6 and 23 months are targeted for iron supplementation in regions where anemia prevalence exceeds 40%. The recommendation is a daily administration of 10 to 12.5 mg of elemental iron for three consecutive months each year. This is often delivered through iron drops or micronutrient powders mixed with food.
The WHO also promotes population-level food-based strategies. Mass food fortification involves adding micronutrients like iron and folic acid to widely consumed staple foods, such as flour, salt, or sugar. Complementary feeding practices for infants emphasize the consumption of iron-rich foods, including meat, poultry, and fish.
Therapeutic Management of Diagnosed Anemia
The WHO defines anemia using hemoglobin concentration thresholds that vary by age, sex, and physiological status. For example, a non-pregnant woman is anemic if her hemoglobin level is below 120 g/L, while the threshold for a pregnant woman is less than 110 g/L. These cutoffs are used to screen populations and classify severity as mild, moderate, or severe.
A diagnosis of moderate anemia, generally defined by hemoglobin levels between 70 g/L and 99 g/L in many adult populations, warrants therapeutic intervention to reverse the deficiency. The first-line treatment for iron deficiency anemia is high-dose oral iron supplementation. This therapeutic dose is significantly higher than prophylactic doses and aims to rapidly correct the hemoglobin deficit and replenish the body’s iron stores.
Treatment involves initial correction followed by a maintenance period. Oral iron should continue for an additional two to three months after hemoglobin concentration normalizes to ensure tissue iron stores are fully replenished. Follow-up is monitored through blood tests, including hemoglobin and serum ferritin levels, to confirm a sustained response and determine when treatment can be safely discontinued.
Management of severe anemia, typically defined by a hemoglobin concentration below 70 g/L, requires urgent and intensive medical care. Patients need immediate investigation to identify the underlying cause, as non-nutritional factors are more likely. In these instances, hospitalization may be necessary, and blood transfusions may be administered to rapidly increase the blood’s oxygen-carrying capacity.
Intravenous (IV) iron infusion is an option for individuals who do not respond adequately to oral iron due to poor absorption or severe side effects. IV iron delivers a high dose directly into the bloodstream, bypassing gastrointestinal issues and ensuring sufficient iron availability for red blood cell production. The selection of treatment pathway depends heavily on the severity of anemia, the likely underlying cause, and the patient’s tolerance for oral medication.
Integrated Public Health Measures
The WHO recognizes that nutritional interventions alone are often insufficient to control anemia in many high-burden regions, necessitating a multi-sectoral approach that addresses environmental and infectious disease factors.
Parasitic Infections and Malaria Control
In areas endemic for parasitic infections, mass drug administration programs, specifically deworming, are recommended for vulnerable groups like school-age children and pregnant women. Parasites such as hookworm can cause chronic blood loss and impaired nutrient absorption, directly contributing to anemia.
Malaria is another major non-nutritional contributor to anemia, particularly in sub-Saharan Africa, where the parasite destroys red blood cells. The integrated strategy mandates that iron supplementation programs in malaria-endemic areas must be implemented in conjunction with robust malaria prevention, diagnosis, and treatment measures. These measures include:
- The use of insecticide-treated bed nets.
- Intermittent preventative treatment for pregnant women.
Water, Sanitation, and Hygiene (WASH)
Improving water, sanitation, and hygiene (WASH) infrastructure is a fundamental public health measure for anemia control. Poor sanitation contributes to the spread of infectious diseases, leading to chronic infections and inflammation that suppress red blood cell production, even when nutritional intake is adequate. By reducing the overall infectious disease burden, WASH improvements make nutritional interventions more effective.
Genetic and Reproductive Health Measures
Comprehensive anemia control programs must account for inherited disorders that cause anemia, such as thalassemia and sickle cell trait. While these genetic conditions are not preventable through diet or infection control, public health measures include screening and management strategies to reduce their impact on health. Other simple but effective measures include:
- Counseling women to wait at least 24 months between pregnancies.
- Promoting delayed umbilical cord clamping for at least one minute after birth to allow the newborn to receive an optimal volume of blood.