Optimizing Benefits While Reducing Risks of Iron in Malaria-endemic Areas

Provision of sufficient iron for brain development in children living in malaria-endemic areas while also protecting them from infection is an unachieved public health goal for >10 years. The 2006 landmark study on malaria-endemic Pemba Island brought the complicated relationship between iron and malaria to the world stage by reporting universal prophylactic iron supplementation increases the risk of child hospitalization and death. Treating iron deficiency in children who have malaria is also an unsolved challenge. In sub-Saharan Africa, iron deficiency and malaria coexist, frequently causing a multifactorial anemia that is a primary cause of hospitalization and mortality in children <5 y. The current World Health Organization standard-of-care regimen of concurrent treatment with antimalarial medication and iron therapy has been unsuccessful, with frequent reports of subsequent infection, including malaria, persistent iron deficiency, and unresolved anemia.

One solution to effectively treat coexisting malaria and iron deficiency is to stagger interventions, treating malaria first and delaying iron. The inflammatory response against malaria induces high levels of the protein hepcidin, which reduces intestinal iron absorption and prohibits release of iron from reticulo-endothelial cells. Iron given orally during or shortly after a malaria episode is thus not well absorbed or distributed to red blood cells or the brain. Moreover, unabsorbed iron in the gut may promote the growth of pathogenic bacteria, potentially leading to subsequent infectious morbidity. A pilot study was recently completed in Ugandan children with malaria and iron deficiency that used iron stable isotopes to test whether iron given 28 days after (delayed group) or concurrently with (immediate group) antimalarial treatment was better incorporated into red blood cells (1R03HD074262). It was found that delayed iron was incorporated twice as well as immediate iron and that iron status at 56 days was similar between groups. An important finding was that children in the immediate group had a higher incidence of infections in the 56-day follow-up period. In this application, the team proposes a large-scale, randomized clinical trial with 12 months follow up powered to capture long-term differences in iron status, morbidity, and neurobehavioral development as a function of immediate or delayed iron following treatment for malaria and iron deficiency. The gut microbiome will be analyzed to elucidate a mechanism of any differences in incidence of infections.

One long-term goal is to develop safe and effective strategies for managing concurrent malaria and iron deficiency in children, with reduction of infections and optimization of neurobehavioral development representing successful outcomes. The objective of this application is to conduct a placebo-controlled, randomized clinical trial to determine whether iron therapy begun with vs. 28 days after antimalarial treatment in Ugandan children 6-48 months with malaria and iron deficiency leads to better iron status, fewer infections, and better neurobehavioral development after 12 months. The central hypothesis is that better iron incorporation and lower incidence of infectious illness observed with delayed iron in our short-term, physiology-focused R03 study will translate into better long-term iron status, fewer episodes of infection, and better neurobehavioral outcomes after 12 months. The rationale is that this study will determine if staggering antimalarial treatment and iron therapy protects against immediate morbidity while also optimizing long-term neurobehavioral development. The Specific Aims are:

Aim 1: Establish the effect of immediate vs. delayed iron treatment on long-term iron status.

It is hypothesized that delayed iron will result in better iron status 6 and 12 months after treatment for malaria due to better initial iron absorption and utilization as compared to the immediate iron group.

Aim 2: Determine the effect of delayed iron treatment on the incidence of infectious illness.

It is hypothesized that the better absorbed delayed iron will result in fewer infections in the 6 and 12 months after treatment for malaria due, in part, to a less pathogenic intestinal microbiome profile.

Aim 3: Establish the effect of delayed iron treatment on neurobehavioral development.

It is hypothesized that delayed iron will result in better neurobehavioral outcomes (as assessed by standardized cognitive and behavioral tests) due to better iron absorption and utilization.

Anticipated Impact: Untreated iron deficiency may protect a child from malaria and other infections, but the consequent potentially permanent damage to the developing brain is an unacceptable alternative. Establishment of methods to effectively ensure brain iron health while protecting the child from infection will promote attainment of full cognitive and behavioral development for tens of millions of children worldwide suffering from malaria and iron deficiency.

Inclusion criteria

for children with malaria:

• Hemoglobin 7.0 - 9.9 g/dL
• ZPP > = 80 µmol/mol heme
• P. falciparum positive by Giemsa smear or RDT positive
• Temperature ≥ 37.5C or history of fever in past 24 hours

Exclusion criteria

for Children with Malaria:

• Any WHO criterion for severe malaria, including severe anemia, prostration, cerebral malaria, repeated seizures or symptoms like persistent vomiting, high temperature (>39.5°C), or tea-colored urine
• Severe malnutrition, as evidenced by severe wasting or bilateral pitting edema
• Known sickle cell disease
• Acute hemorrhage
• Known cancer or leukemia
• Caregiver does not understand English or Luganda

Inclusion criteria

for Community Children:

• Same neighborhood, extended household or nearby neighborhood of a child with malaria
• Same age group as a child with malaria
• Hemoglobin > = 10.0 g/dL

Exclusion criteria

for Community Children

• Clinical malaria infection or any active illness within the past 4 weeks requiring medical care
• Chronic illness requiring medical care
• Major medical abnormalities on screening history or physical exam, including measured temperature ≥ 37.5°C
• Known developmental delay or neurologic disorder
• Prior history of coma
• Caregiver does not understand English or Luganda
• Other severe illness such as pneumonia or cardiac failure