Implication of asymptomatic and clinical Plasmodium falciparum infections on biomarkers of iron status among school-aged children in Malawi

Abstract

Background Iron status is considered as a continuum from an iron deficiency with anaemia, without anaemia, varying amounts of stored iron to iron overload. The burden of Plasmodium falciparum infections is typically high among school-aged children (SAC). Nonetheless, SAC are often less likely to be covered by malaria interventions, making them a group with an untreated reservoir of parasite transmission. This study aimed to assess the effects of asymptomatic and clinical malaria infections on biochemical markers of iron status among SAC in Malawi. Methods Data from the 2015–2016 Malawi Micronutrient Survey (MNS) was used and multivariable logistic regression models using a generalized estimating equation to account for the complex cluster survey design were constructed. Blood samples of 684 children aged 5 to 14 years old were evaluated for clinical and asymptomatic malaria infections. Furthermore, blood samples were used to estimate haemoglobin (Hb), serum ferritin (SF) and, soluble transferrin receptors (sTfR) concentrations. Results Of the 684 SAC analysed, approximately 42% had asymptomatic malaria, while 41.0% had clinical malaria. Anaemia (low Hb levels), iron deficiency (low SF concentration), and functional iron deficiency (high sTfR levels) were found in 20%, 5%, and 30% of the children, respectively. School-aged children with asymptomatic malaria had increased odds of being anaemic (adjusted odds ratio [aOR]: 3.71, 95% confidence interval [CI]: 2.29–5.99) and increased levels of sTfR (aOR: 3.00, 95% CI 2.01–4.47). Similarly, SAC with clinical malaria had increased odds of being anaemic (aOR: 3.54, 95% CI 2.19–5.72) and increased levels of sTfR (aOR: 3.02, 95% CI 2.02–4.52). Conclusions Both asymptomatic and clinical malaria were independent risk factors for anaemia and functional iron deficiency (FID). The notion that asymptomatic and clinical malaria were associated with both anaemia and FID underscores the need for public health programmers to consider adding mass screening and treatment for malaria to existing school-based health programmes.

Nutrition in chronic inflammatory conditions: Bypassing the mucosal block for micronutrients

“…Likewise, also high-performance athletes due to exercise-induced inflammation and obese people due to the presence of low-grade inflammation are suffering from functional iron deficiency. 275 When suffering from functional iron deficiency, ferritin-levels are normal or elevated ranging from 30-500 μg/L, [276][277][278][279] while transferrin saturation (TSAT) values are below 20% and-dependent on inflammation severity-inflammation markers such as C-reactive protein (CRP; for low-grade inflammation high sensitivity-CRP) or α1-acid glycoprotein (AGP) are elevated. 79 Body iron stores may be adequate in "functional iron deficiency"; however, there are reduced levels of "metabolic active iron" as iron is not accessible.…”

Universal iron supplementation: the best strategy to tackle childhood anaemia in malaria-endemic countries?

“…Infectious disease and helminth infections are another significant cause of iron deficiency at a population level, and so deworming programmes are another important avenue to prevent ID, with a paper by Byrne et al , (2021) demonstrating that deworming using albendazole is associated with significantly raised haemoglobin levels in children 11 . A growing evidence base suggests that malaria contributes to the burden of iron deficiency, with a recent paper by Ntenda et al , (2022) concluding that both asymptomatic and clinical malaria were independent risk factors for anaemia and functional iron deficiency (FID) 71 . Therefore, malaria elimination programmes themselves may be an effective strategy to address ID in malaria-endemic areas 10 .…”

Longitudinal changes in iron homeostasis in human experimental and clinical malaria

“… 8 , 16 However, synthesis of sTfR is also increased by erythropoiesis and haemolysis. Thus, while elevated sTfR levels have been observed in children with malaria, 14 , 17 , 18 whether this reflects a functional iron deficiency, erythropoiesis or haemolysis, remains uncertain.…”