Age-specific differences in the magnitude of malaria-related anemia during low and high malaria seasons in rural Zambian children

Clement O Acheampong; Maxwell A Barffour; Kerry J Schulze; Justin Chileshe; Ng'andwe Kalungwana; Ward Siamusantu; Keith P West Jr; Amanda C Palmer

doi:10.1002/jha2.243

Age-specific differences in the magnitude of malaria-related anemia during low and high malaria seasons in rural Zambian children

EJHaem. 2021 Jun 4;2(3):349-356. doi: 10.1002/jha2.243. eCollection 2021 Aug.

Authors

Clement O Acheampong¹, Maxwell A Barffour^{1

2}, Kerry J Schulze³, Justin Chileshe⁴, Ng'andwe Kalungwana⁴, Ward Siamusantu⁵, Keith P West Jr³, Amanda C Palmer³

Affiliations

¹ College of Health and Human Services, Public Health Program Missouri State University Springfield Missouri USA.
² University of Missouri School of Medicine Patient Centered Care Learning Center Columbia Missouri USA.
³ Bloomberg School of Public Health, Department of International Health Johns Hopkins University Baltimore Maryland USA.
⁴ Tropical Disease Research Centre Ndola Zambia.
⁵ National Food and Nutrition Commission Lusaka Zambia.

Abstract

Background: Malaria causes anemia by destruction of red blood cells and inhibition of erythropoiesis.

Objective: We assessed whether the magnitude of the malaria-specific effect on anemia differs by age, during low and high malaria seasons.

Method: In rural Zambian children participating in a pro-vitamin A efficacy trial, we estimated differences in the prevalence of anemia (defined as hemoglobin < 110 g/L for children < 60 months. and < 115 g/L in older children) by malaria status and assessed malaria-age interactions. Regression models (with anemia as the outcome) were used to model malaria-age interaction in both the low and high malaria seasons, controlling for potential confounders.

Results: Average age was 68 months at baseline (n = 820 children). In the low malaria season, anemia prevalence was 29% in malaria-negative children and 54% in malaria-positive children (p < 0.001), with no malaria-age interactions (p = 0.44). In the high malaria season, anemia prevalence was 41% in malaria-negative children and 54% in malaria-positive children (p < 0.001), with significant malaria-age interactions (p = 0.02 for anemia). Age-stratified prevalence of anemia in malaria positive versus negative children was 67.0% versus 37.1% (in children < 60 months); 57.0% versus 37.2% (in 60-69 months.); 46.8% versus 37.2% (in 70-79 months.); 37.0% versus 37.3% (in 80-89 months) and 28.0% versus 37.4% (in 90+ months).

Conclusions: Malarial anemia is most severe in younger children, especially when transmission is intense. Anemia control programs must prioritize this vulnerable group.