Short-Term Changes in Anemia and Malaria Parasite Prevalence in Children under 5 Years during One Year of Repeated Cross-Sectional Surveys in Rural Malawi.

Alinune N Kabaghe,Martin P Grobusch,Willem Takken,Dianne J Terlouw,Kamija S Phiri,Michèle Van Vugt,Michael G Chipeta,Robert S Mccann

doi:10.4269/ajtmh.17-0335

Abstract

.In stable transmission areas, malaria is the leading cause of anemia in children. Anemia in children is proposed as an added sensitive indicator for community changes in malaria prevalence. We report short-term temporal variations of malaria and anemia prevalence in rural Malawian children. Data from five repeated cross-sectional surveys conducted over 1 year in rural communities in Chikwawa District, Malawi, were analyzed. Different households were sampled per survey; all children, 6–59 months, in sampled household were tested for malaria parasitemia and hemoglobin levels using malaria rapid diagnostic tests (mRDT) and Hemocue 301, respectively. Malaria symptoms, recent treatment (2 weeks) for malaria, anthropometric measurements, and sociodemographic details were recorded. In total, 894 children were included from 1,377 households. The prevalences of mRDT positive and anemia (Hb < 11 g/dL) were 33.8% and 58.7%, respectively. Temporal trends in anemia and parasite prevalence varied differently. Overall, unadjusted and adjusted relative risks of anemia in mRDT-positive children were 1.31 (95% CI: 1.09–1.57) and 1.36 (1.13–1.63), respectively. Changes in anemia prevalence differed with short-term changes in malaria prevalence, although malaria is an important factor in anemia.

Highlights

Plasmodium falciparum malaria infection is a major contributing factor to anemia in African children, with both conditions responsible for high morbidity and mortality.[1]
An inverse relationship between malaria parasite density and hemoglobin level exists in children—increasing parasite density leads to lower hemoglobin levels and increasing anemia prevalence.[8,9]
In stable malaria transmission areas, anemia prevalence/hemoglobin level has been suggested as an additional impact indicator for changes in malaria prevalence.[3,6,14]

Summary

Introduction

Plasmodium falciparum malaria infection is a major contributing factor to anemia in African children, with both conditions responsible for high morbidity and mortality.[1]. Malaria control interventions are intended to reduce malaria-related morbidity and mortality, which is challenging to define and measure in sub-Saharan Africa.[6,7] An inverse relationship between malaria parasite density and hemoglobin level exists in children—increasing parasite density leads to lower hemoglobin levels and increasing anemia prevalence.[8,9] Higher parasite densities are seen in high- than in lowtransmission settings.[10,11,12] Reduction in malaria burden, owed to the scale-up of control efforts, reduces anemia prevalence in children.[3,13] In stable malaria transmission areas, anemia prevalence/hemoglobin level has been suggested as an additional impact indicator for changes in malaria prevalence.[3,6,14] Anemia prevalence is reported to be more sensitive to changes in malaria burden compared with parasite prevalence in longterm surveys.[6,15] High-transmission settings are associated with low parasite density and high hemoglobin levels. As hemoglobin assessment for anemia is affordable and reliable in field surveys, anemia may be a suitable indicator of changes in malaria burden in community surveys

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Conclusion