Abstract:
Background: The safety and effectiveness of iron supplementation in malaria endemic areas
may partly depend on host iron status; however, current methods for assessing iron deficiency
risk tend to be confounded by infection and are infeasible to implement at a population level.
Determining the geographical patterns of iron status and infection may provide a practical
alternative means of identifying high risk populations for whom integrated anaemia and
infection control programs are needed.
Objective: Determine the geo-spatial factors associated with iron status and infection risk among
1943 Ghanaian children (6-35 months of age) before and after participating in a randomized iron
home-fortification trial.
Methods: Secondary spatial analyses of iron status and infection outcomes were conducted. Iron
status was defined as serum ferritin concentration corrected for inflammation (C-reactive
protein, CRP) using a regression-based method. Malaria and non-malaria infection outcomes
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were defined using four combinations of inflammation (CRP >5 mg/L) and malaria parasitaemia
(with and without reported history of fever or concurrent axillary temperature >37.50 C).
Analyses were performed using a geographical information system (GIS) and generalized linear
geostatistical modelling with a Matern spatial correlation function.
Results: After adjusting for demographic characteristics such as age, sex, and maternal
education, none of the geo-spatial factors included in the iron status models (including
elevation, and distance to a health facility) demonstrated associations at baseline or endline;
however, there was significant residual spatial variation across the study area. Conversely,
malaria parasitaemia at baseline was associated with greater distance to a health facility and
lower elevation. These relationships did not remain at endline, nor when infection was defined
using CRP only. Mapping the model outputs showed defined low-risk areas that tended to
cluster around villages, particularly near the District centre.
Conclusions: In a malaria endemic area, geographical location may play a role in the risk of iron
deficiency and infection among children. Iron home-fortification likely alters the spatial risk
profile of malaria and non-malaria infection in this setting, though additional research is needed
to confirm the direction of these relationships
