Analysing the nutrition-disease nexus: the case of malaria

Abstract

BackgroundMotivated by the observation that children suffering from undernutrition are more likely to experience disease and are more likely to die if they do contract a disease, mathematical modelling is used to explore the ramifications of targeting preventive disease measures to undernutritioned children.MethodsA malaria model is constructed with superinfection and heterogeneous susceptibility, where a portion of this susceptibility is due to undernutrition (as measured by weight-for-age z scores); so as to isolate the impact of supplementary food on malaria from the influence of confounding factors, the portion of the total susceptibility that is due to undernutrition is estimated from a large randomized trial of supplementary feeding. Logistic regression is used to estimate mortality given malaria infection as a function of weight-for-age z scores. The clinical malaria morbidity and malaria mortality are analytically computed for a variety of policies involving supplementary food and insecticide-treated bed nets.ResultsThe portion of heterogeneity in susceptibility that is due to undernutrition is estimated to be 90.3 %. Targeting insecticide-treated bed nets to undernutritioned children leads to fewer malaria deaths than the random distribution of bed nets in the hypoendemic and mesoendemic settings. When baseline bed net coverage for children is 20 %, supplementary food given to underweight children is estimated to reduce malaria mortality by 7.2–22.9 % as the entomological inoculation rate ranges from 500 to 1.0. In the hyperendemic setting, supplementary food has a bigger impact than bed nets, particularly when baseline bed net coverage is high.ConclusionsAlthough the results are speculative (e.g., they are based on parameter estimates that do not possess the traditional statistical significance level), the biological plausibility of the modelling assumptions and the high price-sensitivity of demand for bed nets suggest that free bed net distribution targeted to undernutritioned children in areas suffering from both undernutrition and malaria (e.g., sub-Saharan Africa) should be the subject of a randomized trial in a hypoendemic or mesoendemic setting.Electronic supplementary materialThe online version of this article (doi:10.1186/s12936-015-0894-x) contains supplementary material, which is available to authorized users.

Beyond causes of death: The social determinants of mortality among children aged 1-59 months in Nigeria from 2009 to 2013

“…Children in the 24–59 month age group have lost their passive immunity [ 22 ], and in the North, most of these children were born to poor families and, therefore, more likely to have a living situation with inadequate sanitation, unhygienic practices, many other children, and overcrowding, all of which might increase their risk of exposure to infectious agents [ 27 , 28 ]. Additionally, people of low socioeconomic status may not be able to afford nutritious food, and inadequate nutrition has been recognized to suppress the immune system’s ability to fight off infections [ 29 ]. Data suggest that despite the Expanded Program on Immunization’s impact on child health, the burden of vaccine-preventable diseases, particularly in the most vulnerable infants, has remained high [ 30 ].…”

Does anthropometric status at 6 months predict the over-dispersion of malaria infections in children aged 6–18 months? A prospective cohort study

“…Such platforms can be useful for malaria screening especially in malaria hypoendemic or mesoendemic settings where targeting malaria interventions to undernourished children has potential to reduce malaria morbidity and mortality [57]. In this setting, socio-economic factors such as household asset scores, maternal education, and food insecurity were significantly associated with malaria.…”