The effect of intermittent preventive treatment on anti-malarial drug resistance spread in areas with population movement

Abstract

BackgroundThe use of intermittent preventive treatment in pregnant women (IPTp), children (IPTc) and infant (IPTi) is an increasingly popular preventive strategy aimed at reducing malaria risk in these vulnerable groups. Studies to understand how this preventive intervention can affect the spread of anti-malarial drug resistance are important especially when there is human movement between neighbouring low and high transmission areas. Because the same drug is sometimes utilized for IPTi and for symptomatic malaria treatment, distinguishing their individual roles on accelerating the spread of drug resistant malaria, with or without human movement, may be difficult to isolate experimentally or by analysing data. A theoretical framework, as presented here, is thus relevant as the role of IPTi on accelerating the spread of drug resistance can be isolated in individual populations and when the populations are interconnected and interact.MethodsA previously published model is expanded to include human movement between neighbouring high and low transmission areas, with focus placed on the malaria parasites. Parasite fitness functions, determined by how many humans the parasites can infect, are used to investigate how fast resistance can spread within the neighbouring communities linked by movement, when the populations are at endemic equilibrium.ResultsModel simulations indicate that population movement results in resistance spreading fastest in high transmission areas, and the more complete the anti-malarial resistance the faster the resistant parasite will tend to spread through a population. Moreover, the demography of infection in low transmission areas tends to change to reflect the demography of high transmission areas. Additionally, when regions are strongly connected the rate of spread of partially resistant parasites (R1) relative to drug sensitive parasites (RS), and fully resistant parasites (R2) relative to partially resistant parasites (R1) tend to behave the same in both populations, as should be expected.ConclusionsIn fighting anti-malarial drug resistance, different drug resistance monitoring and management policies are needed when the area in question is an isolated high or low transmission area, or when it is close and interacting with a neighbouring high or low transmission area, with human movement between them.Electronic supplementary materialThe online version of this article (doi:10.1186/1475-2875-13-428) contains supplementary material, which is available to authorized users.

COVID-19 in malaria-endemic regions: potential consequences for malaria intervention coverage, morbidity, and mortality

“…Since 2010, active malaria intervention control strategies have had a positive effect on lowering malaria burden and morbidity in Africa and worldwide. These strategies include the use of long-lasting insecticide-treated nets (ITNs), indoor residual spraying, 4 and timely access to antimalarial drugs, including the use of intermittent preventive treatment aimed at killing forms of the malaria parasite in infected individuals, 5 , 6 , 7 in addition to the other mechanisms aimed at disrupting the transmission of malaria by exploiting the feeding behaviour and gonotrophic and reproductive cycles of mosquitoes. 8 , 9 , 10 , 11 However, despite the progress of the past decade, evidence suggests that the rate of reduction in malaria mortality in the WHO African Region has slowed since 2016, although total deaths due to malaria decreased overall.…”

The Impact of Antimalarial Use on the Emergence and Transmission of Plasmodium falciparum Resistance: A Scoping Review of Mathematical Models

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Antimicrobial Resistance Risks of Cholera Prophylaxis for United Nations Peacekeepers

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