Application of artemisinin-combination therapy (ACT) for malaria cases supplemented by long-lasting insecticide-treated bednets (LLINs) has significantly reduced malaria in Dielmo and helped the Senegalese village reach pre-elimination levels of malaria incidence, according to a study published in the open access journal PLOS ONE.
The combination of ACT and LLINs has led to a decline in malaria cases globally, leading many stakeholders to seek malaria elimination and eventual eradication. But barriers, such as the loss of anti-Plasmodium immunity in some people previously immunized as well as the occurrence of malaria resurgences have slowed control efforts in malaria endemic places.
Dr Amele Nyedzie Wotodjo of Unité de Recherche sur les Maladies Infectieuses et Tropicales Émergentes (URMITE) of Institut de Recherche pour le Développement (IRD) Dakar, Senegal and colleagues conducted a longitudinal study investigating whether universal implementation of LLINs could help the endemic village of Dielmo reach malaria elimination.
Researchers found a significant reduction in malaria prevalence from 26 percent in 2007 to 0.5 percent in 2014, as well as a decline in per-person incidence of malaria after the implementation of LLINs.
Despite the overall decline in malaria cases post-intervention, there were two periods of malaria resurgence during the study period. The first resurgence occurred in 2011, the third year of LLIN implementation, prompting researchers to replace all LLINs. An investigation revealed the LLINs were 60 percent effective despite anopheles resistance to pyrethoid. The second resurgence occurred in 2014; three years after the renewal of LLINs, and the nets were again replaced.
Malaria prevalence remained low during these periods of resurgence due to the fact that almost all patient infections were symptomatic as well as the use of ACT, allowing for rapid diagnosis and treatment of malaria cases. Although these combined interventions have helped Dielmo to control malaria and to reach malaria pre-elimination phase, this research indicates maintaining these pre-elimination levels or reaching elimination requires additional intervention.
Reference: Wotodjo AN, Doucoure S, Gaudart J, Diagne N, Diene Sarr F, Faye N, et al. (2017) Malaria in Dielmo, a Senegal village: Is its elimination possible after seven years of implementation of long-lasting insecticide-treated nets? PLoS ONE 12(7): e0179528. https://doi.org/10.1371/journal.pone.0179528
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