Ranking of elimination feasibility between malaria-endemic countries

Abstract

Experience gained from the Global Malaria Eradication Program (1955-72) identified a set of shared technical and operational factors that enabled some countries to successfully eliminate malaria. Spatial data for these factors were assembled for all malaria-endemic countries and combined to provide an objective, relative ranking of countries by technical, operational, and combined elimination feasibility. The analysis was done separately for Plasmodium falciparum and Plasmodium vivax, and the limitations of the approach were discussed. The relative rankings suggested that malaria elimination would be most feasible in countries in the Americas and Asia, and least feasible in countries in central and west Africa. The results differed when feasibility was measured by technical or operational factors, highlighting the different types of challenge faced by each country. The results are not intended to be prescriptive, predictive, or to provide absolute assessments of feasibility, but they do show that spatial information is available to facilitate evidence-based assessments of the relative feasibility of malaria elimination by country that can be rapidly updated.

Figure 1

Categorical map of Plasmodium falciparum reproductive number, PfR_c, indicating the extent to which transmission needs to be reduced for elimination Map highlights areas that would require transmission reductions of less than 50% (PfR_c 1–10), 50–90% (PfR_C 10–50), 90–99% (PfR_C 50–100), or greater than 99% (PfR_c>100) to eliminate P falciparum malaria. Unstable transmission is as defined in reference 11.

Figure 2

Quintiles of relative elimination feasibility rankings between malaria-endemic countries (A) Mapped quintiles of mean rankings for Plasmodium falciparum relative technical feasibility. (B) Mapped quintiles of mean rankings for P falciparum relative operational feasibility. (C) Mapped quintiles of mean rankings for Plasmodium vivax relative operational feasibility. (D) Mapped quintiles of mean rankings for P falciparum overall relative elimination feasibility. In each map, the dark red sections and largest numbers represent the lowest feasibility.

Figure 3

A scatterplot of the mean rankings for estimated Plasmodium falciparum relative technical feasibility versus those for P falciparum relative operational feasibility The positioning of countries on the plot highlights the ranking defined different challenges faced relative to other countries. Low mean rank values equate to countries being more feasible than others, whereas high values represent low feasibility. DR=Democratic Republic. *Country that has declared a national policy for malaria elimination or is persuing spatially progressive elimination within its borders.