A new world malaria map: Plasmodium falciparum endemicity in 2010

Abstract

BackgroundTransmission intensity affects almost all aspects of malaria epidemiology and the impact of malaria on human populations. Maps of transmission intensity are necessary to identify populations at different levels of risk and to evaluate objectively options for disease control. To remain relevant operationally, such maps must be updated frequently. Following the first global effort to map Plasmodium falciparum malaria endemicity in 2007, this paper describes the generation of a new world map for the year 2010. This analysis is extended to provide the first global estimates of two other metrics of transmission intensity for P. falciparum that underpin contemporary questions in malaria control: the entomological inoculation rate (PfEIR) and the basic reproductive number (PfR).MethodsAnnual parasite incidence data for 13,449 administrative units in 43 endemic countries were sourced to define the spatial limits of P. falciparum transmission in 2010 and 22,212 P. falciparum parasite rate (PfPR) surveys were used in a model-based geostatistical (MBG) prediction to create a continuous contemporary surface of malaria endemicity within these limits. A suite of transmission models were developed that link PfPR to PfEIR and PfR and these were fitted to field data. These models were combined with the PfPR map to create new global predictions of PfEIR and PfR. All output maps included measured uncertainty.ResultsAn estimated 1.13 and 1.44 billion people worldwide were at risk of unstable and stable P. falciparum malaria, respectively. The majority of the endemic world was predicted with a median PfEIR of less than one and a median PfRc of less than two. Values of either metric exceeding 10 were almost exclusive to Africa. The uncertainty described in both PfEIR and PfR was substantial in regions of intense transmission.ConclusionsThe year 2010 has a particular significance as an evaluation milestone for malaria global health policy. The maps presented here contribute to a rational basis for control and elimination decisions and can serve as a baseline assessment as the global health community looks ahead to the next series of milestones targeted at 2015.

Assessing the impact of next-generation rapid diagnostic tests on Plasmodium falciparum malaria elimination strategies

“…By increasing the sensitivity of the diagnostic tenfold this is increased to an EIR of between 0.5 and 2.5, whereas increasing the sensitivity 100-fold would expand this to an EIR of between 2 and 4. Large areas of southern and eastern Africa have EIR values below 4, indicating that repeated MSAT programmes with a high-sensitivity diagnostic test of the order of 2 parasites per microlitre could be considered as an intervention in these areas 43 . However, the EIR in Burkina Faso is much higher than 4, suggesting that MSAT would not be effective even with a highly sensitive diagnostic test (as confirmed in a recent trial 17,18 ).…”

Alelos mutantes asociados a la resistencia a cloroquina y sulfadoxina-pirimetamina en Plasmodium falciparum de las fronteras Ecuador-Perú y Ecuador-Colombia

“…La malaria es una enfermedad endémica en muchos países tropicales, con formas graves producidas por Plasmodium falciparum (1) . Actualmente, varios de esos países han reducido en más del 75% el número de casos, comparados con el año 2000 (1,2) .…”

“…Actualmente, varios de esos países han reducido en más del 75% el número de casos, comparados con el año 2000 (1,2) . Ello podría deberse a que los esquemas actuales de tratamiento están teniendo éxito en el control de esta enfermedad.…”

Interpreting predictive maps of disease: highlighting the pitfalls of distribution models in epidemiology

“…delivery of adequate supplies of drugs) as described by Gething et al (2011). The types of outputs described above can also provide valuable resources for advocacy purposes, aiding communication to Government bodies, international organisations and the general public.…”