Are malaria elimination efforts on right track? An analysis of gains achieved and challenges ahead

Abstract

Background: Malaria causes significant morbidity and mortality each year. In the past few years, the global malaria cases have been declining and many endemic countries are heading towards malaria elimination. Nevertheless, reducing the number of cases seems to be easy than sustained elimination. Therefore to achieve the objective of complete elimination and maintaining the elimination status, it is necessary to assess the gains made during the recent years.

Main text: With inclining global support and World Health Organisation (WHO) efforts, the control programmes have been implemented effectively in many endemic countries. Given the aroused interest and investments into malaria elimination programmes at global level, the ambitious goal of elimination appears feasible. Sustainable interventions have played a pivotal role in malaria contraction, however drug and insecticide resistance, social, demographic, cultural and behavioural beliefs and practices, and unreformed health infrastructure could drift back the progress attained so far. Ignoring such impeding factors coupled with certain region specific factors may jeopardise our ability to abide righteous track to achieve global elimination of malaria parasite. Although support beyond the territories is important, but well managed integrated vector management approach at regional and country level using scrupulously selected area specific interventions targeting both vector and parasite along with the community involvement is necessary. A brief incline in malaria during 2016 has raised fresh perturbation on whether elimination could be achieved on time or not.

Conclusions: The intervention tools available currently can most likely reduce transmission but clearing of malaria epicentres from where the disease can flare up any time, is not possible without involving local population. Nevertheless maintaining zero malaria transmission and checks on malaria import in declared malaria free countries, and further speeding up of interventions to stop transmission in elimination countries is most desirable. Strong collaboration backed by adequate political and financial support among the countries with a common objective to eliminate malaria must be on top priority. The present review attempts to assess the progress gained in malaria elimination during the past few years and highlights some issues that could be important in successful malaria elimination.

Keywords: Anopheles; Antimalarial resistance; Control programme; Insecticide resistance; Malaria elimination; Plasmodium; WHO region.

Fig. 1

Temporal change in malaria incidences during 2000 to 2015: Country-wise change in number of malaria cases per 1000 people during the years 2000–2015 (Figure taken from www.OurWorldInData.org/malaria; assessed on 15 May 2018)

Fig. 2

Malaria cases in the WHO regions: Malaria burden (× 1000) in WHO regions from 2000 to 2016 (Data taken from WHO, Malaria Report 2017)

Fig. 3

Decline in malaria cases in WHO regions: Percent (%) decrease in malaria cases from 2005 to 2016 in different WHO regions (Data taken from WHO Malaria Report 2017)

Fig. 4

Death percentage to malaria cases: Reported death percentage to malaria cases (2010–2016) in world and WHO regions (data for European Region not included)

Fig. 5

Insecticide resistance status of malaria vectors: Spatial spread of resistance against pyrethroid and/or organophosphate insecticides in major malaria vectors; (a-confirmed resistance marked in red; b-suspected resistance marked in yellow) (Figure taken from IRMapper-www.irmapper.com; assessed on 28 May 2018)

Fig. 6

Prevalence of antimalarial resistance markers: Percent prevalence of potential antimalarial resistance markers in P. falciparum in different endemic countries; (a) pfcrt 76 K/T mutation for chloroquine (data from 1955 to 2018) and (b) kelch 13 mutation for ACT drugs in different WHO regions. (Figure reproduced from WWARN Molecular Surveyor: assessed on 02 Jun 2018)

Fig. 7

Plasmodium vivax burden in some endemic countries: Estimated P. vivax cases in five most vivax malaria endemic countries in the world during the year 2016 (Data taken from WHO Malaria Report, 2017)

Fig. 8

Estimated annual malaria import and export: Average annual malaria cases exported from endemic to non-endemic countries (shown in red) and imported to non-endemic countries from endemic countries (blue) (Figure taken from: Tatem et al., 2017)

Fig. 9

Malaria incidences in E-2020 nations: Malaria cases (× 1000) during 2014–2016 in the WHO assessed malaria eliminating countries (E-2020 countries; assessed to eliminate malaria by 2020) of WHO Regions. (EM: Eastern Mediterranean; SEA: South-East Asia; WP: Western Pacific). (Data taken from WHO Malaria Report, 2017)