19 July 2019
Mapping malaria’s global impact
Published online 20 June 2019
New maps show progress in the fight against malaria has stalled in some areas of the Middle East.
New high-resolution maps of malaria impact highlight global efforts against the disease, identifying areas, including Yemen and South Sudan, where they need to be focused.
Researchers at the Malaria Atlas Project (MAP) at the University of Oxford, UK, in collaboration with colleagues at the Institute for Health Metrics and Evaluation at the University of Washington, USA, combined a variety of data to generate 5 × 5 kilometre resolution malaria incidence, prevalence and mortality maps for the period from 2000 to 2017. These maps, published in two papers in The Lancet, monitor how malaria, caused by the parasites Plasmodium falciparum and Plasmodium vivax, has evolved over time and space. Previous global maps have focused on a single year.
The deadliest of five human malaria species, P. falciparum, is mainly present in sub-Saharan Africa, where more than 90 per cent of the population were at risk of infection in 2017. The number of new clinical cases and deaths caused by P. falciparum malaria fell globally by around 28 and 42 per cent respectively between 2005 and 2017.
While the malaria burden caused by P. falciparum declined, the proportion of cases caused by P. vivax rose. P. vivax is the most geographically widespread malaria species, but monitoring this parasite is not often part of standard practices. The number of people who contracted it decreased from 24.5 million in 2000 to fewer than 14 million in 2017. However, the findings of the last five years of the study period show that not all regions demonstrated progress against malaria, which was even reversed in Afghanistan, Yemen and Somalia.
“There has been a general downward trend for malaria burden in the Middle East for the study period, and progress within the last five years has been limited, with South Sudan losing ground since 2013,” says Daniel J. Weiss, Director of Global Malaria Epidemiology team at the MAP.
“In Yemen, P. vivax malaria incidence has been rising since 2015. In Sudan, data and model predictions showed a small rise in 2015, that has since fallen; whereas currently there is not enough data to quantify malaria incidence in South Sudan,” adds Katherine Battle, director of MAP’s Malaria Mapping for Elimination.
The maps are a tool to identify priority areas, a guide for policymakers, and a baseline to evaluate future anti-malaria strategies.
- Weiss, D. J., et al. Mapping the global prevalence, incidence, and mortality of Plasmodium falciparum, 2000–17: A spatial and temporal modelling study. The Lancet http://dx.doi.org/10.1016/ S0140-6736(19)31097-9 (2019).
- Battle, K. E., et al. Mapping the global endemicity and clinical burden of Plasmodium vivax, 2000–17: A spatial and temporal modelling study. The Lancet http://dx.doi.org/10.1016/ S0140-6736(19)31096-7 (2019).