Trends of the global, regional and national incidence of malaria in 204 countries from 1990 to 2019 and implications for malaria prevention.

BACKGROUND: Malaria is a life-threatening disease worldwide, but lacks studies on its incidence at the global level. We aimed to describe global trends and regional diversities in incidence of malaria infection, to make global tailored implications for malaria prevention.
METHODS: We used the data from the Global Burden of Disease Study 2019. The age-standardized incidence rate (ASR) and absolute number of malaria episodes showed the epidemic status of malaria infection. The estimated annual percentage change of ASR and changes in malaria episodes quantified the malaria incidence trends. The connection between ASRs and traveller number indicated infection risk for travellers.
RESULTS: Globally, the malaria ASR decreased by an average 0.80% (95% confidence interval 0.58-1.02%) per year from 1990 to 2019; however, it slightly increased from 3195.32 per 100 000 in 2015 to 3247.02 per 100 000 in 2019. The incidence rate of children under 5 was higher than other age groups. A total of 40 countries had higher ASRs in 2019 than in 2015, with the largest expansion in Cabo Verde (from 2.02 per 100 000 to 597.00 per 100 000). After 2015, the ASRs in high-middle, middle and low-middle Socio-demographic Index regions began to rise and the uptrends remained in 2019. Central, Western and Eastern Sub-Saharan Africa had the highest ASRs since 1990, and traveller number in Eastern and Western Sub-Saharan Africa increased by 31.24 and 7.58%, respectively, from 2017 to 2018. Especially, most countries with ASR over 10 000 per 100 000 had increase in traveller number from 2017 to 2018, with the highest change by 89.56% in Mozambique.
CONCLUSIONS: Malaria is still a public health threat for locals and travellers in Sub-Saharan Africa and other malaria-endemic areas, especially for children under 5. There were unexpected global uptrends of malaria ASRs from 2015 to 2019. More studies are needed to achieve the goal of malaria elimination. © International Society of Travel Medicine 2021. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.