The World Health Organization says that improved efforts to prevent, detect and treat malaria are allowing several countries to eliminate the disease.Credit: Edwin Remsberg, VWPICS/SPL

The number of malaria infections recorded globally has fallen for the first time in several years, according to the World Health Organization (WHO), which published its annual World Malaria Report on 4 December.

Rising numbers of cases in 2016 and 2017 sparked fears that progress had stalled in the global fight against the mosquito-borne disease. But the WHO estimates that there were 228 million reported cases in 2018, a decrease of around 3 million from the previous year.

This drop can be attributed in large part to fewer cases in southeast Asia (see ‘Malaria in southeast Asia’). The WHO found that, in the past decade, the most marked decline has been in six countries across the Mekong River basin — Cambodia, China, Laos, Myanmar, Thailand and Vietnam.

From 2010 to 2018, malaria cases dropped by 76% in these countries, and malaria-related deaths fell by 95%. In 2018, Cambodia reported zero malaria-related deaths for the first time in the country’s history. India also reported a huge reduction in infections, with 2.6 million fewer cases in 2018 than in 2017.

Source: World Health Organization.

Researchers warn that data on malaria can be inaccurate in countries with poor surveillance systems. Even if the number of officially reported deaths is zero, this doesn’t mean that there are no malaria-related casualties, says Arjen Dondorp, deputy director of the Mahidol Oxford Tropical Medicine Research Unit in Bangkok. However, “malaria cases are definitely going down” in countries such as Cambodia, he adds.

Countries in the Mekong area have made “tremendous progress” in tackling the disease by funding malaria-control programmes and deploying health workers in remote regions to hand out treatments and report new cases, says Abdourahmane Diallo, chief executive of the RBM Partnership to End Malaria, an organization in Geneva, Switzerland, that supports efforts to control and eliminate the disease. He adds that progress in driving down infections is also the result of successful strategies to contain drug-resistant strains of Plasmodium falciparum, the deadliest malaria-causing parasite, which had been spreading across the region.

In other parts of the world, malaria is on the rise. Countries in Africa, for example, reported an increase of 1 million cases from 2017 to 2018, and the continent accounted for almost 94% of global cases and deaths from the disease in 2018. Fragile health-care systems and a lack of funding and infrastructure threaten to undermine the fight against malaria in many areas, says Diallo.

Pedro Alonso, director of the WHO Global Malaria Programme in Geneva, says that, despite the global drop in 2018, malaria cases have stabilized at “unacceptably high numbers” over the past few years. “But this is not a helpless situation,” he says, noting that improved efforts to prevent, detect and treat the disease are allowing several countries to successfully eliminate malaria. The report says that Algeria and Argentina were both certified malaria-free in 2019.