Malaria is a tropical disease caused by a parasite transmitted by the bites of infected female Anopheles mosquitoes. After a period spent in the liver, malaria parasites multiply within red blood cells, causing symptoms such as fever, headache, and vomiting. Malaria is preventable and curable and recently WHO recommended the use of two effective malaria vaccines (RTS,S or R21) for children at risk (WHO, 2023[1]). Still, if left untreated, malaria can become life‑threatening by disrupting the blood supply to vital organs.
As part of the SDG targets, the UN set a goal to end the epidemic of malaria by 2030. After nearly four years of maintaining zero indigenous cases, and after intensive external evaluations including field assessments, Sri Lanka was certified by WHO as malaria-free in September 2016. In 2021, China was certified by WHO as malaria free. To provide technical support to countries aiming to eliminate malaria, WHO developed the Global Technical Strategy for Malaria 2016‑2030 which focuses on: standards, innovation, strategic leadership, and a cross-cutting objective of context-based country support (WHO, 2023[1]).
In 2022, South‑East Asia alone accounted for 2% (5.2 million) of the estimated 249 million malaria cases globally, with 8 000 estimated deaths (WHO, 2023[1]). Although, overall, since 2010 the number of confirmed cases in the countries of the Asia Pacific region herein reported decreased from 3.1 to 1.7 million in 2021, there was an increase in cases in 2022, reporting more than 3.6 million confirmed cases. As seen in Figure 3.28 (left panel), the increase in confirmed cases in 2022 was concentrated in Pakistan, Papua New Guinea, Indonesia and Myanmar. The drastic increase in cases in Pakistan was associated to catastrophic flooding which affected more than 30 million people and more than 1 000 healthcare facilities, which also relates to the increase estimated mortality rate (Figure 3.28, right panel). In Papua New Guinea, most of the increased cases and mortality rates are a result of challenges in the health system and unstable funding (WHO, 2023[1]). The highest mortality rates were seen in Papua New Guinea and the Solomon Islands (Figure 3.28, right panel).
For a balanced understanding, changes in the number of malaria cases should be viewed in parallel with changes in malaria incidence. The number of estimated cases per 1 000 population at risk showed stability in most reporting Asia-Pacific countries and territories from 2020 to 2022, but there was an increase in incidence in Solomon Islands, Myanmar and Pakistan (Figure 3.29, left panel). Although in Myanmar the incidence rate was decreasing from 67.0 per 1 000 population at risk in 2010 to 2.6 in 2020, there was a dramatic increase in the incidence rate to 12.4 in 2022. The increase in Malaria cases in Myanmar was associated to political and social instability in the country, which also impacted in the increase in cases in Thailand, a bordering country.
The number of malaria cases not treated increased to around three out of ten in Papua New Guinea and the Philippines, whereas it decreased significantly to less than one out of ten in Cambodia and Pakistan from 2000 to 2020 (Figure 3.29, right panel). During the same period, the estimated number of malaria cases not treated doubled to one in five in Myanmar, while they remained the same (less than one in ten) in Solomon Islands.
