The World Health Organization (WHO) recently released the World Malaria Report 2022, highlighting progress, challenges and opportunities towards global malaria elimination. The report reveals that in 2021, approximately 247 million people worldwide got infected with malaria, and 619,000 died of the disease. Sub-Saharan Africa accounted for 95% of new infections, an estimated 234 million cases, and 96% of deaths globally, estimated at 593,000. Four in five malaria deaths in the region were children under five, and four countries – Nigeria (31%), the Democratic Republic of the Congo (13%), the Niger (4%) and the United Republic of Tanzania (4%) – accounted for almost half of the malaria deaths globally.
In 2021, countries in the WHO African Region did not meet milestones set by the Global technical strategy for malaria 2016–2030 (GTS). The countries were off track for morbidity and mortality milestones by 45% and 47%, respectively. The GTS seeks to reduce the incidence of malaria cases and the mortality rate from a baseline of 2015 by at least 75% by 2025 and 90% by 2030. These targets will not be met globally if the current trends continue.
Challenges and threats to malaria control
The COVID-19 pandemic continued to have an impact on malaria control efforts, with 63,000 deaths between 2019 and 2021 attributed to its disruption of essential services. This added to other challenges facing control efforts, including reductions in the effectiveness of the main malaria prevention measures, the increasing resistance to antimalarial drug regimens, the invasion of Anopheles stephensi into sub-Saharan Africa, and the declining effectiveness of diagnostic tests.
Insecticide-treated bed nets (ITNs), which are Africa’s primary methods for vector control, are declining in their effectiveness due to several factors such as the vector’s resistance to current insecticides used, limited physical and chemical durability of nets, and species biting and resting behaviours. The second most widely implemented vector control intervention, indoor residual spraying (IRS), also shows declining effectiveness.
Given the region’s heavy reliance on artemisinin-based combination therapies (ACTs), there is growing concern regarding the appearance of artemisinin partial resistance in certain parts of sub-Saharan Africa, as well as worrying signals with respect to partner drugs. Nevertheless, ACTs continue to be efficacious, and the WHO has taken proactive steps to address this threat by launching a strategy in November 2022 focused on combatting antimalarial drug resistance in Africa through strengthening surveillance, better diagnostics, containing the spread, and stimulating research on malaria control tools.
The WHO also launched an initiative in September 2022 to contain the spread of An. stephensi across the continent and eradicate it from invaded areas. The mosquito transmits P. falciparum and P. vivax parasites, is resistant to many insecticides, and can thrive in urban environments. An. stephensi‘s invasion has caused alarm because it is considered to be responsible for at least one malaria outbreak in Ethiopia and the return of malaria in Djibouti city.
Mutations of P. falciparum parasites have resulted in rapid diagnostic tests (RDTs) increasingly being unable to detect malaria through proteins the parasites previously expressed. This is putting in jeopardy a reliable means to diagnose malaria in primary healthcare settings.
Research and development for malaria elimination
Research and development (R&D) has been critical in accelerating the progress towards malaria elimination in sub-Saharan Africa. Thanks to tools such as ITNs, ACTs and RDTs, two billion global malaria cases and 11.7 million global malaria deaths were averted between 2000 and 2021, with the WHO African Region accounting for 82% of averted cases and 95% of averted deaths. R&D is now more crucial than ever to address mosquito and parasite resistance to current interventions by bringing to the market a new generation of insecticides, non-ACT therapies, and diagnostic tests, as well as understanding species’ adaptive behaviours.
Despite this need for R&D, there is significant shortage of its funding and malaria control in general. Funding for basic research and product development in 2021 was US$626 million, the third consecutive year of funding decline since its peak in 2018, and falling short of the annual estimate of US$851 million needed to achieve GTS targets. In 2021, US$3.5 billion was invested in malaria control and eradication efforts, also falling short of the US$7.3 billion needed in the year to reach GTS milestones. Through the Global Fund to Fight AIDS, Tuberculosis, and Malaria (Global Fund), more than 40% of global investments in malaria were made in 2021. And though the largest replenishment in Global Fund history occurred in September 2022, when countries and partners raised a total of US$15.9 billion, this still fell short of the US$18 billion target. These shortfalls will have a negative impact on delivering malaria control interventions as the cost of health commodities continually rise as a result of the pandemic, conflict, and global economic downturn.
The WHO guidelines published in June 2022 highly recommends that countries optimise the scarce malaria resources and other resources from the health system by choosing the best combination of interventions most suitable for their contexts. Other malaria tools are being created or rolled out to combat the disease.
In October 2021, the WHO recommended the RTS,S malaria vaccine for young children to prevent P. falciparum malaria in areas of moderate to high transmission. A scientific development group was convened in November 2021 by the WHO Good Manufacturing Practices team and the Immunization, Vaccines and Biologicals department to work on preferred product characteristics and clinical development issues related to monoclonal antibodies (mAbs) for the prevention of malaria. Regional bodies such as the African Union have recommended the future use of gene drives as a potential tool to complement current interventions.
Equity in and access to quality health care, however, are vital in the fight against malaria. Delays in treatment and ineffective treatments due to poverty and ill-equipped primary healthcare centres continue to impact malaria outcomes, particular the deaths of children from the disease. The overall health system is closely linked to the fight against malaria, and an effective malaria response depends on investments in functional, equitable, and resilient health systems.
Read the full report here.