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Progress and Challenges in the Global Fight Against Malaria
The battle against malaria is witnessing both advancements and setbacks as the world strives towards eradicating this age-old disease. Presently, 44 countries, alongside La Réunion, have been certified as malaria-free, a significant milestone in the global campaign against the illness. Notably, Egypt was recently added to this list, marking a remarkable achievement given that malaria has plagued the region since the times of the pharaohs.
According to a report released by the World Health Organization (WHO) on December 11, the period from 2000 to 2023 saw an estimated 2.2 billion malaria cases and roughly 12.7 million deaths prevented. However, despite this progress, the fight against malaria is far from over.
Recent developments indicate an alarming rise in malaria cases, with 11 million additional cases reported in 2023 compared to the previous year. The majority of these cases occurred in Africa, where malaria continues to claim lives, particularly among vulnerable children. In 2023, approximately 597,000 fatalities due to malaria were recorded worldwide, showing a slight decrease from 600,000 in 2022.
The Urgent Call for Action
The WHO has set an ambitious target to reduce malaria deaths by 75 percent by 2025, using 2015 data as a benchmark. This goal translates to 5.5 deaths per 100,000 individuals at risk. Unfortunately, data from 2023 shows the death rate at 13.7 per 100,000, more than double the intended target. Additionally, the incidence rates of malaria are nearly triple the global objective.
Jane Carlton, a geneticist and director of the Johns Hopkins Malaria Research Institute, highlights the persistent nature of malaria, stating, “It’s been around for a very long time and that’s because it’s so challenging to try and get rid of.”
Key Challenges in Malaria Eradication
A major hurdle in controlling malaria is the evolution of the malaria parasite itself. Carlton notes that the parasite displays remarkable adaptability, developing resistance to nearly every treatment that has been deployed against it.
Currently, there is troubling evidence of partial resistance to artemisinin, a primary treatment drug, with confirmed cases in Eritrea, Rwanda, Uganda, and Tanzania. Furthermore, the WHO has indicated that resistance may also be emerging in Ethiopia, Namibia, Sudan, and Zambia. William Moss, a pediatric infectious diseases expert, expresses concern over the implications of losing effective treatments, which could significantly hinder progress in the fight against malaria.
In addition to drug resistance, the malaria parasite has exhibited genetic changes that affect diagnostic methods. Reports show that in 41 malaria-endemic countries, parasites are missing a key gene linked to rapid diagnostic tests.
Another worrying trend is the rise of Plasmodium knowlesi, a malaria parasite that originally primarily infected monkeys but is now increasingly infecting humans, with reported cases rising from 2,768 in 2022 to 3,290 in 2023.
Mosquitoes, the primary vectors of malaria, are also evolving. Between 2018 and 2023, 55 countries have reported mosquitoes that exhibit resistance to pyrethroid insecticides commonly used in bed nets. Additionally, the invasive Anopheles stephensi species has been detected in eight African countries, raising concerns over urban transmission risks, as this species thrives in city environments.
Moreover, climate change exacerbates malaria’s spread, with extreme weather patterns contributing significantly to case numbers. For example, following severe flooding in Pakistan in 2022, malaria cases surged from 506,000 in 2021 to 4.3 million the following year. Projections suggest that climate change could lead to an additional 550,000 malaria-related deaths globally between 2030 and 2049.
Human factors, such as political instability, armed conflict, and fragile healthcare systems, further complicate efforts to control malaria. Countries with robust health systems have shown promise in reducing malaria incidence, whereas those facing turmoil continue to struggle considerably.
Promising Advances in Malaria Control
Despite the challenges, there are promising developments in malaria prevention and treatment strategies. New malaria vaccines are being rolled out, offering hope for significant reductions in mortality, especially among young children. From 2019 through 2023, about 2 million children in Ghana, Kenya, and Malawi received the RTS,S/AS01 vaccine, which is associated with reduced mortality rates and hospitalizations due to severe malaria.
Genetically modified mosquitoes that could potentially reduce or even eliminate malaria-carrying mosquito populations are also on the horizon, although further research and regulatory approvals are needed before they can be deployed. Carlton mentions the potential benefits of “gene-drive” mosquitoes, which could pass on genes that confer sterility or resistance to the malaria parasite, creating a population that eventually cannot propagate the disease.
Enhanced bed nets incorporating various insecticides are being more widely distributed as a response to insect resistance issues, while seasonal malaria prevention treatments for children are gaining traction. In 2023, around 53 million children received these treatments, a substantial increase from just 170,000 in 2012, with Nigeria making significant strides in treatment administration.
Additionally, a growing number of African countries are providing malaria prevention treatments for pregnant individuals. Despite the 44 percent coverage achieved in 2023, there remains a pressing need to meet the target of 80 percent for eligible pregnant women and girls.
As the global community continues its efforts to combat malaria, a multifaceted strategy that addresses both biological and social challenges will be crucial in making further headway against this persistent public health threat.
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www.sciencenews.org