The WHO’s annual World Malaria Report explores the intersection of climate change and malaria, revealing that climate variations impact Anopheles mosquitoes and disease transmission. Extreme weather events escalate malaria burdens, and climate-induced factors like population displacement and malnutrition contribute to its spread. Climate change, alongside conflicts and resource constraints, undermines global malaria progress, with 2022 witnessing 249 million cases, surpassing pre-COVID-19 estimates.
The report highlights progress with the first WHO-recommended malaria vaccine, RTS,S/AS01, reducing childhood deaths by 13% in Ghana, Kenya, and Malawi. The introduction of a second vaccine, R21/Matrix-M, promises broad-scale intervention. Despite achievements, challenges persist, emphasizing the need for enhanced resources, data-driven strategies, and resilient responses amid climate threats to achieve a malaria-free world.
Trends in the Burden of Malaria
Malaria Cases:
- In 2022, there were 249 million malaria cases globally, a 5 million increase from 2021.
- Major contributors to the rise were Pakistan, Ethiopia, Nigeria, Uganda, and Papua New Guinea.
- The WHO African Region accounted for 94% of global cases, with 233 million cases in 2022.
- Malaria case incidence was 58 per 1000 population at risk in 2022.
- P. vivax cases decreased from 8% in 2000 to 3% in 2022.
- Nigeria, the Democratic Republic of the Congo, Uganda, and Mozambique contributed to half of all cases globally.
Regional Breakdown:
- In the WHO South-East Asia Region, malaria cases declined by 76% from 2000 to 2022.
- India accounted for 66% of cases in the region in 2022.
- Malaria cases in the WHO Eastern Mediterranean Region increased by 92% from 2015 to 2022.
- The WHO Region of the Americas saw a 64% decline in cases, with Venezuela contributing to recent fluctuations.
- The WHO European Region has been malaria-free since 2015.
Malaria Deaths:
- Global malaria deaths declined from 864,000 in 2000 to 608,000 in 2022.
- Malaria deaths in the WHO African Region decreased from 808,000 in 2000 to 580,000 in 2022.
- Nigeria, the Democratic Republic of the Congo, Niger, and the United Republic of Tanzania accounted for over half of global deaths in 2022.
- The WHO South-East Asia Region saw a 77% decrease in malaria deaths from 2000 to 2022.
- The WHO Eastern Mediterranean Region experienced a 45% decline in deaths from 2000 to 2014, then a doubling by 2022.
- The WHO Region of the Americas witnessed a 63% reduction in deaths from 2000 to 2022.
Malaria Cases and Deaths Averted:
- Globally, an estimated 2.1 billion malaria cases and 11.7 million deaths were averted from 2000 to 2022.
- Most averted cases (82%) and deaths (94%) were in the WHO African Region.
Burden of Malaria in Pregnancy:
- In 2022, 36% of 35.4 million pregnancies in 33 African countries were exposed to malaria.
- Without intervention, an estimated 914,000 neonates with low birthweight were expected; current intermittent preventive treatment during pregnancy (IPTp) coverage reduced this to 393,000.
- Improved IPTp coverage could avert additional low birthweights.
Malaria Elimination and Prevention:
- Countries with fewer than 10 indigenous cases increased from 4 in 2000 to 25 in 2022.
- Three countries – Azerbaijan, Belize, and Tajikistan – were certified malaria-free in 2023.
- P. knowlesi cases decreased globally, but Malaysia remained a significant contributor.
- The Greater Mekong subregion reported a surge in indigenous malaria cases in 2022.
- Challenges related to migrants and border areas impact E-2025 countries.
Prevention of Re-establishment:
- Some E-2025 countries faced challenges with migrants and border areas.
- Bhutan, Saudi Arabia, and Suriname actively prevent the reintroduction of indigenous cases.
- The Islamic Republic of Iran experienced a resurgence of indigenous cases after 5 years of zero local transmission.
- WHO is developing guidance for the prevention of re-establishment.
Investments in Malaria Programs and Research
The Global Technical Strategy (GTS) outlines funding requirements for malaria, estimating $6.8 billion (2020), $9.3 billion (2025), and $10.3 billion (2030). An additional $0.85 billion annually is needed for global malaria research and development (R&D) from 2021 to 2030.
In 2022, total funding for malaria control and elimination was $4.1 billion, up from $3.5 billion in 2021 but still below the estimated $7.8 billion globally for GTS targets. The funding gap widened from $2.3 billion in 2018 to $3.7 billion in 2022. Funding reached only 52% of GTS targets in 2022.
Between 2010 and 2022, 66% of malaria funding came from international sources. The United States, France, Germany, and the UK were major contributors. Malaria-endemic countries contributed over $1.5 billion in 2022, a notable increase. Internationally sourced funding in 2022 was almost $2.6 billion, with 39% channeled through the Global Fund.
Low-income countries received 44% of total funding in 2022, and lower-middle-income countries received 43%. Funding per person at risk varied across WHO regions, with an increase in the WHO African Region. In 2022, 80% of the $4.1 billion invested went to the WHO African Region, with other regions receiving smaller percentages.
The global economy showed positive growth in 2022, with low- and middle-income countries rebounding. However, ongoing COVID-19 efforts and geopolitical tensions may impact resource allocation and healthcare spending. Health care expenses were burdensome, with 47% of households in low- and middle-income countries experiencing catastrophic costs in 2020.
Progress Towards GTS Milestones of 2020
The Global Technical Strategy (GTS) aimed for a 40% reduction in malaria case incidence and mortality by 2020. However, global trends suggest that GTS 2025 targets might not be met. In 2022, the global malaria case incidence was 55% higher than the expected GTS 2025 morbidity milestone. Mortality rates were 53% higher than the expected GTS 2025 milestone.
Of 93 malaria-endemic countries in 2015, 24.7% are on track for the GTS 2025 morbidity milestone, 26% made some progress, 27% experienced increased case incidence, and 16% had a significant increase in incidence.
Climate Change, Malaria, and the Global Response
The World Health Organization (WHO) has identified climate change as the most significant health threat humanity faces, emphasizing its potential to exacerbate existing health challenges and widen inequalities. This overview explores the complex interplay between climate change and malaria transmission, recognizing climate change as a major multiplier of threats to global health.
Climate change introduces more extreme and frequent weather events, such as flooding and droughts, impacting malaria transmission. Temperature, rainfall, and humidity influence factors like larval development, mosquito survival, and parasite development, collectively affecting the intensity of malaria transmission. The effects are non-linear, varying across contexts depending on factors like malaria control efforts, socioeconomic development, and environmental management.
While data limitations and parallel determinants complicate assessing climate change’s impact on malaria, long-term data from African highland areas suggest rising temperatures have expanded malaria’s geographical reach. Recent instances, such as extreme monsoon rainfall in Pakistan in 2022-2023, link climate change to intensified malaria epidemics.
A study commissioned by WHO underlines the potential future trajectories of malaria under various intervention, socioeconomic, and climate change scenarios. The analysis, considering shared socioeconomic pathways (SSPs), suggests that, under a moderate climate scenario (SSP2), with current intervention levels, malaria incidence might decrease. Scaling up interventions and maintaining predicted environmental and socioeconomic changes could lead to substantial reductions in malaria incidence.
In response to the climate change threat, proposed strategic actions include a dual focus on malaria eradication and reducing overall climate change vulnerability, emphasizing common narratives and partnerships. Technical actions involve producing climate change–health nexus information, enhancing climate-resilient health systems, and offering guidance for surveillance. Operational actions stress using climate and disease data for decision-making, establishing robust epidemic response systems, and building national capacities.
Despite the ongoing debate about the direction and magnitude of climate change’s impact on malaria, the report advocates for sustainable and resilient malaria responses. The focus is on strategic, technical, and operational actions aimed at eradicating malaria, mitigating biological threats, and developing climate-resilient health systems.
Acknowledging malaria eradication as crucial, the report emphasizes the need for investments in research on climatic influences, effective communication, and reducing the health sector’s carbon footprint. Products and interventions must adapt to a changing climate, considering heat stability and environmental impact.
The commitment to the Green Climate Fund should extend to malaria, recognizing the broader climate mitigation required beyond reducing emissions. Building resilience in malaria responses demands increased financing, local data utilization, and dynamic, subnational interventions.
This condensed summary aims to capture the key aspects of the comprehensive report on climate change, malaria, and the global response.
What the Report Says About India
India has demonstrated significant progress in the fight against malaria, as outlined in the recently released World Malaria Report. The report reveals a substantial decline in malaria cases and deaths in India, with an estimated 33.8 lakh cases and 5,511 deaths in 2022, reflecting a 30% reduction in incidence and a 34% decrease in mortality compared to the previous year.
India’s success is part of a larger trend in the WHO South East Asian region, which remains on track to achieve the 2030 target of reducing malaria cases and deaths by 90%. This positive trajectory is noteworthy amid a global pattern of increasing malaria incidence over the past decade, with a spike of 11 million cases in 2020 and a further 5 million in 2022, totaling 249 million cases globally.
The report attributes India’s achievements to several key factors. A focus on providing primary healthcare to remote areas, backed by digital data for surveillance, has played a crucial role. Additionally, effective tools for mosquito population control, point-of-care tests for quick diagnosis, and adept management of malaria cases have contributed to the declining numbers. Urbanization, by reducing mosquito breeding grounds, has also played a role in lowering malaria incidence.
Investments in insecticide mosquito nets, antimalarial drugs, and point-of-care tests have been instrumental in India’s success. Furthermore, the country’s preparedness in handling extreme weather events, such as cyclones, has contributed to a reduction in malaria associated with these events. States like Odisha, which regularly face cyclones, are now well-prepared to manage such situations.
Climate change poses a significant concern for the spread of malaria, given the sensitivity of the malaria parasite and mosquito to temperature, humidity, and rainfall. Experts warn that rising temperatures, especially in the Himalayan belt, may create new areas suitable for the disease. High-risk zones may emerge in states experiencing periodic heavy rainfall. The report
emphasizes the need for planning malaria interventions to account for extreme weather events.
The report also highlights the importance of improved surveillance as cases decrease. With fewer reported cases, finding and treating scattered cases become challenging. Real-time digital data is crucial for local administrations to plan interventions effectively.
Despite India’s progress, challenges persist, including drug resistance, insecticide resistance, and gene deletions in parasites making diagnosis difficult. The prevalence of vivax malaria, which requires a 14-day course of therapy, presents another challenge as patients often discontinue treatment once they feel better.
To achieve the malaria elimination target by 2030, experts stress the importance of strengthening surveillance, tailoring interventions at the sub-national level based on data, updating policies, and adopting new tools aligned with WHO guidance. The last mile in the fight against malaria, characterized by scattered cases and emerging challenges, requires a comprehensive and data-driven approach
References:
https://indianexpress.com/article/explained/explained-health/world-malaria-report-india-9051244/
https://www.who.int/publications/i/item/9789240086173
https://www.thehindu.com/sci-tech/health/in-2022-india-accounted-for-66-of-malaria-cases-in-who-south-east-asia-region-world-malaria-report/article67597371.ece
https://health.economictimes.indiatimes.com/news/industry/world-at-risk-of-losing-malaria-fight-as-cases-rise-report-says/105645277