Dr. Frankline SEVIDZEM WIRSIY
Associate Director | Global Public Health and Development | Africa
Malaria is a significant public health and development challenge. The African Region carries a disproportionately high share of the global malaria burden. In 2021, World Health Organization (WHO) reported that the Region was home to 95% of malaria cases and 96% of malaria deaths. Children under 5 accounted for about 80% of all malaria deaths in the Region. Climate change is expected to have significant impacts on the transmission of malaria in Africa. Malaria is a mosquito-borne disease, and its transmission is influenced by various climatic factors that affect both the mosquito vectors and the development of the Plasmodium parasite within the mosquitoes. Only infective female Anopheles mosquitoes can transmit malaria and they must have been infected through a previous blood meal taken from an infected person.
[Note: Four kinds of malaria parasites infect humans: Plasmodium falciparum, P. vivax, P. ovale, and P. malariae. In addition, P. knowlesi, a type of malaria that naturally infects macaques in Southeast Asia, also infects humans, causing malaria that is transmitted from animal to human (“zoonotic” malaria). P. falciparum is the type of malaria that is most likely to result in severe infections and if not promptly treated, may lead to death].
Here are some of the key ways in which climate change influences malaria transmission in Africa:
i. Temperature Increase: As temperatures rise due to climate change, the geographic range of infective female Anopheles mosquitoes, is likely to expand. Warmer temperatures can speed up the development of the Plasmodium parasite within the mosquito, leading to increased transmission rates.
ii. Changes in Rainfall Patterns: Climate change is expected to alter rainfall patterns in many regions of Africa. In some areas, this may lead to more frequent and intense rainfall events, creating more breeding sites for mosquitoes. On the other hand, droughts can also create temporary pools of stagnant water that serve as breeding grounds for mosquitoes. These changes can result in fluctuations in malaria transmission rates.
iii. Altered Seasonality: Changes in temperature and rainfall can disrupt the seasonal patterns of malaria transmission. In some areas, transmission seasons may lengthen, while in others, they may become more unpredictable. These changes can affect the timing and intensity of malaria outbreaks.
iv. Altitude Shifts: With rising temperatures, mosquitoes may be able to survive at higher altitudes than before. As a result, areas that were previously considered malaria-free due to cooler temperatures may become susceptible to malaria transmission.
v. Human Behavior and Migration: Climate change-induced disruptions to agriculture, water resources, and ecosystems can lead to changes in human behavior and migration patterns. For instance, people may be forced to move to new areas in search of resources, potentially bringing malaria parasites to previously unaffected regions and contributing to the spread of the disease.
vi. Impact on Vector Control Efforts: Climate change can influence the effectiveness of vector control measures, such as insecticide-treated bed nets and indoor residual spraying. For example, altered mosquito behavior, such as changes in feeding and resting patterns, may reduce the efficacy of these interventions.
The best available strategies for mitigating the impact of malaria transmission from climate change in Africa: Mitigating the impact of malaria transmission via climate change in Africa requires a multi-faceted approach that involves a combination of health interventions, environmental management, and community engagement.
Here are some of the best available strategies:
1. Enhanced Surveillance and Early Warning Systems: Improving malaria surveillance and establishing early warning systems can help identify areas at risk of malaria outbreaks due to climate change. Timely data collection and analysis can facilitate targeted interventions and resource allocation to high-risk regions.
2. Vector Control: Implementing effective vector control measures is crucial to reducing malaria transmission. This includes the distribution of insecticide-treated bed nets, indoor residual spraying with insecticides, and larval source management to target mosquito breeding sites.
3. Climate-Resilient Health Systems: Strengthening health systems to be more climate-resilient can improve preparedness and response to malaria outbreaks. This involves training health workers to recognize and manage climate-related health risks and ensuring the availability of necessary medical supplies and treatments.
4. Environmental Management: Promoting environmental management practices can help reduce mosquito breeding sites. This includes drainage improvement, proper waste management, and avoiding the creation of standing water, which serves as mosquito breeding grounds.
5. Community Engagement and Education: Engaging communities in malaria prevention and control efforts is vital. Educating individuals about the importance of using mosquito nets, seeking early treatment, and understanding climate-related risks can empower them to take appropriate actions to protect themselves.
6. Research and Innovation: Encouraging research and innovation in malaria control can lead to the development of new tools and approaches to combat the disease. This includes researching new insecticides, drugs, vaccines, and novel vector control methods like gene drive technology. As a success story, the RTS,S/AS01 vaccine has been administered to more than 1.7 million children in Ghana, Kenya, and Malawi since 2019 and is safe and effective, resulting in both a substantial reduction in severe malaria and a fall in child deaths. Allocations are progressively been also made for new introductions of the malaria vaccine in Africa.
7. Climate Change Adaptation Measures: Implementing climate change adaptation strategies at both the national and local levels can help reduce vulnerability to malaria. This involves integrating health considerations into broader climate change adaptation plans and policies.
8. International Cooperation and Funding: Malaria is a global issue, and international cooperation and funding are essential for effective malaria control in Africa. Developed nations, organizations, and donor agencies can provide financial support and technical assistance to affected countries.
9. Collaboration Across Sectors: Addressing malaria transmission requires collaboration between the health sector, environmental agencies, agriculture, and other relevant stakeholders. A multidisciplinary approach can lead to more effective and sustainable solutions.
10. Empowering Local Communities: Empowering local communities to take ownership of malaria control efforts can lead to more sustainable and context-specific solutions. Involving community members in decision-making processes and leveraging local knowledge and practices can enhance the effectiveness of interventions.
It’s essential to note that while climate change plays a significant role in malaria transmission dynamics, it is not the sole factor. Socioeconomic conditions, public health infrastructure, access to healthcare, and the effectiveness of disease control measures also play crucial roles in determining the overall burden of malaria in Africa. Addressing the challenges posed by climate change and malaria requires a comprehensive and integrated approach that involves health, environmental, and social interventions. Also, it’s important to recognize that no single approach can fully eliminate the impact of malaria transmission via climate change. A combination of these strategies, tailored to specific regional and country contexts, is essential for effective malaria control and mitigation efforts in Africa.