Climate change and malaria control: a call to urgent action from Africa’s frontlines

Abstract

In December 2024, L’Initiative-Expertise France organized a workshop in Musanze, Rwanda, for National Malaria Control and Elimination Programmes (NMC/EPs) representatives from 19 sub-Saharan African countries. The workshop focused on surveillance, modeling, climate forecasting, and innovative control methods to mitigate climate change impacts on malaria. Participants shared challenges, experiences and best practices. Key challenges highlighted include shifts in malaria transmission seasons, disease spread to mid-altitude regions, and infrastructure damage from extreme weather. Additional factors, such as drug and insecticide resistance, the spread of Anopheles stephensi, and changes in vector behaviour, are exacerbating malaria transmission in African cities. Participants stressed the need for collaborative efforts to tackle these evolving threats. This comment reflects the expertise and insights of 19 NMCPs actively managing malaria control and aims at raising awareness, inform policy discussions, and strengthen global partnerships to address the intersection of malaria and climate change.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12936-025-05431-5.

Background

Malaria is a climate-sensitive vector-borne disease. Rainfall creates breeding sites suitable for the proliferation of Anopheles malaria vectors. Temperature directly affects the growth and biting rates of mosquitoes as well as the sporogonic cycle, that is the development of the malaria parasite within the mosquito’s body. Furthermore, habitat changes influence vector distribution and disease transmission dynamics. In addition, weather extremes also have multi-faceted impacts on malaria control and the epidemiology of the disease.

Thanks to continuous efforts by National Malaria Control/Elimination Programmes (NMCPs/EPs) and other key actors, global malaria mortality has declined by approximately 11% since 2015. However, this progress remains insufficient to meet the African Union’s interim target of a 75% reduction by 2025 [1, 2]. This plateau in malaria control is attributed, among others, to operational challenges, funding gaps, the emergence of resistance in both the parasites to antimalarial drugs and the mosquito to insecticides, but also the accelerating impacts of climate change. Accordingly, the World Malaria Report 2023 included, for the first time, a chapter dedicated to the nexus between climate change and malaria [3].

In December 2024, l’Initiative-Expertise France and the Institute of Applied Sciences INES-Ruhengeri (Rwanda) organized a workshop about malaria and climate change for representatives of NMCPs from 19 francophone sub-Saharan African countries in Musanze, Rwanda (Fig. 1). This multidisciplinary workshop included training sessions on surveillance, modeling, climate forecasting and innovative control methods, providing participants with essential tools and best practices to enhance preparedness and mitigate the impact of climate change on malaria. Importantly, participating countries shared recent challenges, experiences, initiatives, and best practices related to malaria control efforts. This Commentary aims to (i) provide a brief review of the impact of climate change on malaria control with a focus on Africa, (ii) highlight emerging challenges and threats, and (iii) emphasize the essential needs and strategies identified by these NMCPs to sustain progress toward WHO goals of reducing malaria morbidity and mortality across the African continent.

Fig. 1.

Countries participating in the climate change and malaria control workshop. For a detailed list of participants and countries, see the acknowledgment section

Modelling studies have shown that warmer temperatures may increase the risk of malaria transmission in mid-altitude regions in the future [4]. Historical data indicate that Anopheles mosquitoes have already spread to higher elevations in Africa during the twentieth century [5]. The Rwanda Ministry of Health noted that while malaria cases remain primarily concentrated in the warmer Southern and Eastern regions of the country, sporadic and unusual malaria cases are now being reported in some hotspots of Musanze, a northern high-altitude district located at around 1850 m, where the local population has not been exposed to the disease. This fact is not unprecedented; a study demonstrated the association between higher minimum temperatures and the malaria outbreak that affected people living at high-altitude in 1987 in the Gikonko Health Centre in the Butare prefecture [6]. In 2024, Madagascar reported unexpected malaria outbreaks around Antananarivo, at elevations exceeding 1350 m. Similarly, shifts in malaria transmission seasonality have been linked to changes in minimum temperature in the Katanga Plateau of the Democratic Republic of Congo over the twentieth century [7].

Rainfall plays a crucial role in shaping malaria seasonality and interannual variability. Over the past five years, the West African monsoon has been particularly intense, bringing high amounts of rainfall to the Sahel. As a result, longer malaria seasons and increased transmission have been observed. In Agadez, a semi-arid district of Niger, adults and adolescents are now increasingly being affected by malaria [8]. Similar trends have been observed in other semi-arid regions of Mali [9], Burkina Faso [10], Togo and Chad. The varying thermal tolerances and ecological preferences of Anopheles species contribute to changes in seasonal patterns of some malaria vectors, including extended activity periods, geographical shifts, increased abundance, and altered feeding behaviour (e.g. increasing outdoor biting over indoor biting) with significant implications for vector control measures [11].

Extreme weather events, such as floods and heatwaves, are increasing and affecting critical sectors such as health, (healthcare access and infrastructures), agriculture, food and water security. For instance, Cyclone Idai resulted in significant destruction in Mozambique in 2019, leading to a threefold higher odds of malaria infection in individuals residing in impacted households a year after the storm [12]. Initially, heavy rainfall washes away mosquito larvae through the “flushing effect”. However, the remaining standing water leads to a rebound in mosquito populations and malaria cases some weeks later. In addition, floods may lead to population displacement, increased human-vector contacts, and restrain access to healthcare, thereby exacerbating the transmission of malaria. Heat waves can hinder the use of LLINs due to the discomfort they cause in hot weather, consequently affecting the protection of communities. They also have the potential to disrupt the roll-out of rapid diagnostic tests by healthcare workers in the field and compromise the cold storage of pharmaceuticals.

The aforementioned climate change-related effects pose significant challenges for (i) preventive chemotherapy, which primarily targets children under five years of age and pregnant women, and (ii) the implementation of vector control strategies due to the changes in the distribution, abundance and seasonal activity of Anopheles mosquitoes. Modification in vector behaviour is also a critical issue too. For instance, a study has shown that Anopheles species are also shifting their biting activity during daytime in Bangui in the Central African Republic [13]. These challenges underscore the urgent need to continuously monitor and assess shifts in rainfall patterns and malaria seasonality to ensure timely and effective delivery of malaria preventive and curative treatments to the most vulnerable populations.

Malaria mainly affects vulnerable populations in Africa’s rural and peri-urban areas with poor sanitation and drainage. This is due to the ecology of major malaria mosquitoes which usually prefer to lay eggs in temporary and non-polluted water bodies. Nevertheless, rapid population growth and poor drainage can increase malaria transmission risk, like in Nouakchott, Mauritania. In addition, the introduction of Anopheles stephensi, a competent vector for both Plasmodium vivax and Plasmodium falciparum, is increasingly causing malaria issues in East Africa [14]. In 2012, Djibouti was close to malaria elimination, with about 27 reported cases. After the introduction of An. stephensi the number of malaria cases rose to about 73,000 cases in 2020. Since its arrival in Djibouti in 2012, An. stephensi has spread to Ethiopia, Eritrea, Kenya, Somalia, Sudan, Nigeria and Ghana. Anopheles stephensi prefers artificial container habitats in urban settings and is resistant to insecticides, challenging existing malaria control measures. Climate change and urbanization, with Africa's urban population expected to triple by 2050 and reach approximately 1.5 billion residents, will exacerbate the spread of An. stephensi.

Fortunately, effective tools are available to combat malaria, such as medications, vaccines, core vector control interventions such as Indoor Residual Spraying and bed nets. However, climate change can undermine their effectiveness. Current vaccines offer only a partial protection if used alone and require four doses which poses operational challenges to ensure optimal coverage. These challenges can be further exacerbated by issues in cold chain preservation, disruption of supply chains, and limited healthcare access due to flooding or other climate-related disruptions. Moreover, disruptions in the delivery of treatments could lead to the resurgence and spread of malaria. Resistances to standard antimalarial drugs such as chloroquine and, more recently, artemisinin [15] are increasing. Inadequate distribution and use of LLINs may also contribute to the development of insecticide resistances among mosquito populations. New vector control methods, such as novel mosquito repellents, larvicides and attractive sugar baits can also be impacted by extreme climatic conditions.

Addressing the increasing impact of climate change on malaria transmission and control necessitates the implementation of customized strategies tailored to this evolving reality. Traditional methods must be enhanced with innovative, integrated and multi-sectorial solutions, as demonstrated by the initiatives and recommendations proposed by the NMCPs:

• Increasing multi-sectoral collaborations at country level across ministries and with the academic and research sectors, in particular with climate and environmental services

• Developing new multi-disciplinary training to foster the next generation of malaria control experts

• Embedding climate-driven early-warning systems into routine surveillance tools such as dashboards

• Increasing and strengthening the capacity of community actors in addressing climate change and malaria

• Unlocking finance and building capacity, developing novel and flexible funding streams

• Organizing forums at a pan-African scale to regularly share ideas, challenges and solutions for combating malaria

• Integrating climatic and entomological data into routine malaria surveillance and dynamically tailoring entomological monitoring based on vector behaviour changes, resistance to insecticide and shift of vector species

• Utilizing modelling tool for decision-making to anticipate response to potential upcoming challenges and strategically optimize allocation of resources

• Promoting community empowerment and awareness for active engagement and encouraging behavior change

The fight against malaria and climate change is a shared urgency. Early effects of climate change on health and control systems require immediate collective action. By leveraging technological innovations, enhancing collaborations, and using forecasting systems and responses, current challenges can be turned into opportunities. Without urgent action, there will likely be significant human and economic impacts. Let us act now, together, to protect the hard-won progress gained in the last decades in reducing the burden of malaria.

Competing interests

The authors declare no competing interests.

Author contributions

C. Caminade wrote the main manuscript text. All authors reviewed the manuscript.

Funding

Not applicable.

Data availability

No datasets were generated or analysed during the current study.