Global temperatures are on the rise and weather patterns are changing in ways that are increasingly evident among human populations and their environments. An especially alarming consistency is the relationship between climate change and the emergence of infectious diseases. In Uganda, a country that ranks high among the world’s nations vulnerable to climate variations, we can observe this relationship most clearly in the context of malaria. Why is the impact of climate change felt most keenly in malaria transmission in the case of Uganda?
The Malaria Burden in Uganda
Malaria is still a major public health problem in Uganda that contributes largely to the high morbidity and mortality in children under five and pregnant mothers. The parasite, Plasmodium, is transmitted by the bite of the female Anopheles mosquitoes. Despite the tremendous measures put in place for malaria control, the vector remains a challenge. These efforts have been made worse by many factors, including climate change.
With an estimated 7 million cases amounting to one of the highest burdens of malaria in Africa, Uganda is among the most highly malaria-endemic countries in the world, as reported by the World Health Organization (WHO). The tropical climate of Uganda is favorable for malaria transmission with seasonal and geographic high and low prevalence. Uganda has made progressive efforts in malaria control with successful implementations of insecticide-treated nets, indoor residual spraying, and effective diagnosis and treatment interventions. However, these gains are being undermined by changing drivers of the evolving climate patterns.
Climate Change and Its Impact on Malaria Transmission
Climate change impacts the transmission of malaria in several ways, including altering the habitats and behaviors of the Anopheles mosquitoes that transmit the disease. Factors include:
Higher Temperatures: Mosquitoes are heat-loving creatures. Higher temperatures cause an expansion of the range and activity of Anopheles mosquitoes. Warmer temperatures can also result in more rapid development of the malaria parasite within the mosquito, which increases transmission rates. Higher temperatures in Uganda may extend the geographic range of malaria up into the hills, and possibly into formerly malaria-free areas.
The rainfall cycle influences malaria by affecting the timing and frequency of rainfall, which in turn determines the quantity and availability of aquatic habitats required by mosquitoes. Supplementary rain leads to increased breeding sites (eg, larvae-forming pools). Changes in the rainfall cycle (eg, droughts) also affect the breeding of mosquitoes, although this can be temporary; the return of rains can lead to a sudden proliferation of mosquitoes.
Humidity Levels High humidity levels help mosquitoes to survive, and also make them better vectors for malaria, meaning that they transmit malaria more readily. A rise in humidity, linked to changes in climate patterns, can increase the number of mosquitoes and raise the likelihood of malaria outbreaks.
Extreme Weather Events: Extreme weather events such as floods and unseasonal scorching dry periods can create transient ecological conditions that are favorable for mosquitoes. Floods can produce many new breeding places, while heavy rainfall after a dry spell can create conditions for a surge in mosquitoes.
The Current Situation in Uganda
Recent research suggests that climate change is intensifying the malaria situation in the country. Studies have illustrated how rising temperatures correlate to rising malaria incidence.
Yet the dynamics are still very apparent, particularly in places in Uganda that were traditionally highland, uncommon places for malaria. At lower temperatures, these highland areas saw very low to no occurrence of malaria, but now with a change in the climatic patterns, the areas have been experiencing increased instances of malaria transmission. This projects a unique concern and challenge to public health authorities dealing with public health issues. One has to adapt.
Adapting to the Challenges
The necessary protective and preventive adaptions required in Uganda to minimize the negative effects of climate change on malaria comprise the following:
- Upgraded survey surveillance systems can track malaria transmission patterns and enable interventions during outbreaks. Knowing where potential hot spots are emerging early on can help to deliver interventions in the right places at the right time.
- Integrated Vector Management: Multipronged tactics to reduce mosquito vectors (through insecticide-treated nets, indoor residual spraying, and environmental management) combined with modifying these strategies to account for changes in mosquito ecologies due to climate change.
- Climate-Resilient Health Systems: It is essential to build more climate-resilient health systems. This means ensuring that more people can access healthcare and that health facilities and workers are ready to respond to the rise in malaria cases and other climate-related health challenges.
- Community Awareness and Engagement: Informing communities about the key roles that climate change plays in malaria, and raising awareness about what individuals can do to reduce breeding sites of mosquitoes can help people to better prepare themselves.
Research and innovation should ensure rapid and far-reaching investments in research to understand the complicated connections between climate change and malaria, and the development of innovative technical solutions such as climate-resilient mosquito control; and new vaccines.
Policymaking and planning: The policymaking community needs to mainstream climate change and malaria control considerations into disease mitigation and public health planning. In short, as countries look to adapt to climate change, policymakers should also plan how to prevent disease.
In the end, then, addressing the nexus between climate change and malaria means that governments, health organizations, researchers, and communities will all have to act to blunt the impacts of climate change and improve Ugandan health.
