IMPACTING

The challenge

Climate change and environmental disruption are having a profound impact on the spread of infectious diseases, including in sub-Saharan Africa. Changing temperatures and weather patterns are affecting the distribution of vectors that spread key diseases, and changing land use is disrupting ecosystems, bringing these vectors into closer contact with people.

These effects are hugely significant, as vector-borne diseases account for an estimated 700,000 deaths a year, mostly of young children. Although epidemiological studies can provide insights into the current distribution of disease and areas at risk, understanding how these are likely to change and which areas will be at greatest risk in the future is critical to inform public health planning.

The project

Focusing on Cameroon, Kenya and Mozambique, the IMPACTING project is undertaking a range of activities to highlight areas most at risk of future outbreaks of vector-borne disease.

It is exploring diseases linked to a range of insect vectors, including:

• Mosquitoes: Malaria, dengue, chikungunya, yellow fever.
• Tsetse flies: Human African trypanosomiasis (sleeping sickness).
• Blackflies: Onchocerciasis.
• Ticks: Congo–Crimea haemorrhagic fever. 

At multiple sites, project team members are sampling the environment to determine the prevalence of different species of vectors. This information will be used to map the existing distribution of vectors and model how their distribution will change in response to climatic or environmental changes. This work requires several innovations, including the development of new traps and attractants to capture insect vectors more effectively. 

A second strand of the project focuses on environmentally friendly approaches to disrupting disease transmission by insect vectors. It has recently become clear that the presence of some commensal bacteria can inhibit pathogen development inside vectors. Infecting insects with these bacteria could therefore block transmission without harming the vectors themselves, thereby removing selection pressure to drive resistance – a constant challenge for pesticide-based vector control strategies. The project will initially focus on two species of transmission-blocking commensals, Serratia and Microsporidia MB, and develop strategies to identify further candidates. 

A third strand of work focuses on community engagement. The project team aims to involve community members, including women and young people who are often excluded from these activities, in the co-creation of strategies for community-based vector surveillance and vector control.

Based on these activities, the team plans to work with policymakers to develop a multifunctional, multi-disease dashboard to visualise high-risk areas under different climate and environmental scenarios, to inform preventive and rapid-response activities.

Impact

The IMPACTING project is addressing the growing challenge posed by climate and environmental change to health in sub-Saharan Africa. It will: 

• Provide better methods for monitoring the distribution of insect vectors of key infectious diseases.
• Identify and begin evaluating commensal-based approaches to control the transmission of vector-borne diseases.
• Involve communities in the development of grass-roots activities to disrupt disease transmission.
• Provide health officials with tools for monitoring vector-borne disease and identifying areas at high risk of outbreaks.

Through these activities, the IMPACTING project will equip policymakers and communities with tools to better predict the impacts of climate change and other environmental factors on vector-borne diseases and to intervene more effectively to reduce the burden of such diseases.