Time to innovate:
Malaria in a changing world
Every minute, a child dies of malaria. One of the world’s oldest diseases, malaria used to be widespread around the world, including the UK. Thomas Jefferson, Alexander the Great, Julius Caesar – these are just a few of the people who were said to have had malaria. Today, 95% of malaria cases and 96% of malaria deaths are concentrated in sub-Saharan Africa, with cases rising every year and existing interventions showing reduced effectiveness due to resistance by the malaria mosquito and parasite.
This year’s theme for World Malaria Day on 25 April is Time to Deliver Zero Malaria: Invest, Innovate, Implement. The changing planet is having an important impact on malaria transmission, with transmission rates being affected by the climate crisis, changing mosquito behaviour, and increasing resistance to current interventions.
Across Imperial College London, PhD students are focusing their research to deliver zero malaria, because it is time to innovate to end this disease in their generation.
Detecting disease more easily
Dimbintsoa Rakotomalala Robinson, Digital Diagnostics for Africa Network
I come from Madagascar, a country with a high morbidity and mortality in terms of tropical and infectious diseases, particularly malaria. As a medical doctor, I saw first-hand the ravages of these diseases on people’s lives. Although my role as clinician was important, it was limited, and I wanted to move to a field that may have larger impact.
My PhD project focuses on the evaluation of a novel digital diagnostic test for the detection of malaria parasite infections in Africa. The test has high sensitivity, so can detect asymptomatic infections and low levels of parasites, which are often missed by conventional diagnostics.
To achieve the goal of malaria elimination, it is important to detect and treat these infections because they constitute a substantial malaria reservoir that helps maintain malaria transmission. The test could also be used as a point-of-care test, with a time to result of less than 30 minutes, making it suitable for the African context where access to a laboratory is often difficult.
Climate change and land use changes represent great threats for malaria control, and the African continent is especially vulnerable to these changes. It is crucial to closely monitor the trends in terms of infections and deaths attributable to malaria with a robust and timely surveillance system. For this system to be effective, having an accurate and easily deployable diagnostic tool able to detect all malaria infections is required.
Before its deployment at large scale, however, we need to understand if the test performs accurately and efficiently in real field conditions. This represents the focus of my PhD project.
If the digital diagnostic test is found to meet the required conditions, it has the potential to represent a great tool for malaria surveillance and other public health interventions such as mass testing and treatment.
I think the youth, and especially the African youth, have a fundamental role in the fight against malaria, including in research. I was very lucky to have been selected to do my PhD thesis with the Digital Diagnostic for Africa research group, but there are many young people in Africa very motivated and with new ideas just waiting to be encouraged and supported.
Genetically modifying mosquitoes
Anna Strampelli, Target Malaria, Department of Life Sciences
I spent many years of my upbringing in countries that are affected by malaria and other vector-borne diseases. Working on malaria is particularly important to me, because it’s a disease that predominantly kills very young and poor children in sub-Saharan Africa, who should have the right to a healthy childhood.
One of the top priorities in the malaria agenda is the research and development of new tools addressing key challenges such as resistance to insecticides and antimalarials – and I hope that my work contributes towards this goal.
I chose to pursue a PhD in genetic engineering because I found the science fascinating and, on a more practical level, I truly believe it can bring about an important contribution to the fight against malaria. My research centres around developing self-limiting genetic strategies to suppress populations of the main malaria mosquito in Africa, Anopheles gambiae. In practice, this means genetically modifying this mosquito species to create versions of it that, if released, could reduce wild populations of this disease vector.
Importantly, the effects of this reduction are temporally and geographically localised. The hope is that these or other self-limiting strategies could be released, both as population-reduction tools, and to strengthen the regulatory pathway for the potential release of the more powerful gene drive mosquitoes.
The changing world is affecting malaria in several ways, from climate change that threatens to widen the geographical scope of this disease, to the emergence of pandemics that hamper malaria programs, to migration of vector species in regions where they are not native to. On the other hand, the changing world also means more research on new tools, socioeconomic development and better health systems, so there are also good reasons for being cautiously optimistic.
Preventing disease in young children
Gina Cuomo-Dannenburg, School of Public Health
The intervention I work on is called seasonal malaria chemoprevention, which aims to prevent disease in young children specifically. In areas with high levels of malaria transmission, which is very seasonal, community health workers go house to house once a month to deliver preventive medication to children at high risk of severe disease. However, there is established resistance to the medicines we use for seasonal malaria chemoprevention in most of East and Southern Africa. My work revolves around using a variety of approaches to estimate the effectiveness of seasonal malaria chemoprevention in places where resistance is already high.
The malaria parasite is highly adaptive and has developed resistance to every treatment used, as well as diagnostic tools. My work is predominantly orientated around understanding the impact of resistance on malaria chemoprevention, how environmental factors affect seasonality and how to combine this to most effectively use our current tools to save lives in a changing landscape.
My background is in mathematics, and I always really enjoyed mathematical biology, but had only done a tiny bit of mathematical epidemiology before I applied for my PhD at Imperial, totally on a whim.
I always knew I wanted to do something that used maths to have a positive impact on the world and honestly this work is the perfect fit that I never knew existed.
My advice to other young scientists is to invest in your network, especially with researchers living and working in countries affected by your field of research. These conversations and relationships have been one of the most rewarding parts of my work and being able to align my research with public health priorities allows my work to have the most impact. But most of all, don’t lose hope. Sometimes tackling malaria burden can feel insurmountable, but remembering that even small gains have the potential to save lives keeps me motivated.
My hope is that we are able to reverse the trends we have seen in current years of the malaria burden increasing year on year and starting to see decreases again in cases and deaths globally.
Investigating drivers of malaria transmission
Isaac Stopard, School of Public Health
I am part of an interdisciplinary team that develops mechanistic models to predict malaria transmission given different intervention strategies.
By predicting malaria transmission, I hope our research can help inform malaria control programmes and have a positive impact on malaria elimination and hopefully global eradication.
My specific project involves what it takes for an individual mosquito to transmit malaria. One important factor is that infected mosquitos must survive while the parasite matures (the extrinsic incubation period, EIP). However, while the parasites need 10 days to reach maturity, the average adult mosquito lifespan is typically less than 10 days. We think that a small number of long-living mosquitoes are responsible for a disproportionate amount of transmission.
During my PhD, we developed a mathematical model of parasite development within the mosquito to characterise variability in EIP. We then investigated how incorporating these new EIP estimates into a malaria transmission model affected the ability of the model to predict long-term changes in malaria transmission in a high-transmission region of Senegal.
One of the many reasons insecticide-treated bed nets (ITNs) have been so important for reducing malaria is because the insecticide can reduce the average mosquito life expectancy even if they do not completely block biting. However, resistance to the class of insecticides used on nets is spreading, so we have been modelling the short-term public health impact of distributing nets treated with a new insecticide.
I strongly believe social justice and public health are integral to reducing the burden of malaria. Inequality in the geographic distribution of malaria is extremely high, and within endemic countries malaria disproportionately affects people who are most economically marginalised.
There is, however, hope: since 2015, nine countries have been certified by the World Health Organization (WHO) as malaria-free, and with continued funding, political will and a reduction in global inequality more countries will be able to reach elimination.
Charting the impact of insecticide resistance
Mara Kont, School of Public Health
Health inequalities across the world is something I have always sought to proactively remedy. The complexity of malaria as a disease, its global burden, as well as the impact that global issues and politics can have on it make it a fascinating and challenging field of study.
Malaria is a complex disease at the intersection of human social patterns, demography, economics, and environmental factors – and any change in these patterns may affect disease transmission and our strategies to combat it.
Since the 1950s, insecticides have been one of the most effective tools in driving down the spread of malaria. Resistance to these insecticides has steadily been emerging ever since in malaria mosquitoes, and we now see many high-transmission malaria areas with very complex and intense resistance patterns.
Adding extreme environmental variations caused by climate change to this will likely impact current transmission patterns and highlights the need for new adaptable tools to control malaria. My work focuses on characterising these different resistance patterns and tries to understand how these changes may impact malaria transmission, so we can adapt our control strategies in a timely manner.
For our research to be meaningful, we need to collaborate with researchers and engage with communities in settings most affected by malaria. In doing so, we can make the science and solutions we produce more trusted and valuable for public health.
Over the next 10 years, I’m hoping to see a range of new tools to prevent and control malaria, including new insecticides, vaccines, and gene-drive technologies. This would have to be combined with greater community engagement and empowerment in malaria-affected areas, as well as improved access to diagnosis and treatment.
I also hope for more political commitment and funding for malaria control and elimination, both domestically and internationally. New partnerships and collaborations, particularly between malaria-affected areas, will hopefully also be something we see more of in the next decade.
Continued innovation is essential to stay ahead of the malaria mosquito and parasite, and at Imperial College London interdisciplinary researchers from across all four of our faculties channel their expertise into malaria research via our Network of Excellence on malaria, as well as collaborating with researchers, policymakers and local communities across institutions and continents, including Target Malaria, the Digital Diagnostics for Africa Network, the Institute of Infection, the School of Public Health and the MRC Centre for Global Infectious Disease Analysis.
Want to make a difference? You can support organisations like Malaria No More and their Zero Malaria campaign, or the RBM Partnership to End Malaria.