What kind of career can a childhood fascination with dinosaurs, bugs, and the natural world lead to? For new 51³Ô¹ÏºÚÁÏ School of Public Health professor Louisa Messenger, this resulted in a journey around the world as a scientist. For the last decade, she has played a key role in finding ways to prevent deadly, vector-borne diseases like malaria, which kills over 700,000 people globally each year.
Can you give a brief overview of your research, and what inspired you to do this type of work?
I develop and evaluate new tools and strategies to interrupt the transmission of vector-borne diseases. These are infectious diseases that are spread by insects. Let's face it, we all hate being bitten by mosquitoes and other bugs, but it's a lot more egregious if that insect then transmits a disease that can potentially kill you.
These vector-borne diseases are a major global health problem. They account for more than 17 percent of all infectious diseases worldwide, and cause the deaths of more than 700,000 people each year all across the world.
As a kid, I think a lot of us went through that phase where we're obsessed with dinosaurs; we're obsessed with bugs; we're obsessed with the natural world. I just never really grew out of it! I always knew that I wanted to be a scientist, and when I was studying for my undergraduate degree, I was fascinated with the interaction between infectious diseases and the natural world. It really doesn't get more intricate or complicated than how parasitic diseases and insect vectors have co-evolved their mutual symbiotic relationships over many millennia. And now these pathogens are able to cause such a considerable burden of global disease.
It was really just my fascination with the subject in general that led me to this route.
What was one of your first experiences working with insects and infectious diseases?
When I started my career in public health, I was working in Latin America trying to improve the control of a parasite there called American Trypanosomiasis, or Chagas disease. It's a really horrible, neglected tropical disease, which is transmitted by a type of insect called a triatomine bug. They are these really large beetle-like insects, and at night while you're asleep, they come out the holes in house walls and bite you. And while they're biting you and sucking your blood, they defecate on you. There’s a parasite in the feces of that bug that enters your body through the bite wound or your eyes, nose or mouth, which you contaminate while you’re sleeping, by subconsciously touching your face.
So it's a pretty nasty disease in the first place, but it causes really devastating pathologies. It often goes undiagnosed and becomes a chronic infection. It's really difficult to treat if you are not diagnosed early, and it's actually the leading cause of infectious heart disease in the world. So years after you become infected, you begin to develop irreversible, potentially fatal, heart disease as a result of this. And in endemic communities in South America, more than 97% of individuals over the age of 30 are infected, with 30% of these people progressing to end-stage heart failure, decades after contracting the disease.
I spent about six years of my early career working on this disease all across Latin America, but as with all neglected tropical diseases, obtaining long term sustainable funding for it is really difficult. So in 2015, I moved to sub-Saharan Africa, to Tanzania and I've been mainly working in malaria control ever since.
Malaria control is a big part of your work. Can you describe this disease’s current impact and how it can be prevented?
Malaria, despite being entirely preventable with the deployment and the use of the right health interventions, is still one of the top three communicable diseases worldwide alongside HIV and tuberculosis. It’s also still the leading cause of mortality in children under the age of five in low income countries.
The main way that we control malaria is by distributing insecticide-treated bed nets. So if you are asleep in your bed, completely covered by your insecticidal net, it physically stops mosquitoes from being able to bite you. The insecticide in the net can then also kill the mosquito when it contacts the net while trying to bite you.
The other thing that we can do is spray long-lasting insecticide on inner house walls. What mosquitos tend to do is, once they've taken a blood meal from you while you're sleeping, they go