Patterson Scholar: Shannon Bennett

As an undergraduate student, I volunteered in Liberia, West Africa, to lead an educational theater program designed to address basic public health issues. Before long, I contracted malaria, followed closely by a case of amoebic dysentery and a staphylococcal infection that all together landed me in a leper colony for treatment. An experience that would have spelled the end for most people’s enthusiasm for tropical adventure served as inspiration. I was instantly determined to specialize in parasitology, to better understand the evolution and transmission of microscopic organisms that make their hosts so profoundly ill.

Today, my research advances science and sustainability by making a direct connection between human health and the health of natural systems from the lens of biodiversity conservation and resilience. I am focusing on mosquito and mosquito-borne viruses that circulate in biodiverse natural systems, to understand the diversity of viromes in nature, identify potential viral pathogen progenitors, and identify the evolutionary and ecological factors that drive zoonotic events - the jumping of a pathogen from a non-human animal system into humans - and emerging infectious disease.   We’re learning that biodiversity of the host and vector communities drives biodiversity of viruses in a way that could prevent invasion by disease agents. For example, in remote forested environments there is a high diversity of vertebrates and mosquitoes as well as their microbes, few of which have been associated with disease, whereas in urban and peri-urban environments diversity drops and the community becomes dominated by a handful of invasive mosquito species known to carry dengue, Zika, chikungunya, Japanese encephalitis, and other pathogens. These invasive disease agents continue to rapidly evolve adaptations that result in increasingly severe disease with urbanization and the globalization of human society.

"My research makes a strong case for conservation of naturally biodiverse systems to sustain all life on earth by making a direct positive connection between human health and the health of natural systems."

I study the diversity and evolution of pathogenic viruses and other microbes in natural systems including humans, and my research focuses on two areas.  First, I explore the evolutionary and ecological origins and drivers of pathogenic viruses.  We use the unique signatures of virus genomes to track how, when, from where, and ultimately why viruses emerge into humans from natural systems.  We also document the unique genetic signatures of other organisms with which viruses co-occur, to ask how biodiversity, from the macroscopic (mosquitoes and their vertebrate meal providers) to the microscopic (the wealth of fellow microbial dwellers nested within the macroscopic diversity), plays a role in virus emergence in humans.  Second, I document the drivers, through evolutionary and ecological patters, of ongoing virus emergence of known pathogens such as dengue, Zika, chikungunya and hantavirus in human-dominated systems that are under increasing pressures from crowding, habitat degradation, lack of resources, and globalization of humans, invasive species, and economies. 

The exploration of new life is fundamental to the Academy’s mission to explore, explain, and sustain life.  As a Patterson Scholar support, I am discovering novel viruses and other microbes, documenting new ranges and records for mosquitoes, characterizing their rich viromes and microbiomes, and archiving the tangible evidence of these diverse life forms in physical, cryogenic and digital collections.

Critical to this work is tracking the presence and distribution of mosquitoes, leveraging iNaturalist to make observations and identify species, and developing a sample-return protocol to conduct genetic analyses of citizen scientist-collected data using our in-house genomics center.  Building on a recent collaborative NSF grant to resolve the family tree of mosquitoes, of which there are over 3,800 species worldwide, citizen science-collected specimens characterized for their viromes will allow us to map the diversity of viruses, including known and potential pathogenic microbes, across the mosquito tree of life as well as across diverse natural and human-dominated communities.

With our increasing understanding of the distribution of viral diversity across a handful of habitats and mosquito species, some of which are highly invasive, we hope to greatly expand our studies to more mosquito species from increasingly complex natural systems.  This will reveal increasingly important insights into the farthest corners of virus diversity and lead to new discoveries of the identity and ultimate origins of zoonotic viruses, of which SARS-CoV2 (the virus behind COVID-19) is just the most recent.  Meanwhile, known viral agents of disease continue to evolve and spread: as the Zika epidemics and emergence of 2015-2016 wane, dengue resurges, showing evidence of adaptive evolution that may have much to do with the emergence of Zika, a close relative.  We have expanding projects tracking dengue evolution in Nicaragua as well as the Philippines, as well as advancing frontline capacity to survey viral agents of fever in field settings across three major tropical geographic regions.