Georgia Titcomb ’14 on the interrelationship between climate change and infectious disease transmission

Jun 11, 2020

Had it not been for the coronavirus, Georgia Titcomb ’14 would’ve graduated this month with a PhD from the University of California, Santa Barbara (UCSB).

Although she won’t defend her dissertation in ecology, evolution, and marine biology until this August, the alumna is already involved in her next project: researching disease transmission between humans, wildlife, and domestic animals in Sava, Madagascar. 

The project, a collaboration between UCSB, Duke University, the University of Chicago, and the Madagascar-based University of Antananarivo, will build on her current work in studying the impact of a warming biosphere on waterborne diseases. The National Institutes of Health Fogarty International Center awarded the $2.4 million grant to Duke University in October 2019 through the Ecology and Evolution of Infectious Diseases (EEID) program.  

The interdisciplinary cohort of researchers headed to the northeastern city of Sambava, the region’s capital, will be identifying “networks of contact” within various environments through the use of analytical approaches to determine when and where people are most at risk of zoonotic disease transmission.  

“People [in Sambava] may go to the forest to get wood for their homes but then also work on vanilla plantations,” Georgia said (around 80 percent of the world’s supply of vanilla is grown by farmers in Madagascar). “In many ranching areas, wildlife and livestock share the same space.”

While scientists widely agree that climate change will affect the spread of disease, there is little agreement among them about just how the consequences will play out in biodiversity hotspots, she said. The ecologist co-authored a paper on methods for detecting emerging infectious diseases at the wildlife-human interface last April. 

“Warming temperatures accelerate the development of larval stages for all kinds of parasites and pathogens,” said the doctoral student, pointing to the projected increase of cholera outbreaks due to more frequent flooding. “There’s also an upper threshold for survival, so seeing diseases declining in one region doesn’t mean that they are declining overall.” 

She said that in recent months the pandemic has caused her even greater worry for the resilience of rural populations in responding to public health crises. As the number of humans traversing the earth continues to grow (the world’s population is projected to reach a whopping 10.9 billion by 2100, according to the United Nations’ 2019 Revision of World Population Prospects), we can expect the magnitude of infectious diseases to expand, too, according to Georgia.

“We should be thinking more about Africa, India, and other locations that have a lot of rural areas lacking the infrastructure and resources to handle big weather events and the diseases that stem from them,” said the wildlife researcher, whose field sites as part of her PhD program included the Mpala Research Centre and Ol Pejeta Conservancy in central Kenya.

In addition to extreme weather events, disease transmission and the over-exploitation of natural resources are interlinked, Georgia said. 

As one example, the disturbing of mosquito habitats by cutting down forests can lead to increased transmission of vector-borne diseases such as malaria, Dengue, and Zika virus fever. Bushmeat hunting, or the killing of wild animals in African forests and savannas for food, is another way that potentially dangerous viruses can be spread. 

“Bushmeat hunting may seem barbaric to us, but it’s a tradition and a necessity for others; it’s a deeply social, as well as medical, issue,” she said, stating that close to 75 percent of emerging infectious diseases originate from an animal source, including the novel coronavirus. “The more we harvest animals and expose ourselves to them, the higher the potential for some transmission event to happen.” 

The economic burden placed on agricultural workers from China’s suspension of wildlife trade in February has demonstrated some of the many difficulties that come with severing or at least disrupting established practices, each of which is associated with culturally specific values. In order to enact meaningful change, local policymakers and world leaders alike will need to take all of these complex and geographically specific issues into account, according to the alumna. 

“Cultural sensitivity is going to have to be a part of this conversation, as will paying closer attention to scientific knowledge, investing in the preservation of our natural world, and increasing understanding of how human overlap and infringement affects disease transmission,” said Georgia, who graduated from Carolina with degrees in biology and studio art, as well as a minor in chemistry. 

While many have been (justifiably) terrified by the threat and aftereffects of the coronavirus, one only has to look to the animal kingdom to appreciate just how commonly pandemics occur.  

“Humans have gotten really good at preventing and even outsmarting diseases, so when something new comes along it can feel especially bad or shocking,” she said. “Pandemics come, so we should always be prepared and look to the past because we’re not going to always beat nature.”

Georgia received her Master of Arts degree in statistics and analytics from UCSB. Learn more about her research. 


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