Cary asks: Can birds promote Lyme disease?

MILLBROOK — The Cary Institute of Ecosystem Studies often shares news about its research with the press. On Wednesday, Jan. 27, Erin Frick, a communications assistant and writer at the Cary, shared news about the institute’s recent look into whether birds promote Lyme disease, which Cary Institute Disease Ecologist Barbara Han and Daniel Becker, of Indiana University’s Department of Biology and the Center for the Ecology of Infectious Disease,  investigated.

The scientists discovered that birds do play a part in the spreading tick-borne diseases, not surprisingly because of their ability to travel long distances, and because they usually migrate around the world. Their part in the spread of disease is not always apparent, but scientists are studying the role they play, identifying the species that are most likely to transmit the disease. Many species are, due to climate change, making adjustments to their migratory patterns and all of this must be taken into account. Such information could help predict where these tick borne diseases will show up, posing a health threat to local populations.

Published in the journal, “Global Ecology and Biogeography,” this study by Han and Becker used machine learning to discover which bird species had the  most potential to transmit the disease to  feeding ticks. After developing a model they were able to identify those species with an 80% accuracy, and identified them and prioritized them for surveillance.

Becker was the lead author of the study.

“We know birds can infect ticks with the Lyme bacterium; however, until now, no one has systematically studied the ecological and evolutionary drivers that influence which bird species are most likely to host and spread Borrelia burgdorferi on a global scale,” he said. “We set out to fill this gap by identifying traits of bird species that are most likely to pass Lyme to feeding ticks.” 

Due to climate change, migration patterns of birds are changing, shifting north and so are the ticks. Birds existing in highly populated areas have close proximity to people, which increases the chance of contact and infection. This has an impact on health. Lyme disease can be difficult to diagnose. Being aware of the possibility of infections can improve chances of diagnose and successful treatment. 

“Birds don’t spread Lyme directly to people” said Becker, “but they can carry infected ticks to new locations with no history of Lyme occurrence. A tick could drop off a bird and into a garden or yard, where it could later bite and infect a person. If local medical practitioners are unfamiliar with Lyme symptoms, proper diagnosis could be delayed. Identifying where ticks are spreading could improve medical response to Lyme and other tick-borne diseases.”

“These findings remind us that pathogen competence varies tremendously, even among animals of the same family,” added Han, senior author of the study. “These predictions could provide crucial information to guide early interventions [and] prevent disease spillover.”

The Cary Institute stated on its web site that, “Barbara Han’s research is at the intersection of ecology, computing and global health. Han uses machine learning to forecast outbreaks of new zoonotic diseases — those that ‘jump’ from animals to humans.” 

The Cary Institute is located in Millbrook and currently its programming is being done virtually. For more information, go to www.caryinstitute.org.