Late last November, a young man walked into Renee Salas’ emergency room with a circular rash spreading across his leg. Salas, an attending physician at Massachusetts General Hospital in Boston, treated him for possible Lyme disease from a tick bite—a diagnosis that bloodwork later confirmed.
At the start of her career in the early 2000s, Salas would never have suspected Lyme so late in the year. Ticks used to be a summer problem. But since the 1990s, a warmer climate has shortened winters, extending Lyme’s duration and expanding its reach throughout New England. Incidence of the infection has nearly doubled. “I think about it all times of year now,” Salas says. “I have to consider Lyme for every rash.”
Lyme isn’t the only disease whose range and seasonality is shifting, at least in part, as a result of climate change. Although the impact will likely vary based on a variety of factors, some clear trends are emerging. High latitudes and altitudes seem poised for the most dramatic spikes in disease risk. Warmer and wetter conditions in these places have started to lure ticks and mosquitoes up mountainsides and across borders into areas once too cold and dry to support them.
Read more at: https://www.pnas.org/content/119/7/e2200481119