Climate change and pediatric infectious disease

When one thinks about global warming, one doesn't necessarily connect it to increased infectious disease in children, but that is exactly what is happening. Dr Saul R Hymes, MD, assistant professor of clinical pediatrics, Stony Brook University Renaissance School of Medicine, Stony Brook, New York, spoke of this phenomenon at the virtual 2020 American Academy of Pediatrics National Conference & Exhibition.

Hymes first pointed to a number of climate change consequences that are already known. Heat-elevated temperatures, for example, can cause heat-related death and illnesses. Outdoor air quality affects everything from wildfires to asthma. Flooding can contaminate waters and cause drowning, and warmer weather year round is upping the numbers of vector-borne infections like Lyme Disease.

"A number of human infections are spread by insects, from black-legged ticks, which carry Lyme Disease, to mosquitos that carry a number of infectious diseases," Hymes noted. Between 2001 and 2013, the Centers for Disease Control reported a huge increase in Lyme Disease across the United States. The Environmental Protection Agency lists Lyme Disease as one of the biggest indicators of climate change's impact on human health. And with more and more warmer months year round, the disease is also moving north, and expanding into the winter months of November, December, and January, where "more and more people have been pulling ticks off themselves during warm spells of these months," says Hymes.

Hymes then discussed the fascinating pathway of what was known as the "Lone Star tick," which previously had only been recognized in the Southeastern United States. Bizzarely, this tick, after biting a human, transmits a delayed allergic reaction a few hours after someone eats red meat or pork, often resulting in vomiting, stomach cramps, and anaphylaxis in all forms. And while it is not infectious, it cannot be treated. "This tick is now being found in the Upper Midwest, the mid-Atlantic states, and New England," says Hymes.

Natural disasters, such as hurricanes and tornadoes, can have a profound affect on patient health in ways health care providers might not initially suspect. "They bring saltwater organisms into the water and food supply; there is sewage contamination due to overloaded sewers; and they spread displaced animal vectors like rats," Hymes points out. Saltwater organisms can cause diarrhea and wound infections, while freshwater and soil organisms can produce botulism and pneumonia, among other illnesses. Without clean water and with sewage contaminations, people can contract cholera, typhoid, E coli, and hepatitis A/E. Meanwhile, displaced rodents can transmit typhus, salmonella, rabies and more. "With Hurricane Katrina, we saw 6 cases of cholera, cases of E coli, salmonella, flu, and pneumonia, all which included problems from overcrowding of evacuees," says Hymes.

And while all this is grim news indeed, Hymes stresses ways that pediatricians can be at the forefront of prevention. "Familiarize yourself with diseases like Lyme and Zika, and expect usual suspects at unusual times," Hymes says. "In other words, Coxsackie virus—in February? If it's a warm February, yes, it's possible." Hymes also suggests checking infectious disease risks in your patients. "Are they evacuees, do they have access to clean water, are they living in an overcrowded place?" asks Hymes. "Consider the odd organisms, and call your local infectious disease doctor if you are not sure."

Finally, Hymes suggests that we can all help contain the problem of climate change personally, with our own life adjustments. "Purchase an electric or hybrid car; convert to solar power if you can, and purchase carbon offsets."

(To read more about climate change and its impact on health, see this panel discussion on climate change and women's health​ ​as well as climate change and preterm birth from our sister publication, Contemporary OB/GYN).)