The number of illnesses from mosquitoes, ticks, and fleas tripled between 2004 and 2016, the Centers for Disease Control and Prevention reported Tuesday.
Diseases like West Nile virus, Zika, Lyme disease, and yellow fever have spiked in the U.S. In 2004, about 27,000 cases of insect-borne illnesses were reported, but more than 96,000 cases were confirmed in 2016. Worryingly, officials reported Tuesday that the nation's health-care systems are not well-equipped to handle the huge increase in incidences of these previously-obscure conditions.
"A growing list of diseases" have confronted the U.S. in recent years, CDC Director Robert Redfield said. "And we don't know what will threaten Americans next." There is a vaccine for yellow fever, but all other diseases are largely unpreventable aside from the use of insecticide, which the CDC notes is becoming less effective as insects become resistant.
Mosquitoes and ticks thrive in warm weather, but the CDC declined to connect the increase in infections to rising temperatures caused by climate change, The New York Times reports. Researchers did point out that ticks are living in areas that were previously too cold for their survival, and noted that mosquito-borne infections increase when temperatures spike. Local jurisdictions are tasked with handling outbreaks, but the CDC reports that they have been underfunded and overburdened in recent years, and many have struggled to surveil, report, and handle the sudden uptick in cases.