by Lisa Gross, Ensia
County public health officials in South Carolina weren’t thinking about bees in August, when they realized that four residents in a single town had returned from travel abroad infected with Zika. Like health officials around the world, they were thinking of the babies born with heartbreaking birth defects in Brazil. And they were thinking about mosquitoes.
After reports emerged in January that thousands of Brazilian infants had been born with microcephaly, a debilitating neurodevelopmental condition marked by severely stunted head and brain growth, the World Health Organization declared an international public health emergency to figure out why. Scientists thought Zika might be a cause, and within months the U.S. Centers for Disease Control and Prevention confirmed that it was.
In the U.S., the primary Zika-transmitting mosquito species, Aedes aegypti, have been known to inhabit areas ranging from California through the Midwest and Southeast and as far north as Connecticut. When travel-related cases showed up in South Carolina, health officials had one thing in mind: prevent those mosquitoes from biting an infected person and passing Zika to someone else. So they quickly launched an aerial spraying campaign against mosquitoes using the insecticide naled.
Naled, it turns out, is highly toxic to bees.
Officials acknowledged the unintended casualties — more than 2.5 million bees, according to local beekeepers — and apologized. They also determined that no rules had been violated in efforts to prevent a mosquito-borne public health threat.