A population of wild monkeys introduced into a Florida state park decades ago will double in the coming years, raising alarm among some conservationists because many of them carry a rare and deadly form of herpes virus called herpes B.
In the 1930s, an operator of glass-bottomed tour boats at Florida’s Silver Springs State Park purchased and released six rhesus macaques onto a small island in the park. The monkeys, native to Southeast Asia and skilled at swimming, soon escaped into the surrounding woods, so another six were released on the island. They escaped as well.
After the population reached around 400 monkeys in the 1980s, Florida began trapping the primates and selling them to biomedical research facilities. That practice ended in 2012 after a public outcry. By 2015, the population stood around 176. The Wildlife Society estimates that the number of rhesus monkeys in the park will double by 2020 unless some of them are culled or sterilized.
The monkeys are known to attack or fling feces at humans who get too close. And the Centers for Disease Control estimates that about 30% of the monkeys carry the herpes B virus, which can cause brain inflammation and lead to death in humans. Transmission of the virus from monkeys to humans is very rare, but can spread through the monkey’s saliva, urine or feces.
According to a story in National Geographic magazine, no humans are known to have contacted herpes B from wild monkeys, although one medical researcher died after getting the bodily fluids from a captive monkey in her eye. Steve Johnson, a professor at the University of Florida, told the magazine that the odds of catching herpes from a wild rhesus macaque are “really, really low, but the consequence is really, really high—sort of like the lottery.”
Florida officials are weighing their options of containing the growth of the monkey population in Silver Springs State Park, but some locals enjoy having them there and want them to stay, the magazine said.