Florida Monkeys Possibly Carrying Deadly Herpes Virus Could Double Population Size By 2022

monkey florida herpes b
In this photograph taken on August 5, 2014, monkeys sit on a fence in the backyard of a home in New Delhi. A recent study found that the rhesus macaques that live in Florida could double in population size without management intervention. SAJJAD HUSSAIN/AFP/Getty Images

While the monkey population has drawn tourists to Silver Spring State Park in Florida for years, a recent study found that without wildlife management, the population could double and possibly be dangerous to humans.

The study, published in Wildlife Management, explained that the rhesus macaques, a species of monkey, were originally introduced to forests located along the Silver River in central Florida to increase tourism. A total of 12 monkeys were introduced in the 1930s and 1940s and by the mid-1980s, the population grew to 400.

Although the increase in monkeys increased the appeal of the state park, it also increased the chances of interactions with humans. So, from 1984 to 2012, wildlife management removed about 1,000 animals, according to the study. However, public outrage forced the halting of the practice and researchers noted that there has been no population management since 2012.

"We estimated this population was growing and will likely double in size by 2022 without management intervention," the study said.

A tour boat operator called "Colonel Tooney" released six of the original monkeys onto a small island inside the state park, according to National Geographic. His goal was to create a Tarzan-themed attraction, but, now, the influx in monkeys could spur health concerns for visitors.

Rhesus macaques can carry the herpes B virus, which Dr. David Priest, the medical director for infection prevention at Novant Health, told Newsweek can be dangerous for human beings. The virus, which causes mild illness in monkeys, can be "deadly for humans," according to Priest.

Priest explained that it's extremely rare for humans to contract herpes B, but said it's possible if they are bitten or scratched by a monkey or in contact with a monkey's body fluids or tissue.

"Only about 50 human cases have been reported in the last 80-plus years," Priest explained. "People who are most at risk for acquiring this infection are veterinarians and laboratory workers."

Symptoms from the infection in humans include a rash or flu-like symptoms such as fever, chills and headache. The virus becomes potentially deadly if it causes encephalitis, which is the inflammation of the brain.

If someone were to contract herpes B, Priest explained they would have their wounds thoroughly cleaned and antiviral medications would be administered.

This isn't the first complication the park has experienced with regard to the monkey population. In July 2017, Silver Springs State Park closed the Ross Island Boardwalk and Sea Hunt Deck after multiple guests complained of aggressive monkey behavior.

Steve Johnson, associate professor of wildlife ecology and conservation at the University of Florida, estimated to the Ocala Star-Banner that there were 200 monkeys living in and around the park at the time. He partially credited the aggressive behavior to the monkeys learning to associate humans with food.

The concept of removing the monkeys from their non-native habitat is controversial but after a study was released in January about the herpes B virus, the Florida Fish and Wildlife Conservation Commission supported the measure.

A statement sent to the Orlando Sentinel stated that the monkeys' presence could have serious health and safety risks for humans and that the commission supported removing the monkeys to "help reduce the threat they pose."

The study published in Wildlife Management recommended removing at least 50 percent of subadults and adults biennially. It noted that the population of monkeys could be reduced to the size it was in the fall of 2015 by sterilizing at least 50 percent of adult females annually or at least 80 percent biennially.