A 16-year-old boy in Florida was infected with the Keystone virus in what seems to be the first-ever human case of the mosquito-borne illness. Doctors reported it took more than a year to identify the virus in the patient.
Researchers from the University of Florida (UF) detailed the case in a paper published in the journal Clinical Infectious Diseases on June 9.
The virus was first discovered in 1964 at Keystone, Florida, which is where it gets its name from. It was found in several animals including white-tailed deer, raccoons, and squirrels and was spread by aedes atlanticus, a type of mosquito commonly found in Florida.
While the virus has never been identified in humans before, study author Dr. J. Glenn Morris stated the infection may actually be fairly common in North Florida.
“It’s one of these instances where if you don’t know to look for something, you don’t find it,” said Morris, who is the director of the UF Emerging Pathogens Institute.
The teen was infected with the virus while attending a band camp in North Florida in the summer of 2016. In August of the same year, he went to an urgent care clinic in North Central Florida reporting symptoms such as a skin rash and fever.
“We couldn’t identify what was going on,” Morris explained. “We screened this with all the standard approaches and it literally took a year and a half of sort of dogged laboratory work to figure out what this virus was.”
After tests for Zika and other viruses turned up negative, viral cultures from the patient samples finally revealed the teen was infected with Keystone.
While this is the first documented case of human illness caused by the infection, the experts indicated the virus may have gone undetected for many years due to lack of symptoms or incorrect diagnosis.
Nearly 20 percent of people tested in the Tampa Bay region carried Keystone virus antibodies, according to a 1972 article in the American Journal of Tropical Medicine and Hygiene.
First author John Lednicky from the Emerging Pathogens Institute explained Keystone comes from a group of viruses known to cause inflammation in the brain.
But it is not yet known whether the Keystone virus itself will have such an effect. In this case, the teen only reported mild symptoms similar to a viral infection. As of now, there is no evidence to suggest the infection is life-threatening.
“All sorts of viruses are being transmitted by mosquitoes, yet we don’t fully understand the rate of disease transmission,” Morris said.
He believed more research on vector-borne diseases was needed to “shine a light on the pathogens that are of greatest concern” to the health of animals and human beings.
In conditions or places where the risk of mosquito bites is high, he also recommended wearing repellents to prevent the possibility of disease transmission.