Editor's note: Ryker Roque passed away on Sunday, Jan. 14, family members said. "We are so sad to say that Ryker lost his fight last night," read an update on his GoFundMe page.

Jan. 10, 2018 -- A 6-year-old boy in Florida is fighting for his life after getting rabies.

Ryker Roque had hallucinations and then seizures a few weeks after an infected bat bit him. His parents rushed him to the emergency room, where doctors broke the devastating news.

Rabies in the U.S. has become very rare. According to the CDC, there were only three cases reported in humans in 2015, the latest year for which numbers are available.

It is nearly always fatal once symptoms start. But Ryker’s doctors haven’t given up. They are betting that a controversial experimental treatment -- which has worked on just two others in the U.S. -- will help him pull through.

Ryker’s family posted the details of his case along with an appeal for aid on a GoFundMe page. The Florida Department of Health confirmed there is a case of human rabies in the state and the person was infected by a bat and is being treated.

So far, Ryker has survived longer than he was expected to, which is giving his family hope.

The treatment has been dubbed “The Milwaukee Protocol” after the city where it was first tried in 2004. Doctors will place Ryker in coma and then treat him with a cocktail of antiviral drugs, some of which were made to treat Ebola, says Rodney Willoughby, MD, a pediatrician at Children’s Hospital of Wisconsin who came up with the treatment. The treatment is freely available to health care providers on the Internet.

“We have 18 survivors, hopefully more soon,” Willoughby said, adding that he could not talk about any specific patient’s case. A study published in August offers different numbers. It says there are just five published cases of human survivors of the treatment.

Most of the survivors have been in Peru, Willoughby says, which has far more human cases than the U.S. Only two of them are in the U.S. -- his patient in Milwaukee, he says, and one in the California.