A University of Florida research team has found rat lungworm in five counties in Florida. This potentially deadly parasite can cause meningitis in humans as well as severe medical issues for pets.

Rats and snails have recently tested positive for rat lungworm in Alachua, Hillsborough, Leon, St Johns, and Orange counties, but currently no human cases of the infection have been detected.

Almost 3000 humans have been diagnosed with rat lungworm worldwide, but it is thought that many more may gone undetected or misdiagnosed.

Rat lungworm can cause meningitis if it becomes trapped and dies in the brain, but is rarely fatal in humans. Researchers warn the parasite can be infiltrate the human body by eating infected snails, frogs or crustaceans.

Symptoms of the infection in humans can include headache, fever, vomiting, a stiff neck, nausea and paralysis of the face, arms and legs.

“The parasite is here in Florida and is something that needs to be taken seriously,” UF assistant professor Heather Stockdale Warren says in the report. “The reality is that it is probably in more counties than we found it in, and it is also probably more prevalent in the southeastern U.S. than we think. The ability for this historically subtropical nematode to thrive in a more temperate climate is alarming.”

The recent report showed that almost 23 percent of rats and 16 percent of rat fecal samples in 18 Florida counties tested positive for the parasite.

Florida residents are being encouraged to be look for snails in living areas that might be accessible to pets.