(FOX 13) - After sampling, rats, snails, and soil, University of Florida researchers have found evidence of the rat lungworm (Angiostrongylus cantonensis) in several Florida counties farther north than had been documented previously.
The counties include Hillsborough, Orange, Alachua, St. Johns, and Leon. Although there have been no human infections yet reported in Florida, the researchers wanted to also raise awareness to its presence to alert health care workers.
The study's authors say, "The ability for this historically subtropical nematode to thrive in a more temperate climate is alarming," and expressed concern about climate change in relation to the parasite's spread.
The worm begins its life cycle - as suggested by its name - in a rat. The worm eggs hatch and make their way into the rat's lungs. Stage 1 larvae are coughed up and swallowed, and excreted in the rat's feces, and then picked up by a snail or slug. That's where the larvae mature to stage three. After the snails excrete them, the rat ingests them and the cycle starts all over again.
The worms eventually die in infected "accidental hosts" such as humans. But the worms can trigger an immune reaction in the body causing eosinophilic meningitis, also called A. cantonensis.
Illness from A. cantonensis usually lasts between 2-8 weeks. People present with symptoms of bacterial meningitis, such as nausea, vomiting, neck stiffness, and severe headaches.
According to the CDC, most infections of A. cantonensis resolve over time without specific treatment because the parasite cannot survive for long in the human body. Symptoms of and tests for A. cantonensis are similar to those of bacterial meningitis, but test results for someone infected with A. cantonensis will reveal eosinophils cells instead of bacteria-fighting cells.
The infection may be difficult to diagnose and serious complications can occur, leading to coma or death. For this reason, researchers hope to make medical professionals aware of the parasite's presence.
Prevention includes not ingesting raw or undercooked snails and slugs, freshwater shrimp, land crabs, frogs, and monitor lizards, or potentially contaminated vegetables, or vegetable juice.
Removing snails, slugs, and rats found near houses and gardens should also help reduce risk. Thoroughly washing hands and utensils after preparing raw snails or slugs is also recommended. Vegetables should be thoroughly washed, leaf by leaf, if eaten raw.
There is also concern that the slime secreted by the snail or slug may also contain larvae. If water becomes contaminated with larvae, chlorine does not affect them.
Infections from the parasite have also been reported in dogs, non-human primate, opossum, and birds.