A dangerous parasite that can produce serious health issues in humans, previously found in snails that have infested South Florida, is even more widespread than previously thought, experts say.
Previously detected in invasive giant African snails, the tiny worm parasite that can strike humans, dogs, horses and birds with a potentially fatal disease has been found in three more non-native species in snails in the state, researchers at the University of Florida say.
The parasite, which can also be carried by rats, is known as the rat lungworm.
Following the initial discovery, researchers say they have been engaged in testing snails throughout the state to try and determine how far the parasite may have spread.
"Determining the geographic distribution of this parasite in Florida is important, due to the hazards to human health," says Heather Walden, an assistant professor of parasitology in the university's college of veterinary medicine.
The research was initiated when a privately owned orangutan in the Miami area, which was known to eat snails, began to exhibit neurological symptoms in 2012.
It was brought to the university, and when it subsequently died, researchers analyzed snail species where they animal had been living and found the parasite in three more species of snail, the Cuban brown snail, striate drop and Asian trampsnail.
The parasite, scientifically known as Angiostrongylus cantonensis, has been identified as a public health threat throughout much of Asia and in Hawaii.
Although previously detected in Florida and Louisiana, it had not been considered common in the continental United States.
The parasite can cause a fatal form of meningitis in people but is only dangerous if eaten, the researchers say. In Hawaii, there have been dozens of cases of people falling ill, usually from ingesting tiny snails in produce or on salad greens that were improperly washed.
"Humans can't become infected with this parasite unless they eat an undercooked or raw snail," says Walden, lead author of a study published in the Journal of Parasitology. "As long as food is cooked and you wash your produce, you will most likely never ingest it."
However, the researchers say, the parasite presents a particular risk for dogs and other animals, and officials in Miami-Dade County say at least one dog in the area is thought to have died after eating giant African snails.
"If you know you have a snail problem, try to keep your pet away from that area," Walden suggests.