Officials in Florida are again battling a highly aggressive, extraordinarily destructive giant snail species capable of spreading parasitic worms that invade human brains.
Giant African land snail (GALS) —aka lischtina fulicaAccording to the Florida Department of Agriculture and Consumer Services, it can grow up to 20 centimeters (8 in) long and is considered “one of the most invasive pests on the planet”. It ruthlessly feasts on more than 500 plant species—including many valuable fruits, vegetables and ornamentals—while pushing out several thousand eggs over its multi-life span, spawning in abundance.
In late June, Florida state officials confirmed the presence of GALS at a property in Pasco County, on the state’s west-central coast, north of Tampa. They have since set up a quarantine zone around the property and started snail-killing insecticide treatments last week.
While snails are a serious threat to agriculture and natural vegetation in the state, invasive mollusks also pose a health risk. They are known to transmit rat lung parasites, which can invade the human central nervous system and cause a type of meningitis. For this reason, officials have warned people not to handle the giant snail without gloves.
You may recall that rat lungworm made headlines a few years ago when Hawaii’s Department of Health tallied more than a dozen cases in 2018 and 2019. In 2018, the Centers for Disease Control and Prevention also published data on several unrelated cases from eight continental states between 2011. And 2017, suggesting a wider presence.
Rat Lungworm-aka Angiostrongylus cantonensisReceives its name mainly by infecting the lungs of rats and other rodents. In the lungs, adult worms mate and females lay eggs, which develop into larvae. Mice then cough up and swallow those young parasites, then expel them.
From those laden logs, the larvae infect snails and slugs (intermediate hosts), in their soft bodies or in the event that mollusks feast on infected feces. In the final stages of this gut-altering life cycle, rats nosh on infected snails and slugs, delivering late-stage larvae that move from the rodent’s abdomen to their brains, where the worms develop into young adults. Huh. Those mature worms then go back into the lungs of the mice for breeding time.
Humans are the casual host in this cycle. People pick up the infection by eating undercooked snails or slugs; eating fruits and vegetables contaminated with infected snails or slugs; or eating undercooked animals that may have eaten snails and slugs, such as frogs or crabs. Just like in rats, when insects are ingested by humans, they make their way into the central nervous system.
third eradication effort
But, in humans, they generally do not make it. They die somewhere in the CNS. Sometimes, this results in a symptomless infection – the worms die silently and require no treatment. In other cases, the worms seep through the brain, wreaking havoc before kicking the bucket and causing a wide range of symptoms, including nausea, vomiting, neck stiffness, eye problems, unusual sensations in the arms and legs. and headaches that are often global. And serious, according to the CDC. In severe cases nerve damage, paralysis, coma and death can occur.
For all of the above reasons, Florida officials are eager to stamp out these grisly woes. But, sadly, this isn’t the first time Florida has battled mollusks. The giant African land snail was declared extirpated from the state in 1975 and again in 2021. They were initially introduced to Flordia in the 1960s after a child brought back three from Hawaii as pets, which were eventually released into the wild. It is unclear how recently they were brought back, but some believe that they may have taken a ride on cargo or were brought to the kingdom by religious groups for use in healing rituals.