Rat lungworm (known by scientists as angiostrongylus cantonensis) was first identified as a problem for people in 1943, when Japanese doctors found the worms in the spinal fluid of a Taiwanese boy. It has been in the United States since the 1980s, according to infectious disease specialist, Aileen Marty, MD. Although Dr. Marty was not directly involved in the University of Florida study, she has been studying rat lungworm for the past two decades. Rat lungworm is responsible for close to 3,000 human infections annually, and “the risk increases with the rate of wild rodents carrying it,” Dr. Marty told Reader’s Digest.
However, the problem really begins with snails—the first cases were attributed to eating the garden pest. Rat lungworm burrows into the snail’s body—or the parasite can survive in the snail’s intestines if a snail eats it. Should you decide to indulge in undercooked escargot, the lungworm can penetrate your intestine and find its way to your brain, triggering the dangerous inflammation known as meningitis.
“Snails aren’t a common human food,” Dr. Marty points out, “but humans sometimes eat them, either as a delicacy or for medicinal purposes.” In addition, snails can be the source of rat lungworm in other animals, such as shrimp, crabs, frogs, and certain fish. Should you eat an infected creature, you’ll get the parasite. Rats get the lungworm from eating snails as well—and if rat droppings contaminate other foods—even fresh vegetables and drinking water—again, you can end up infected.
The symptoms can begin anywhere from 12 to 28 days later, and how sick you feel will depend upon how many worms got into your system. “The more worms, the worse you will feel,” Dr. Marty says. Early stage symptoms include intermittent dry cough and acute, severe, throbbing headache.
As meningitis kicks in, your symptoms could include irritability, light sensitivity, headache, stiff neck, mental confusion, fast breathing, fast heart rate, and fear of loud sounds. About 80 percent of patients experience nausea and vomiting. Some patients experience sensory symptoms such as tingling and numbness or a burning sensation that worsens with touch. “Sometimes weird sensations appear as sudden attacks at night,” Dr. Marty adds; in rare cases, she says, people will suffer hallucinations, illusions, confusion, disturbed pupil reflexes, incontinence, lethargy—even a coma that can end up being fatal. While children will have a shorter duration of symptoms like fever and lethargy, they have a much greater risk of suffering serious brain damage.
The study authors point out that presence of the rat lungworm is most likely more widespread than indicated in the study, and Dr. Marty agrees. As a result, it’s impossible to give an accurate risk estimate to those living in or traveling in Florida. In addition, although rat lungworm has been a problem primarily in tropical and subtropical climates, climate change may encourage the spread of rat lungworm northward, according to the study authors.
However, don’t be afraid of fruits and vegetables. In fact, eat more (because this is what happens to your body when you don’t eat enough of them)! Just be sure to wash your produce thoroughly. And, as Dr. Marty advises, don’t eat raw or undercooked snails, or the raw or undercooked flesh of any of the animals that feast on snails. Always wash your hands after handling any of these creatures—and before meals. And make sure you wash your hands the right way!