At 38 weeks pregnant, Hawaii island resident Alyx Barnett’s heart dropped in mid-March when she realized she had bit into a tiny leopard slug that was tucked into a piece of her kale salad.

Barnett considers herself lucky that she is aware of rat lungworm disease, how it’s carried by slugs that feast on vegetables and the risks she faced if exposed. But she didn’t realize what lengths she would have to go to to get medical help or cover the cost of a prescription.

Barnett, like many patients, faced hurdles in navigating the sometimes contradictory advice offered by hospitals and doctors about what to do after being exposed to the rat lungworm parasite. Further complicating the matter was her pregnancy.

Alyx Barnett was launched on a medical odyssey when she accidentally bit into a minuscule slug in her salad. Courtesy: Alyx Barnett

Barnett’s story is emblematic of how even those who know they’ve been exposed confront barriers to getting a complete diagnosis and treatment. She still has not been diagnosed with it, although the slug she bit into has been confirmed to carry the parasite and she’s experienced some symptoms. She gave birth to a healthy baby boy on Wednesday.

Hunting For Advice

As the health department advises, Barnett washed the kale leaves thoroughly but somehow the slug, which weighed less than a gram, managed to stick around.

Barnett declined to name the farm where she purchased the kale. She called to alert them, but isn’t planning to take legal action.

Rat lungworm, or angiostrongyliasis, is a stand-out among its fellow tropical parasitic diseases because of the neurological harm it can do. Humans are exposed if they accidentally eat parasite hosts such as small slugs or snails hiding among uncooked produce.

It’s called rat lungworm because the parasite infects rats and tends to settle in their pulmonary arteries. It spreads through rat feces to hosts such as slugs or snails.

Barnett said she called Hilo Medical Center for advice, but it seemed no one knew what to do because she was pregnant, and potential drug treatments could be risky. It was also a Sunday.

“The hospital had no idea what to do,” she said. “I spoke to a person at an emergency clinic and a physician. They said, ‘We don’t know. If you start having seizures or going numb then come in to the emergency room.’”

Hilo Medical Center spokeswoman Elena Cabatu said she could not comment on Barnett’s case, citing patient confidentiality.

How To Avoid Rat Lungworm Disease

On Monday, Barnett drove to the headquarters of the Rat Lungworm Working Group at the University of Hawaii Hilo College of Pharmacy, frozen slug sample in hand. By Tuesday, a $25 molecular test confirmed the slug she bit into had tested positive for the angiostrongyliasis parasite’s DNA.

Rat lungworm disease still eludes many medical personnel who are not familiar with it. Patients can suffer for weeks without knowing the cause because of its varied symptoms. The road to a proper diagnosis can take awhile, since an invasive spinal tap is currently the only definitive test for the parasite.

By the time a patient is officially diagnosed, the parasite may have already done serious long-term damage. Mild cases can prompt flu-like symptoms, while the most severe have resulted in coma, long-term disability or death.

Mysterious Disease, Uncertain Treatment

The proper treatment of the disease is still highly contested even among doctors and pharmacists, and most experts agree not enough research has been done to develop the best protocol. No medication has been proven effective or endorsed by the medical community.

Preliminary findings from a UH Hilo study found over-the-counter pinworm medication helped to kill larvae in test samples, but it’s still uncertain if it works in humans. Hilo Medical Center issued a public recommendation for it anyhow.

Barnett’s albendazole prescription. Courtesy: Alyx Barnett

Another drug called albendazole, an anti-worm medication, is a common treatment, despite insufficient data on its efficacy.

Albendazole was also included on a list of treatments issued by the Hilo Medical Center in 2020.

Ultimately, Barnett decided to pay $50 for an over-the-counter pinworm medication and secured a prescription for albendazole. The doctor agreed her pregnancy was in a late enough stage that the benefits would outweigh risks to her child.

“Knowing that the slug was in my mouth and it did test on the higher level for having it (angiostrongyliasis), I felt like there wasn’t any other option other than to get treatment,” she said.

With a prescription in hand, the next challenge was to find a pharmacy that actually carried it. The first pharmacy she visited in Keaau did not, so the pharmacist called several others until she found one that would be able to fill it in Hilo.

“I’m kind of flustered obviously at this point, and stressed,” Barnett said.

Then came the price tag: $8,599.99.

“That was the most shocking and disappointing thing to me,” she said.

Barnett at the time happened to be covered by two insurance plans, which turned out to be critical.

Neither covered her prescription in full, but together they did. That was a relief to Barnett, who lost most of her income as a fitness trainer and hiking and cycling tour guide during the COVID-19 pandemic.

But why would a medication that costs only a few cents in some countries be sold for thousands of dollars in the U.S.?

Dr. Vernon Ansdell, an associate professor at the school of Tropical Medicine, Medical Microbiology and Pharmacology at the University of Hawaii John A. Burns School of Medicine, said very few manufacturers make it in the U.S., so drug companies in the absence of competition can set the price high. It’s so rarely used that many pharmacies do not bother to carry it at all.

“They came up with this ridiculous price of several thousand dollars compared to a few cents in many countries,” said Ansdell. “And you’re talking about the same drug.”

Treatment Guidelines Are Confusing

Ansdell was on the team that updated the clinical guidelines for rat lungworm patients, which was published in an article in the journal Parasitology in February.

Ansdell, the lead author, said the major takeaway is that it’s crucial to diagnose cases early and start treatment as soon as possible. But that’s what makes this disease so challenging.

“Making an early diagnosis is very difficult,” he said. “The symptoms are vague and it’s kind of like a flu-like illness, so patients aren’t aware that this is something potentially important and many physicians aren’t really aware of it.”

Dr. Lorrin Pang, Hawaii’s chief health officer for Maui, searches for semi-slugs in Hana. The rat lungworm parasite lives in rats, but can be spread among snails, slugs, frogs, and other animals. Tad Bartimus/Civil Beat

The study found albendazole to be among the best treatment options when accompanied by steroids and supervised by a physician, but acknowledged only one study in Thailand has been conducted thus far.

Until more data are available, the authors of the study say taking steroids helps prevent any harmful inflammatory response to the parasite as the medication kills it. The study’s authors also note that the use of anti-worm medications has remained controversial for decades due to the concern it could trigger a harmful inflammatory response, but those concerns are not supported by clinical or animal studies.

“We believe that in most cases … the potential benefits of albendazole outweigh the theoretical risks,” the authors wrote.

After Barnett’s slug tested positive for angiostrongyliasis,  she took the over-the-counter pinworm medication followed by a week of albendazole. She’s felt mild headaches and some arm, neck and face tingling. 

Doctors may disagree about whether the treatment Barnett came up with is the best option.

The Hilo Medical Center’s recommendation to take pinworm medication, though made in good faith, lacks thorough medical backing, according to Ansdell.

“To be honest there’s no data on that whatsoever, and it’s purely speculation that it would work,” Ansdell said.

Albendazole, on the other hand, is likely to help but must be supervised, he said.

“It’s a potentially dangerous drug, like any drug,” Ansdell said. “Especially if you’re using it to treat rat lungworm, you can get bad inflammatory responses when it starts to kill the parasite. There should be a physician involved in following the patient.”

More Common Than We Know

But even patients who are prescribed albendazole sometimes don’t take it because they can’t afford it.

Without albendazole, the patient could face prolonged illness or relapse. Some patients resort to other unproven medications that could actually do more harm than good, such as ivermectin, an antiparasitic drug intended for horses. Some people find ways to buy it online or in animal feed stores, according to Ansdell.

“Drugs intended for animal use are not approved for use in humans and are potentially very dangerous,” he said. “Ivermectin is approved for use in several human parasite infections, but not rat lungworm disease.”

He estimated the fatality rate of rat lungworm disease in Hawaii to be between 1% and 3%.

In 2018, the Centers for Disease Control and Prevention issued a warning that the disease and exposure to the parasite could be more common than people realize.

And yet patients still face a difficult journey to even get a diagnosis.

As Civil Beat reported last year, the official government case count is likely an underestimate, according to a study from the University of Hawaii Hilo.

The state doesn’t collect information about presumptive cases, or people who report eating slugs later confirmed to carry the parasite. In cases where someone doesn’t know they ate a slug or the source of their mysterious pain, it may not be recorded at all.

The Hawaii Department of Health reports only cases in which a patient gets a spinal tap to demonstrate they have the disease, using a needle to collect a sample of cerebrospinal fluid, and their physician reviews several factors such as evidence of exposure.

In 2020, the health department reported five rat lungworm cases, including two on Oahu, two on the Big island and one on Maui, all Hawaii residents.

So far in 2021, it’s counted two cases on the Big Island among locals. Barnett is likely not counted among them, since she did not get the spinal tap required for an official diagnosis. Barnett said she believes her case was only considered an exposure and is not included in state records.

“It’s confusing to me,” she said. “They should make it public to people as to how many people are exposed.”

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