HILO, Hawaii — The University of Hawaii’s pharmacy school on the Big Island is emerging as one of the key players as Hawaii continues to fight against rat lungworm disease.
Dr. Susan Jarvi, the head of the rat lungworm working group at UH’s Daniel K. Inouye College of Pharmacy, says new state funding has allowed her to add two full-time rat lungworm researchers.
As the third case of rat lungworm this year has been confirmed in Hawaii, her team has been working on is speeding up the diagnosis by developing tests based on antibodies and DNA in blood, rather than spinal fluid.
In a press release last week, the state Department of Health said that all three cases had occurred on the Big Island — two in East Hawaii and one in North Hawaii.
Rat lungworm is caused by a microscopic parasitic worm that lives part of its life-cycle in rats and part in slugs, snails or aquatic hosts such as freshwater shrimp. If humans eat raw or partially cooked seafood or accidentally ingest a slug in a salad, the worms can cause symptoms ranging from mild fever to nerve and/or brain damage, paralysis, blindness and death.
According to the DOH’s official web page on rat lungworm, the most common way to diagnose the disease is through a combination of the patient’s history of possible exposure and the symptoms exhibited, “as well as laboratory finding of eosinophils (a special type of white blood cell)” in the patient’s cerebrospinal fluid.
Jarvi’s team hopes to develop a much faster, cheaper test, using blood instead of cerebrospinal fluid. They’ve been working with the blood of animals suspected of having the disease, with promising results: the tests so far have detected rat lungworm DNA in eight out of 16 dogs and two of six horses.
Working with federal inspectors, Jarvi’s researchers also have been identifying rat lungworm larvae in other creatures, including centipedes, greenhouse frogs, cane toads and even mongoose — and in 21 out of 24 coqui tested so far.
Private funding from retired cardiologist Richard Robbins has allowed five pharmacy school researchers, led by Kathleen Howe, to work on another front. While the official DOH site only mentions “food contaminated by the larval stage of A. cantonensis worms” — chiefly by accidentally eating slugs or undercooked snails — as a vector for the disease, Howe and her colleagues recently completed a scientific paper that suggested that the parasites could also be conveyed by water.
That paper was scheduled to appear in an online scientific journal called Plos One this month. Jarvik sent Civil Beat an advance copy. Among its findings: if an infected slug or semislug fell into water and drowned, rat lungworm larvae could escape the drowned host and survive in the water itself for at least 21 days.
This could have particularly dire consequences on the Big Island, where tens of thousands of households rely on rainwater catchment water tanks.
Some catchment systems are protected by filters to designed to remove bacteria and sediments. But Howe’s team tested five such filters, including commonly used wound polypropylene fiber models, and found that some of the agile worms could wriggle through most of those filters. The only one that the group has tested so far that stopped all the larvae was a five-micron carbon block filter.
Howe has also developed a grade school curriculum unit in which students actually do research about the disease, learning how to safely collect slugs and other non-native mollusks, identify them and tally them. A pilot project involving five Big Island schools has created “story maps” recording the data each school collected, giving some idea as to what mollusk pests are located where.
With Frannie Kinslow-Brewer of Big Island Invasive Species Council, Howe recently taught a course for teachers on how to use the curriculum.
A Victim’s Story
Mark LeRoy was the second case on record this year. The disease has cost him five ER trips and an extended hospital stay, and has left him with memory loss and nerve damage. But before he was finally diagnosed, he says, emergency room doctors repeatedly refused to consider rat lungworm as a diagnosis.
LeRoy had the exposure and the symptoms. In January, he’d found a slug — one of the most common carriers for the disease — in a salad he was eating. About 10 days later, while on a trip to Oahu, he developed severe pain and nausea and went to an emergency room. The ER doctors simply sent him home with medications for the pain and nausea.
But the symptoms persisted. Three days later, he went to the ER at North Hawaii Community Hospital. The doctors drew spinal fluid to check for eosinophils, but found only a 1% count. The DOH standards, LeRoy was told, called for a 10% count. Again, he was sent home.
“It wasn’t until between my fourth and fifth visit to the ER that they officially diagnosed me at my second spinal tap,” he says.
The eosinophils count then was still only 7%. But because it had risen so quickly, and because, he believes, his wife and his primary care doctor backed him up, the doctors went ahead and tested for the parasite itself. That test came back positive.
Meanwhile, his symptoms had gotten steadily worse, including pain so bad that “I couldn’t control it. I was screaming at the top of my lungs.”
He was hospitalized for a week, and dosed with steroids, fentanyl, Oxycontin, Ambien, and a morphine drip; after his release, it took him a full month to wean off all of the drugs except Ambien, which he still needs in order to sleep.
He believes that if his primary care physician hadn’t advocated for him, he’d never have been diagnosed correctly. He thinks many other patients who didn’t get that extra help have never been diagnosed.
When the DOH, UH Hilo and three other state organizations held a joint informational meeting on rat lungworm in North Kohala on April 22, Leroy and his wife, Maya Parish, were on stage with them, sharing their experiences. He hopes to address physicians themselves at a meeting in Hilo in early June, to raise the doctors’ awareness of the problem.
The Hilo Medical Center has set up a support group for rat lungworm survivors and their caregivers, who meet every second Wednesday of the month at the Keaau Community Center, 16-186 Pili Mua St., from 4 p.m. to 6 p.m.
Stay Up To Date On The Coronavirus And Other Hawaii Issues
Not a subscription
Civil Beat is a small nonprofit newsroom, and we’re committed to a paywall-free website and subscription-free content because we believe in journalism as a public service.
That’s why donations from readers like you are essential to our continued existence.
Help keep our journalism free for all readers by becoming a monthly member of Civil Beat today.
Alan D. McNarie has been covering the Big Island's people and issues for various publications for over a quarter century. He's published two novels: "Yeshua" and "The Soul Keys." He lives in Volcano. Email Alan at email@example.com