Addressing rat lungworm disease: Experts say more research is needed

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WAIMEA — Darlene Turner first thought she had rat lungworm disease (RLWD) on Oct. 18, 2015.


WAIMEA — Darlene Turner first thought she had rat lungworm disease (RLWD) on Oct. 18, 2015.

“I went to my primary physician in late September 2015 and he said I had a really bad cold. My symptoms kept getting worse, so on Oct. 13, I went back to him and he said I had the flu and if it didn’t get better he would schedule a spinal tap,” she said. “He later told me he had suspected rat lungworm.”

Although extremely sick, Turner went to church Oct. 18 where a friend told her he recently attended a talk in Honokaa given by Kay Howe, an Integrated Pest Management curriculum development specialist at The Research Corporation of the University of Hawaii. She also works with Hawaii Island Rat Lungworm Working Group led by Dr. Susan Jarvi at the Daniel K. Inouye College of Pharmacy at UH-Hilo.

Her talk focused on what RLWD is, how it is contracted, diagnosed and treated. Howe’s son, Graham, had been admitted to Hilo Medical Center in late December 2008, and a month later went into a coma while suffering from RLWD. She administered Chinese medicine that had been shown to help in a similar case of a young man in a coma from the same disease.

Graham was released from the hospital April 30, 2009.

“I went home immediately and Googled the disease and knew immediately that I had rat lungworm disease,” Turner said.

According to State of Hawaii Department of Health website, RLWD affects the brain and spinal cord. Caused by a roundworm parasite, infected rodents (including rats) can pass larvae of the worm in their feces to snails, slugs and certain other animals including freshwater shrimp, land crabs and frogs. Humans can become infected if they eat a raw or undercooked infected intermediate host, thereby ingesting the parasite.

“I went back to the doctor the next day and told him I thought I knew where I’d gotten it from. Normally I cook all my kale, but in September I had bought kale at the grocery store and saw a tiny skeleton of a slug on it,” Turner said. “I washed it and put the raw kale in a smoothie.”

She said her doctor then sent her to the ER, where they took blood samples and did a CT scan and an MRI.

“The diagnosis was that I had nothing wrong with me,” Turner said. “I was told I could be flown to Oahu for a spinal tap but I had learned it doesn’t always show RLWD and is a potentially dangerous procedure. The ER doctor explained there was no treatment for RLWD and sent me home.”

Her on-going symptoms ranged from brain pressure, joint and body aches to numbness, sensitivity to light, skin crawling sensations and intestinal issues, among others.

Turner decided to call Howe for advice.

“Armed with the information she gave me from Graham’s treatments, I went to my naturopathic doctor in Waimea, Michaela Martin. She immediately began naturopathic and acupuncture treatments aimed at killing the parasites, and researched what had been done or could be done to treat RLWD,” she said.

Dr. Martin said she felt relieved there were options to support her patient and rid her body of the parasites.

“I worked to boost her immune system and reduce inflammation in her nervous system, using a variety of nutrients and started her on IV vitamin therapy,” she said.

Turner also continued chiropractic treatments, acupuncture and essential oils. She went on disability for more than six months before returning to work part-time in May 2016.

“I’m still recovering,” Turner said Wednesday. “I’ve improved a lot but am still receiving IV vitamin therapy once a month. I still have some of the symptoms but they are less severe and debilitating.”

Earlier this month, she attended a RLWD talk at Tutu’s House given by Jason Dela Cruz, a public health preparedness health educator for Hawaii State Department of Health (DOH), and shared her story with the group.

“Ms. Turner’s hybrid use of both medical and naturopathic medicine is somewhat unique and demonstrates that cooperation between all parties involved in the prevention, diagnosis and treatment can have positive results,” Dela Cruz said. “We can all work together better to address this issue and should work collaboratively as much as possible.”

He continued, “Officially, the DOH, Department of Agriculture (DOA) and College of Tropical Agriculture and Human Resources (CTAHR) outreach collaborative formed in May of this year. They have been working on this topic for many years to consolidate the current understanding and best practices regarding RLWD. The general presentation we share touches on all points that we determined relevant. It includes input and guidance from our disease investigators, vector control and sanitation programs.”

During the talk he stressed the important of preparing vegetables safely.

“We all should consider that a good portion of rats, slugs and snails in Hawaii are likely infected. It’s important to inspect, wash and store all produce carefully, and reduce or prevent snails/slugs from entering gardens by using raised beds, copper tape and poison control,” Dela Cruz said. “Like many health issues, prevention is key.”

“Rinsing with water does not kill the parasite. The infective larvae are invisible to the naked eye. When in doubt, throw it out or thoroughly cook veggies and fresh water prawns, snails, frogs, crayfish or crabs to kill the parasite,” he added.

Another option is freezing vegetables, after washing them, for 24 hours before using them.

According to a DOH report from 2007-2016, 10 RLWD cases were confirmed in Hawaii County in 2016. DOH plans to continue giving rat lungworm presentations around the island to inform residents.

Jarvi, PhD, studies host-parasite and parasite-parasite interactions and influences on transmission and virulence of infectious disease at UH-Hilo Department of Pharmaceutical Sciences.

“We initiated research and educational outreach in 2012,” Jarvi said. “We’ve completed one study evaluating a diagnostic test developed in Thailand on human exposure to the rat lungworm parasite and are in the process of isolating the proteins needed from Hawaii’s rat lungworm as a diagnostic test for comparison.”

They are also working with the Centers for Disease Control, who is preparing the proteins in a different manner, she said.

“In the next year we hope to have a comparative study completed with these three tests on the same 435 human blood samples previously collected,” Jarvi added.

For research and education outreach funding, Sen.Russell Ruderman submitted bills for the Jarvi Lab in 2015 and 2016, but both were denied.

“In 2017, Sen. Kai Kahele submitted the bill for funding $1.4 million to be spread over two years for us. The bill passed both Senate and House Committees unanimously and unopposed with very strong testimony support, however the bill was killed in the last hours of the 2017 Legislative Session,” Howe said.

Jarvi, Howe and Turner submitted testimony for the bills.

“We attempted a third time to obtain state funding and were again unsuccessful. In the final week of the session, Ways and Means Chair Senator Jill Tokuda gave $1 million to the Hawaii State DOH,” Howe said. “The research and education being done in the UH-Hilo Jarvi Lab is not only beneficial to Hawaii, but also to the mainland and other countries impacted by rat lungworm disease.”

Hawaii Island Rat Lungworm Working Group recently received donations from other sources, including $35,000 from the Max and Yetta Karasik Family Foundation to investigate the effectiveness of commercially available water filters in blocking rat lungworm larvae from entering household and agricultural rainwater catchment water supplies, and the effects of UV light on RLW larvae. Hawaii Catchment Co. in Keaau supplied a “laboratory-sized” catchment system.

A $10,000 donation came from the Anderson-Beck Fund of the Hawaii Community Foundation to create a brochure with information on safer buying, cleaning and storing fresh produce eaten raw. Jarvi said it will be made available for all interested grocery stores, markets, produce stands and CSA food boxes on the island.

The James Shingle Family Fund and Edwin and Cynthia Sorenson funded the printing of general audience brochures and several thousand copies of “The Mystery of Rat Lungworm Disease,” an activity book that will be made available to second-grade students at schools on Hawaii Island.

“Education is important, but research is critical if we are to understand the modes of transmission, identify disease ‘hotspots,’ determine the effectiveness of vector control, develop a reliable blood-based diagnostic and evaluate acute and chronic treatments,” Jarvi said.

While earning a Master of Science from the Tropical Conservation Biology and Environmental Science Program at UH-Hilo last year, Howe’s thesis work focused on five partner schools with school garden projects, including Kanu o ka Aina.

“Hawaii Island has the highest incidence of rat lungworm disease of all the Hawaiian Islands and the mainland,” she said in her report. “In collaboration with five partner schools on Hawaii Island, (we) worked with students and teachers to develop an integrated pest management plan for school garden projects.”

But Howe thinks more needs to be done.


“The state needs to realize we could lead the nation in research, and to get over the fear of telling tourists,” she said. “Ignoring this problem that started to be evident back in 2005-2007 has led to the spread of the parasite and its hosts. Now it will be a much bigger problem. This disease is debilitating if you have a serious case. We have had deaths and permanent disability from rat lungworm disease on Hawaii Island over the past 10-15 years and nothing was done.”

Info: Donations can be made to the University of Hawaii Foundation, Rat Lungworm Research at To schedule a DOH rat lungworm talk contact Jason Dela Cruz at

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