Rat lungworm diagnosis, care guidelines offered

Report calls for mass killing of parasite, treating inflammation

A governor’s task force released new preliminary guidelines Thursday for rat lungworm diagnosis and treatment.

The guidelines generally adopt protocols developed by doctors on the Big Island working on the front lines of the disease.

Since 2017, most of the state’s 23 confirmed cases of the debilitating disease have occurred on the Big Island. There have been seven confirmed and one probable case during the same period on Maui, the Health Department said. Only one of the cases on Maui, which involved an adult, occurred this year.

The disease is caused by a worm that attacks the brain and spinal cord of human beings, the department said. The worm larvae are passed to humans who ingest raw or undercooked freshwater shrimp, land crabs and snails or raw produce that contains infected slugs or snails and their slime.

The parasite causes a rare type of meningitis. Its symptoms include severe headaches and neck stiffness, tingling or painful feelings in the skin or extremities, low-grade fever, nausea and vomiting. Some effects can be permanent and create lifestyles changes, such as the inability to walk or drive.

The damage is “caused by worms crawling around your brain,” said Maui District Health Officer Dr. Lorrin Pang, a member of the task force, on Thursday.

The new preliminary protocols, which will continue to be studied, involve killing all of the worms in one “big blast,” then preventing the “collateral damage” from the body’s response to the mass kill-off with anti-inflammatory drugs, Pang explained.

“It’s a nice, reasonable” approach, he said.” Kill ’em and reduce the flare-up.”

There initially was some opposition to the treatments employed on the Big Island. In November, Civil Beat reported that the Centers for Disease Control web page on the disease said that most people infected with rat lungworm fully recover without treatment. The most common treatment focuses on the symptoms rather than a cure.

The story reported that the Health Department website said that anti-parasitic drugs have been ineffective and that attempts to treat the disease may make the symptoms worse because the body’s immune system deals with the rapidly dying worms.

Pang said Big Island doctors “did their own thing on a case-by-case basis.” He noted that if the infection were caught early and the parasite had not reached the brain, where the major damage would occur, doctors would attempt to eradicate the worms.

The Big Island doctors used Albendazole to kill the worms, and the steroid Prednisone to treat the body’s reaction, he confirmed.

He said Albendazole is cheap, less than $1 a dose, but there are reports of significant price increases. He said he hopes that government agencies can get a decent price for the drug and worries that cost may lead people to turn to animal dewormers.

“I wouldn’t do that,” he said about using animal dewormer drugs to treat rat lungworm.

The new guidelines may be used by Hawaii physicians immediately and provide clear diagnosis, treatment and management guidance for timely identification and care for patients who have contracted the disease, the Health Department news release said Thursday.

“One of the top priorities of the joint task force has been to develop sound, evidence-based guidelines for physicians to use in diagnosing and treating angiostrongyliasis (rat lungworm),” said Kenton Kramer, chairman of the joint task force and associate professor of the Department of Tropical Medicine, Medical Microbiology and Pharmacology with the University of Hawaii John A. Burns School of Medicine.

He said that the clinical subcommittee of the task force, made up of physicians and specialists statewide, spent the last year researching and consulting with national and international specialists “to carefully craft the new guidelines.” Pang noted that subcommittee officials took a trip to Southeast Asia to gather information.

There were “no clear, reliable diagnosis and treatment protocols available to Hawaii physicians for this potentially serious and debilitating disease,” said Dr. Vernon Ansdell, an associate professor at the UH Burns School of Medicine and a physician with more than 45 years of experience specializing in internal and tropical medicine.

A diagnosis of rat lungworm “can be problematic because patients infected with the parasite do not always present the same symptoms,” said Ansdell.

“These preliminary guidelines provide critical guidance to physicians to help them make timely and accurate diagnoses and give their patients the best possible treatment available,” he said.

The preliminary guidelines will be presented at the annual meeting of the American Society of Tropical Medicine and Hygiene in November. Clinical subcommittee members also will be working to undergo the rigorous academic process to expand the preliminary guidelines and to submit them for scientific peer review and official publication.

The next steps also include offering physician training statewide, the Health Department said. Members of the clinical subcommittee will be offering Continuing Medical Education courses through the UH Burns School of Medicine in all counties, starting in Hilo on Oct. 10.

The courses will be offered on Maui and the rest of the state in early 2019, the news release said. Information on the courses may be found at manoa.hawaii.edu/tropicalmedicine/?page_id=3783.

“Updating and improving the guidelines for physicians to better diagnose and treat rat lungworm disease is a major accomplishment for the joint task force,” said Health Department Director Bruce Anderson. “We are excited to be a partner in this process and look forward to supporting this project as the guidelines move toward publication and national recognition.”

Pang said the guidelines “took kind of a long time.” Since a sharp increase in cases last year, the Health Department has been able to control the disease vectors and educate the public about the risks.

Efforts are underway on Maui to create barriers to slugs entering farms and contaminating vegetables, he said.

On the Big Island, health officials are focusing on de-rat lungworming rats. Rats harbor the parasite and pass the larvae along in their feces, which can be ingested by slugs, snails, frogs and freshwater shrimp.

The preliminary guidelines are posted on the Health Department’s website at health.hawaii.gov/docd/for-healthcare-providers/news-updates/ and health.hawaii.gov/docd/disease_listing/rat-lungworm-angiostrongyliasis/#info_for_clinicians. It also is posted on the UH Burns School of Medicine website at manoa.hawaii.edu/tropicalmedicine/?page_id=3783.

* Lee Imada can be reached at leeimada@mauinews.com.

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