November

24

2011

BY DAN FLYNN | NOV 16, 2011

© Food Safety News

In paradise, they still have to worry about rat lungworm.

Hawaii's top experts on the debilitating infection gathered last week at the University of Hawaii-Hilo's College of Pharmacy out of growing concern about rat lungworm.

Earlier this year, the Hawaii Department of Health (DOH) had to issue a warning about rat lungworm-- also known as angiostrongyliasis -- over four cases on the Big Island.

There were nine cases of rat lungworm in Hawaii last year, with most also being on the Big Island. Those might not seem like large numbers, but what happens to people who get this entirely preventable infection is very disturbing.

By eating the wrong raw snails or slugs, or possibility by touching their "slime trails," you can find yourself suffering from nausea and abdominal pain that can quickly turn into urinary problems, coma, and even death.

Even with the best, rapid treatment, full recovery is often not possible, says Dr. Jon Martell, medical director at Hilo Medical Center. Martell was one of the experts participating in the UH-Hilo panel.

There is no "clear convincing studies to show effective treatment of rat lungworm," he said. Treatment now include both anti-worm medicines and anti-inflammatory steroids.

Rat lungworm infections were first identified on Oahu in 1958, according to Mariena Dixon, a DOH investigator who works in East Hawaii.

Rats eating snails or slugs ingest "third stage" worms or parasites that penetrate through the intestine to the bloodstream. The parasites then reach the central nervous system of the rat, reaching the "fifth stage" or young adulthood.

They mature in the bloodstream and mate in the rat's heart and pulmonary artery. The female parasite lays eggs that hatch into "first stage" worms that are expelled in the rat feces and then eaten by slugs or snails.

According to UH snail researcher Rob Cowie, it is when people touch or eat raw snails or slugs or their "slime trails" that the threat to human health occurs.

Cowie says that is because the worms can get into the human circulation system, moving to the nervous system, and then the brain. That's where the worms go to die, but by that time it may be too late for the infected person as well.

The death of the worms appears to be what causes symptoms of rat lungworm infection, according to Cowie.

Slugs and snails can be clear and less than an inch long, making them hard to spot, but each one can carry thousands of worms.

In its public health alert, DOH cautioned people to wash produce thoroughly, clean food preparation areas, and make sure children are not putting "foreign items" in their mouths.

"The parasite can be found in snails, slugs, and rats throughout the State of Hawaii and may also be found in freshwater varieties of prawns, and crabs," the DOH warning said. "Eating contaminated uncooked or undercooked snails, slugs, and freshwater prawns may cause the infection which can lead to serious illness."

Hawaiians were urged to keep their home gardens free of rodents, snails, and slugs and wash all fruits and vegetables before visually inspecting them to make sure they are free of slugs or snails.

Carriers of the rat lungworm include Asian semi-slugs, Cuban slugs, and flatworm, according to USDA entomologist Rob Hollingsworth.

The "Rat Lungworm Disease" What DO We Know?" panel attracted interest from Big Island vegans, including some who've survived a round with the infection.