Hawai'i residents should wash produce thoroughly to prevent exposure to to pesticides, bacteria, and parasites that can cause a rare form of meningitis, the state Department of Health warned this morning.

The advisory comes in the wake of six probable cases of illness caused by angiostongylus or rat lung worm in 2008. All those who got sick were residents of the island of Hawai'i and regularly ate fresh raw vegetables from backyard gardens.

The parasite Angiostrongylus cantonensis causes a rare form of meningitis called eosinophilic meningitis or angiostrongyliasis. The condition is also referred to as "rat lung worm" because rats are part of the life cycle of the parasite. The parasite is found in snails, slugs, and freshwater prawns, crabs, fish, and possibly the flatworm in Hawai'i. Eating uncooked snails, slugs, freshwater prawns and fish can cause the rare infection, which can lead to serious illness.

"It's important to always wash raw vegetables and fruits thoroughly before eating them to remove insects, parasites, bacteria and other possibly harmful contaminants," said Dr. Sarah Park, state epidemiologist and Chief of the Disease Outbreak Control Division. She suggests carefully inspecting fresh vegetables to make sure they are free of slugs or snails.

Keeping home gardens free of rodents, snails and slugs can also reduce the risk of rat lung worm disease, Park said.

Signs of rat lung worm disease can include severe headaches, nausea, vomiting, neck stiffness, and other problems related to the brain and spinal cord. Most patients recover from the infection without treatment. If you think you may have angiostrongyliasis, see your healthcare provider and let him/her know of your exposures.

The state Health Department also warns that freshwater prawns, crabs or fish and mollusks such as snails should be cooked thoroughly before eating. Sufficient heat — such as boiling 3 to 5 minutes — kills the parasites, officials said.

For more information call the East Hawai'i District Health Office at 808-933-0912 or the West Hawaii District Health Office at 808-322-4877.

On the Web, more information is also available on the Centers for Disease Control and Prevention site at: www.dpd.cdc.gov/DPDx/HTML/Angiostrongyliasis.htm.