Rat lungworm disease detected on Kauaʻi

The Hawai‘i Department of Health (DOH) has confirmed a case of neuroangiostrongyliasis, or rat lungworm disease, in an adult on the island of Kaua‘i. Rat lungworm disease is known to be endemic in all islands of the state of Hawai‘i. This individual had no history of travel to other neighbor islands, or outside the state or country.

The individual experienced symptoms including headaches, nausea, vomiting, neck stiffness and photophobia (aversion to bright light) and sought medical care. The diagnosis of rat lungworm was confirmed by newly available sensitive testing at the DOH State Laboratories Division. The investigation was not able to identify an exact source of infection.

From Jan. 1, 2014 to the present, a roughly 10-year period, 102 cases of rat lungworm disease have been reported statewide — 78 from Hawai‘I County, 13 from Maui County, seven from Honolulu County and four from Kaua‘i County (including the case reported this week). Hawaiʻi residents make up 84% of that count, with the other 16% of cases reported in visitors. Seventy-three percent of those with a laboratory-confirmed diagnosis were hospitalized. The last Kauaʻi case was in 2019.

“Thoroughly inspecting and washing all fresh fruits and vegetables under clean, running water is the most effective way to reduce the risk of rat lungworm disease,” said Dr. Sarah Kemble, state epidemiologist. “Small slugs and snails on produce can be difficult to see. Cooking food thoroughly also kills the parasite that causes rat lungworm disease.”

The DOH provides the following recommendations to prevent rat lungworm disease:

• Wash all fruits and vegetables under clean, running water to remove any tiny slugs or snails. Pay close attention to leafy greens. This is important whether produce comes from a local retailer, farmers market or backyard garden.
• Control snail, slug and rat populations around homes, gardens and farms. Get rid of snails, slugs and rats safely by clearing debris where they might live. Consider using traps and baits.
• Maintain water catchment systems and replace filters regularly. Cover and protect catchment tanks, as slugs can crawl up the tank and get into the water.

Early diagnosis helps target treatment to reduce the long-term effects associated with this disease. It is also important to rule out other dangerous diseases that can cause similar symptoms. Individuals with symptoms should consult their healthcare provider promptly.

For more information about rat lungworm disease and how to prevent its spread, visit: https://health.hawaii.gov/docd/disease_listing/rat-lungworm-neuroangiostrongyliasis/

Neuroangiostrongyliasis, commonly known as rat lungworm disease, is caused by a parasitic roundworm and can have debilitating effects on an infected person’s brain and spinal cord. In Hawai‘i, most people become ill by accidentally ingesting a snail or slug infected with the parasite Angiostrongylus cantonensis. Symptoms vary widely between cases; the most common ones include severe headaches and neck stiffness. The most serious cases experience neurological problems, severe pain and long-term disability.