Hawaii confirms 2 cases of rat lungworm disease in Big Island visitor, resident

At least two people on Hawaii’s Big Island — one visitor and a resident — recently contracted “rat lungworm,” state health officials said Wednesday.

The first person, who the Hawaii State Department of Health did not identify, contracted the disease while vacationing in North Hawaii last year. He or she first became ill in December 2018 but was “not diagnosed until they were hospitalized for their symptoms when they returned to the mainland,” health officials said in a news release.


The visitor, who has since recovered, became the ninth confirmed case of rat lungworm in Hawaii in 2018, the state department of health said.

More recently, health officials confirmed a case of rat lungworm — scientifically known as angiostrongylus cantonensis — in an adult from East Hawaii. This person, who the state department of health also did not identify, first became ill in January before he or she was hospitalized in early February.

The resident’s case is now the first confirmed case of the disease in Hawaii in 2019.

Officials are not sure how either person contracted the disease but noted that department of health investigators are “conducting a detailed investigation to learn more about the patients and possible sources of infection.”

“Determining the exact source of infection in any individual is challenging since it requires a deep dive into a person’s food consumption history as well as where they may live, work, travel and recreate,” state health director Bruce Anderson said in a statement.

Rat lungworm is a parasite that’s found in rodents. The infected rodents then pass the parasite’s larvae through their feces, later infecting snails and slugs, among other creatures, when they ingest the larvae. Humans who eat raw or undercooked snails or slugs that contain the parasite can be infected, the Center for Disease Control and Prevention (CDC) reports.

Rat lungworm disease can have “debilitating effects on the infected person’s brain and spinal cord,” the Hawaii State Department of Health said, noting most people in the state becoming ill “by accidentally ingesting a snail or slug infected with the parasite.”


“Symptoms vary widely between cases, and the most common ones include severe headaches and neck stiffness. The most serious cases experience neurological problems, severe pain and long-term disability,” it added.

The news comes after health officials in the state recently confirmed a 2018 case of rat lungworm in a Hawaii infant. That case marked the sixth confirmed case of rat lungworm on Hawaii’s Big Island last year.

Fox News' Alexandria Hein contributed to this report.