Rat Lungworm Disease Concerns Grow Across Hawaii

Got story updates? Submit your updates here. ›

Residents on Oahu have reported seeing an unusually high number of snails around their homes due to prolonged rainfall, raising concerns about the potential spread of rat lungworm disease. The disease, which affects the brain and spinal cord, is caused by a parasite found in rats, slugs, and snails and can occur on all Hawaiian islands.

Why it matters

Rat lungworm disease is a serious public health concern in Hawaii, as the state has seen a rise in cases in recent years. While the Big Island has historically had more reported cases, the disease can be contracted on any of the islands. With increased rainfall bringing more snails and slugs, the risk of exposure has grown, prompting health officials to remind residents about prevention measures.

The details

According to the Hawaii Department of Health, rat lungworm disease is caused by a parasite that is passed from rats to slugs and snails. People can become infected by eating raw or undercooked produce that contains a small snail or slug, or part of one. Symptoms can include severe headaches, nausea, vomiting, and in some cases, temporary paralysis. To avoid the disease, the DOH recommends thoroughly washing produce, practicing good hand hygiene, eliminating food sources that attract rats, and removing standing water where snails and slugs may thrive.

• Increased rainfall has been ongoing for nearly a month on Oahu.
• As of April 1, 2026, three cases of rat lungworm disease have been confirmed on the Big Island, with no cases reported in Honolulu County.

What’s next

The Hawaii Department of Health will continue to monitor the situation and provide guidance to residents on preventing rat lungworm disease. Residents are encouraged to remain vigilant in their efforts to eliminate snails, slugs, and rats around their homes and to thoroughly wash all produce.