There has been a spike in confirmed rat lungworm cases recently in Hawaii. Puna, a district on the Big Island, has been dealing with threats of rat lungworm disease since 2004, and now Maui has seen recent cases of rat lungworm disease. Tragically, two of these recent cases were a couple on their honeymoon, and as a result there has been a surge of media attention on the parasite.

Some people on the Big Island have been trying to bring more awareness to this parasite for years and have been fighting for more state funding for research and public education. There has been criticism that the State has not been doing it’s job of alerting tourists about this parasite because they are afraid of a decrease in tourist revenues.

So, what is rat lungworm exactly? Why does it have such a disgusting name?

Rat lungworm is a parasite that humans can contract by ingesting infected slugs or snails. The rat lungworm parasite lives out its life cycle between rats and slugs/snails. The slugs eat rat poop which contains the parasite, and in turn, the rats eat slugs/snails.

When a human gets infected, the parasite travels up the spinal cord and into the brain where it lives out its life cycle. There is not really a pretty way to put this: the worms will crawl around the brain trying to find a way out, until they eventually die. Humans are dead end hosts to the parasite.

There is no cure and it is difficult to diagnose, and it is thought that there are many unreported or unconfirmed cases. Symptoms can be debilitating and severe- and can even lead to death or permanent disability. The disease can cause meningitis, excruciating nerve pain, paralyses, inability to urinate, and more.

The introduction of an invasive semi-slug species is correlated with rat lungworm disease cases.

Luckily, with awareness, rat lungworm disease can be easy to prevent. Here are some tips/info for avoiding rat lungworm disease during your Hawaii vacation:

  • If you prepare your own food and eat raw local greens, thoroughly wash and check each INDIVIDUAL leaf for slug slime or slugs. Those of you staying in vacation rentals with kitchens will need to have extra awareness if you prepare your own meals.
  • Remove each leaf by hand- do not cut first- you can accidentally cut a little slug in half and not notice it that way. Baby slugs are very tiny and hard to spot. Rinse, rinse, and rinse again with potable water.
  • Some greens like kale are really difficult to clean thoroughly- I would recommend not eating kale raw unless if you are meticulous about checking every little fold in the greens.
  • Washing with vinegar does NOT kill the parasite.
  • Some have recommended soaking greens in ice water before cleaning, which helps harden any slugs and makes them fall off. Couldn’t hurt to try, as long as you wash each leaf by hand after.
  • Wash any fruits or vegetables you eat- don’t eat fruit right off the tree or veggies right from the garden.
  • Always wash your produce with potable water. If you are staying at a vacation rental that is on catchment water, don’t use it as drinking water. Buy bottled water or refill water jugs with city water (there are public water stations around that you can fill up at).
  • Cooking or freezing greens kills the parasite. If you’re into kale smoothies, why not just throw your kale into the freezer for a day? Then you’ll know for sure that it is safe to ingest. Or, cook them! This way you can still eat healthy and also rest assured that you will not have any risk of rat lungworm disease.
  • Do not handle slugs with your bare hands or walk barefoot in the jungle. We know that the parasite can travel through abrasions on the skin, so theoretically, if you have cuts on your hands and you handle a slug and the slime goes into your cut, you could be infected. A small number of the parasites can be found in the slime of slugs and snails.
  • Be careful eating salads at restaurants and any potlucks/gatherings. You might want to ask the waiter if they use local greens and if they use rat lungworm prevention strategies. Most typical restaurants will use greens from Costco which are imported from the mainland, so the risk of contamination is a lot less.
  • Don’t stress out too much about it or cancel your trip! If you are aware, you can avoid the parasite. The State of Hawaii and the Department of Heath have not done a good job at helping spread awareness of this terrible parasite. Most of the education so far has been done by researchers at the University of Hawaii at Hilo and local community members.

If tourists are aware of the parasite, they can know to take necessary precautions!

For more detailed information on rat lungworm disease, you can check out