Everything You Need to Know About Rat Lung Worm Disease

Learn about how people can get rat lung worm disease and how it can be prevented.
October 25, 2019

What is rat lung worm disease?

Rat lung worm disease is an infection caused by a parasitic worm that mainly lives in rodents, but can also infect snails, slugs, freshwater crabs, shrimp, prawns and frogs.

Rat lung worm disease is rare in Australia, but has gained notoriety in recent years following a few widely-publicised cases, such as the tragic story of Sam Ballard, a 19-year-old who developed a brain infection after eating a slug on a dare.

Mr Ballard died eight years later, after suffering permanent brain damage and paralysis of all four limbs.

How do you get rat lung worm disease?

Adult worms are found inside the lungs and digestive tracts of rats. Infected rats excrete the parasite’s larvae in their faeces, which infect snails and slugs that come into contact with it. Freshwater crabs, shrimp, prawns or frogs can also become infected if they eat an infected slug or snail.

People can become infected if they eat (deliberately or accidentally) raw or undercooked snails, slugs, freshwater crabs, shrimp, prawns or frogs that are infected with the parasite.

They can also become infected if they eat unwashed lettuce or other raw leafy vegetables that have been contaminated by the slime of infected snails or slugs.

Symptoms of rat lung worm disease

Some infected people don’t experience any symptoms of rat lung worm disease or only have mild symptoms. Rarely, rat lung worm disease causes an infection of the brain called eosinophilic meningo-encephalitis.

People who develop eosinophilic meningo-encephalitis may experience:

  • headaches, neck stiffness
  • tingling or pain in the skin
  • fever, nausea and/or vomiting
  • temporary facial paralysis
  • light sensitivity

Anyone experiencing all or many of these symptoms should seek medical attention immediately.

Why should Food Handlers be aware of rat lung worm disease?

While rat lung worm disease is rare, Food Handlers in every food sector in Australia must be aware of the dangers of rat lung worm disease for two reasons:

  1. Rat lung worm is found in Australia
  2. Rat lung worm disease can cause serious health problems and life-threatening complications

In a food business or establishment that does not serve raw or undercooked snails, frogs or freshwater crustaceans, unwashed produce that is contaminated with parasitic larvae poses the biggest risk to customers.

How to prevent rat lung worm disease

To prevent rat lung worm disease, it is necessary to:

  • Wash fresh vegetables and lettuces well before serving.
  • Wash hands thoroughly with soap and water after handling unwashed lettuces or leafy greens.
  • Cook snails, frogs and freshwater crustaceans thoroughly (75°C is recommended).
  • Follow safe food handling policies and procedures set out in the business’s Food Safety Plan.

All Food Handlers must be trained to follow safe food handling techniques and procedures to protect customers, clients or the people in their care from food-borne diseases — whether it’s from a rare parasite like rat lung worm or from common bacteria like Salmonella, Campylobacter or Listeria.

Food safety training in Australia is regulated and mandatory. The Australian Institute of Food Safety provides information about Australian food safety laws and regulations in simple, straight-forward language to help food businesses understand their obligations.

Contact our support team for information about our nationally recognised food safety training.