An Australian man is gravely ill in hospital after eating two slugs as part of a dare.

Doctors believe that the 21-year-old, who has not been named, contracted the rare rat lungworm parasite from the slugs.

The disease, which is a type of meningitis, can lead to swelling of the brain and spinal cord and has been known to be fatal.

The rat lungworm parasite, also known as Angiostrongylus cantonensis, is passed to slugs from rodent droppings. It can also be caught from raw vegetables or fruit which have not been washed properly.

Doctors said the man told them he had swallowed two slugs from a Sydney garden after a dare, and had then fallen ill.