The doctors believe the woman became infected after foraging for warrigal greens (aka New Zealand spinach) around a lake near her home that was inhabited by carpet pythons. Usually, O. robertsi adults inhabit the snakes' esophagus and stomach and release their eggs in the snakes' feces. From there, the eggs are picked up by small mammals that the snakes feed upon. The larvae develop and establish in the small mammals, growing quite long despite the small size of the animals, and the worm's life cycle is complete when the snake eats the infected prey.
Doctors hypothesize the woman picked up the eggs meant for small mammals as she foraged, ingesting them either by not fully washing or cooking the greens or by not properly washing her hands or kitchen equipment. In retrospect, the progression of her symptoms suggests an initial foodborne infection, followed by worm larva migrating from her gastrointestinal tract to multiple organs. The prednisolone, an immunosuppressive drug, may have inadvertently helped the worm migrate and get into the central nervous system.
Kennedy, a co-author of the report on the woman's case, stressed the importance of washing any foods foraged or taken from a garden. She also emphasized proper kitchen safety and hand washing.