Gardening with potting mix linked to multiple Legionnaires' infections in New Zealand

In 2013, Christchurch resident Anne-Marie Prendeville became seriously ill with Legionnaires' disease after working with potting mix, eventually needing a ventilator before improving with targeted antibiotics. Gardener Robin Wilson contracted the illness three times—in 2011, around 2016, and three years ago—each episode following exposure to dry compost dust, leading to hospital stays and intravenous therapy. Health New Zealand data show Canterbury reported 36 cases in the year to August 31, representing nearly a quarter of the country's 152 cases, with most South Island patients hospitalized.

Experts identify older adults, smokers and those with chronic conditions as most vulnerable, and point to commercial potting mix as a primary source of infection. They advise wearing masks, gloves, dampening dry material and thorough hand washing to reduce risk.