Health New Zealand recorded 152 legionellosis cases nationwide between September 1, 2025, and August 31, 2026, with 135 people requiring hospitalisation for the severe form of pneumonia. Officials issued warnings urging spring gardeners to wear N95 masks, gloves, and handle potting mix outdoors after data revealed the South Island recorded the highest regional caseload in the country over the past year.
South Island Leads Nationwide Cases as Hospitalisations Reach 135
Health NZ figures show that 54 of the 152 notified cases occurred in the South Island, resulting in 46 hospital admissions. The region encompasses Nelson-Marlborough, Canterbury, South Canterbury, the West Coast, Otago, and Southland.
Regional breakdowns show close margins across the country. The Northern region, covering Northland and Auckland, recorded 49 cases and matched the South Island with 46 hospitalisations.
In the Midland region, which comprises Tairāwhiti, Taranaki, Bay of Plenty, and Waikato, 32 hospitalisations and 38 cases were recorded. Meanwhile, the Central region stretching from Hawke’s Bay to Wellington recorded 11 cases, with all 11 patients admitted to hospital.
Did You Know? Legionnaires’ disease is a type of pneumonia caught by breathing in legionella bacteria that thrive in moist environments and stagnant water, including potting mix, compost, and other soil products.
Handle gardening products safely to reduce bacteria exposure
National Public Health Service medical officer of health Dr Matthew Reid said public health records an increase in cases linked to gardening products each spring. To reduce the risk of breathing in legionella bacteria, officials urge gardeners to handle potting and compost mix bags outdoors or in well-ventilated areas.
Gardeners should open bags carefully and away from their face. Additional precautions include wearing gloves and a well-fitting face mask, with an N95 mask recommended where possible.
Reid noted that N95 masks can generally be bought at DIY and gardening stores or local pharmacies. Officials also recommend dampening down soil products to reduce dust, and washing and drying hands thoroughly after handling potting mix.
Symptoms and Vulnerable Populations
Inhaling the bacteria does not always result in sickness, and some individuals experience only a less severe condition known as Pontiac fever. However, Health NZ advises that people aged over 50, smokers, and those with chronic illnesses or weakened immune systems are more susceptible and should take particular care.
Comparable to a flu-like illness, symptoms can include muscle aches, headaches, nausea and vomiting, stomach aches, diarrhoea, excessive sweating, fever, chills, a cough, and shortness of breath. Some people also develop mental confusion or disorientation.
The illness typically worsens over several days and requires antibiotic treatment, with most cases needing hospital care. People experiencing symptoms after using potting mix or compost should contact their usual health care provider or call Healthline for free on 0800 611 116.
Identify groups at risk and recommended mask types
Who is most at risk of contracting Legionnaires’ disease from gardening?
Health NZ states that people aged over 50, smokers, and those with chronic illnesses or weakened immune systems are more susceptible to the disease.
What specific mask do health officials recommend wearing?
Dr Matthew Reid recommends wearing a well-fitting face mask, noting that an N95 mask is best and can generally be bought at DIY and gardening stores or local pharmacies.
How many people were hospitalised nationwide over the recorded period?
Health New Zealand figures show that 135 people ended up in hospital out of 152 notified legionellosis cases between September 2025 and August 2026.
What steps will you take in your garden this spring to minimise exposure to soil-borne bacteria?
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