Melioidosis and wet-season yard work in Cairns: who is at risk and how to stay safe

Melioidosis peaks in the wet because rain brings the bacteria to the surface. Queensland Government health information says the bacteria, Burkholderia pseudomallei, live in deep soil in northern Australia and rise up to muddy surface waters in the wet season. Most cases follow heavy rain or flooding, usually between December and May in Queensland.

Cairns has seen how closely the two are linked. Researchers at the Cairns and Hinterland Hospital and Health Service found a strong link between weekly rainfall and the number of people who fell ill, and the 120 cases recorded between December 2024 and April 2025 were the highest number ever recorded in a Cairns wet season. Statewide, Queensland Health recorded 261 cases and 37 deaths in 2025, against a five-year annual average of 85 cases from 2020 to 2024.

A record year does not mean every year will match it: Queensland Health says future numbers depend on how often heavy rain falls and how people behave. The bacteria stay in the soil either way, which is why the yard after rain is where the precautions count.

Melioidosis is rare in healthy adults and children, and most people exposed do not get sick. Queensland Health and the Cairns Public Health Unit name these higher-risk groups:

• People with diabetes, cancer, or chronic lung or kidney disease.
• Older people. Queensland Health's surveillance reports count people aged 50 and over among those most vulnerable.
• People who drink heavily or binge drink.
• Anyone on treatment that lowers the immune system, such as chemotherapy or long-term steroids.

The risk is concentrated: of the 84 Queensland cases recorded from 1 January to 28 June 2026, Queensland Health reports that 94 per cent were in people most vulnerable to infection, such as people aged 50 and over, people with long-term health conditions or people who drink heavily, and the Cairns Public Health Unit says healthy people under 50 with no underlying conditions are at very low risk.

A parent with diabetes who still weeds the garden after rain is exactly who this advice is for. For ways to take yard work off an older person's hands, see our guide to lawn and garden help for older Cairns residents.

Melioidosis gets in through broken skin, the lungs or, less often, contaminated drinking water. Queensland Government health information lists three routes: through skin cuts and sores, by breathing it in, and by drinking contaminated water. Queensland Health adds two that matter in a yard: walking through floodwater or muddy water with an open cut, and using a high-pressure hose on muddy surfaces and breathing in contaminated droplets. The Northern Territory Government also notes that the bacteria can be blown around in the air when it is windy.

A Cairns case shows how ordinary the exposure can be. The Cairns and Hinterland Hospital and Health Service reported on a White Rock woman who came home in really heavy rain and cleared grass and debris out of the drain near her driveway so it would not block. She was not wearing much protection, thought she must have had a small cut, and believes that is how she was infected. She spent a month in hospital. Her advice: do not garden after heavy rain, and wear gloves, boots, even masks if needed. The bacteria do not usually spread from people or animals, so the risk is the soil and water itself.

The same few precautions cover every wet-season job: keep soil and muddy water away from broken skin, keep your feet covered, and keep your face out of spray. Here is how they apply to the jobs most Cairns yards need after rain.

• Mowing and line trimming a wet lawn: Queensland Government advice for people at risk is to avoid contact with soil or muddy water, particularly after heavy rain, so the simplest step is to wait until the ground dries. If it cannot wait, wear waterproof boots rather than thongs and cover cuts on hands and legs first. Our guide on how often to mow in the Cairns wet season covers how long to wait after rain for the lawn's sake.
• Weeding and digging garden beds: this is direct contact with soil. Wear rubber gloves, which the Queensland Government advises people at risk to use for gardening, cover any wounds with waterproof dressings before you start, and wash your skin thoroughly afterwards.
• Clearing drains, gutters and storm debris: the White Rock patient believes her infection started at a driveway drain. Put on gloves and waterproof boots before touching wet leaves and silt. Queensland Health advises anyone in an at-risk group to stay inside during heavy downpours, so leave the job until the rain stops or hand it over.
• Hosing or pressure cleaning near soil: consider wearing a mask when using a high-pressure hose around soil or spraying bore water, and keep the spray off muddy ground where you can.
• Walking through flooded or muddy parts of the yard: never in bare feet or thongs. Wear waterproof boots. Queensland Health notes that foot and wound care is important for people with diabetes.
• Picking up palm fronds and green waste after a storm: gloves and closed-in shoes, then wash your hands with soap and water.

Much of this work can be done in the dry, before the risk rises. Our pre-wet-season yard and gutter checklist sets out what to get done in October. After a storm, our green waste removal service clears palm fronds, prunings and storm debris from the property.

Leptospirosis is a different bacterial infection, but it rises with the same weather and the same precautions help. It is caused by Leptospira bacteria spread through the urine of infected animals, including rats, mice, cattle, pigs, horses and dogs. Healthdirect says it occurs mainly in humid tropical areas such as Northern Queensland, and the Queensland Government says it spreads more easily after heavy rain or floods.

You catch it by touching water, soil or mud that carries the bacteria, which get in through cuts, open wounds, or the eyes, nose or mouth. Gardening is on the Queensland Government's list of activities that raise the risk, and its prevention advice reads like a yard routine:

• Wear gloves when gardening and closed-in shoes when outdoors.
• Wash cuts and sores with clean water and cover them with waterproof dressings before touching soil, mud or water.
• Wash your hands often with soap and water, especially after being outside.
• Keep the property free of mice and rats by cleaning up waste and food.

There is no vaccine for humans, and you can catch leptospirosis more than once. Standing water after rain brings a separate problem, covered in our guide to mosquito breeding in Cairns yards.

See a GP promptly if you feel unwell after working in wet soil or muddy water, and tell them about the exposure. Melioidosis symptoms may include fever, cough and difficulty breathing, or ulcers and skin sores that do not heal, usually 1 to 21 days after infection. Leptospirosis usually begins suddenly, about 5 to 14 days after infection, and can bring fever, headache, nausea, sore or red eyes and muscle pain, especially in the calves.

The Cairns Public Health Unit's advice is specific. A wound that won't heal or a fever that lasts for weeks after the wet starts means a GP visit, mentioning possible melio exposure. If you are immunosuppressed and suddenly feel really unwell after heavy rain, get medical help straight away and say you are worried about melio. Treatment is antibiotics, usually for at least three months.

For advice at any hour, call 13 HEALTH (13 43 25 84) to talk to a registered nurse, 24 hours a day, 7 days a week, for the cost of a local call. In an emergency, call 000. Queensland Health's melioidosis fact sheet has the full detail.

For anyone in a higher-risk group, the most reliable way to stay out of wet soil is to have someone else do the yard. Trisim runs lawn mowing across Cairns as a standing fortnightly round, on the same day each cycle, so the wet season never gets a head start. Edging, line trimming and a clean-up of the hard surfaces come with the cut, and mulch mowing returns the clippings to the lawn instead of bagging them.

Storm debris, palm fronds and prunings can be cleared through green waste removal: we load and take it, and the disposal is inside the quote. Every job is quoted before it starts. See our lawn mowing pages for Manoora, Westcourt and Edmonton.