Wet season storms bring melioidosis and Ross River virus risks

NT Government

The monsoon season has officially arrived in the Top End, bringing an increased risk of diseases due to high rainfall, high humidity and fresh water pools.

NT Health is urging Territorians to be on high alert for the potentially deadly melioidosis and debilitating Ross River virus during this wet season.


Case numbers in the most recent wet season (1 October 2022 to 30 April 2023) were higher than usual, with NT Health recording over 80 cases of melioidosis and six deaths in the Northern Territory (NT).

On average around 50 cases of melioidosis are reported in the NT annually, with the vast majority of those diagnosed between November and April. To date this wet season, two cases have been reported.

Melioidosis is a disease caused by the bacterium, Burkholderia pseudomallei, found in tropical soil and water. While melioidosis bacteria live deep in the soil at the start of the wet season, heavy rain brings the bacteria to the soil and water surface. Wind can allow the bacteria to be blown around in the air, allowing it to be inhaled through dust and droplets.

Melioidosis bacteria in soil and surface water most commonly enter the body through cuts and sores so it is important to protect your skin.

Melioidosis most often causes lung infections and can also affect many variable parts of the body causing abscesses. Skin sores that do not heal can be caused by Melioidosis bacteria.

If left untreated, melioidosis can lead to severe pneumonia and blood poisoning, with around 10 per cent of infections leading to death.

To take precautions against melioidosis, Territorians are advised to:

• wear covered waterproof footwear when outdoors

• wear gloves while working in the garden or a soil-based environment

• wash then cover sores and abrasions with waterproof dressings

• wear a face mask while using high pressure hoses around soil and paths

• stay indoors during heavy wind and rain

• seek medical attention early.

Ross River virus

All Territorians living near or visiting wetlands are reminded to exercise caution as Ross River virus is spread through mosquitoes that can live up to three weeks during the rainy season.

On average, 250 cases of Ross River virus are diagnosed in the NT annually, with 67 recorded to date in 2023 – a decrease due to this year’s dry weather. The high risk period is from December to March due to rainfall.

Ross River virus is a debilitating disease that can last for months, with symptoms including swollen and painful joints and muscles, a red rash, fever, fatigue and swollen glands.

To prevent mosquito borne diseases, including Ross River virus, Territorians are advised to:

• avoid locations where mosquito activity is high, especially after sundown

• use mosquito-proof accommodation and camping facilities at night

• wear light-coloured clothing with long sleeves, long trousers and socks, especially between dusk and dawn in areas where mosquito are likely to bite

• use a protective repellent containing DEET, picaridin or extract of lemon eucalyptus (PMD) as a supplement to protective clothing, with creams providing best protection

• use mosquito coils, mosquito lanterns and barrier sprays in patio and outdoor areas near houses

• tip out any water holding containers around the yard or store them upside down or under cover to prevent mosquito breeding

• ensure children and animals are adequately protected against mosquito bites.

• seek medical attention early.

Anyone concerned about having symptoms of melioidosis or Ross River virus should visit their local GP or hospital.

People are advised to seek medical attention early so appropriate diagnostic testing can be completed and treatment started at an early stage.

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