A mouse plague is wreaking havoc in rural areas across several states in Australia, increasing the risk of illnesses such as leptospirosis — as well as poor mental health.

Feeding off bumper crops after the end of the drought and enjoying cosy living conditions, mice have been multiplying and crippling farmers. Some graziers have resorted to burning their own produce to slow the rodents down.

Mouse plagues occur now and again in ‘Straya’. But there are some things you can do to protect your health and wellbeing.

How a mouse plague can affect your health

Mice can contaminate food — which can lead to food poisoning and spoilage.

Rampant rodents can also carry diseases that may spread to humans. While rare, these types of disease can transfer via direct contact with infected mice or contaminated soil, food and water. Many of them can be treated with antibiotics.

Leptospirosis: an infection caused by the bacteria Leptospira, which is found in the urine of infected animals including mice, rats, cattle, pigs and dogs. Symptoms include:

• fever and chills
• headache
• sore muscles
• diarrhoea
• vomiting
• red eyes

Murine and scrub typhus: types of infection transmitted by the fleas carried by rodents and by larval mites that live on rodents, respectively. Murine typhus is also known as ‘endemic typhus’. Symptoms are severe and begin suddenly, including a rash on the trunk (torso) of the body which may spread — but not to the face, palms or soles of the feet.

Lymphocytic choriomeningitis virus (LCMV) infection: usually caused by exposure to the urine, faeces or saliva of infected rodents, LCMV infection can lead to flu-like illness and sometimes meningitis. Symptoms can, however, be mild.

Gastrointestinal infections: these include the (scary-sounding) infections salmonellosis, campylobacteriosis and cryptosporidiosis. They’re normally passed through food but can also be transmitted by mice. Symptoms may include:

• diarrhoea
• vomiting and abdominal (stomach) pain
• fever
• headache
• body aches
• lethargy (fatigue)

Rat-bite fever: this is a bacterial illness that can be contracted through the bite of an infected animal — or from water or food contaminated by rodent urine or faeces. Often, the bite wound isn't visible by the time the person is unwell.

Symptoms of rat-bite fever may include:

• fever
• muscle or joint pain
• rash
• vomiting
• headache

If left untreated, rat-bite fever can lead to deep infections and sepsis.

How to avoid mice-borne illnesses

Don’t make your home more hospitable to mice and rats. Follow these tips to help keep rodents at bay, and to avoid exposure to illness.

In the house

• Store food in the pantry in sealed containers.
• Throw out food scraps straight away — including pet food — and wipe down kitchen and dining surfaces. Ensure rubbish bins have tight-fitting lids and are emptied regularly.
• Throw away any food or drinks that may have had contact with mice.
• Wash cookware and cutlery in very warm water with detergent before use. Wash your hands well before preparing food or eating.
• Block access points to the pantry and any cupboards containing food-preparation utensils.
• Cover floor vents with wire mesh no coarser than 1 millimetre and check these regularly.
• Seal any holes or access points in the house.
• Clean out storage areas and get rid of unwanted items.
• Wear shoes or slippers in the house and don’t lie or sleep on areas where mice have been active.
• If you’re bitten by a mouse or rat, immediately clean the wound with soap and water and seek medical advice.

Outside the house

• Clean out sheds and storage areas and get rid of unwanted items.
• Keep stacked building materials, such as timber or bricks, at least 30 centimetres (a ruler length) off the ground to prevent mice from nesting there.
• Remove any overgrown foliage — such as grass, trees, bushes and creeping plants — that might give mice access to your roof.
• Store firewood away from the sides of sheds and fences, and off the ground if possible.

On the farm

• Clean up fallen fruit, seed and waste from aviaries and chicken pens, and muck out animal faeces regularly.
• Remove fruit and nuts from trees or vines at the end of the season.
• Store animal fodder, such as poultry food and bird seed, in containers with tight-fitting lids, if possible.
• Avoid having open compost heaps and don’t compost any animal products, such as fish, meat, chicken or dairy.
• Cover rainwater-tank openings with wire mesh no coarser than 1 millimetre and check these regularly.
• Keep your property clear of rubbish.
• Seal any holes and access points to all buildings.

Stay safe when using chemicals and traps

Avoid accidental poisoning: keep rat poisons (or, rodenticides) in a locked cupboard out of reach of children. Accidental poisoning is more common among children aged 4 years and under who live in rural and remote areas than among any other group.

Use according to the label: mouse baits and poisons should only be used according to the instructions. Those intended for agricultural use only should never be used in or near your home.

Clean up mouse carcasses: wearing gloves and protective clothes and footwear, remove dead rodents promptly. Wash your hands well after cleaning up carcasses, especially before eating. This task should be done by household members who are not pregnant or immunocompromised.

Beware of phosphine gas: agricultural mouse bait products containing zinc phosphide release phosphine gas when they react with moisture or acids. When phosphine gas is inhaled, it can react with moisture in the lungs to form phosphoric acid, which can be serious or fatal. Symptoms of poisoning from inhalation include:

• coughing or tightness in the chest
• headache, double vision or dizziness
• nausea and vomiting

Children and pets should be kept away from areas where mouse baits have been used. Read more about phosphine gas at worksafe.qld.gov.au.

Mental health support during a mouse plague

Mouse plagues can impact your mental wellbeing. For help, you can contact:

• Lifeline on 13 11 14 — 24 hours a day
• Beyond Blue on 1300 22 4636 — 24 hours a day
• Suicide Call Back Service on 1300 659 467 — 24 hours a day
• PANDA (Perinatal Anxiety and Depression Australia) — if you’re at home with a baby and are struggling, you can speak to a counsellor on 1300 726 306, Monday to Friday, 9am to 7:30pm (AET)
• ifarmwell — a free online toolkit that helps farmers cope with mental health challenges
• your GP, who can help you with any mental-health concerns. If you don’t have a regular doctor, you can find any type of health professional — wherever you are in Australia — using the healthdirect Service Finder.

Help fight the plague

If you’re on the land, you can use the MouseAlert app to record and report mice on your property. This free resource helps you to notify producers in your region about changes in mouse activity, as well as local biosecurity authorities.