Report 1MiceNSW Health’s advice, read on the Downs
Mouse plagues and the household
In a mouse plague the risk to people comes from contact: NSW Health lists leptospirosis, LCMV, rat bite fever and gut infections among the illnesses people can catch from mice, and its advice is about keeping mice, their urine and their droppings away from people, food and water. This report reads that advice for a whole household: who is most exposed, what to mention to a doctor, and which baits belong where.
General information, not medical advice. The advice is NSW Health’s, written for New South Wales; Queensland Health and the Queensland Poisons Information Centre are named where they add to it. All four pages are listed at the foot of this page.
Who in the house is most exposed, and why
Read line by line, NSW Health’s factsheet singles out some members of a household more than others.
- Anyone pregnant
LCMV infections usually come from the urine, droppings or saliva of infected rodents. NSW Health says infection in pregnancy “has not been recorded in Australia”, and also that “there have been cases where LCMV infection in pregnancy has resulted in adverse outcomes (fetal death or congenital conditions affecting the central nervous system)”.
- Anyone immunosuppressed
The factsheet names this group beside pregnancy: “Ideally, any handling of mouse carcasses should be undertaken by household members who are not pregnant or immunosuppressed.”
- Small children and pets
“Children and pets should be kept away from areas where mouse baits have been used.” The Queensland Poisons Information Centre suggests rat baits enclosed in plastic bait stations, which children find harder to get at than loose pellets or gels.
- Anyone with a cut or graze
Leptospirosis bacteria may be in mouse and rat urine, and get into the body through cuts and grazes, and sometimes through the eyes, nose or mouth. Queensland Health’s advice is to wash cuts and sores with clean water and cover them with waterproof dressings before touching soil, mud or water.
- Whoever works with stock or crops
Queensland Health lists people who work near animals or where rodents are found, farmers and crop pickers among them, as more at risk of leptospirosis. NSW Health names farmers among its higher-risk groups too.
- Whoever cooks
Gut infections such as salmonellosis can pass from rodents by direct contact or through contaminated food preparation surfaces. NSW Health’s advice is to keep food in thick, well-sealed containers, clean up spills and leftovers promptly, and not to set mouse traps near where food is prepared.
What to mention to a doctor
Leptospirosis can take days or weeks to show after the contact, which is why NSW Health asks people to tell their doctor about it:
“If you become sick in the weeks following possible exposure to animal urine or a contaminated environment, it is important to tell your doctor about the exposure.”
NSW Health, leptospirosis fact sheet
- Leptospirosis symptoms usually start 5 to 14 days after infection, and can take anywhere from 2 to 30 days.
- NSW Health says leptospirosis is relatively rare in Australia but more common in warm, moist regions such as north-eastern NSW and Queensland.
- You can get leptospirosis more than once, Queensland Health notes, because there are different strains of the bacteria.
- With rat bite fever, NSW Health notes, the wound is usually not visible by the time the illness appears.
For any other worry about illness from rodents, NSW Health’s factsheet makes a plain suggestion: speak with your GP.
A farm bait and a house bait are not the same thing
NSW Health draws the line between them in four sentences, quoted here whole:
“Mouse baits must always be used in accordance with the instructions on the label. Mouse baits licenced for agricultural use must never be used for domestic purposes. Agricultural mouse bait products containing zinc phosphide release phosphine gas when they react with moisture or acids. Children and pets should be kept away from areas where mouse baits have been used.”
NSW Health, staying healthy during a mouse plague
The Queensland Poisons Information Centre adds advice of its own for poisons at home: keep them in their original containers, never decanted into a food or drink container, follow the instructions, and do not bring industrial-strength chemicals home.
The Queensland Poisons Information Centre’s first aid for a swallowed poison, in its own words:
- “Call Triple Zero (000) if someone has collapsed or isn’t breathing. Otherwise, call us on 13 11 26 for advice.”
- “If someone has collapsed or isn’t breathing only call us after you’ve called Triple Zero (000).”
- “Before calling, get the name of the product and any information about the ingredients from the label, if possible.”
- “Don’t try to make them vomit.”
- “Wipe or rinse their mouth or face.”
The centre can help anywhere in Australia, 24 hours a day, 7 days a week.
Keeping them out of the house and the tank
NSW Health’s first line on keeping mice away is the simplest: “Seal any holes or gaps inside your home.”
On a property that drinks from a rainwater tank there is a second line to hold. NSW Health says “Tank inlets and overflows should have screens installed to prevent entry of mice and other small animals and leaves. Check the tank regularly to ensure there are no gaps.” If a mouse has already got in, the clean-up report quotes NSW Health’s tank advice in full.
The leptospirosis bacteria may be present in rat urine as well as mouse urine. The roof report explains how to tell a rat in the ceiling from a possum.