Mouse Droppings and Hantavirus: The Cleanup CDC Requires

The CDC has recorded 890 hantavirus cases since 1993 and 35% were fatal. Why sweeping and vacuuming are the wrong move, and the protocol that replaces them.

The CDC has recorded 890 hantavirus cases in the United States since surveillance began in 1993, and 35% of those people died. The risk is not the droppings themselves but disturbing them dry: sweeping and vacuuming send virus-bearing particles into the air. CDC guidance is to ventilate the space for 30 minutes, soak the contamination with disinfectant or a 1:10 bleach solution, wait 5 minutes, then clean it up wearing gloves.

Almost nobody who finds mouse droppings in a garage gets hantavirus. The disease is genuinely rare. It is also lethal often enough that the cleanup method is worth getting right the first time, and the most common household reflex, reaching for the vacuum, is the one thing public health guidance tells you not to do.

What the numbers actually say

Through the end of 2023, the CDC counted 890 cases of hantavirus disease in the United States since 1993. That total breaks into 859 cases of hantavirus pulmonary syndrome and 31 non-pulmonary infections. Across all reported cases, 35% were fatal.

The CDC states the fatality rate a second way, and the difference matters: 38% of people who develop respiratory symptoms may die. The two figures have different denominators, so they are not interchangeable and should not be averaged.

Roughly 29 cases a year across the whole country puts this in perspective. A single cleanup is very unlikely to hurt you. The protocol exists because the consequences sit at the far end of the scale, and because the exposure is invisible while it is happening.

Not every mouse is the same mouse

This is the distinction that most cleanup advice skips. The CDC names four North American rodents that carry hantaviruses causing pulmonary syndrome, and the house mouse is not among them.

The careful phrasing is that the CDC does not list the house mouse as a hantavirus carrier in the United States, rather than that house mice cannot carry it. The practical reading: a mouse problem in a city apartment is a different risk picture from droppings in a rural cabin, shed or outbuilding where deer mice nest.

That does not make the house mouse harmless. It is the primary host of lymphocytic choriomeningitis virus, and rodent droppings are also a route for leptospirosis and salmonella. The cleanup rules below are worth following regardless of which species left the mess, for reasons that do not depend on hantavirus at all.

The CDC cleanup protocol, step by step

These steps come from CDC guidance and its underlying MMWR recommendations. Several numbers circulating online conflict with the CDC figures, so the sourced versions are given here.

1. Open doors and windows for 30 minutes before you start, and leave the area while it ventilates. The CDC figure is 30 minutes, not the hour often repeated elsewhere.
2. Put on rubber or plastic gloves. For heavy contamination the CDC calls for a half-mask air-purifying respirator with N-100 or P-100 filters, which is not the same thing as a dust mask.
3. Soak the droppings, urine and nesting material until very wet with an EPA-registered disinfectant or bleach mixed at 1.5 cups per gallon of water. That ratio is a 1:10 solution; the two are the same instruction stated differently.
4. Let it sit for 5 minutes, or follow the dwell time on the disinfectant label.
5. Wipe up with paper towels and place them in a plastic bag. The prohibition on sweeping and vacuuming applies to dry, undisinfected material; once surfaces have been wetted and disinfected, mechanical cleanup is permitted.
6. Double bag the waste, sealing the first bag inside a second and tying the ends.
7. Wash your gloved hands with soap and water or disinfectant before removing the gloves, then wash your hands again afterwards.

The reason for the wetting step is mechanical rather than chemical. Dry disturbance aerosolises the material, and the CDC describes the hazard plainly: sweeping or vacuuming can cause tiny droplets containing viruses to get into the air.

When it stops being a job for you

The CDC defines a heavy infestation as one where piles of faeces, numerous nests or dead rodents are visible. That applies both to occupied homes and to buildings that sat empty long enough to attract rodents. For heavy contamination, the guidance moves to full protective equipment and a 2-gallon sprayer or similar device that keeps dust down.

On who to call, the CDC recommendation is unusually specific, and it splits the work into two trades:

For substantially severe or persistent infestations, contact a pest-control professional for rodent eradication or a building contractor for rodent exclusion.

In practice there is a third trade. Killing the rodents, sealing the structure and decontaminating what they left behind are three different jobs, and the company that does one does not necessarily do the others. Biohazard remediation firms handle heavy contamination, particularly where droppings have got into insulation or ductwork. Pest control companies handle the animals. General contractors handle the sealing. Ask which of the three you are actually buying before you agree to anything.

For the removal side of the problem, see our guides on what rodent removal costs and when to call a professional about mice. Sealing the building afterwards is covered in pest-proofing your home, and the fastest way to notice the problem early is in early signs of infestation.

The detail that should change how you think about risk

In early 2025, three people in the town of Mammoth Lakes, California, died of hantavirus pulmonary syndrome, with all three illnesses beginning in February. The county public health officer described the cluster as tragic and alarming. What makes it instructive is what investigators did not find: no major infestations were identified, and the third decedent’s home showed no evidence of mouse activity.

The lesson is not that hantavirus is common. It is that visible infestation and exposure risk are not the same measurement. A shed or cabin that has been closed up for a season, where deer mice have been and gone, can hold dried contamination without any live animals present. If you develop fever or breathing difficulty within 45 days of a cleanup like that, the CDC advises seeking medical attention and telling the clinician about the exposure.

Frequently asked questions

Can you get hantavirus from mouse droppings?

Yes, though it is rare. The virus is contracted by breathing in particles from urine, droppings, saliva and nesting material, usually when dried contamination is disturbed. The CDC has recorded 890 cases in the United States since 1993. Cleaning droppings dry, by sweeping or vacuuming, is the action that creates the airborne exposure.

Do house mice carry hantavirus, or only deer mice?

The CDC lists four US rodents as hantavirus reservoirs: the deer mouse, white-footed mouse, rice rat and cotton rat. The house mouse is not among them, and the deer mouse spreads the virus responsible for most US cases. House mice are, however, the primary host of lymphocytic choriomeningitis virus, so their droppings still warrant the same handling.

Why can’t you sweep or vacuum mouse droppings?

Because dry disturbance puts the material into the air where it can be inhaled. The CDC states that sweeping or vacuuming can cause tiny droplets containing viruses to get into the air. The prohibition applies to undisinfected material; after surfaces have been soaked with disinfectant and allowed to sit, normal cleanup is acceptable.

How long should you air out a room before cleaning up droppings?

The CDC figure is 30 minutes with doors and windows open, and you should stay out of the space while it ventilates. Longer times circulate online but 30 minutes is what both the CDC consumer guidance and its underlying MMWR recommendations state.

What bleach to water ratio is recommended for rodent droppings?

1.5 cups of household bleach per gallon of water, which the CDC also describes as a 1:10 solution. An EPA-registered disinfectant used according to its label is an accepted alternative. Soak the material until very wet and allow 5 minutes, or the dwell time on the product label.

Is a dust mask enough to clean up mouse droppings?

For light contamination the CDC guidance calls for rubber or plastic gloves rather than specifying a respirator. For heavy infestations it calls for a half-mask air-purifying respirator fitted with N-100 or P-100 filters. A loose dust mask is not equivalent, because protection depends on the seal as much as the filter.

When should you hire a professional instead of cleaning it yourself?

The CDC points to professional help for substantially severe or persistent infestations, and defines a heavy infestation as visible piles of faeces, numerous nests or dead rodents. Contamination in insulation or ductwork, long-vacant buildings and anything beyond a small surface area are reasonable thresholds. Note that eradication, exclusion and decontamination are three separate trades.

What are the first symptoms of hantavirus?

Early symptoms typically include fever, fatigue and muscle aches, which can be followed by breathing difficulty as the illness progresses. The CDC gives an incubation range of 1 to 8 weeks after contact with an infected rodent, and advises anyone who becomes unwell within 45 days of a potential exposure to seek medical attention and mention the exposure.

Sources

• U.S. Centers for Disease Control and Prevention, Hantavirus Cases and Data. Page updated April 2026. cdc.gov
• U.S. Centers for Disease Control and Prevention, About Hantavirus. Reviewed May 2024. cdc.gov
• U.S. Centers for Disease Control and Prevention, Cleaning Up After Rodents. Reviewed April 2024. cdc.gov
• CDC, Hantavirus Pulmonary Syndrome: Updated Recommendations for Risk Reduction. MMWR Recommendations and Reports 2002;51(RR-9). cdc.gov
• CDC, Notes from the Field: Seoul Virus Infection Among Rat Breeders. MMWR 2018;67(4). cdc.gov
• Mono County Public Health, Third Hantavirus-Related Death Confirmed in Mono County, April 2025. monocounty.ca.gov