Hantavirus protocol and gardens

October 20, 2014 12:47 AM

When we picked up the small, wooden compost bin in our community garden plot, a group of mice ran out from underneath it. Then my spouse flipped the bin face down, probably kicking up some dust. I am concerned about hantavirus exposure when the bin was upended, and also about how to clean up the site.

This is in a community garden plot in front of a large high school. The mice ran away and hid. My questions are

1. If we were exposed to hantavirus, is there anything to do about it now?

2. What's a good way to clean up the remaining wooden bin and the soil where the mice were? I know the CDC recommends spraying with a bleach and water solution. I'm not thrilled about spraying bleach and water into soil where people plant vegetables, but I guess that's better than hantavirus...? (How long does the virus live anyway?)

3. Should I return and try to trap the mice? Are they likely to return to our plot? Are they going to endanger students, gardeners etc if they aren't caught?

I could also use some help evaluating the level of danger here. I have had a tough year and this hantavirus idea has caught my imagination and is freaking me out. I live in an urban part of a state which has had a medium level of hantavirus cases. Is it appropriate to be freaked out?

Thanks for your help, AskMe.

posted by feets to Health & Fitness (9 answers total)

Bleach is fine to spray around your garden. It's corrosive, but also very short lived and not long-term poisonous in the sense of pesticides or heavy metals. I mean, don't pour gallons of it on the ground as it will salt the earth (because it contains lots of salt). But in any reasonable amount it's not going to hurt anything. It might kill leaves if you spray it directly on plants.
posted by ryanrs at 1:19 AM on October 20, 2014 [2 favorites]

"Through December 31, 2013, a total of 637 cases of Hantavirus Pulmonary Syndrome have been reported in the United States. Of these, 606 cases occurred from 1993-onward, following the initial identification of HPS, whereas 31 cases were retrospectively identified. Thirty-six percent of all reported cases have resulted in death." So that's an average of 31.85 per year.

"Odds of being struck by lightning in a given year (estimated total deaths + injuries) 1/960,000". Us population is currently 318,935,000ish.

So you are more than ten times more likely to be struck by lightning, which is itself a one in a million thing, than to contract hantavirus.

Wear a dust mask so you don't get boogers and you'll be fine yo.
posted by vapidave at 1:55 AM on October 20, 2014 [20 favorites]

It's usually best to wear some protective clothing while gardening anyway - gloves, long sleeves, long pants, boots, potentially masks - because of microbes in potting mix and soil, etc. Just make sure you do this to reduce being exposed to further things and look after yourself and your immune system so that you could fight anything off if necessary. I don't think you really need to worry about this potential exposure that much. How many times could you have been exposed to rodent germs without knowing? Lots! Just because you actually saw mice this time, doesn't mean it's more dangerous than any other time that you have gardened.
posted by kinddieserzeit at 2:08 AM on October 20, 2014

1. If we were exposed to hantavirus, is there anything to do about it now?

I don't know, but unless there's some extenuating circumstances, this should not be a major concern

2. What's a good way to clean up the remaining wooden bin and the soil where the mice were? I know the CDC recommends spraying with a bleach and water solution.

Bleach will turn into salt very, very quickly - far more quickly than it will take vegetables to establish and grow in a new garden. If you're concerned, rinse it down with regular water a day or two later.

3. Should I return and try to trap the mice? Are they likely to return to our plot? Are they going to endanger students, gardeners etc if they aren't caught?

Yes, you should try and trap the mice because unless they find somewhere more congenial, they will want to come back, esp if vegetables are growing and it's warm there. I would say that they don't really represent an immediate "danger" to anyone, again, unless you have reason to believe they are carrying a particular disease. Don't get me wrong, mice suck, but more as a nuisance than an existential threat.
posted by smoke at 3:02 AM on October 20, 2014

Also going forward - your compost bin, in order to work effectively, needs to be kept moist at about a wet sponge level. If it is wet the mice will go elsewhere and you will not encounter dust. When I had a yard and composted I routinely added "compost activator"* mixed with water. Also you should stir/aerate the compost once a week or so. This disturbance will also discourage critters.

* compost activator = pee
posted by srboisvert at 6:48 AM on October 20, 2014 [2 favorites]

First of all, are you sure they're the kind of mice you can get hantavirus from? (Deer mice or white footed mice, which look like this.) In a garden, voles (also known as meadow mice) seem a bit more likely. They look like this. Or if you're in an urban area, house mice might also be likely. They look like this.

There's probably not much point in trying to clean up the soil and bin. The virus only lives in fresh dropping and urine, so if you just leave the area alone for a few days it should be safe - unless there are still mice living there and depositing fresh droppings, in which case a one-time cleanup obviously won't solve the problem.

Trapping the mice may not have much effect. Anywhere there is suitable habitat you can expect to find a healthy population of mice that can't easily be eliminated. I expect your garden always has been and always will be occupied by mice. You may be able to keep their numbers down by regular trapping, but you shouldn't expect that trapping some now will lead to a permanently mouse-free garden.
posted by Redstart at 11:48 AM on October 20, 2014 [2 favorites]

Where do you live? Are you in the four corners; Arizona, New Mexico, Colorado? Here in New Mexico, where it's pretty known, there are very few reported deaths.

Unless you're in a rural area in a dry climate, where the Hanta-incubating mice live, and you're in the right seasonal cycle it's beyond a remote possibility.
posted by answergrape at 12:08 PM on October 20, 2014 [1 favorite]

Oh.... and aerosolized mouse droppings are WAY more dangerous than fresh, so leaving mouse poop around to dry and become dust, provided it came from the mice species that incubate the virus, is actually worse.
posted by answergrape at 12:30 PM on October 20, 2014

Response by poster: Thanks everybody, I appreciate both the facts and the talking-down :)
posted by feets at 10:21 PM on October 20, 2014