Many places I've lived, leaving a ladder outside led to burglaries being committed with them. I don't know if your neck of the woods has that issue, but something to think about.

My best understanding as a non-scientist, non-medical professional, is that the COVID19 virus can live on surfaces up to three days in a lab environment. Out in full sun I'd be confident in one day -- the Sun's UV radiation kills viruses quickly. Out in steady rain I'd be confident in one hour.

If you can spare a disinfectant wipe or two, I'd probably wipe it down and put it away immediately. If you have an open bottle of bleach, use a capful of bleach in a cup of water, a paper towel and a kitchen glove, and wipe it down with that. Hot soapy water will work as well, but require more work. Remember, though, that bottles of bleach start turning into water once they're opened.