How often do you change your kitchen sponge?

Whenever it looks too dirty, or I think that it's been around too long, to come close to anything that's going in my mouth. That translates to not a long time.

I never use one! I use a clean dishcloth everyday! Sponges--ICK!

If you wait until the sponge is completely dry, I believe you can microwave it to kill bacteria.

Every couple weeks. Once a week is too soon cuz the sponge is still in good shape, after 3 weeks you can just tell it’s time to go, starting to crumble, stains that don’t wash off like from scrubbing a pot. One thing I do in the name of sustainability is buy packages of sponges made of recycled material in bulk, like 12 or so at a time, and CUT THEM IN HALF! Because sponges are so porous and hold water and soap, you really only need half of it to do hand washing. Also, half a sponge fits in my hand better and along the rims of glasses and inside narrow things easier. So, even if I change the sponge every 2 weeks (it’s really closer to 3), then a 12 pack of sponges lasts me 24 weeks, or really 6 months. I only need to buy sponges twice a year, if that, and the cost is minimal, couple bucks. Also, I put the sponge in the dishwasher, top rack, every time I run it (along with other hand washing tools, scrub brushes), and it gets sanitized over the few weeks period that I use it. Finally, when the sponge is on it’s last legs (time to throw out), after a good rinse, I use it one final time as an opportunity to clean my sink. Then I feel good about throwing it in the garbage after I’ve gotten it officially too scummy to keep using, and I have a clean sink to boot! Probably more than you EVER wanted to know or consider about sponge use, but there you go! 😂

I have not used sponges in our kitchen for many years. I use cotton or microfibre
cloths that can be sanitized in the washing machine.
I switched when my kids became teenagers and made questionable hygiene decisions, such as wiping out the dog dish, cleaning mud off bike tires with kitchen sponges. It seemed the risk was too great to keep them around. I use them in other areas of my home, but never the kitchen.

When I investigated this topic (about 3 years ago and a quick look yesterday in response to this question), there is divided opinion (divided research and/or interpreting it) about whether washing sponges is effective in getting rid of enough of the bacteria. to continue using.
So for now, I change them once a week.
I buy cheap sponges in bulk, so it's a low enough cost for this safety measure, especially in time of virus. However, if I run out, I will wash them in either laundry or dishwasher to bridge the days until I get a new supply.

I run mine through the dishwasher when I run it and change it altogether every 2-3 weeks. And yes, if it comes in contact with raw meat, it goes straight into the dishwasher.

I know I’ll probably get some flak, but I’ve always thought that, with the use of common sense precautions, we have an immune system. If we don’t use it, it won’t protect us when we need it.