Central line infections can be deadly. And they used to be extremely common: just a decade ago, hundreds of thousands of patients got them every year. Now, that number is closer to 9,000 annually. That's still high, but it's a dramatic drop in just ten years. So how did that happen? On this episode of the Impact, we talk to the doctor who discovered that central line infections are, in nearly all cases, completely preventable. Physicians just need to follow a checklist to make sure the line stays safe and sterile. And we’ll explore why, if this infection is preventable, some hospitals still have several cases of them each year. This episode includes content that might be upsetting for listeners, so please be aware. Many thanks to Vox's Johnny Harris, who originally recorded footage for this story. For more on this topic, read Sarah’s story on central line infections from 2015. Please subscribe, leave us a rating and a review, and email us your feedback at impact@vox.com.   Learn more about your ad choices. Visit podcastchoices.com/adchoices