<img src="https://npr.brightspotcdn.com/dims3/default/strip/false/crop/6000x4000+0+0/resize/6000x4000!/?url=http%3A%2F%2Fnpr-brightspot.s3.amazonaws.com%2Fdb%2Fe0%2Fe077c11d4af68938d74039929127%2Fimg-6256.JPG" alt="Linda Kim, a nurse at the Washtenaw County Health Department in Michigan, has been helping to investigate more than 900 cases of...