Why does Diana call the threading of the bobbin "The kiss of death" in Katherine Paterson's Lyddie?

There is an interesting bit of history regarding Diana's "kiss of death."  In Lyddie, Diana puts in a new bobbin of weft thread into the shuttle.  In order to feed the thread through the final part of the shuttle, Diana places her mouth on the end of the shuttle and sucks out the end of the weft thread with her breath.  Then she tells Lyddie that it's called the "kiss of death."  

It's called "the kiss of death" because many more textile mill workers were dying from a strange lung disease than those in other forms of work.  It wasn't until 1882 that Robert Koch successfully isolated the tuberculosis bacteria in the saliva of patients.  The connection to the textile mills was quickly made.  A single weaver with tuberculosis could contaminate many shuttles simply by placing his/her mouth on it in order to suck the weft thread through.  Then any other weaver that did the same thing to that shuttle would contract the tuberculosis bacteria.  At the time, tuberculosis was a death sentence.  Hence the name, "kiss of death."