haven't been able to look at the link (and I refuse to read the daily mail), but even before blood tests were developed iirc diagnosis was achieved through illumination of other diseases iyswim.
My assistant at work died of CJD in 2005. It was a horrible illness and tbh death for her was a relief. she had been diagnosed about a year before her death, but exact cause of death couldn't be confirmed until afterwards.
tbh I'm not sure what is to be achieved by publishing articles about people dying of cjd, other than to cause further panic like before.