Five years ago, during the first North American outbreak of the cattle disease CXC, the death rate from the disease was 5 percent of all reported cases, whereas today the corresponding figure is over 18 percent
It is clear, ttherefore, that during these past 5 years, CXC has increased in virulence
Since the first outbreak, farmers have learned to treat mild cases of CXC and no longer report them to veterinarians or authorities.