It was more convenient to call it "infectious" rather than "toxic," then no one could be blamed.

It is not the first time that a “Viral” disease has been legally debunked.

Smon was officially proved not to be a “virus” in 1978 but caused by a chemical drug Clioquinol. Suprise surprise. pic.twitter.com/gB1kslJ1PQ

— Jamie Andrews (@JamieAA_Again) February 5, 2026

In Japan, it took 30 years and teams of lawyers to dismiss in court the idea that a virus was the cause of SMON, a blindness and paralysis that by 1971 had affected 11,000 people and cause thousands of deaths.  It was more convenient to call it infectious rather than toxic, then no one could be blamed.  It was only when professor Tadao Tsubaki, in true detective style, tracked the symptoms down and found that this disastrous nerve damage was a toxic reaction caused by a common antidiarrheal drug that the infectious theory was dropped and the toxic reaction accepted.