My goodness, that’s one all over the shop post.
“This type of outbreak” refers to respiratory diseases caused by viruses that jump from animals to humans. Literally every seasonal flu in history originated in China from poultry or swine. There are a few exceptions and obviously they can start anywhere, but they are more likely to start where animal handling and slaughtering practices are so lax. Wet markets are literally breeding grounds for zootonic diseases.
The origin of the Spanish flu is not known, but the most compelling evidence suggests China. I could explain it to you but you wouldn’t understand it.
The relevant point on BSE and foot and mouth is they were quickly suppressed with minimal loss of human life. That negates the original point that the idiot glas made.