The entertainment news Web site said the clip posted Friday was shot Sunday at a concert in Ottawa, Canada, while the 40-year-old recording artist sang his song "Beautiful People."
Manson reportedly was standing only a few feet away from fans in the front row when he emptied his nostrils.
"So I have officially been diagnosed, by a real doctor, with THE SWINE FLU," Usmagazine.com quoted Manson as saying on his Facebook page. "I know everyone will suggest that (expletive) a pig is how this disease was obtained. However, the doctor said, my past choices in women have in 'no way' contributed to me acquiring this mysterious sickness. ... Unfortunately, I am going to survive."