According to The Associated Press, Dave Mustaine is infested with parasites. When Megadeth finished up touring recently, Mustaine saw a health practitioner who did an analysis of his body.

The health practitioner told Mustaine he had 51 parasites in his body, many of which were varieties of worms. Mustaine was shocked.

He thinks he picked up the parasites staying in less-than-clean hotel rooms and other hazards of being on tour. It doesn't stop him from freaking out that he's going to catch germs from fans.

Mustaine said he has fans cough into their hands and then shake his, or they give him hugs. It is just part of the hazard of him being so outgoing and affectionate, he is sick a lot.

I don't think Metallica has this problem. I doubt Lars would be staying in "less-than-clean" hotel rooms. To illustrate this point I did some research. I found the bathroom of one of hotels that Mustaine stayed in and one Lars did.

Mustaine's shower:



Lars' Bathroom