What kind of touching? Not all touch is equal. If causal touch were a common transmission pathway, then MP would have leaked out into the general population much faster than it has. MP is not strictly speaking sexually transmitted, but functionally it behaves as such.

You can probably get MP by massage, but you can get crabs the same way (crab lice infestation functions as a STI even though strictly speaking it is not). I have been able to avoid crabs by not having casual sex, even though I have probably encountered people who have it (in environments with high gay male concentration).

Edit: I'm not really a fan of trying to downplay the sexual component of this. Even if 10% of transmissions end up being nonsexual, it doesn't detract from the fact that most of the time transmission will have occurred through sexual contact. I've about had it with gay men who are so committed to casual sex that they will avoid obvious conclusions about disease transmission in order to continue behavior that is unhealthy both physically and emotionally. I actually do have some experience with infectious disease epidemiology so I'm not a moron about how this operates in a complex system.