> air-tight, sterile and single-use That's the packaging. Once you break the seal, it's contaminated from the surrounding air. But that's not even relevant. Wh

> air-tight, sterile and single-use That's the packaging. Once you break the seal, it's contaminated from the surrounding air. But that's not even relevant. When the catheter is inserted, it picks up bacteria from the genitals. No washing and disinfection can remove all of them. Also, like @cyberax said, the catheter can move. The longer it's kept in place, the more bacteria gets upstream.