Primary infections may also occur in the presence of intravenous catheters, urinary catheters and implantable devices. Secondary infections from a biofilm source may affect the brain, kidneys, joints and intervertebral spaces.
In cystic fibrosis, excess mucus production in the airways hosts bacteria such as Pseudomonas aeruginosa, which mop up dead white blood cells from the immune system, enabling them to construct their protective biofilm coat.