Systems and methods for cleaning and disinfecting contaminated tube lumens are described herein. One system includes an ultraviolet light source and a sterile fluid reservoir fluidly coupled to a liquid light guide. The system is configured to allow simultaneous access and propagation of ultraviolet light and fluid in a tube having a lumen to be cleaned and disinfected. The light guide can be moved inside the tube and simultaneously emit ultraviolet light through its walls and at its distal end into the interior of the contaminated tube. A flush of sterile fluid from an open end of the liquid light guide removes debris and micro-organism detached from the inner surface during light exposure. The sterile fluid can be a high refractive index ionic solution promoting light propagation.