A team of researchers from the University of Maryland collected 487 cultures from 32 hospital rooms occupied by just-discharged patients with a known history of MDR A. baumannii both before and after terminal cleaning of the rooms. Over half of the rooms positive for the A. baumannii bacteria prior to cleaning remained contaminated after terminal cleaning had occurred.

Fifteen rooms (46.9 percent) and 41 sites (n=268, 15.3 percent) tested positive for MDR A. baumannii before cleaning. Post-cleaning, eight rooms (25 percent) and 12 sites (n=219, 5.5 percent) still tested positive for the pathogen. Sites with post-cleaning contamination included the floor (12.5 percent), call button (10 percent), door handle (9.4 percent) bedside table (7.4 percent), and supply cart (3.8 percent).

"Persistent room contamination serves as a potential reservoir for transmission and colonization of future room occupants," state the authors in the article. "Current cleaning techniques in terms of products used or thoroughness of cleaning may not be adequate in the decontamination of this pathogen."

Acinetobacter baumannii is a type of bacteria that has become increasingly prevalent in healthcare facilities and is resistant to most antibiotics. Infections from this pathogen primarily occur in very ill, wounded, or immunocompromised patients. The germ can remain on wet or dry surfaces for longer than most other organisms, making it harder to eradicate.

"This study shows how difficult it is to ensure removal of particularly resistant organisms from the environment even upon thorough discharge cleaning," said Anthony D. Harris, MD, MPH, lead study author and professor of epidemiology and public health at the University of Maryland School of Medicine. "With new, innovative means of monitoring cleaning processes that we have incorporated since the study was done, coupled with other infection control efforts, we are seeing lower rates of A. baumannii at our hospital."