The dental community is on alert after an 82-year-old Italian woman died in February due to complications related to Legionnaires’ disease—a life-threatening type of pneumonia caused by Legionella bacteria—which she acquired while receiving dental care. A detailed report of the incident was published in the February issue of The Lancet. The article states that the elderly woman was hospitalized after becoming ill with a fever and respiratory distress. After chest X-rays revealed lung consolidation, the patient tested positive for Legionella pneumophila and was promptly diagnosed with Legionnaires’ disease. Despite medical efforts, the patient died 2 days later, and an investigation into the source of the bacterial infection was launched.

Because the patient had left her house only twice over the prior 2-week period to seek dental care, it was clear that the infection originated from either the dental office or her home. Samples taken from the dental office’s tap and high-speed dental turbine contained positive traces of L. pneumophila, while the samples obtained from the woman’s home were negative.

A naturally occurring Gram-negative bacterium found in man-made and natural water systems, L. pneumophila is most infectious when inhaled from aerosolized water, such as that created by high-speed dental turbines. Once inhaled, this contaminated water has the potential to cause Legionnaires’ disease, especially among people with compromised immune systems.

This case emphasizes the importance of implementing—and monitoring—effective infection control protocols for cleaning and maintaining dental waterlines. To minimize this potential source of contamination, waterlines must be aseptically maintained with the same thoroughness as other aspects of the dental operatory.

For information about waterline maintenance protocol, read “Dental Waterline Safety” by Susan Lynn Tolle, BSDH, MS, from the January 2012 issue of Dimensions of Dental Hygiene.