The Orange County Health Care Agency (OCHCA) now reports 48 cases of mycobacterial infection—15 confirmed, 33 probable, with all 48 hospitalized at some point—involving children between the ages of 3 and 9 years receiving pulpotomies at the Children’s Dental Group facility in Anaheim between March 1 and August 5, 2016. More cases may await, however, as symptoms have been appearing between 15 and 85 days after the infection.
After the initial reports of infection, OCHCA ordered the practice to stop using water in its procedures. The agency then found mycobacteria in 5 water samples taken from the facility. While mycobacteria are common in the environment and generally pose minimal risk, OCHCA believes that the organism multiplied to dangerous levels in the waterlines of the practice’s dental units. Remediation efforts are now underway.
“Mycobacteria is naturally occurring within water. All water that comes from our treatment plants has a recommended number of colony forming units (CFUs) allowable by the federal Environmental Protection Agency (EPA), and that’s 500 CFUs or less,” said Leann Keefer, RDH, MSM, director of education and professional relations with Crosstex, which is now working with Children’s Dental Group to replace its water system.
“Mycobacerium, Legionella, and Pseudomonas are the 3 most common opportunistic pathogens, and you will find them in low numbers,” Keefer said. “The issue comes into the dental unit waterlines because those lines are so narrow, and the flow is relatively low. The water stagnates, and that’s how the biofilm develops. And they multiply into much higher numbers that have the potential for causing disease.”
When dental unit waterlines haven’t been treated, CFU counts could exceed one million as biofilm develops and sticks to the inside walls of those lines. As water flows over that biofilm, it starts to break away from the inside walls and join the stream entering the patient’s mouth. Or, it may enter any aerosol being used as part of that waterline, which then puts the dental professionals at risk as well.
Not all people who are exposed to these bacteria, even in large quantities, necessarily get sick. Outbreaks such as this one and a similar case in Georgia in 2014 and 2015 may have affected children so significantly because their immune systems are still developing, Keefer said. Even then, only 1% of the pediatric patients who were treated at that Georgia practice came down with the infection water picker. The Children’s Dental Group says that it treated about 500 children with pulpotomies, and only children treated for pulpotomies are at risk in the current outbreak.
“But in my mind, one child is too many. One patient is too many,” said Keefer. “This is something we could easily control.”
OCHCA has approved the Children’s Dental Group’s replacement plan for the infected water system, which will be installed by October 31. The new system will include clean water sources, institutional infection control and water routing devices, and ongoing monitoring of purification levels dental implant machine.
“Some people think that using distilled water in your bottle is treating the water. It’s not. The distilled water is still running through those lines. It could be contaminated,” Keefer said. “So if you’ve not been doing anything, you pretty much know that you’re going to be off the charts with CFUs, so it’s time for you to evaluate which method would be best for your particular practice vacuum forming machine dental.”
The ADA says that dental unit water that remains untreated or unfiltered is unlikely to meet the 500-CFU/mL standard, so one or more commercial devices and procedures designed to improve water quality should be employed. Commercially available options include independent water reservoirs, chemical treatment regimens, source water treatment systems, daily draining and air purging regimens, and point of use filters.