Infection preventionists consulting with dental practices or doing community outreach should be aware of reports of invasive Mycobacterium abscessus (MAB) infections among children following pulpotomy dental procedures sometimes termed “baby root canals.”
Public health officials in Orange County California recently sent out alerts to dental and medical providers after 68 children were infected in an Anaheim dental practice. The infections, which all required hospitalization at some point, included 22 confirmed and 46 probable case. The children underwent pulpotomy procedures at the same dental practice over an 8-month period in 2016.
The procedure involves the removal of infected pulp tissue to prevent the loss of a tooth. Where did the MAB come from?
Dental unit waterlines can become contaminated with bacteria, creating biofilms that can be difficult to completely eradicate, Orange County health officials warned in the letter.
“In dentistry, biofilms form on the walls of small-bore plastic tubing in dental units that deliver coolant water for high-speed dental hand-pieces, air-water syringes, and ultrasonic scalers,” they reported. “Although water coming into buildings from city water supplies meets drinking water standards, it is not sterile and contains a number of waterborne bacteria and trace amounts of nutrients that may support growth of bacteria.”
MAB causes slow-growing infections that may appear as swelling around the infected tooth weeks or months after a procedure. The infection may require recurrent IV antibiotic treatment, and can result in tooth loss and permanent damage. These symptoms are similar to those from other types of infections, but are significantly harder to treat and therefore more likely to lead to permanent, long-term health consequences.
The most likely source of both outbreaks was the dental water systems, which commonly use tap water in equipment for routine dental procedures. However, both the American Dental Association and the CDC recommend that sterile water should be used for dental surgical procedures, including pulpotomies.
Monitoring clinic water
A similar outbreak in Georgia was reported at the IDWeek meeting last fall in New Orleans.1
“Dental clinic water monitoring should be mandated, especially in areas where they have had outbreaks,” said Lindsay Hatzenbuehler, MD, MPH, assistant professor at Emory University Children’s Healthcare of Atlanta. “We do believe that this may promote policy change. This may not be a rare occurrence. We believe that a pediatric pulpotomy should be considered a surgical procedure. It should be considered the equivalent of an adult root canal. We recommend use of sterile and treated water.”
As described in her talk at IDWeek, Hatzenbuehler and co-investigators identified 23 children (57% confirmed cases; 43% probable) with MAB infections who had pulpotomies at the same dental practice. They ranged in age from 3 to 11 years old, and all were hospitalized, with a median length of stay of eight days. Eleven had complete surgical excision, 11 received intravenous antibiotics, 1 received oral antibiotic monotherapy, and 11 completed more than 12 weeks of drug treatment.
“One girl required six surgeries; most required two,” Hatzenbuehler said. “There were a significant number of adverse events. [This outbreak] resulted in significant morbidity, surgical complications, and antibiotic toxicity.”
Lasting Effects on Children
The adverse events for some of the children included permanent tooth loss, aminoglycoside associated high-frequency hearing loss, and adverse drug reactions.
“There was also a psychosocial component,” she said. “The children affected are requesting to have their dental procedures under general anesthesia. Thankfully, no children have suffered disease recurrence at six- and 12-month time periods.”
The challenges of identifying these types of outbreaks include the slow growth of MAB infections and the varying clinical presentations, she said. The median time between the pulpotomy and onset of infection was 74 days, with a range from two weeks to up to 262 days. As with other infections with long incubation periods, it may be difficult to identify the source until a cluster of cases is identified.
“The key findings were that tap water was used for pulpotomies, and the dental clinic had no active water monitoring,” Hatzenbuehler said. “The goal of presenting this is to raise awareness among practitioners. Any child that presents with subacute presentation of lymph node or jaw swelling, be aware that they may have had a recent dental procedure. Definitely think about Mycobacterium abscesses or other slow growing organisms.”
REFERENCE
- Hatzenbuehler L, Drenzek C, Tobin-D’angelo M, et al. Pediatric Dental Clinic Associated-Outbreak of Mycobacterium abscessus Infections. IDWeek Oct. 26-30, 2016. New Orleans, LA.
