Bacteria in dentist's water sends 30 kids to hospital
By Jason Kravarik, CNN
Updated 7:26 AM ET, Wed October 12, 2016
30 kids were infected with Mycobacterium abscessus from water used in pulpectomies
The dental clinic is cooperating with a joint state-county investigation
Anaheim, California (CNN)
An outbreak that sent 30 children to Southern California hospitals and could have long-term effects on their health, is raising awareness about the risk of bacterial infection from water at the dentist's office.
All of the children had a pulpotomy, essentially a "child root canal" and were infected by water used during the procedure, said Dr. Matthew Zahn of the Orange County Health Care Agency.
The cases have been traced to the Children's Dental Group in Anaheim, with patients ages 3 to 9 years old all visiting the clinic between March and July.
"Several hundred people had these pulpotomies, so we are anticipating that for at least the next several weeks or months, we're going to see more cases," Zahn said. He added that the infection, called Mycobacterium abscessus, is slow-moving and can take weeks or months to show symptoms.
Swelling, redness and pain around the infected tooth can occur, with the bacteria often spreading to the gum and jawbone. In those cases, Zahn said, stopping the infection often means removing part of the jaw itself, making it "a long-term issue for these children."
Investigators believe the bacteria grow in low-level stagnant water that isn't flushed. In a dental setting, that water is used during treatment, and when a tooth is capped, it can trap the bacteria inside.
Calling it "a weak bug," Zahn said most people who encounter M. abscessus simply flush it away during their daily life. But patients who have had a pulpotomy aren't able to get to the infected area inside the tooth, allowing it to grow.
Cecilia Roman claims it happened to her child, who she said initially went in to have her teeth cleaned.
"At the end of the day, she had three teeth taken out. Her face was swollen," Roman told CNN affiliate KCBS/KCAL. "I feel like I let my daughter down."
Investigation is underway
The Dental Board of California is investigating whether proper procedures were followed at the Children's Dental Group office in Anaheim. The company operates other offices throughout California, but none of those has been linked to the outbreak.
The state of California mandates that water lines be "purged with air or flushed with water for at least two minutes" each day, according to documents provided by the Dental Board.
"We want to make sure they were doing what they were supposed to be doing," board spokeswoman Joyia Emard said.
She said the clinic, which is still open, is cooperating with a joint investigation between the state and county. The water lines at the clinic are not in use, pending the outcome of the investigation. The company tells CNN it will replace the lines and begin ongoing monitoring of its water purity.
Some parents think that the clinic could have acted sooner and that it placed profits over the safety of patients.
"I want their license revoked," Roman said. "I want that place to be shut down."
Zahn, who is heading the investigation for Orange County, said it's not clear how soon the clinic knew of the outbreak and began notifying at-risk patients. He said it probably took time before doctors even diagnosed the cases.
"Unless you know you're looking for it and culturing for it, it's not easy to identify, and they take a period of time to show up," Zahn said.
In a statement, Children's Dental Group CEO Sam Gruenbaum said he "regrets even one patient has developed this condition" and is working hard to "make sure every single person is seen for a precautionary examination." He said 842 children received the pulpotomies since March.
Outbreaks are rare
With dozens of children hospitalized -- and hundreds more at risk -- the impact of this outbreak has been wide-ranging. But it's still only the second such outbreak linked to a dental clinic, said spokesman Richard Quartarone of the Centers for Disease Control and Prevention.
The first was identified last year in Georgia when 20 children got sick after having pulpotomies. As in California, investigators linked the outbreak to contaminated water lines at a single clinic.
The CDC issued recommendations to properly disinfect water lines and avoid "dead ends in plumbing where stagnant water" can form. But now, with the California case bringing more attention to the issue, some wonder whether those warnings should be amplified.
"Do we modify any guidelines that make sure these specific events don't happen?" Zahn asked. "These are not common events, but they do have very significant consequences."
Infection Outbreak Shines Light On Water Risks At Dentists Offices
September 30, 201612:03 PM ET
Mimi Morales recovers in Children's Hospital of Orange Country in late September after surgery for a dental infection she contracted at Children's Dental Group in Anaheim, Calif. She had three permanent teeth, one baby tooth and part of her jawbone removed. Mindy Schauer/Courtesy of The Orange County Register
When people go to the dentist, they generally expect to leave in better health than when they walked in.
But the water that dentists use to rinse teeth sometimes carries infectious bacteria.
The Orange County Health Care Agency in California says that nearly two dozen children who received so-called baby root canals, or pulpotomies, are thought to have developed dangerous bacterial infections. Dentists perform pulpotomies to remove infected pulp inside a baby tooth so the rest of the tooth can be spared.
The infections were caused by Mycobacterium abscessus, which the health department traced back to the water at Children's Dental Clinic of Anaheim.
"The reason we're so concerned is this infection is very hard to treat with antibiotics," says Dr. Eric Handler, health officer with the Orange County Health Authority. Instead, the tissue is surgically removed. "Treatment can be very traumatic and deforming."
As of Sept. 27, three confirmed and 19 probable infections have been linked to the clinic. In each case, the children had to be hospitalized. In an email to Shots, Children's Dental Group CEO Sam Gruenbaum said, "I am currently devoting all of my time and energy to making certain our patients are taken care of."
In a Sept. 23 letter to patients, Gruenbaum asked the families of patients who had received pulpotomies since April 1 at the Anaheim clinic to come in and be examined for signs of infection. The letter said that the Orange County Health Care Agency had found abnormal levels of microbes in the water, and the clinic is no longer using office water for patient procedures.
Deepa Bharath and Courtney Perks at The Orange County Register report that several children have had surgery to treat infections, including a 7-year-old girl who had "three permanent teeth, a baby tooth, and a part of her jaw bone" removed.
Although infections like these are rare, this isn't the first time Mycobacterium abscessus has been traced to a dental office. In Georgia in 2015, more than 20 children who had pulpotomies were later hospitalized with confirmed or suspected mycobacterium infections.
Still, according to the federal Centers for Disease Control and Prevention, the Georgia outbreak of dental mycobacterium infections is the only other one on record. The investigation into Georgia cases found that 1,386 children received pulpotomies and were potentially exposed to the bacteria. But only about 1 percent of them got sick.
"Infections from mycobacterium are very rare," said Dr. Melissa Tobin-D'Angelo, a medical epidemiologist with the Georgia Department of Public Health who investigated the 2015 outbreak. "We don't want to discourage parents from having their children see their dentists two times a year as recommended. The reason children had to have this procedure is because they had decay to begin with."
Investigators learned that the water supply to the building wasn't contaminated. Ultimately, they traced the infection to the dental unit waterlines — the flexible plastic tubes that carry water to the hoses that rinse your mouth.
The researchers weren't surprised that the tubes turned out to be the source of the problem. Keeping waterlines clean can be a challenge for dentists.
A bacterial incubator
Dental unit waterlines are very good at growing bacteria, says Dr. Nuala Porteous, an associate professor of dentistry at University of Texas Health Science Center Dental School in San Antonio. In her research, she looks at how to control infection risks in dental offices, including the microbes that live in waterlines.
Mimi Morales says she's "flabbergasted" that her granddaughter, Mimi, 7, ended up in the hospital with an infection following a pulpotomy in July. Mindy Schauer/Courtesy of The Orange Country Register
"If you think about the last time you went to the dentist, they only use the water sometimes," Porteous says. "It's very start and stop. They work and then they rinse, so there's a lot of stagnant water."
And bacteria love to grow in stagnant water. How prevalent they are is hard to say. A study of dental waterlines in the U.S. found harmful bacteria 68 percent of the time. Still, another study was reassuring, barely finding any contamination in dental offices in London and Northern Ireland.
Mycobacterium isn't the only kind of germ that can thrive in waterlines. Pseudomonas and legionella can, too. Both types of bacteria can cause pneumonia-like illnesses. Despite studies showing that dentists are more likely to have antibodies for legionella than the general population, very few actual illnesses have been directly linked to dentistry.
"These are organisms that are typically found in water and groundwater, things like that," says John Molinari, a microbiologist and professor emeritus at the University of Detroit Mercy School of Dentistry. "They wouldn't normally get you sick. It's when you have high concentrations in a certain person that illness happens." The elderly and people with an underlying illness are most at risk.
"With legionella, you're more likely to get sick when there's a lot of bacteria, like when you get biofilms," says Molinari.
A biofilm is a group of microorganisms — typically bacteria, fungi or a mixture of microbes — that live in a colony. These microbes communicate with each other and even feed and protect each other. And that can make them very hard to remove.
"Think of the plaque that grows on your teeth," says Molinari, "That plaque is a biofilm. At first you can wash it off with water, but after 24 hours you need to brush your teeth and use chemicals to remove it. Even mouthwash alone isn't enough."
The biofilms in waterlines do the same thing. The outer layers might die as cleaning chemicals rush through the pipes, but the inner layers can survive.
A paper published online Sept. 13 in the journal Pathogens and Disease looked at dental practices using industry-standard sterilization techniques. "We found fungi, bacteria, viruses, and protozoa in dental unit waterlines. In our study, decontamination procedures worked but not completely," Damien Costa, at the University of Poitiers in France and the lead investigator on the study, told Shots in an email.
Costa says there aren't any set procedures for sterilizing waterline units in France, where his research was conducted. He hopes his study will provide data that will help the government create guidelines.
In the United States, the CDC says dentists should "consult with the dental unit manufacturer for appropriate methods and equipment to maintain the recommended quality of dental water." Waterlines vary depending on the dental equipment, so a one-size-fits-all approach wouldn't be effective, a CDC spokesman told Shots.
Generally, dental offices use a combination of chemicals. Some are added continuously to the water in low concentrations, while other, stronger disinfectants are used intermittently. Filters and disinfectant cartridges can be added to the ends of lines, and the ADA recommends occasionally draining and purging the waterlines with air.
Dentists should be able to tell if the bacteria-killing maintenance for their equipment is working. Porteous says chairside kits that check for bacteria are available. Dentists can also send water samples to testing companies to make sure bacterial counts fall within CDC guidelines.
The CDC says that the water dentists use should meet the same quality standards as drinking water. But the CDC and the American Dental Association don't say how often dentists should test their water.
"Without water testing, it's impossible to tell if your treatment works," says Mark Frampton, owner of ProEdge Dental Products, a manufacturer of disinfectants for dental lines. Frampton's company also analyzes water quality for dentists. "In our experience, about a third of the time people that have maintenance programs will still fail our tests because they don't always follow the treatment instructions. People don't always do everything perfectly."
Frampton recommends that dentists check their water quality at least quarterly, or more often depending on the treatment product they use.
University of Texas Health Science Center's Porteous recommends dentists check the water coming out of dental lines at least weekly. "I would hope that all dentists take note of these cases that have been occurring recently in Georgia and under investigation in LA," she says. "It's very sad, and I hope that it makes all dental institutions sit up and take note."
Back in California, the dental clinic linked to the mycobacterium infections isn't taking any chances. It will replace its entire water system.