August 22, 2022

Waterline Contamination Leads to 221 Lawsuits in Landmark Anaheim Pediatric Dentistry Case

What happened in 2016 Anaheim pediatric dentistry case regarding dental unit waterline infection

Up until the last five years, the danger of waterline contamination from biofilm went largely unnoticed in the dental community. In many ways, the emphasis was placed on other areas of infection control that if handled poorly could injure hundreds if not thousands of patients. As infection control continues to slowly step into the spotlight, so do dental unit waterlines.

It is reported that 1 in 4 adults have untreated cavities and nearly half of adults ages 30 and older have signs of gum disease. Generally, the reason for delayed treatment is due to the cost of care. However, this attempt to delay immediate expenses may end up costing far more as every year it is estimated that there are 2 million visits to hospital emergency departments for dental pain. With this considered, it would not be surprising to learn that many instances of dental waterline-related complications go unreported.

But in 2016, tragedy met happenstance when, in what is now considered to be the landmark case due to dental unit waterline contamination, a pediatric infectious disease specialist in Anaheim, California connected the dots between her patients’ symptoms and their recent visit to the dentist.

How Dr. Ashouri discovered the waterline contamination 

The discovery in Anaheim was made by chance when Dr. Negar Ashouri, a pediatric infectious disease specialist, was on call when one of the first impacted patients came to the hospital. The patient required surgery and eventually, lab results revealed a mycobacterium infection in her jaw.

Dr. Ashouri said upon treating the patient that she’d never seen such a severe oral infection.

This patient was Mimi Morales, the 7-year-old who quickly became the face of the outbreak. Once she was checked into the hospital, an oral surgeon removed part of her jawbone and permanent teeth. Heavy doses of antibiotics with serious potential side effects usually used for bacteria-resistant strains were prescribed to fight her infection for months.

“The doctor said she removed as much bone as she could without disfiguring her,” said Mimi’s grandmother.

Even after Mimi recovers, she will require significant additional dental work, including bone grafting, to receive her dental implants which will have to wait until she turns 18 years old.

About a month later, Dr. Ashouri just so happened to be on call again, and another young girl came into the hospital with similar symptoms.

When Dr. Ashouri saw the similarities between the patient’s symptoms, she called Mimi’s family and discovered that both children had undergone procedures at the same dental practice in Anaheim.

The doctor notified the county health department, and a full investigation was launched into the dental office. The investigation blew up, connecting the dots to 500 pediatric patients that had been exposed to potential infection. Additionally, at least 71 children were infected with mycobacterium abscessus.

The natural question is how many more cases would have happened if Dr. Ashouri hadn’t recognized this connection?”, said Dr. Matt Zahn, Director of Epidemiology for Orange County’s Health Care Agency.

Like Anthony Garcia, a father to Kylah, 10, another child infected said, “This should never happen to any family again.”

The children affected were given CT scans, blood tests, surgery, and months’ worth of federally regulated intravenous antibiotics originally developed to treat leprosy.

Dr. Ashouri and her colleagues worked overtime. “It reaffirms the reason why we all went into medicine. It all comes down to the kids.

The spotlight lands on dental waterline infection prevention procedures

Soon, local news sources caught word of the story. Then, national outlets like CNN, NPR, and Good Morning America ran headlines bringing widespread attention to the scene.

“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” (NPR, 2016).

Lawyers began advertising on Google and network television, seeking families that may have been affected. Hundreds of claims were filed. As of 2022, there are 221 ongoing lawsuits filed against the practice. The results of these suits will likely redefine the standard of infection prevention and infection control within dentistry.

The rippling impact of the dental waterline infection 

The following data is published by the Open Forum Infectious Diseases, Volume 5, and details the full impact of the Anaheim outbreak:

“Of 1,089 patients at risk, 71 cases (22 (31%) confirmed and 49 (69%) probable) (Figure 1) had been identified as of March 19, 2018 (Figure 2). Median case age was 6 years (range 2–11 years). Symptoms began a median of 85 days (range 1–409 days) after pulpotomy (Figure 3). Pain and/or swelling on admission were reported in 79%; 21% were asymptomatic. CT findings included 49/70 with abnormalities of the mandible or maxilla, 13/70 with lymphadenopathy, and 19/68 with pulmonary nodules. Only 6/60 had erythrocyte sedimentation rate >40  mm/hour. Of 71 cases, 70 were hospitalized and underwent surgical debridement, for an average of 8.5 inpatient days (range 1–60 days); 23 had >1 hospitalization and 26 required >1 inpatient surgery. Permanent teeth were lost in 45/65 (range of 1–6 teeth lost). Intravenous antibiotics were administered to 32 cases for a median length of 137 days (range 113–282 days). Clofazimine was obtained for 29/32 cases as part of the regimen. Medical therapy was complicated by peripherally inserted central catheter malfunction/replacement/infection (18/27), rash (2/27), neutropenia (12/27), and elevated creatinine (7/27). All treated children showed evidence of jaw healing with resolved or improving lung nodules at 1-year follow-up.”

Anaheim waterline contamination timeline:

  • January thru September 2016 – Practice performs pulpotomies on 1,089 children 
  • September 6, 2016 – Practice stopped doing pulpotomies 
  • September 15, 2016 – Department of Health confirms 5 water samples contained mycobacterium
    abscessus from the practice’s waterlines. Orders the practice to cease using water for dental care and install a new water system. The practice closes. 
  • September 21, 2016 – Orange County Register reports 14 children infected 
  • September 24, 2018 – Orange County Register reports 20 children infected 
  • September 29, 2016 – Mimi Morales becomes the face of the Anaheim Outbreak after infection required surgery to remove permanent teeth and part of her jaw. 
  • October 2016 – The practice replaces the entire water system 
  • October 6, 2016 – Orange County Register reports 29 children infected 
  • October 12, 2016 – CNN reports on Anaheim Outbreak 
  • November 8, 2016 – Department of Health lifts cease order and the practice reopens. Confirmed infection cases reach 50 children. 
  • December 16, 2016 – Department of Health confirms multiple new water samples contained mycobacterium abscessus. Orders the closure of the practice.
  • April 11, 2017 – Orange County Register reports 58 lawsuits have been filed and 68 children have been infected. 
  • April 18, 2017 – Practice allowed to reopen 
  • April 26, 2017 – CBS News reports on Anaheim Outbreak 
  • March 19, 2018 – 71 confirmed infection cases 
  • January 16, 2019 – 150 confirmed lawsuits against the practice in question, with more expected to come. 
  • May 30, 2019 – Dr. Edwin Zinman participated in a talk called “Pre-Conference Workshop – DSOs: Infection Control in a Dental Service Organization” at the 2019 Organization for Safety, Asepsis, and Prevention annual conference and made the statement that at least 102 patients received treatment. 

Another story of waterline contamination that resulted in dental infections 

While scenarios like this are rare, more instances are surfacing. In the year preceding the Anaheim case, a similar disaster occurred from contaminated dental water in a Georgia dental clinic with 20 confirmed cases of children who suffered the same trauma as those in California.

As the CDC noted in their report, “M. abscessus, a rapidly growing, nontuberculous mycobacterium (NTM), is found ubiquitously in the environment in water, soil, and dust. It commonly causes skin and soft tissue infection and can cause disease in multiple organs (1). NTM species display tolerance to commonly used disinfectants and are frequently found in the plumbing of healthcare facilities and water distribution systems (2). Improperly maintained dental unit water lines can permit the growth and amplification of microorganisms, including NTM, which can form a biofilm and replicate within waterline tubing (3). Outbreaks have been reported in different clinic settings, including acupuncture clinics, a cosmetic surgery clinic, and a general medical clinic, although not dental clinics (4–7).”

Unfortunately, even with these heartbreaking cases making the headlines, many practices are unaware of the best way to prevent biofilm buildup in their DUWLs.

What to do if allegations of contamination are related to your dental practice?

As the leading dental water lab in the nation, ProEdge has been on the receiving end of more than one panicked call from dental practices. Whether you are concerned that your dental unit waterlines have biofilm build-up or have an infection related to your dental office’s water quality, it’s important to act quickly to ensure no further damage occurs.

First things first, if you do have a patient complaint, you must report this to the health department. Then, in accordance with the CDC, ADA, and OSHA, we recommend taking these 3 steps to address possible contamination:

  1. Test your dental unit waterlines
    Especially if you have a patient who believes the infection came from your practice, it is essential that you test the water in all your chairs and document the results of that testing.
  2. Shock your dental unit waterlines
    If you receive failing test results, you will need to shock your waterlines (not your evacuation line). The purpose of this is to remove any biofilm and bacterial build-up in the lines to give your stations a fresh start.
  3. Test your lines (again)
    Yes, you will want to test your water again to see if the initial shock was enough to reset your lines. If you have failing results again, repeat steps 2 and 3 until you get passing results.
  4. Follow the proven protocol for waterline maintenance
    Once you get your lines squeaky clean, it’s essential that you maintain their passing status with treatment products like straws or tablets.

How can dental unit waterline infections be prevented? 

The frustrating truth to the entire dental world is that these infections are 100% preventable. In many ways, while every dental practice prioritizes patient safety, there is still a need for improvements in infection prevention and infection control in the industry.

We saw this first-hand when ProEdge conducted the largest treatment efficacy study to date. Cited in the article “Treating & Monitoring Dental Water,” by John A. Molinari, PhD and Nancy Dewhirst, BS, RDH, this study of over 22,000 real-world waterline tests found that 31% of treated waterlines still fail to meet the CDC standard of ≤ 500 CFU/mL for safe water. Additionally, 61% of practices had at least one failed waterline.

A continuous waterline treatment protocol is necessary to keep the environment free from biofilm so your patients and your practice are safe.

One of the greatest weapons we have against infections like those in Anaheim and Atlanta is simply knowledge. In the world of dental infection control, knowledge really is power, and—in this case—knowledge is safety.

What should dental practices do now?

It’s often said that the best offense is a good defense. Even if your practice is not in a compromising situation, it’s essential that dental professionals know how to maintain waterlines so that conversation never needs to arise.

As we mentioned, the best way to get started is to follow the proven protocol. However, if you have any questions or concerns, our next recommendation is to connect with a safe water expert to customize your protocol as needed. Simply schedule your informational consultation here.

Additional resources on the Anaheim outbreak:

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Publish Date:

August 22, 2022


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