Government of New Brunswick

Between early 2020 and the end of May, 2021, there were a total 48 individuals who were identified as having some clinical signs and symptoms that were similar to those associated with Creutzfeldt-Jakob Disease (CJD) yet presented with atypical characteristics. 

These 48 patients were referred by three physicians in New Brunswick. Forty-six of the 48 identified cases were referred by a single neurologist and the two other cases were referred by two separate neurologists.

The 3 referring physicians in New Brunswick engaged the Public Health Agency of Canada’s Creutzfeldt-Jakob Disease Surveillance System (CJDSS) to actively investigate the possibility of human prion disease, but to date, all test results have been negative for known forms of human prion disease. Due to some noted commonalities in signs and symptoms and the lack of a confirmed diagnosis among cases, the individuals were categorized as being part of a cluster of a potential neurological syndrome of unknown cause by the main referring physician and CJDSS.

At the time of referral by their health-care provider, most of the individuals under investigation were living in the southeastern and northeastern regions of New Brunswick, around the Acadian Peninsula and Moncton areas. However, the investigation has not found any evidence suggesting that the residents of these regions are more at risk than those living elsewhere in the province. It is also noted that locations could be a reflection of the catchment area of the referring physicians. No other cases have been identified in other provinces and territories.
 


Common symptoms among patients in the cluster include:

  • memory problems
  • muscle spasms
  • balance issues, difficulty walking or falls
  • blurred vision or visual hallucinations
  • unexplained, significant weight loss
  • behaviour changes
  • pain in the upper or lower limbs
     


 Investigation status 


 Active 

 Cases under investigation

 48

 Deaths

 9*

 Illness onset date range in years

 2013 – 2020**

 Gender

 50% female – 50% male

 Age range in years

 18 – 85


*   Of the original 48 cases, nine have died. Autopsies have been completed on 6 of those individuals. The autopsies confirm that all 6 individuals died of known causes or diseases. A review of the clinical files for the other three cases is still pending.

** The referring physician(s) have reported that symptoms started in 2018, 2019 or 2020 for most cases. Only one case identified retroactively by the referring neurologist in 2020 was reported to experience symptoms in 2013. This case had originally been referred by the physician to CJDSS as a suspected case of CJD.

 

Timeline

 

  • The Creutzfeldt-Jakob Disease Surveillance System (CJDSS) routinely works in partnership with the Regional Health Authorities in New Brunswick to detect all types of human prion disease.
  • Through routine case management, the CJDSS noted some common symptoms and similar potential diagnostic profiles among some recent New Brunswick referrals to the surveillance system. These referrals tested negative for Creutzfeldt-Jakob Disease and it appeared to CJDSS that these referrals represented a cluster of cases that were worth further investigation.
  • In December 2020, the CJDSS notified Public Health New Brunswick to actively include us in the investigation.
  • The first draft for the case definition was prepared at the end of January 2021, and a memo regarding this potential case definition was sent to physicians in New Brunswick on March 5.
    • The memo’s purpose was to inform and encourage any health-care provider with patients that may meet the case definition for this possible neurological syndrome of unknown cause, to contact the CJDSS or the Mind Clinic for more information.
  • In April, Public Health began collecting consent and contact information from those impacted by the investigation to undertake an investigative survey.
    • With input from local and national subject matter experts, Public Health drafted an enhanced epidemiological questionnaire to gather information from New Brunswickers suspected of being part of this cluster and identify areas that warrant further research and investigation. This questionnaire asked for lots of information including but not limited to, the persons’ environment, residence, potential exposure and travel history. Detailed information is needed to better explore potential commonalities and may help to determine if there are potential shared environmental or infectious sources for these cases.
  • In May, Public Health began calling individuals to schedule survey appointments. Surveys were conducted with 34 of the 48 cases. The respondent could be the individual identified in the cluster, their proxies, or the individual with the support of their proxy during the questioning. Of the remaining 14 cases, nine chose not to be interviewed. Public Health nurses were unable to contact the last five, who did not respond to the registered letters inviting them to participate.
     


New Brunswick’s Epidemiology and Surveillance branch has released its report on the investigation of the potential neurological syndrome of unknown cause. The report is exploratory in nature and does not establish any causality relationships between common exposures and the potential neurological syndrome.  However, it does provide very useful information about those exposures and, when combined with the results of a clinical review of the cases, can further inform additional investigation and research areas. The epidemiological report concludes that New Brunswickers should feel confident that they are not putting themselves or their families at risk by consuming regional foods and that there are no specific behaviours or environmental exposures that can be identified as potential risk factors.

Since concerns have been raised about exposure to algae blooms, the team took extra care to explore this potential area of exposure. The epidemiological investigation does not point to algae blooms as being a potential source or cause of symptoms.

The epidemiological report is one part of a two-pronged investigation.

An Oversight Committee made up of six neurologists was tasked in June with ensuring that all clinical due diligence was taken, and to rule out any other potential causes or plausible diagnosis. It is currently reviewing all 48 case files, medical charts and records and will re-interview and re-evaluate patients if needed.

The Oversight Committee is expected to present its report early in the new year.
 


If you suspect that you, or your loved one, may be experiencing changes in personal health that may be similar to those described above, please speak with a health-care provider.

As the cause of the neurological syndrome is currently unknown, only a health-care provider can assess if the symptoms an individual is experiencing may be related to this NSUC investigation.
 


The Government of New Brunswick is committed to protecting the health of all citizens from new and emerging diseases in the province. The investigation is ongoing and Public Health New Brunswick will continue to investigate, working with the following partners:

  • New Brunswick Department of Agriculture, Aquaculture and Fisheries
  • New Brunswick Department of Natural Resources and Energy Development
  • New Brunswick Department of Environment and Local Government.
  • Public Health Agency of Canada
  • Canadian Food Inspection Agency
     
 

Frequently Asked Questions


What is a cluster?

A cluster is defined as several things of the same kind, and/or a group of things or persons close together. Occasionally, an outbreak or cluster of cases is discovered, for which the cause is unclear, and epidemiologists and biostatisticians must work diligently to assess whether a true cluster of disease exists.

In this investigation, the term cluster is being used because the ill individuals have reportedly similar clinical signs and symptoms for which a known cause has not been identified and are located in the same geographical area.

Is it unusual to see this many cases of unknown neurological disease in New Brunswick?

Occasionally, an outbreak or cluster of cases is identified, for which the cause is unclear, and epidemiologists and biostatisticians must work diligently to assess whether a true cluster of disease exists.  This cluster of individuals experiencing signs and symptoms of a potential neurological syndrome of unknown cause in New Brunswick is unexpected, which is why the cluster is being actively investigated by Public Health New Brunswick in collaboration with the established Oversight Committee comprised of neurologists and chaired by VPs from both RHAs.  In addition, other local and national subject matter experts and health-care providers will be engaged as required.  

Are there cases in other provinces or countries?

To date, no cases of individuals with neurological syndrome of unknown cause have been identified outside of New Brunswick. However, public health officials across Canada have been informed of this investigation and advised to contact New Brunswick Public Health for further information. The Public Health Agency of Canada has been in contact with other countries to provide further information and will be notified if potential cases are identified outside of Canada.

Do other cases under investigation have the same symptoms and/or severity of symptoms?

Individuals under investigation have reported similar symptoms for which a known cause has not been identified by their neurologist. The most frequently reported symptoms include memory problems, muscle spasms, balance issues (e.g., difficulty walking or falls), blurred vision or visual hallucinations, unexplained, significant weight loss, behaviour changes and pain in the upper or lower limbs. The severity of symptoms varies among individuals.

Is it safe to live in the Acadian peninsula or Moncton areas if purported cases included in this cluster lived here too?

At the time of referral by their health-care provider, most of the individuals under investigation were living in the southeastern and northeastern regions of New Brunswick, around the Acadian Peninsula and Moncton areas. However, the investigation has not found any evidence suggesting that the residents of these regions are more at risk than those living elsewhere in the province. All but two of the cases in the potential neurological syndrome of unknown cause were referred by one neurologist and locations could be a reflection of that physician’s catchment area. Neurologists from across the country were asked to report cases with similar symptoms but none have been reported to date.