The Province of New Brunswick is collaborating with local and national subject matter experts and health-care providers to investigate a group of individuals who are experiencing signs and symptoms of a neurological syndrome of unknown cause (NSUC).
New Brunswick Cluster of Neurological Syndrome of Unknown Cause
At this time, the investigation is active and ongoing to determine if there are similarities among the reported cases that can identify potential causes for this syndrome, and to help identify possible strategies for prevention. The investigation team is exploring all potential causes including food, environmental and animal exposures.
Since early 2020, physicians in New Brunswick have been identifying a number of individuals with an unusual combination of neurological symptoms. Despite extensive medical investigation, a diagnosis for these individuals has not yet been determined.
Local health-care providers in New Brunswick have 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 commonalities in signs and symptoms and the lack of a confirmed diagnosis among cases, a cluster of NSUC has been identified.
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, so far our investigation has not found any evidence suggesting that the residents of these regions are more at risk than those living elsewhere in the province.
Canadian health-care providers have been alerted to this investigation and are advised to contact New Brunswick Public Health for further information or to make referrals for individual cases.
Cases under investigation
Illness onset date range in years
2013 – 2020**
50% female – 50% male
Age range in years
18 – 85
* In some cases, additional information is needed to determine if the cause of death was a result of this syndrome.
- 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 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 became apparent that these atypical 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 potential 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 neurological syndrome of unknown cause, to please contact Public Health, 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 epidemiological questionnaire to gather information from New Brunswickers suspected of being part of this cluster. This questionnaire asks for lots of information including but not limited to, the persons’ environment, residence, potential exposure and travel history. Detailed information is needed to better understand and may help determine if there is an environmental or infectious source of these cases and if so, to help identify ways to prevent more cases from occurring. Data collected will be incorporated into the investigation to help identify potential sources of the syndrome.
- In May, Public Health began calling individuals to schedule appointments to conduct the surveys.
- The first interview was completed on Wednesday, May 26, 2021.
- To date, 23 surveys have been conducted, and several more are being scheduled and followed up on.
Some symptoms include, but are not limited to:
- 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
What you can do
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.
What the Government is doing
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 asses whether a true cluster of disease exists.
In this investigation, the term cluster is being used because the ill individuals have similar clinical signs and symptoms that do not have a known cause 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 discovered, for which the cause is unclear, and epidemiologists and biostatisticians must work diligently to asses whether a true cluster of disease exists. This cluster of individuals experiencing signs and symptoms of a 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 to identify potential causes.
Are there cases in other provinces or countries?
To date, no unusual clusters 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 cases are identified outside of Canada.
Do other cases under investigation have the same symptoms and/or severity of symptoms as (case)?
Individuals under investigation have similar symptoms that do not have a known. 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.
What is being done to identify the cause? Are you doing any testing to find out if there are hazards in the environment?
Public Health New Brunswick has developed, with input from local and national subject matter experts, an epidemiological investigation questionnaire to gather exposure information from individuals in NB suspected of being part of this cluster. The information collected from these interviews will be analyzed to look for common exposures that can be investigated further.
The investigation team is exploring all potential causes, including food, environmental and animal exposures. At this time, there are no specific behaviours or foods that have been identified to avoid. As new information becomes available in this investigation, this will be communicated to the public through the New Brunswick Public Health webpage.
Is it safe to live in the Acadian peninsula or Moncton areas if cases who developed this disease 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, so far 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. As new information becomes available in this investigation, this will be communicated to the public through the New Brunswick Public Health webpage.
As the investigation evolves, this webpage will be updated to provide new information about the ongoing investigation.
Last updated: 2021-07-08 - Updates made to “Timeline” section.