A possible cluster of a mysterious brain illness afflicting people in New Brunswick, Canada may be larger than officially reported, according to an investigation published by the Guardian earlier this week. As many as 150 people may have developed unexplained neurological symptoms dating back to 2013, including cases where people became sick after close contact with another victim. But it is not clear whether local health officials will conclude that any of these cases are truly connected, pending an upcoming report of theirs expected later this month.
The first public notice of the cluster came in March 2021, when a memo from New Brunswick health officials sent to health care workers in the area was leaked to the press. The memo warned that some people in the area had developed dementia-like symptoms with no known cause, along with rapid weight loss, trouble moving, and hallucinations. The early investigation ruled out possible explanations such as prion disease, which can cause similar symptoms. By April, 48 cases including nine deaths were officially recognized as possibly linked to the cluster as far back as 2013, with patients having tested negative for prions and with no other apparent cause.
According to the Guardian, however, there have been many more similar cases unofficially documented by doctors. Citing multiple sources, the Guardian reported that as many as 150 cases may be out there. In nine of these cases, a person developed symptoms following close contact with someone else similarly sick, often while caring for them. What’s more, younger people, who rarely develop these sorts of neurological symptoms, have been identified within and outside the official cluster.
“I’m truly concerned about these cases because they seem to evolve so fast,” an anonymous employee with the Vitalité Health Network, one of two health authorities in the province, told the Guardian. “I’m worried for them and we owe them some kind of explanation.”
Families, as well as some officials and experts, have reportedly been frustrated by the local government’s investigation into the cluster. The Vitalité employee said that they stepped forward to discuss the other cases due to their concern over the growing number of younger patients and their rapidly declining symptoms. They’re also worried that this cluster may not be limited to New Brunswick alone.
The cases among close contacts suggest a common environmental factor. And there has been some speculation by experts that β-Methylamino-L-alanine (BMAA)—a toxin produced by blue-green algae—could be to blame. Some earlier research has shown that lobsters, a popular harvested food in the province, can potentially carry high levels of BMAA. But efforts by federal scientists to examine the brains of those deceased for BMAA, the Guardian reports, have so far not been allowed by the New Brunswick government, despite families themselves wanting the tests to be done.
Later this month, New Brunswick is set to release a report discussing the cluster, led by neurologists across the province, but seemingly without the involvement of the neurologist who first discovered these cases, Alier Marrero. In recent months, local officials have appeared to minimize Marrero’s role in studying the cases and even seemed to question the validity of the cluster.
In October, a preliminary report by other neurologists looking into eight of the deaths concluded that they were not connected and were likely caused by other disorders misdiagnosed at the time. But other scientists interviewed by the Guardian have disagreed with this conclusion, arguing that the relatively high number of these cases in the same area, along with the younger age profile of many patients, simply doesn’t make sense without a connected cause.
Should the government’s forthcoming report be as skeptical as many fear, it seems likely that it won’t be the final word on this possible cluster.