No longer a sure thing: Records show how N.B. investigation into mystery illness changed over time

For three months last year, medical and environmental experts in New Brunswick, along with many from beyond the province, met with provincial public health officials about what they described as a "neurological syndrome of unknown cause."

But that all changed on May 6, 2021, when provincial health officials halted those meetings.

According to the province, the syndrome of unknown cause has affected 48 people who have symptoms such as memory problems, balance issues and behaviour changes.

Hundreds of pages of records obtained by CBC News through access to information reveal new details of those meetings, and how New Brunswick's strategy around investigating the syndrome changed over time.

An oversight committee, made up mostly of neurologists from within the province, has been doing a clinical investigation with patients from the cluster.

Their report is expected to be released early this year and could conclude there isn't a mystery syndrome.

Health Minister Dorothy Shephard said in October that officials were questioning the validity of the theory of an unknown syndrome. 

The health minister has said eight patients, six of whom were part of the original cluster of 48, who died had autopsy results indicating they died from known diseases, such as cancer, Lewy body dementia and Alzheimer's disease.

Around the same time as the meetings with experts were cancelled, the government's messaging around the syndrome began to shift, from something definite to being described with words like "potential."

It was also then the province began to distance Dr. Alier Marrero, who identified 46 of the 48 patients, from the investigation. 

The minister of health moved from pointing to Marrero as leading the investigation in April to saying in October that he was never the lead and that an investigation "should be from an unbiased perspective."

CBC News asked Marrero to respond to Shephard's comment, but his employer, Vitalité Health Network, declined comment because the investigation is ongoing.

Critics, including some patients and Marrero, have questioned the province's strategy. 

"We were told we didn't have the right to update the newest cases," Marrero said in an interview with Radio-Canada's Enquête in October, as he described provincial officials' shift in strategy last spring.