WINNIPEG -- Dr. Frank Plummer, the former scientific director of Canada’s National Microbiology Lab in Winnipeg, is being mourned as a “maverick.”

He died Tuesday at the age of 67.

Canada’s chief public health officer described Plummer’s death as “sudden” in a statement where she referred to him as her mentor.

“He was a scientific maverick who helped set up and make PHAC's National Microbiology Laboratory a world class institution. He made outstanding contributions to public health, both through his research and his leadership,” said Dr. Theresa Tam, chief public health officer.

Tam said Plummer’s expertise, counsel and courage will be missed. She shared thoughts for his wife, friends and family.

Dr. Keith Fowke, head of medical microbiology at the University of Manitoba, told CTV News in an email that Plummer died of a heart attack Tuesday in Nairobi, Kenya.

“I was with him last week in Nairobi and he was full of energy and enthusiastic about his future and the work he was doing on an HIV vaccine,” said Fowke, who was also a former student of Plummer’s who described him as a mentor.

Plummer was in Nairobi to speak at the celebration of the 40th anniversary celebration of the collaboration between the U of M and University of Nairobi.

UNRAVELLING MICROBIOLOGY MYSTERIES

The U of M, where Plummer first graduated medicine in 1976 and eventually became a distinguished professor of microbiology and a former Canada Research Chair, released a statement about Plummer, describing the “tremendous impact” his work had on global public health.

He was on the forefront of AIDS research, completing work in Nairobi that first revealed the disease could impact women and heterosexual men, not just gay men as was thought at the time.

The university said his best-known research “unraveled the mystery” over a group of Kenyan women who were naturally immune to HIV by looking into their immune systems and genetics for answers. Plummer’s work laid a foundation for subsequent interventions, and was used to guide vaccine and drug development.

He won many awards during his career, for his research into HIV transmission and for providing leadership at the National Microbiology Lab during the SARS outbreak, including the Canada Gairdner Wightman Award in 2016. He was also at the helm of the lab during Ebola scares and during the 2009 H1N1 pandemic.

Plummer was an Officer of the Order of Canada, and has received the Order of Manitoba, the McLaughlin Medal of the Royal Society of Canada, and the Prix Galien Research Award.

In the statement from the U of M, Dr. Digvir Jayas, vice-president and distinguished professor, said Plummer was an “outstanding scientist.”

“His contributions have had a cumulative global impact on saving the lives of tens of thousands of people for decades and also improving the lives of HIV positive people around the world,” he said.

FINDING RELIEF FOR ‘BRAIN-BASED ILLNESS’

In December, Plummer shared details of a personal battle with alcohol-use disorder, after undergoing experimental brain surgery to treat it.

He told CTV News how using alcohol to relax after work progressed to a habit that saw him drinking up to 20-ounces of whiskey a night, leading to a cirrhosis and end-stage liver disease diagnosis in 2012.

Citing the stress of responding to pandemics, he said he was unable to stop himself from returning to alcohol after a 2014 liver transplant.

“I kept on thinking as we went through this, you know, he’s the smartest man in Canada,” his wife, Jo Kennelly, told CTV News in December. “He’ll be able to figure this out, we’ll get through this, he’ll want to survive, he’ll want to stop, he’ll want to do these things.”

Plummer eventually underwent surgery to implant electrodes to provide novel brain stimulation, targeting an area of the brain linked to addiction.

After a year, he said the treatment removed his obsession with drinking.

"It’s given me my life back,” he told CTV News, adding that he was happier than he had been in many years.

-With files from CTV News’ Avis Favaro and Alexandra Mae Jones