‘We all now know the power of infectious diseases,’ says Division Chief Dr. Karl Weiss

In the years before Dr. Karl Weiss started medical school in 1984, society was less concerned about infectious diseases as their threat had diminished.

But Dr. Weiss, now Division Chief of Infectious Diseases at the Jewish General Hospital (JGH), is glad he made the field his life’s work.

By the early 1980s, sanitation, antibiotics and vaccines had tamed most of the major infectious diseases that had been scourges for millennia: smallpox was totally eliminated; mass killers and disablers such as typhoid, diphtheria, polio, measles and other infections were under control. As a result, average life expectancy had jumped not by years, but by decades.

People started talking optimistically about the total elimination of infectious diseases as a major health problem in the developed world. Then came AIDS – a deadly disease, eventually found to be caused by a new virus, HIV.

Since then, Dr. Weiss noted, infectious diseases have returned to affect our lives in many ways – not just AIDS, but SARS, Ebola, West Nile virus, H1N1, Zika virus, C. difficile and other hospital infections, many of which have become resistant to treatment due to the overuse and misuse of antibiotics for many years.

And then came COVID-19. “We all now know the power of infectious diseases,” he said. “The word pandemic was likely the word most used in the world over the past two years.”

‘COVID-19 vaccines changed the world’

We have been saved from the worst ravages of COVID-19 thanks to research into infectious diseases.

“The COVID-19 vaccines changed the world,” said Dr. Weiss. “They have allowed us to learn to live with COVID. I’ve had it; almost everyone has had it, but because most of us are vaccinated effectively, and with new treatments, we can manage it now.”

At the JGH, which was and remains a major centre for treating those seriously ill with COVID-19, Dr. Weiss said that thanks to the vaccines, new treatments and knowledge learned, COVID-19 can now be managed like other infectious diseases, allowing overall operations “to completely return to normal.”

However, “normal” means the continuing appearance of other infectious diseases, such as seasonal influenza, which almost disappeared during the height of the pandemic. As we have all learned, the fight against infectious diseases never ends. “It also has a vital role to play in other advances in medicine,” added Dr. Weiss. “Modern surgery or cancer treatment would be impossible without adequate infectious diseases control.”

That’s why Dr. Weiss is very excited about the work that will be conducted over the coming years at the hospital’s newly named Jess and Mark Pathy Centre of Excellence in Infectious Diseases, which he heads. The Centre was named in November last year to honour Montrealers Jess and Mark Pathy for their lead donation to the successful multi-million fundraising campaign for the Centre, led by the JGH Foundation.

After many years at Montreal’s Maisonneuve-Rosemont Hospital, Dr. Weiss came to the JGH in 2016 to take on the challenge of leading the department at the hospital that has the largest clinical volume of infectious diseases patients in Canada.

“I wanted to grow the potential of capitalizing on that high volume of patients to increase the hospital’s research and leadership in this crucial field of medicine,” he said.

The Centre is now restarting in full, with new hiring in progress following the pandemic shift of resources towards acute care. “We have to remember that just a few months ago we had a pandemic curfew here in Quebec,” said Dr. Weiss. “We’re just coming out of it. Things were hectic until recently.”

Three axes for the Centre’s work

The Centre’s work is divided into three axes that are crucial to understanding and managing infectious diseases: epidemiology, clinical trials and laboratories.

Epidemiology research studies how infectious diseases are transmitted among populations and therefore how to develop better means to limit transmission depending on the nature of the pathogen causing the disease. Many such epidemiology-based controls were put in place for the COVID-19 pandemic, such as mask-wearing, closures and crowd restrictions, sanitation requirements such as hand-washing, curfews and more. Some were more effective than others.

The clinical trials axis of the Centre is focused on developing the necessary infrastructure at the hospital to allow participation in world-leading clinical studies of new anti-infective therapies. Along with helping medical knowledge progress, these studies will give hospital patients access to the newest treatments which could save lives or greatly reduce the length or seriousness of an infection.

The microbiology laboratory at the JGH has the vital job of building in the future an understanding of the molecular nature of infectious diseases, knowledge which is necessary for the development of new and better treatments for existing infections or which can be put to ready use when – not if – new viruses or diseases present themselves.

The expanded Centre will also play an important role in contributing to the JGH’s overall program to incorporate new developments in artificial intelligence into how it cares for patients, thanks to AI’s ability to analyze vast amounts of data.

“We are working to learn how we can use AI to change things and help the hospital become a leader in this field,” said Dr. Weiss, “We’re collaborating with other fields such as psychiatry to use AI to examine the impact of infectious diseases on mental health, as well as to use economic data to learn more about the full impact of illness.”

“There are many potential implications that could have a big impact on society. That’s what’s so exciting about the infectious diseases work we are doing here at the JGH.”

To make a donation to the JGH Foundation, please go to www.jghfoundation.org