What infectious disease specialists say they would never do

Infectious diseases like COVID-19, group A streptococcus and measles are making the rounds in Canadian communities. Health-care experts are watching as cases increase in clinics and hospitals through the cold and flu season.

Although it is sometimes impossible to avoid illness, some infectious disease specialists say there are certain things they do -- and don't do -- to keep healthy.

Don't skip your shots

"I'm unabashedly a vaccine booster — if you pardon the pun," Dr. David Fisman, an epidemiologist from the University of Toronto, told CTVNews.ca in an interview.

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Fisman says he is up to date on all his shots, including COVID-19 boosters, flu vaccines and longer-term vaccines like tetanus shots.

"Our big tool for changing immunity without getting sick is vaccines,” he said. “They not only protect vaccinated people but unvaccinated people.”

When people don’t get vaccinated, there can be a resurgence of infections like measles, Fisman says.

Vaccines are a tool for herd immunity, he says, but they also provide other benefits like reducing the risk of illness and lowering the chances of infecting someone else.

Some shots are "underutilized" in Canada like the pneumococcal vaccines, which can protect against lung and sinus infections, says Fisman. They can also protect against streptococcus pneumonia, a possible outcome of strep A.

"People have to talk to a nurse practitioner, physician or pharmacist about whether they're eligible at a particular age … And they work really well," he said.

Infectious disease physician in St. John's, N.L., Peter Daley says he would "never" refuse vaccination.

"Vaccination is a tremendously helpful public health intervention that has saved literally millions of lives," Daley told CTVNews.ca in an interview. "The very first thing that an infectious disease physician would never do is refuse a vaccination."

Risk management for activities

Many infectious diseases are spread through aerosol droplets, like COVID-19. According to Fisman, clean air is a must to stay healthy during cold and flu season.

"It's remarkable that ventilation can be as simple as cracking a window open," he said.

If people are not able to open the windows — like at Fisman's office — a HEPA filter can help keep the air circulating and clean.

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"If you've ever used one of these filters and had to change it … you see all this stuff that's pulled out of the air that you would have been breathing in. It's pretty incredible," he said.

Fisman said he and other infectious disease specialists assess risk based on the three Cs:

• Close—are people coming in close contact;
• Closed—is there proper ventilation;
• Crowded—Are there a lot of people all in one place

If the activity he wants to do involves being close to people, in an environment where there is no air circulation and it's crowded, Fisman said he will opt for a mask.

"I usually go to a little local grocery store that's kind of small, pretty crowded, and I don't know what the ventilation is like," he said. "So, I'll use my respirator."

Infectious diseases can also be transmitted in other ways, Daley said.

"I would never have sex with somebody who I don't know whether they have an infection that I could acquire," he said.

Unprotected sex could leave you with a sexually-transmitted infection, Daley said, like syphilis, gonorrhoea, chlamydia and trichomoniasis.

Limiting the risk comes down to reducing the number of sexual partners you have, using protection and being up to date on vaccines that prevent infections.

Travelling to some countries can also increase the risk of becoming sick, Daley said.

"If you're travelling to Europe, Australia, the U.S., you're unlikely to acquire an infectious disease," he said. "(But) if you're travelling to endemic countries like… Southeast Asia and Africa, you're going to accept risk."

Malaria is a common illness, he said, but prevention measures like taking medication, using a mosquito net and staying in a high-quality hotel reduces risk.

Risks are different for everyone

Both infectious disease experts say they don't allow the risk of catching something to dictate their lives.

Fisman says people should calculate the risks before doing something, especially during heightened periods of transmission.

"Sometimes, there are things that are important in your life that you can take a calculated risk," he said.

For Fisman, there are times when the desire to do something outweighs the risks associated.

"I'm not going to be reckless, but there are also things that I have to do maskless with other people as part of living my life," he said.