What is RSV? Here’s what to know about the virus as cases surge in Canada

Canada is reporting an increase in respiratory syncytial virus (RSV) activity that is “above-expected levels for this time of year” — leading to a surge of cases in ERs and hospitals across the country.

According to the Canadian Pediatric Society (CPS), respiratory syncytial virus (RSV) “is the most common virus that can infect the lungs and breathing tubes.” The infection is “most serious in young babies.”

The Health Canada website states that the federal positivity rate for RSV currently stands at 3.5 per cent, although that data is a week behind and covers the week ending Oct. 15.

Thanks to masking, distancing and hand-washing, Canada recorded just 239 cases of RSV between Aug. 2020 and May 2021, compared with nearly 19,000 in 2019, Global News reported previously. This year, the number stands at 486.

Montreal and Quebec City have the highest positivity rate so far compared to the rest of the country, standing at 15 per cent.

The national figures show a positivity rate of two per cent in Ontario and 3.4 per cent in Atlantic Canada. The lowest rates were reported in British Columbia (1.4 per cent), one per cent on the Prairies and two per cent in the Northwest Territories.

The virus, which typically emerges a little bit later in the fall and winter seasons, is taking off earlier than usual this year as reflected in testing that is no longer focused on COVID-19 and loosened public health measures, says Dr. Donald Vinh, an infectious diseases specialist at McGill University Health Centre.

“In the last two years…the testing policy was focused on COVID-19, so obviously we lost track a little bit of what was going on with the other viruses,” Vinh told Global News.

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“The other aspect is the fact that we’ve had two and a half years of people…wearing masks and distancing…and of course that works extremely well, not just for COVID-19 but for other respiratory viruses,” he added.

Vinh says that while it may “probably (be) the first time in humanity, where we were able to get rid of some of these viruses,” but with people no longer wearing masks and following public health measures, ERs and hospitals are now “overflowing” with respiratory-related cases.

“RSV is for sure in the lead right now. That’s the one that is taking off,” he said, especially among young children.

The respiratory syncytial virus (RSV) is common, very contagious, and infects the respiratory tract of most kids below two years of age. For most children, the infection doesn’t manifest beyond a cold. But for a small group, RSV can lead to bronchiolitis, which is an inflammation of the lungs, or pneumonia, according to the U.S. Centers for Disease Control and Prevention (CDC).

“RSV is…very transmissible, particularly in schools, so school-age children are the ones who spread RSV first to each other,” said Vinh. “Beyond the age of two, we think that all children have at one point been infected with RSV. That’s how contagious it is.”

However, adults can get RSV too, the Mayo Clinic website states, but symptoms are “mild and typically mimic the common cold.”

Children, on the other hand, can transmit the virus to other demographics, including those aged 12 months or less, said Vinh.

“This includes adults…the elderly…Anybody who has underlying heart or lung disease, RSV tends to cause very bad problems in those people,” said Vinh.

The chance of severe infection, however, is greatest for babies born prematurely, kids under two born with heart or lung disease, and kids with weakened immune systems.

The Canadian Paediactric Society says symptoms of RSV says symptoms include coughing, runny nose, fever, and a loss of appetite and energy.

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Dr. Mélissa Langevin, an emergency medicine pediatrician at CHEO in Ottawa, says nasal and respiratory congestion is common in RSV cases.

“You can imagine that the smaller you are, the more that congestion affects your ability to breathe, ability to eat and drink, and be comfortable,” said Langevin to The Canadian Press.

A bout of RSV usually lasts for more than a week, says Langevin, with fever typically lasting one or two days and the peak of illness arriving on days four and five.

“This usually gets worse before it gets better. And that is a natural course of RSV. And after that peak, children usually do then turn the corner and start doing much better,” said Langevin.

Vinh says there’s no vaccination or medication available yet for RSV.

“When people get in hospital for RSV, the major problem is that there are no drugs to treat it…so what we do is provide them with what we call supportive care…we help them with their breathing and provide them medical care as their body tries to fight off RSV,” he said.

He says the best way to avoid spreading RSV in at-risk group settings is by wearing a mask, washing hands, and maintaining physical distancing.

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Dr. Jesse Papenburg, a pediatric infectious disease specialist at the Montreal Children’s Hospital, recommends the same thing and suggests that people do not visit young children if they’re sick.

“Even if it’s just a mild cold. Avoid visiting especially newborns,” he said. “When you’re out in crowded indoor areas, wearing a mask can help reduce the risk as well for children and adults. “

For babies at very high risk of severe infection, a monthly injection of a monoclonal antibody called palivizumab can be given during RSV season to help cut the risk of hospitalization in half, says Papenburg.

But for the most part, Papenburg said only a small proportion of cases are severe enough to require hospitalization — most kids can be treated and recover at home.

Dr. Antonio D’Angelo, head of the pediatric emergency department at Montreal’s CHU Sainte-Justine says it’s key to maintain hydration and comfort. For babies, it’s especially important to clear out the nose because they rely on a liquid diet and have to breathe while drinking and swallowing.

“If they’re completely congested, what happens is they’ll take a lung full of air from their mouth and while they’re breathing they can choke,“ he says.

He suggests clearing a baby’s nose with saline so they’re able to drink properly. The drops can provoke a cough, and that’s good, he adds.

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“They sometimes even cough to the point where they vomit some secretions and that’s good because you want those secretions to be out of their bodies,” he says.

Langevin recommends a “snot sucker” for kids under six months who are very congested. If clearing the nose and expelling secretions doesn’t help, consult your primary care provider.

“I always tell families, don’t worry too much about solids, your children may not be very hungry for solid foods, but you want to be drinking lots very frequently.”

Langevin says infants should be watched closely for signs of difficulty breathing. That may include pulling between the ribs or pulling at the neck.

Take your child to an emergency department if they have trouble breathing or lips that look blue, the Canadian Paediactric Society says.

Babies younger than three months with a fever should always be taken to the ER, adds CPS, or if they are unable to suck or drink.

For those a bit older, the society says symptoms that warrant a doctor’s attention include a fever for more than 72 hours, loss of appetite or vomiting, or coughing to the point of choking or throwing up.

Watch for any signs of difficulty breathing and monitor fatigue, eating and drinking, says D’Angelo.

“If they’re not able to drink half of what they would normally drink, or if they’re in so much distress that they’re becoming fatigued … then obviously they have to be seen by the emergency department,” he says.

— With files from The Canadian Press