It’s a snapshot of a superspreading event: one person unknowingly infected with COVID-19 transmitted the contagion to 23 other passengers scattered on a tour bus, even those sitting seven rows behind.
The image presented in last month’s study of what happened on a sunny, breezy day in eastern China is dramatic, experts say.
For those who have been studying how the public has responded to messages from authorities during the pandemic, it’s the kind of story that public health officials should harness more often in their communications.
“They tell a very compelling story,” said Prof. Kim Lavoie, who holds the Canada Research Chair in behavioural medicine at the University of Quebec at Montreal. “If you can represent that visually, people get it. People see the good things that happen when I adhere to these policies and the not-so-good things that happen.”
The Chinese study documented what happened in late January during the peak Lunar New Year travel season. The novel coronavirus was spreading in China’s Hubei province when a group of 126 Buddhists living in the community took two buses to a temple ceremony in Ningbo, hundreds of kilometres east of the city of Wuhan, the original epicentre of the coronavirus.
A woman who had recently dined with friends in Hubei rode on one bus. The presumed index case started to have a cough, chills and muscle aches after returning from the temple. She sat, unmasked, for the 100-minute round trip on a vehicle with cooling units recirculating the air. Two windows on each side of the bus were open.
The close, crowded conditions on a bus for a long period with someone who was likely highly contagious — with most of the 68 passengers and driver not wearing masks — suggested “airborne transmission likely contributed to the high attack rate,” the researchers wrote.
The Public Health Agency of Canada said it does not have a definition of superspreading events for this country and instead monitors outbreaks.
Several local medical officers of health across the country also don’t refer to superspreaders. For example, Dr. Elizabeth Richardson, Hamilton’s medical officer of health, was asked Tuesday if the city’s largest current outbreak at a spin studio — one of the worst fitness studio outbreaks in the country — would be considered a superspreader event.
Richardson said the public health department generally doesn’t use that term, instead calling it a “very large outbreak” with a lot of transmission.
(CBC News)
Nonetheless, Dr. Kieran Moore, the medical officer of health for Kingston, Ont., and surrounding communities, said that during an outbreak at a nail salon in June that led to 37 cases, a “superspreading event contributed to 38 per cent of total cases.”
Successful public health measures during COVID-19 can also be used to tell a story and illustrate cause and effect for the public, Lavoie said.
The collective sacrifices of individual Canadians succeeded in bending the curve when only essential workers ventured out, cases dropped and then the effective reproductive number fell below one, pausing the disease’s exponential growth during the summer. Australia’s more recent success is another positive example.
To keep people engaged with public health measures over time, Lavoie suggests that governments in Canada share more personally relevantinformation to help individuals make informed decisions, rather than what she called a “pretty please” approach.
“I think ‘pretty please’ without supporting data is not very compelling, particularly when you’re asking people to make massive sacrifices without demonstrating that the sacrifices are worth it.”
(CBC News)
Early on, Dr. Bonnie Henry, British Columbia’s provincial health officer, was praised for clearly showing people what was happening and why, in easy-to-understand terms.
“I honestly believe that had a huge impact,” Lavoie said. “It felt like ‘We respect you, we trust you with the information, and now that you have it, we have confidence you’ll make the right decision.'”
What’s more, when missteps were made initially, such as outbreaks in B.C.’s long-term care homes, Henry took full responsibility, she said.
What motivates people to sacrifice?
Behavioural medicine also suggests that moving away from a one-size-fits-all message to a more personalized approach would work better at motivating people to make important sacrifices.
Lavoie and Simon Bacon, a professor of health, kinesiology and applied physiology at Concordia University in Montreal, have been surveying people throughout the pandemic about what motivates them as part of the iCARE (International COVID-19 Awareness and Responses Evaluation Study) project.
The findings suggest that younger people might be more motivated by the socio-economic fallout of reimposing restrictions rather than risk to their individual health from COVID-19, compared with people over the age of 65.
“Show how long it’s going to take us to pay down the debt, this is how long it’s going to take, the longer we remain in this,” Lavoie said.
Individual goals matter, too.
“I think we do need to have positive messaging,” Lavoie said.
Barbershop manager Georgette Simms gets a haircut from her partner, Jason Carter, at their business, Social Barber Studio, in Brampton, Ont., in July. Positive messaging from public health officials can help people understand that adhering to COVID-19 safety measures can be beneficial, such as by protecting their business. (Evan Mitsui/CBC)
A common message from public health officials is: “We’re all going to get through this.” But to Lavoie, that doesn’t go far enough.
Her version is: “We are going to get out of this only together. This is how and this is why, and this is what’s in store for us the quicker we achieve that,” she said. “We’re all going to benefit. Some of you will benefit by protecting your health. Some of you will benefit by protecting your business. Some of you will benefit by being able to have your dream wedding.”
It’s a numbers game
The field of finance also shows how communicating in terms of time, not case numbers, makes a difference in perception.
Daniela Sele, a PhD candidate at the Center for Law & Economics at ETH Zurich, turned from studying exponential growth in financial decision-making, like compound interest, to the exponential growth of infectious diseases like COVID-19.
Sele found that how numbers are presented matters in how people perceive them.
Portraits of Dr. Bonnie Henry, left, B.C.’s provincial health officer, and Dr. Theresa Tam, Canada’s chief public health officer, are dismantled at a picture-framing shop in Vancouver in May. Henry was praised at the time for clearly showing people what was happening during the COVID-19 pandemic and why, in easy-to-understand terms. (Maggie MacPherson/CBC)
In a preprint study posted in August, Sele asked about 450 students to estimate how many cases could be avoided through interventions like physical distancing, handwashing and wearing a mask.
Sele and her co-author found people drastically underestimated how many cases could be avoided.
But if the same numbers were framed in terms of doubling time — how long it takes cases to double from, say, 100,000 to 200,000 — people assessed the benefits correctly.
The classic example of framing exactly the same number differently is saying two-thirds of people will survive versus one-third of people will die.
“I think it’s interesting to think about could we talk about how long until the health-care system capacity is reached in our local community?” Sele said. “Because people, according to our data, seem to understand that better than the actual pace of the pandemic.”
WATCH | The role of superspreading events in COVID-19 transmission:
More research into how COVID-19 is spread shows that because not everyone sheds the same amount of virus, many infections are spread by a few people known as superspreaders. 2:01
Prevent superspreading events
Ashleigh Tuite, an infectious disease epidemiologist and mathematical modeller at the University of Toronto’s Dalla Lana School of Public Health, said when it comes to superspreading events like the tour bus in China, a small proportion of people are responsible for a greater share of the transmission.
“You don’t know ahead of time what will result in a superspreading event,” Tuite said.
The message? Like the woman who boarded a tour bus, it’s impossible to know if your silent infection will affect many others, so everyone needs to heed public health precautions.
It’s a combination of biology, such as being at the peak of infectiousness, and performing an activity in a location that’s really conducive to transmission — think indoor, crowded places — that come together to create superspreading events, Tuite said.
The Canadian government says it will donate up to 200,000 vaccine doses to fight the mpox outbreak in Congo and other African countries.
It says the donated doses of Imvamune will come from Canada’s existing supply and will not affect the country’s preparedness for mpox cases in this country.
Minister of Health Mark Holland says the donation “will help to protect those in the most affected regions of Africa and will help prevent further spread of the virus.”
Dr. Madhukar Pai, Canada research chair in epidemiology and global health, says although the donation is welcome, it is a very small portion of the estimated 10 million vaccine doses needed to control the outbreak.
Vaccine donations from wealthier countries have only recently started arriving in Africa, almost a month after the World Health Organization declared the mpox outbreak a public health emergency of international concern.
A few days after the declaration in August, Global Affairs Canada announced a contribution of $1 million for mpox surveillance, diagnostic tools, research and community awareness in Africa.
On Thursday, the Africa Centres for Disease Control and Prevention said mpox is still on the rise and that testing rates are “insufficient” across the continent.
Jason Kindrachuk, Canada research chair in emerging viruses at the University of Manitoba, said donating vaccines, in addition to supporting surveillance and diagnostic tests, is “massively important.”
But Kindrachuk, who has worked on the ground in Congo during the epidemic, also said that the international response to the mpox outbreak is “better late than never (but) better never late.”
“It would have been fantastic for us globally to not be in this position by having provided doses a much, much longer time prior than when we are,” he said, noting that the outbreak of clade I mpox in Congo started in early 2023.
Clade II mpox, endemic in regions of West Africa, came to the world’s attention even earlier — in 2022 — as that strain of virus spread to other countries, including Canada.
Two doses are recommended for mpox vaccination, so the donation may only benefit 100,000 people, Pai said.
Pai questioned whether Canada is contributing enough, as the federal government hasn’t said what percentage of its mpox vaccine stockpile it is donating.
“Small donations are simply not going to help end this crisis. We need to show greater solidarity and support,” he said in an email.
“That is the biggest lesson from the COVID-19 pandemic — our collective safety is tied with that of other nations.”
This report by The Canadian Press was first published Sept. 13, 2024.
Canadian Press health coverage receives support through a partnership with the Canadian Medical Association. CP is solely responsible for this content.
HALIFAX – The Nova Scotia government says it could be months before it reveals how many people are on the wait-list for a family doctor.
The head of the province’s health authority told reporters Wednesday that the government won’t release updated data until the 160,000 people who were on the wait-list in June are contacted to verify whether they still need primary care.
Karen Oldfield said Nova Scotia Health is working on validating the primary care wait-list data before posting new numbers, and that work may take a matter of months. The most recent public wait-list figures are from June 1, when 160,234 people, or about 16 per cent of the population, were on it.
“It’s going to take time to make 160,000 calls,” Oldfield said. “We are not talking weeks, we are talking months.”
The interim CEO and president of Nova Scotia Health said people on the list are being asked where they live, whether they still need a family doctor, and to give an update on their health.
A spokesperson with the province’s Health Department says the government and its health authority are “working hard” to turn the wait-list registry into a useful tool, adding that the data will be shared once it is validated.
Nova Scotia’s NDP are calling on Premier Tim Houston to immediately release statistics on how many people are looking for a family doctor. On Tuesday, the NDP introduced a bill that would require the health minister to make the number public every month.
“It is unacceptable for the list to be more than three months out of date,” NDP Leader Claudia Chender said Tuesday.
Chender said releasing this data regularly is vital so Nova Scotians can track the government’s progress on its main 2021 campaign promise: fixing health care.
The number of people in need of a family doctor has more than doubled between the 2021 summer election campaign and June 2024. Since September 2021 about 300 doctors have been added to the provincial health system, the Health Department said.
“We’ll know if Tim Houston is keeping his 2021 election promise to fix health care when Nova Scotians are attached to primary care,” Chender said.
This report by The Canadian Press was first published Sept. 11, 2024.
ST. JOHN’S, N.L. – Newfoundland and Labrador‘s chief medical officer is monitoring the rise of whooping cough infections across the province as cases of the highly contagious disease continue to grow across Canada.
Dr. Janice Fitzgerald says that so far this year, the province has recorded 230 confirmed cases of the vaccine-preventable respiratory tract infection, also known as pertussis.
Late last month, Quebec reported more than 11,000 cases during the same time period, while Ontario counted 470 cases, well above the five-year average of 98. In Quebec, the majority of patients are between the ages of 10 and 14.
Meanwhile, New Brunswick has declared a whooping cough outbreak across the province. A total of 141 cases were reported by last month, exceeding the five-year average of 34.
The disease can lead to severe complications among vulnerable populations including infants, who are at the highest risk of suffering from complications like pneumonia and seizures. Symptoms may start with a runny nose, mild fever and cough, then progress to severe coughing accompanied by a distinctive “whooping” sound during inhalation.
“The public, especially pregnant people and those in close contact with infants, are encouraged to be aware of symptoms related to pertussis and to ensure vaccinations are up to date,” Newfoundland and Labrador’s Health Department said in a statement.
Whooping cough can be treated with antibiotics, but vaccination is the most effective way to control the spread of the disease. As a result, the province has expanded immunization efforts this school year. While booster doses are already offered in Grade 9, the vaccine is now being offered to Grade 8 students as well.
Public health officials say whooping cough is a cyclical disease that increases every two to five or six years.
Meanwhile, New Brunswick’s acting chief medical officer of health expects the current case count to get worse before tapering off.
A rise in whooping cough cases has also been reported in the United States and elsewhere. The Pan American Health Organization issued an alert in July encouraging countries to ramp up their surveillance and vaccination coverage.
This report by The Canadian Press was first published Sept. 10, 2024.
