A Doctor of Epidemiology Rides a Bike During a Pandemic – An Update

Meg Thorburn BSc, DVM, MPVM, PhD

The times they are a changing and what a long strange trip it’s been – Bob & Jerry

Epidemiology: The study of how diseases arise and spread within populations; the identification and quantification of risk factors that increase the frequency and severity of a disease in the population; the evaluation of preventive and mitigation factors.

Epidemiologist: A medical professional who investigates patterns and causes of disease and injury in humans and animals. Epidemiologists seek to reduce the occurrence and consequences of negative health outcomes through research, community education and health policy.

With regard to the novel coronavirus that causes the disease COVID-19 (SARS-CoV-2), we are now at a place of better understanding of a good number of things, some of them scientific and medical, others more a commentary on the social anthropology of how society reacts in circumstances with limited, varying, and at times, conflicting information – so what was the toilet paper thing really about?

It’s great to be in such intelligent company, however, knowledge and understanding evolves, hopefully for the better. Some things I have written below you already know, but I will state them anyway for clarity without assumptions.

For example, we now know that surfaces and objects are not as significant a mode of transmission as we originally thought – earlier suggestions on the risk of surface contamination were laboratory examples and greatly exaggerated by comparison to real world measurements and examples.

The novel coronavirus is not “cooties” – you won’t be infected simply by being within two metres of an infected person, or just by sitting in a chair they were in. There are many pathways of transmission that have to be navigated by the virus before you actually get infected, all of which combine to reduce your likelihood of infection. While being two metres apart in the outside world almost guarantees no transmission of the virus, it is however, not true that simply being less than two meters guarantees infection. The virus still has to leave someone’s mucus membranes and get to yours in a viable enough state to colonize and reproduce.

As most of us know, Canada’s two metre rule is about a physical distance limitation of how far virulent droplets can be projected when a person sneezes or coughs or speaks (sings) ‘moistly’. This distance has been established in controlled conditions and does not cover all the possible variations of temperature, UV, wind and humidity or the variable force of a cough or a sneeze. It is worth noting that most developed countries are having equal or better success with less than two-metre Social Distancing, and that the WHO recommends a minimum of only one metre.

Outdoor Transmission: After more than a half year of this pandemic and over 14 million cases, there are very few documented examples of the virus having been transmitted outdoors, and those that have occurred have involved prolonged close proximity and/or physical contact with an infected individual.

The likelihood of being in the proximity of an infected person is currently extremely low in Guelph (twelve known cases at the time of this writing). If all the known infected people chose not to obey their order to self-isolate, the chance of coming within range of one of them would be 12 in 135,474 or a 0.009% chance. Even if we use the most extreme assumption that there are four asymptomatic cases to every one known case, the likelihood would be 0.04%. I hate to use this comparison, but as a cyclist, your chances of being hit by a car are most likely higher.

Masks outside of the healthcare system: Very simply in the words of the Chief Public Health Officer of Canada, doctor Theresa Tam, “You wear a mask to protect me and I wear a mask to protect you”.

Ontario is now entering Stage Three of Phase 2 in it’s Framework for Reopening our Province in responding to COVID-19 and here are three key elements that are relevant to group cycling:

“Limiting outdoor gatherings to a maximum of 100 people, or less, to maintain physical distancing.”

“Physical distancing must be maintained, except if playing a team sport or as needed for personal training.”

“Amateur and recreational sports leagues may resume so long as they do not allow prolonged or deliberate physical contact between players or if they have modifications to avoid physical contact between players.”

It is always important to understand the risk factors. There are examples of people taking measures to protect against the virus that pose a higher risk than the virus itself. In protecting our health, we must ensure that we don’t endanger our health with bad precautions. Be smart, be safe.

Riding a bicycle on public roads is almost a perfect metaphor for this pandemic. Like a virus, cars are a risk factor for cyclists. The fewer there are and the further they pass from us, the safer we are. If there are more of them and they pass closer to us, the risk to our health increases. Neither of those factors guarantee injury, but the risk of injury increases.

We know there is inherent risk in cycling. To mitigate that risk, we take precautions. We choose quieter roads for our routes, we ride in double pace-line typically keeping cars further away from us and we train and practice our group riding. When members don’t follow the rules, we teach them better practices, expect compliance or refuse their participation in order to keep the group safe. We do all this to be safe and healthy… and happy.

Ontario has struck a similar balance in their approach to sports and other outdoor activities in the Stage Three opening by allowing flexibility in physical distancing for team sports, personal training, outdoor playgrounds, etc, and allowing sports leagues such as soccer to resume while avoiding prolonged physical contact. Inevitably, we will phase in more and more activities. The City of Guelph is also opening up its pools, wading pools and splash pads.

Am I ok with that as a professional in the field? Yes. Am I going to return to my sport of group cycling? Yes. My opinion is that the risk is now low enough. Should everyone return to their sporting activity? No. Individuals have to gauge their own risk, and in some cases, consider other factors – and ultimately, they must feel comfortable with their decision.

To some degree, we are all living in a giant experiment that’s being tweaked along the way. Are we ever going to be perfectly safe? Will the world be rid of this coronavirus? We don’t know. Will the world go back to being the same as it was before? I hope not. I am hoping we can be better than before. Let’s quit allowing people to go to work when they’re sick and let’s get them paid when they need to stay home – it’s cheaper for employers and society in the long run. The pandemic exposed a long list of social weaknesses that need improvement. It’s time to right some wrongs. We’re in this together. Safer together.

Working towards better days,

See you on your bike,

Meg Thorburn

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SRCC Big Gravel Ride 2020!

COVID-19 Version

This Club Event was originally planned for Sunday June 7th, 2020. But… well, you know.

Obviously we will not be riding this together as a club or in groups, but whenever you like, just go ride the route on your own or with those in your bubble. It’s a real treat of a route and we think you’re going to love it.

We had such a great event last year on a 70 km route that was almost entirely inside Guelph, we thought we would try one that was almost entirely outside of Guelph. And like last year, we guarantee there will be sections that are unknown territory for you.

About the route: It’s 75.8 km long – 63% of it is unpaved (47.8 km). In the middle there is one very long, continuous 27.5 km gravel section – bolt on your gravel aero bars! The start and finish currently are at the Boathouse (yes, you can SD an ice cream there). The official club event was planned to have been ‘from and to’ Fixed Gear Brewing. As of the time of this posting you can’t SD a beer at FGB, but they are doing take-away! Please support our sponsors…responsibly.

Several club members have ridden this already and small tweaks have been made. A few veteran P2A types have weighed in and given their seal of approval. The route is really good!

Get out and ride this when you can. Take snacks as there is nothing en route. A rest stop was planned at County of Wellington Forest Tract Benham at kilometer 31.9 in the small parking lot, but now you’re on your own.

“Get on your bikes and ride!” – Freddie Mercury

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Epidemiologist Rides a Bike

By now, some of you may have heard of the Dutch/Belgian study whose authors recommended that fast runners maintain at least 10 m distance and fast cyclists maintain at least 20 m distance from others in their “slipstream”. It received a lot of media attention, enough that runners and cyclists felt a bit demonized.

The researchers used existing wind tunnel measurements to computer simulate how far droplets traveled after being coughed, sneezed or exhaled by a fast moving person.

There were many limitations to this study. Mainly, the study was about droplets, not infectious particles, and none of the authors were medically trained. Many medical experts have responded that the study in no way addresses the risk of spreading infection. There are many more factors to consider. Droplets disperse much differently outside than inside and are subject to the effects of temperature, humidity and wind currents; all can significantly reduce or eliminate the ability of the virus to reach and/or infect another person. Finally, the work has not been peer-reviewed, something we require in the scientific world for anyone to make any serious claim about the results of anything. Anything less than that is just conjecture.

As SRCC’s resident doctor of epidemiology, I still strongly recommend that you ride solo or only with those with whom you cohabit. If for some reason you simply must ride with others, exercise extreme caution. Only ride with one or two people whom you’ve frequently ridden with before in order to reduce the risk of accidents. This will also make it easier to ride side-by-side or stagger. Choose quiet roads as they lower your chance of car/bike incidents. Stay out the hospitals as much as you can.

Keeping the number in your group low (one, two or three max) directly lowers the risk of transmission. It also helps avoid having to ride in someone’s slipstream. And riding in larger groups may not only be risky, it sends the wrong message to the rest of the community about cyclists.

So how far away is good enough to be safe and beyond the reception of someone’s virulent personal droplets? Scientifically, we simply don’t know. Obviously, the further apart the better, and certainly no closer than 2 metres. For a given distance, the above-referenced study indicates that side-by-side is less likely to lead to transmission than riding single file. No shit Sherlock.

Never forget why we’re doing this. We’re not doing this so we don’t get sick, we do this so we don’t get other people sick. And step one in that is: don’t get sick.

These days everyone needs to do their part. And when we’re seen, we need to be seen doing our part. Simply, group riding is verboten. Don’t be a douche, doctor’s orders.

Wash, rinse, repeat.

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