The First Wave Never Left Us
For a moment, I am going to stray from the common mantra that there will be a second wave of SARS-CoV-2 coronavirus infections (COVID-19) this fall or winter. It is a fallacy to compare this pandemic to the 1918 influenza pandemic (that killed up to 50 million). Why?
- This is not the influenza virus. Sars-CoV-2, the virus which causes COVID-19 is a new virus. It’s a zoonotic virus (jumped from animal to animal to human). Coronaviruses have been with us for the ages. However, we have never experienced (or at least documented) a severely pathogenic coronavirus pandemic. SARS (2003) and MERS (2012-active) were certainly wake-up calls to virologists and governments, with their high fatality rates. Yet governments failed to take the message to heart, with a lack of PPE for healthcare workers, a shortage of ventilators, and little capacity for epidemics within their healthcare systems. Ironically, Ontario cut funding to its public health system in the fall of 2019.
- Influenza, coronavirus, and rhinovirus activity in populations fluctuate with the seasons. Why? People congregate together indoors during the winter, with more closed air circulation, facilitating transmission. In fact, a detailed study of infections in Wuhan, China demonstrated that nearly all new infections were transmitted indoors. Influenza viruses also appear to spread more efficiently in cold, dry air environments: The flu is droplet spread (like SARS-CoV-2), and in an animal model (guinea pig); cool, dry, air was the most efficient environment in spreading it to uninfected animals (v. humid, warm air). It is believed that droplets laden with flu virus readily evaporate in this environment and become airborne, and therefore much easier to inhale. So the more time we spend outside this summer, the better.
- However, one important factor is not addressed in the above “seasonality” explanation for an anticipated waning of Coronavirus cases this summer: The Ro (R naught) of this virus is very high. The CDC calculated a median Ro of 5.7 (i.e. one person infects 5.7 people on average). However, this number was based on symptomatic persons who presented for testing. We now know about 30% of people who become infected have no symptoms. This means the Ro is likely higher than 5.7. How high, is the question? The higher the number, the more likely that physical factors (like humidity or temperature) will have less modulating effects. In Brazil, where the climate is warm and humid, the coronavirus epidemic is exploding. The upward trajectory of cases and deaths are the worst observed to date. Actuals deaths are likely far in excess of 1000 per day. Mass graves are being employed as reported by CNN. (https://www.cnn.com/videos/world/2020/05/21/brazil-sao-paulo-icu-covid-19-walsh-pkg-ebof-vpx.cnn ). Population dense slums, poverty, poor nutrition, and little access to healthcare have proven optimal breeding ground for this virus. It’s an unfathomable tragedy unfolding all over developing nations.
4. Back to Canada, Ontario specifically (where I live): It turns out some Ontario families may have ignored stay at home orders and got together on the Mother’s Day weekend. Ontario has also relaxed their stay at home restrictions, permitting retail stores to open on May 19, provided they were not in malls. Premier Ford did this, despite new daily case counts in excess of 300–400 per day (most new cases are concentrated in urban centres).
Recall the median incubation period for COVID19 is 5 days, and 97.5% of people who develop symptoms, do so by 12 days after their exposure. We can now seen a sustained upward tick in new cases from May 15 (5 days after Mother’s Day) — See the well crafted chart by E. Chan PhD below.
5. This is not an isolated phenomena. All over the world, relaxing of stay at home orders have promptly led to a rise in cases. Before any significant relaxation of stay-at-home orders can be “successful”, communities/regions must reduce their cases to single digits, and follow with extensive testing, tracing (asymptomatic contacts and symptomatic), and isolation. Wide scale population screening operations are necessary to identify those asymptomatic people who are unknowingly spreading the coronavirus.
6. One possible approach to population screening is fecal screening. Fecal shedding of the virus is probably the most accurate way to diagnose #COVID19 (though we persist with nasopharyngeal swabs), see the prepublication by B. Borremans et al (UCLA) https://osf.io/evy4q/ . Virus can be detected in feces very early on in the infection, and it remains present for up to a month after the initial infection. It’s not subject to operator error, given it’s not easy to reach the nasopharynx for some testers. Mail in kits, similar to colorectal cancer screening, could be devised to test at home. Such testing is available in the USA. Given PCR can amplify the smallest of viral RNA fragments, sampling sewage effluent from communities, or even from segments of communities has been proposed to give accurate picture of COVID19 presence. This approach could predict outbreaks days before they become apparent.
Therefore, it’s best not to think of the Coronavirus SARS-CoV-2 pandemic as hitting us in large waves —Though we will no doubt see successive oscillations in local epidemics. The virus is here, it hasn’t left us, and it’s not going to abate soon unless by some miracle a less pathogenic viral mutation overtakes the current virus. Any waves that occur are due to our own actions. To believe we’ll soon resume our old lives is simple denial (a common stage in grief that I have often observed as an oncologist). It’s an understandable reaction, but the time has come for governments to accept a new reality. We must quickly adapt and promote economic growth and jobs in novel ways that permit physical distancing and working from home. PPE production must be ramped up in Canada. Factory workers must be protected, even if they require full body suits with respirators. We must also, collectively, help developing nations through PPE donations and medical aid.
Multiple therapies will soon arrive that help lessen severity of illness and reduce mortality. Remdesivir appears to be the first. Herd immunity is not a suitable strategy, though at the rate this virus is spreading globally, it is possible it will be achieved before a vaccine is available. Let’s hope not. Today, 5.25 million have been infected worldwide in just 5 months (the number is probably closer to 8–10 million including asymptomatic persons) and at least 339,000 deaths from COVID 19 have been reported. This doesn’t include bystander mortality from those usual crises such as heart attacks, strokes, ruptured appendices, that were not treated on time because of scarce health resources or patient reluctance to visit hospitals rich with COVID19 cases. Excess mortality studies are just beginning to document this impact. This final observation highlights the importance that each urban centre designate non-COVID hospitals. We cannot put those patients on indefinite hold. Surgery must continue and heart disease must be treated.
