As community members and scientists, we think it is imperative to take stock of where Tucson sits with respect to the COVID-19 pandemic and where we are headed – which will be determined by choices we all make from today onward.
First, what is the actual situation our city, county and state are in? The short answer is that, like most places in the United States, we do not know for certain.
Delays and shortages in the materials needed for testing have put the U.S. behind most developed nations in our capacity to test for the virus. There will be a time to dissect precisely how this occurred, but the bottom line is that the multiple cases of COVID-19 confirmed to date — dozens in Pima County in just the last few days — are the tip of an iceberg.
This virus has its hooks deep into our community and it is likely that hundreds of people are already infected locally.
As a reminder, the virus is highly contagious, it can stay on plastic and cardboard for more than a day and 20% of those diagnosed require medical treatment.
The original data showed that if you are over 65 or have medical conditions that include high blood pressure, obesity or type 2 diabetes, there would be a strong chance you would require medical care if you were infected by this virus. We now know that younger people can also be greatly impacted by this virus.
Given this, we must not be lulled into a false sense of security that what has happened in Wuhan or Northern Italy or New York City somehow won’t happen here. Absent aggressive measures, the number of people infected with this virus doubles roughly every week. This sort of exponential growth seems slow at first, then quickly transitions into an explosion.
Sometime in April or May, our health-care system can be expected not just to become overwhelmed, but to collapse catastrophically, unable to provide life-saving care to most COVID-19 patients or to those with other ailments coronavirus patients will crowd out.
Many people who could have been saved with precious, limited resources — intensive care unit beds, ventilators, healthy nurses and doctors — could die lonely and painful deaths we recently believed were the stuff of the medieval past or far-off, war-torn countries.
This point deserves emphasis: The risk this virus poses to the community is not a fixed feature of the virus; it depends on how out of control its spread gets.
COVID-19 case fatality rates (the proportion of patients who die out of the total number diagnosed) are varying from less than 1% in South Korea to nearly 10% in Italy. We are on a trajectory that looks like Italy, and our population tilts toward the elderly as well. We need to get on a path that looks like South Korea.
How do we do that?
First we buy time and use it to arm ourselves for the battle ahead. Then we take the offensive against the virus. Several states (including our neighbors in California and New Mexico) and other countries have imposed short-term, extreme measures to limit the opportunities for virus transmission, closing all nonessential enterprises and limiting trips outside the home to essentials like food and medicines.
A few weeks of these measures, which we recognize will present extreme difficulties for many, will serve to temporarily suppress transmission of the virus — to lengthen the fuse and delay the explosion in cases.
But it is essential that this be a means to an end, not an indefinite state of attrition. We need to use that time to better equip our health-care system and to solve the problems the have bedeviled widespread testing, not just a lack of testing re-agents but also a lack of swabs to take samples, chemicals to isolate the genetic material from the virus, and so on.
Already, great progress is being made by University of Arizona researchers in collaboration with county health officials to meet this challenge, and progress is being made nationally as well.
Tedros Ghebreyesus, director-general of the World Health Organization (WHO), recently advised all countries with what he called a simple message: “TEST, TEST, TEST!!!!!!” As he went on to say, “without testing ALL suspected patients there can be no isolation of cases and the chain of infection will not be broken. We cannot fight this pandemic blindfolded.”
There are now dramatic examples of stopping the epidemic in its tracks by aggressive testing in South Korea, Hong Kong and Singapore. Perhaps most dramatic is the Italian village of Vo where aggressive repeated testing of all 3,300 inhabitants stopped all new infections entirely.
With massive testing abilities in place — including innovations being used elsewhere like home delivery of self-swab kits, highly automated sample processing and, soon, rapid serological tests akin to a 15-minute pregnancy test — we must then combine testing with shoe-leather (or laptop and cell phone) epidemiology to find and isolate not only people known to be infected but also those they have recently come in close contact with.
This is the approach that has allowed South Korea to control the pandemic, even in the absence of economically damaging measures. Targeting testing toward these contacts will help detect cases even before symptoms occur, which is important given the evidence that asymptomatic carriers account for a good deal of transmission of the virus.
And since no county health department has the resources to conduct this amount of contact tracing, we need to find ways to spread that burden, for instance using volunteers from the UA and the rest of the community.
Instantaneous digital contact tracing, where phone location data is used to alert those who have come in close contact with infected people, could be used as well if ethical considerations can be addressed.
Improved testing and triaging should gain purchase in the next month. Meanwhile, collective, committed “social distancing” is our most important, rational, lifesaving action.
These measures together — an initial period of extreme social distancing to buy time, followed by a relaxation of these stringent actions but the rolling out of aggressive testing, case finding, and case isolation, are the one viable way to remove the blindfold and create a path out of the current crisis.
This will involve boldness, sacrifice, courage and creativity by our community, but we are equal to the challenge. There are evident concerns of how these measures can affect the economy, but a devastating epidemic will certainly not help our economy or our health.
We should not stop the aggressive distancing and shutdown measures we have now until we control the pandemic. We should not let the exigency of the day cloud our good judgment. Let’s make it happen.
Michael Worobey is the head of University of Arizona’s ecology and evolutionary biology department; Joaqin Ruiz is the UA’s vice president of global environmental futures and director of Biosphere 2; and Tom Grogan is the founder of Ventana Medical.
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