That is something we would like to know on the medicine/public health side so that we can plan how to respond with vital resources and people to care for patients. It would also give most of us a sense of relief to know that there is an end to this crisis here in Maine, and around the world.
To figure out when an epidemic with peak, we have to consider multiple factors. There were early reports from China that wave of COVID-19 peaked at about 8-9 weeks. If that is true, it may have been due to excessive containment strategies, rather than a natural cycle of the outbreak. South Korea also was able to control the outbreak through a concerted effort to test huge numbers of people, track down contacts, isolate, quarantine, and the society was engaged in the ethos and practice of social distancing. It is less clear around the world whether the same period of time will occur, though according to news reports it appears Italy may be in a plateau, with a stable number of new cases over the last few days. I don’t think the duration of the outbreak is a universal number, though with infectious disease epidemics we often do see periods of time which seem to be the “season” for that disease, such as the range of time we see seasonal influenza. The SARS-CoV-2 virus that causes COVID-19 is a novel virus, and it spreads rapidly in populations. There are many unanswered questions about this pandemic.
One simple place to start in trying to determine the time a wave of a new epidemic will take is with the incubation period (the time from exposure to illness). We know the incubation period is between 2 and 14 days, and the average time that symptoms develop in those affected is 5 days. Using just this, we should be able to estimate that effective flattening of the curve would take up to two weeks to occur (if as many people as possible are social distancing, for example). In other words, if we were able to completely separate all of the people in our state, it would take two weeks to see no new cases. A virus needs a host to spread, and can’t do that if there is no one else around. The problem is that complete isolation is not possible.
Complicating matters, there are many other factors at play, such as the stability of the population size. Many cases of COVID-19 have been associated with travel, and we are seeing an influx of non-residents and residents coming back from out of state locations (more below). Although on March 16 educational facilities closed, and on March 25 non-essential services closed, essential workers are still in contact with people, in some cases, a lot of people. Other factors include resources, the ability of health systems to withstand a surge of patients, what the size of that surge might be, and whether the percentage of healthcare workers who become ill is stable (17% of cases overall as of 4/3/20 when it was reported last), to name a few.
There are many people in our state who are trying to model the pandemic within our regional outbreak. You can be certain that every hospital system is trying to do this. Dr. Nirav Shah, Director of the Maine CDC has said during his daily briefings recently that they are tracking various models, though none should be treated as completely predictive.
“The modeling tools are only as good as the assumptions we put in, and then on the other side, how well Maine people follow those assumptions.”
Nirav Shah, M.D.
The Institute for Health Metrics and Evaluation (IHME), part of the University of Washington, and the recent recipient of a 10-year, $279-million investment by the Bill & Melinda Gates Foundation, is tracking the COVID-19 outbreak across the U.S. and making models of how the outbreaks are projected to increase and peak in every state. April 1, 2020 the IHME reportedly projected that Maine’s health care system might become overwhelmed by April 25, based on the concurrent trajectory of the outbreak, and social distancing and business restrictions in place at the time. April 2 Governor Janet Mills’ Stay Healthy at Home mandate took effect. There was however, much public concern about the influx of people coming in from out of state, including from hot spots such as the state of New York, the current epicenter of the epidemic in the U.S.
A common facet in the history of epidemics is that those in the center of an outbreak flee. However, this invariably spreads the epidemic while exhausting resources. Another commonality is a less than welcoming response by those in the receiving territory.
On April 3 Governor Mills issued an Executive Order Mandating Quarantine Restrictions on Travelers Arriving in Maine to Protect Public Health and Safety which required that travelers arriving in Maine, regardless of state of residency, self-quarantine for 14 days.
“The Order directs the Maine Department of Transportation, the Maine Turnpike Authority, and others to post this guidance at all major points of entry into the State, exempts individuals who are providing essential services as defined by Governor Mills’ March 24 Executive Order.”
Mills further instructed visitors not to travel to Maine if they are displaying symptoms of COVID-19 and advised them not to travel to Maine if they are traveling from cities or regions identified as COVID-19 hot spots.
“To deter travel, the Order also suspends lodging operations, including hotels, motels, bed and breakfasts, inns, and short-term rentals such as those available through VRBO Airbnb, RV parks and campgrounds, and all public and private camping facilities as well as online reservations effective April 5, 2020 at 12:00 p.m.”
There are some exceptions, such as vulnerable populations: children in emergency placements, persons at risk of domestic violence, and homeless individuals as permitted by the state, accommodations for health care workers, or other workers deemed necessary to support public health, public safety, or critical infrastructure.
The IHME projections for Maine as of 4/3/20 indicated hospitals would hit peak resource usage on 4/17/20, involving 1,179 beds (118 more than available), and 179 ICU beds (with a shortfall predicted). Per Dr. Shah as of 4/3/20 at his weekday press briefing, there are 272 ICU beds in the state, but availability is a number which changes daily, based on more than just COVID-19 (we still have seasonal influenza, community acquired pneumonia, and many patients with chronic lung diseases in Maine). IHME predicted we would need 143 ventilators for COVID-19 patients at peak. Dr. Shah reported we have about 348 ventilators in the state, along with just under 200 “alternative” ventilators designed for medical procedures such as surgery. IHME projects that by 4/15/20 deaths related to COVID-19 will peak at 12 per day in Maine. Sadly, it is projected that by June we will see a total of 364 deaths due to this epidemic in our state. That number appears to be flat through August. That is of course, with assumption of only be one wave of this outbreak.
While these numbers are frightening, they pale in comparison to some other parts of our country. In the U.S. 9,458 people have died from COVID-19, and over a third of the 331,234 cases in the U.S. as of this writing, are in New York. Over 60% of the states have case numbers in the thousands. New Jersey has over 37,000 cases, and several states have over 10,000. There are only 7 states in the continental U.S. with fewer cases than Maine: Nebraska, West Virginia, Montana, South Dakota, North Dakota, Wyoming, and Alaska, (in that order). We have fared better as a group of less densely populated states. Maine has the willingness of Mainers to pitch in to the effort. We need everyone on board with that effort.
We have still seen an unacceptable number of cases and should have had more testing a long time ago. The entire country is in that position. I will say again that we don’t really know how many people are sick. We, like the majority of the country are only able to test people who meet a narrow set of criteria. Many people have been, or still are sick at home with what is probably COVID-19, but have not qualified for testing. The CDC states that probably 25% of all of those infected are asymptomatic, but capable of spreading disease. It is imperative that we markedly increase testing.
Today in Maine there are 470 cases of confirmed COVID-19, and 86 people have been hospitalized. There have been 10 deaths since the start of the outbreak, and all but one county, Piscataquis, have had cases. It is not time to relax. We could still overwhelm our hospitals. Take a close look at the graph. The number of cases has more than tripled in the last 10 days. What might that look like in 10 more days? We must flatten the curve. If we approached this pandemic the way experts have recommended, we could crush the curve.
Though our nation has the highest number of cases in the world, this is going to get better. On the other side of the peak is a downslope. We just need to continue to stay home, practice social distancing, wear cloth masks in public, wash our hands, to not touch our faces, and to help each other get through this. We are going to have to flexible, and we will likely come out of this a changed nation. May we all learn from this. May we be better prepared in the future. May we never allow our government to weaken the CDC and our defenses against infectious disease again. May we again learn to let the experts in science and medicine do their jobs. We are better and smarter than this.
