Updated: May 26
This is the third in a series of blog posts about the coronavirus that leads up to a finale just for cancer patients.
There is no "spin" in science. So welcome to the no politician zone. My promise to you is that I will quote and cite the best medical journals in the world (Lancet, JAMA and the New England Journal of Medicine) and the World Health Organization. If I have to quote the media, it will be clearly stated.
This post might be tough to read if you didn't see the last one.
The good news:
1) In 30 cycles of this, 12.39 billion people (way more than the 7.7 billion on earth) would *only theoretically* have the Coronavirus because ... at some point so many people are infected that the virus has nowhere else to go—no one else to infect. Imagine a large nursing home with 5,000 patients. In this model, on Day 11, 3,863 people would have the virus. But the virus will not magically find the uninfected people on the next day to knock out all 5,000. So, the 2.2 is not a static number. It drops in heavily infected environments or environments where social isolation, social distancing and quarantining occurs. (Interestingly, when R-naught changes, we just call it “R.” Once R goes below 1, it is only a matter of time until the end of the epidemic).
2) Florence and Corey would not have paid every day; the frequency in the metaphor is too high. In other words, the average coronavirus patient is infecting 2.2 people over several days of being sick—not just one. So, the virus isn’t actually moving as fast as I’ve described in the model.
3) Scientists are still studying whether or not the virus transmits more efficiently in cold weather. Some viruses (like the flu) are hampered by warmth, which is why it dies out in the spring (except on days when it's raining, as it turns out). Keep your fingers crossed that it does, but simultaneously know that hope is not a strategy for protecting yourself.
Now, this is highly simplified. R-nought doesn’t tell us how fast a disease spreads. It just tells us how many people are going to get the disease. There are many other factors that contribute to the speed of disease spread. We’ll consider just two of them here.
Let’s compare two scenarios to illustrate differences in the potential for geographic spread.
Imagine a small native tribe in the Amazon rain forest. These are some of the most closed societies in the world; few people go in and few go out. If the virus had started there, even if the R-nought were 18 (as high as measles), it would infect everyone in the tribe but may never leave the area.
On the other hand, if this virus had started in a city that hosts millions of international travelers every year such as New York City, London or Tokyo the rate of spread would have been far higher than it was given the virus’ birth in Wuhan, China.
The Number of Patient Zeros
The initial number of patient zeros (i.e., how many people ate the infected bushmeat in Wuhan) is an additional factor in how fast it has spread. Was it a young man and his girlfriend who purchased and consumed one small infected animal? Or was it a quick-serve restaurant who purchased a large piece of bushmeat and served it to sixty customers that day?
The question for us in the United States, however, is how many people flew in from China that were already infected before our government shut down those flights? Those were our patient zeros. If we knew that number it would help us chart how fast the disease will spread. Because of delayed testing, however, there was no way to ever know this number.
Spread In America
So on the whole, given what we know now, this virus is highly contagious. How much will it spread in the United States? That’s a huge question that has yet to be answered. However, the Lancet and other journals have given us some clues. The percentage of people who will be infected is represented as 1-(1/R0). (See graphic below). As we said, the estimated R-nought is 2.2. If that number is correct, we’ll see 55% of the country get infected, unless serious social distancing, isolation and quarantine measures occur, bringing R-nought down. Of course, that number is merely our best estimate. Epidemiologists (those who study epidemics) have used advanced statistics to determine that they are 95% confident that the actual R-nought lies between 1.4 and 3.9. The corresponding infection range is 29% to 74%.
According to Dr. Bruce Aylward, the Team Lead for WHO-China Joint Commission, 60 million people were on complete lockdown in much of the Hubei province where the disease was most prevalent.
The response outlined in the above link was nothing short of extraordinary:
1) The government was able to force-mobilize a massive workforce. 40,000 Chinese workers and volunteers went into the Hubei province.
2) They were given free food delivery.
3) Prescriptions were ordered online and delivered for free.
4) They performed 200 diagnostic CTs (AKA “Cat Scans”) per day per machine.
5) Two hospitals were built to care for the very sick in less than one week.
6) They had test results in four hours.
7) Gyms and stadiums were converted into isolation centers.
8) Families were completely separated, knowing that parents are going to want to irrationally hug their children for comfort, further spreading disease.
These are seemingly impossible initiatives in America. As I write this, some companies have told their employees to work from home and they are wise to do so. But questions remain. Will we isolate ourselves when we get sick? Will we stop going to concerts and conferences? Will we stop traveling on planes and trains? Will schools be shut down? We may have to do all of these things and more to lower R-nought—to stop the spread of the disease.
Other issues lie in our healthcare system. For a person who thinks they may be infected, should they go to the Emergency Room? Or is it wiser to simply call a doctor? Surely, it’s the latter, as showing up in the ER would subject that person to other infected people—not so smart, especially if the person doesn’t have the virus. But in most scenarios, the doctor won’t be reimbursed to talk to you on the phone. They’re incentivized financially to have you come in. That’s problematic.
Another issue: what about the minimum-wage patient with two jobs? Faced with a $50 ER co-pay plus the cost of the test and the prospect of having to miss work, are they going to seek medical care? Or will they wait until things are so horribly bad that they are hospitalized and spend six days in an ICU at an astronomical cost—that others will pay through higher premiums? Chances are they won’t show up until it’s too late, potentially infecting more people as they go to work sick. All things considered—and this is just my point of view—I don’t think we are in a position to minimize R-nought in any meaningful way.
Now that we have an appreciation of the spread, we have to consider how bad the sickness gets. That's the subject of the next post.