Moves to “reopen” Texas could very likely prompt a surge in COVID infections that will overwhelm area hospitals and lead to thousands of deaths, two experts told City Council yesterday.
Lauren Ancel Meyers, a UT professor of biology and statistics who has been modeling the progress of the disease in the Austin area, attributed Austin’s relatively low body count to its success in reducing person-to-person interaction over the past five weeks. She estimates that interactions are down 95%.
If we drop back to a semi-normal situation, where interactions are only down 40% from their usual level, the model projects that area hospitals will exceed their surge capacity in early to mid-June. If no additional social distancing measures were ordered to reverse the trend, Austin will experience a “catastrophic” three months that would Meyers said would resemble the chaos that engulfed Italy and New York City in recent weeks.
However, the death toll in that scenario will vary widely depending on how effectively we “cocoon” high-risk populations: the elderly and those with certain health conditions. If overall interactions are reduced by 40% but the at-risk population is able to avoid 95% of interactions, her model projects 2,900 deaths in the metro area by September. If, however, the at-risk group’s interactions only stay 80% below normal, deaths would shoot up to 6,500.
For what it’s worth, it’s hard for me to imagine how a change in most of our behavior would not also impact the behavior of those in at-risk groups. It’s one thing to tell retired people to stay at home, but many people at-risk are younger people who are not able to get out of work, despite underlying health conditions. So far the governor has not suggested that those people will be eligible for unemployment or disability.
Assuming no measures were taken to counteract the catastrophic scenario Meyers described, the community would reach “herd immunity,” at some point in September, which would significantly reduce the spread of the disease.
The prospect of another lockdown
Meyers also offered another scenario, in which state government responds to a major surge in cases by putting in place another lockdown.
For instance, if the goal was to reduce overwhelming hospitals, a logical “trigger” for another lockdown would be 100 COVID hospitalizations per day. If we only reduce interactions by 40%, we’ll hit that point in mid-June and then lock down for another three months, likely forcing schools to delay opening until mid-September.
The good news, she says, is that the second lockdown would probably be the last. Drastic measures will not be necessary after that due to herd immunity.
The consequences of exceeding hospital capacity
Clay Johnston, dean of the Dell Medical School, said that Meyers’ model likely understated the limits on hospital capacity. There are only about 1,000 available hospital beds in the metro area right now, he said. The 3,200 beds in her model is the “surge capacity” that would involve doubling up of beds and putting people in hallways and the emergency room.
Johnston also noted that Meyers’ model does not assume that the death rate will increase as hospitals overcrowd. In fact, patients will be far more likely to die in that scenario because they won’t be getting adequate care, said Johnston.
So what do we do?
If we don’t dramatically increase testing capacity and boost contact tracing, it won’t make much of a difference whether we reopen now or some time in the future, says Meyers. The benefit of continuing the lockdown for at least a couple more weeks is that it will “buy us valuable time” to ramp up testing, she said.
Travis County still has a far higher testing rate than the other major urban counties in Texas. At about 66 per 10,000, we’re way ahead of Harris, Dallas, Bexar, El Paso and Tarrant. It appears that most people who report symptoms of the virus can get scheduled for tests within 24 hours, but the testing capacity is still nowhere near what it would need to be at to effectively manage the spread of the disease through testing and contact tracing.
Until we have a vaccine, the most likely way to prevent a catastrophic spread is to conduct widespread testing, including of people who don’t have any symptoms, so that those who test positive can quarantine.
What will people do?
It will take a few weeks before we see whether the grim scenarios Meyers’ discussed come to pass. Her model cannot predict exactly how people will behave in the coming weeks. She had to make an educated guess about how people will act in a situation that we’ve never experienced before; therefore her model assumes that in the coming weeks the average Austinite will be engaging in 40% fewer interactions than they would be in the pre-COVID world.
It’s very possible, however, that interactions will not increase that much. Or that they’ll increase even more. Only time will tell.