COVID-19 Forecast for El Paso County – July 13

Plus, our resident microbiologist on why you shouldn’t get too excited about the Moderna vaccine trial

In Colorado Springs, warning signs are blaring. 

Consider how the mayor’s office kicked off the weekend:

Local media had been watching a “recent increase” in cases for days. 

“Since mid-June, the average number of people testing positive in El Paso County for the virus daily has increased steadily and has surpassed previous highs for average daily new cases set in April and May,” reported The Gazette on Friday. 

Today, we contextualize this uptick with data from our resident microbiologist Phoebe Lostroh who offers her weekly COVID-19 forecast for El Paso County, and explains why she believes we’re entering a danger zone. She also talks with us about what she’s working on as a new member of Colorado College’s Scientific Advisory Group and discusses the Moderna vaccine trial that is coming to the Springs. 

Lostroh is a professor of molecular biology at Colorado College on scholarly leave who is serving as the program director in Genetic Mechanisms, Molecular and Cellular Biosciences at the National Science Foundation. In June, Lostroh spoke with the American Society for Microbiology about her career as a microbiologist and her advocacy for LGBTQ+ initiatives. 

➡️ICYMI: On Friday, we recapped the Safety and Testing Town Hall and looked at how U.S. service academies are bringing students back.  

Phoebe’s Forecasts

NOTES: These forecasts represent her own opinion and not necessarily those of the National Science Foundation or Colorado College. She used the public El Paso County dashboard for all data. Data used for these forecasts was gathered on July 9. 

⚖️ How her predictions last week shaped up: July 11 is the last day of Morbidity and Mortality Weekly Report week 28 in the national public health calendar. It is the 18th week since the first case was detected in El Paso County, and 116 El Paso County residents have died of COVID-19 since March 13. Last week, using the most recent trend, Lostroh forecasted 2,897 cumulative reported cases as of July 9 and in reality, there were 2,940 reported cases

We are in a period of heightened danger in Colorado Springs. Because of how long it takes for someone to notice they are sick and seek testing or medical attention, the number of reported cases on July 9 reflect the actual cases in the community as of about one to three weeks ago. The number of reported cases in the last seven days is 336 — so cases in our community right now most likely exceed 1,000. 

Other signs that we have entered a danger zone include:

  1. The 14-day rolling incidence of reported COVID-19 cases in El Paso County was at its highest recorded level (88.1) on July 9 and had reached 95.1 as of 4 p.m. on July 10. This level is well within the range the Colorado Department of Public Health and Environment regards as “high viral spread,” or 50-100 cases per 100,000 people. 

  2. The percent positivity in testing has risen consistently since June 16 and has reached 8.6%. The percent positivity is 3.3-fold higher than it was on June 16, while the total number of tests is only 1.5-fold higher. So, percent positivity has increased at twice the rate as the increase in local testing. Additionally, The New York Times recently reported that Colorado as a state is only doing 40% of the testing necessary to get the epidemic under control.

  3. The predicted increase in reported cases has surpassed the “worst-case scenario” that I had been using for all of the forecasts to date. 

  4. The county allowed gyms, theaters, receptions, indoor water parks, and many other indoor businesses to open at 50% capacity on June 29, when our reported cases and percent positivity were rising. Since June 29, the rolling seven-day percent positivity rate has increased from 4% to 6.6%, and the number of cumulative reported cases has increased by 563. The rolling 14-day incidence per 100,000 increased dramatically in the same time period, from 58 to 88.

  5. The independent COVID Act Now academic group says the current reproduction number for COVID-19 in El Paso County is 1.30 and puts us in the high risk category, one level below the worst “critical” level. The reproduction number means each infected person infects 1.30 new people, or 100 infected people infect 130 new people, as of the most current data.  

Predicted cumulative reported cases in El Paso County

Prediction for reported cases in El Paso County for the next four weeks

🗝️ Key points: I have simplified my prediction with the following assumptions: 

  1. People will keep behaving the way they have been unless something significant changes.

  2. The virus will spread exponentially because most of the population is susceptible. 

Thus it is reasonable to fit exponential curves to the reported cases in order to project a few weeks ahead.

Prediction for 14-day rolling incidence in El Paso County for the next four weeks

🗝️ Key points: I used the predictions as in the first graph to calculate the 14-day-rolling incidence for the most optimistic (purple boxes), worst-case (filled red triangles), and most likely (green open triangles) predictions. We could achieve the optimistic curve by returning to stay-at-home orders.

Nasopharyngeal Swab Testing for SARS-CoV-2 and Percent Positivity in El Paso County, seven-day rolling averages

🗝️ Key points: The rolling number of total tests administered in seven days is plotted on the right-hand axis using open symbols (the top curve) whereas the percent positivity for the rolling seven days is plotted using the left axis and filled symbols. Rolling percent positivity has been rising steadily since June 16, faster than any increase in testing.

10-day rolling cumulative COVID-19 hospitalizations and deaths in El Paso County

🗝️ Key points: People with COVID-19 who are hospitalized but not in an ICU bed usually stay about 10 days (using national averages). The rolling 10-day hospitalizations have been increasing since June 26, while deaths remain low.  

Q-and-A with Lostroh: Our resident microbiologist on the CC Campus Scientific Advisory Group and the Moderna vaccine trial

This interview has been edited for length and clarity.

CC COVID-19 Reporting Project: What are you and the other members of the CC Campus Scientific Advisory Group working on?

Lostroh: The people on the committee are very well-chosen faculty who have expertise in mathematical modeling of infectious disease and other kinds of epidemiological models, ethics, and social considerations when it comes to testing and tracing and all those other things. I think it’s a good combination of people who are going to try to find the most urgent science that we need for the biggest decisions we have to make on the fastest timescale. One big question that came up was whether anyone had really thought through exactly what will happen if you come to campus and take a class in person. What will your day-to-day life be like, if we are doing all of this social distancing? Where will you wash your mask? How many masks will you have to have, and how often will you wash them? What will happen if you forget your mask and have to go back and get it? And then if someone gets sick and needs to go into isolation, but they’re not so sick that they need hospital care, what happens? 

CCRP: What do you think of CC’s plans not to test upon entry and the argument that those tests would only provide a “snapshot,” like an EKG?  

Lostroh: The big question right now is: CC really isn’t going to test anybody when they come back? That seems like an interesting choice, and it is consistent with the CDC recommendations and with El Paso County Public Health recommendations, but many people suspect that those recommendations, especially at the CDC level, are based more on politics than on good science. And so, I’m sure the advisory group is going to look into that and try to find some evidence about whether that’s really the case. We do know that not everybody who’s positive is going to test positive, and it depends on the timing of the sampling and the kind of kit. I would argue that detecting even one case is extremely beneficial for the cost that goes into detecting that case because so much spread is happening among asymptomatic people who may or may not ultimately develop symptoms. And most spread is happening indoors in family-type settings or institutional-type settings, which to me describes students living with their roommates. It’s going to be really hard to physically distance all the time. I think people will try their best but it’s going to be hard. 

CCRP: Should we get excited about the Moderna vaccine trial coming to Colorado Springs?

Lostroh: This phase three trial will go on for two years. They need to track people for a year. I think they’re thinking it will take three to six months to enroll enough people, and then three to six months to analyze the data, so you’ve got three to six months of enrollment overlapping with about a year of following people. But anyway, that’s how long it takes, and that’s the fastest we can go.

CCRP: You’ve been saying COVID-19 spreads through aerosols for a while, and the WHO just said aerosol transmission is possible. 

Lostroh: There’s been such strong evidence from the beginning that it’s aerosol, even just looking at asymptomatic spread. Nobody wants it to be aerosol. It’s scary that it’s aerosol. It’s harder to control. It’s bad news, all around that it’s aerosols. It’s aerosols, dammit.

About the CC COVID-19 Reporting Project

The CC COVID-19 Reporting Project is a student-faculty collaboration by Colorado College student journalists Miriam Brown and Arielle Gordon, Journalism Institute Director Steven Hayward, Visiting Assistant Professor of Journalism Corey Hutchins, and Assistant Professor of English Najnin Islam. Work by Phoebe Lostroh, Associate Professor of Molecular Biology at CC and National Science Foundation Program Director in Genetic Mechanisms, Molecular and Cellular Biosciences, will appear from time to time, as will infographics by Colorado College students Rana Abdu, Aleesa Chua, Sara Dixon, Jia Mei, and Lindsey Smith.

The project seeks to provide frequent updates about CC and other higher education institutions during the pandemic by providing original reporting, analysis, interviews with campus leaders, and context about what state and national headlines mean for the CC community. 

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