Why are we seeing more cases than we did in the fall?
While they have dropped significantly recently, COVID-19 prevalence rates (daily new cases divided by population) spiked in Maine after the holidays and were roughly 10 times higher when we began Jan Plan than when we returned to campus in August. Based on that factor alone, we anticipated a higher number of cases on arrival and over the semester. And our modeling was correct. We identified five positive student cases on their return to campus, in addition to 18 students who were identified with our pre-arrival testing.
Over the last two months we have also noted a number of positive test results for employees who became infected as a result of off-campus community exposure due to contact with COVID-19-positive family or friends.
While we should continue to expect variation in the prevalence of COVID-19, we are currently seeing a decline in cases in Maine. As of early February, the number of positive cases is roughly half what it was in early January.
What has contact tracing revealed about positive cases?
Our key finding is that our community must be more vigilant about basic mitigation guidelines – social distancing and face coverings.
- In one case, an infected student invited friends to watch television in a residence hall room; the students were not distancing or consistently using face coverings.
- In a separate case, contract tracing identified 12 positive cases associated with a sequence of interactions, from eating together to attending variously sized gatherings of people, again with lack of appropriate distancing and inconsistent use of face coverings. These interactions also resulted in 42 students being placed into quarantine as close contacts.
It appears that the successful fall semester may have caused some to let their guards down. In addition, the introduction of the rapid antigen test may have increased a feeling of safety. Unfortunately, given the nature of this virus, in these circumstances it does not take long for one person to infect several others.
How is testing compliance, and how are students held accountable?
Student testing compliance has increased from 95 percent to 98 percent in January, and just a small number of students have missed more than one test. For other compliance infractions, four students have been disciplined.
We’ve heard about multiple variations of the virus now here in the U.S. What does that mean for Colby?
We are closely monitoring reports of new variations of the virus and higher transmission rates. While the Broad Institute’s COVID-19 assay will detect different strains of the virus, its testing procedures do not specify variants in individual samples. Broad is, however, engaging with other labs and public health authorities in surveillance efforts.
As we shared in the fall, testing frequency is a critical factor in any health program. We increased testing in January to three times per week (from twice weekly in the fall) and will conduct two PCR tests and one rapid antigen test each week for February and March. (We will continue to assess the health environment as we plan testing for April and beyond.)
What’s the difference between PCR and rapid antigen tests?
While the tests are similar—specimens are collected through use of a nasal swab—they are very different tests. PCR tests are molecular tests that identify the RNA of the virus. These tests are run in a laboratory, and, in our case, results are generally provided within 24 hours of arrival at the Broad Institute. Antigen tests detect the presence of certain proteins on the virus; at Colby, results are available within 30 minutes, hence the reference to “rapid” tests.
The PCR test can detect even very small traces of the virus. This can be at the very early stages of the disease when the individual has a very low viral load and the virus is not transmissible. It can also detect very small amounts of virus that linger months after the person has recovered. The antigen test does a good job of detecting the virus when a person’s viral load is high—and therefore likely to be infectious—but it is less likely to identify the virus at the very early and very late stages of infection. This does mean that even with an antigen test, an individual may be infected. A key benefit of the antigen test is that it not only identifies individuals with a high viral load, but also the result is available within 30 minutes, allowing the person to enter isolation more quickly, pending a PCR test, and prevent infection of others.
What if there is a conflict between the PCR and antigen test—which one rules?
For Colby’s purposes, we are using the antigen test as a health surveillance tool and the PCR test as our test of record. When there is a difference, we make decisions based on the PCR test result.
I’ve noticed that the numbers on Colby’s COVID-19 dashboard can change significantly one day to the next. Why is that?
The College updates the COVID-19 dashboard on a daily basis when the College is in session. The dashboard is typically updated around 4 p.m. on weekdays and 2 p.m. on weekends. We have, however, seen fluctuations in various elements (e.g., number of tests, positive cases, individuals in quarantine). There are several reasons for this variation.
- Colby is collecting PCR test kits for most students, faculty, and staff three times per week over six testing days (Monday through Saturday); daily test volume ranges from 800 to 1,400 based on schedules. Therefore, on a day when more people are being tested, more people may test positive.
- The kits are sent to the Broad for processing by courier twice per day (one departs at 12:30 p.m. and the other at 4:30 p.m.). While the Broad has been completing most tests within 24 hours of receipt at the lab, the processing time has ranged from seven hours to as much as 36 hours. Therefore, the College may receive large batches of results at once, again leading to the potential for more positive cases at one time and sometimes causing a lag in reporting on the dashboard. Test results are reported based on the date of test collection.
- The number of close contacts associated with positive cases determines the quarantine figure. We had several cases in January in which there were no close contacts; we have had multiple cases in which contact tracing identified a dozen or more close contacts, each of whom needed to be quarantined. The “in quarantine” dashboard data will show significant fluctuation as these students go into and out of quarantine.
What lessons have you learned from Jan Plan and what will be different about the spring semester?
We have gained important insight from our return to campus this month.
- It is clear that the higher case counts nationally and in Maine require extra diligence by all of us to keep our community safe.
- We need a longer initial quarantine period on student arrival to allow our testing, contact tracing, and isolation/quarantine protocols to work and stabilize campus health. With the return for spring semester, students will quarantine from Monday, February 8 until Sunday, February 14, and classes will be remote for the first three days of the semester.
- Antigen testing has been a useful new tool to identify contagious individuals on arrival and as part of our ongoing surveillance program.
- We have enhanced our education efforts to emphasize the basics:
- How easily this virus can be spread from one individual to another.
- The need for adherence to distancing, face coverings, and handwashing/hygiene guidelines to prevent transmission; behaviors that were less risky in the fall, when prevalence rates were lower and more time was spent outside, are now riskier.
- Testing does not prevent infection. It does allow us to identify cases more quickly and isolate/quarantine individuals to reduce further spread.
- Compliance with testing schedules is essential so that we can identify cases early and reduce the likelihood of further transmission.
- The increased prevalence rate means that we have to be even more diligent in adhering to safety protocols than in the fall.
- Our individual efforts are critical to the health and safety of the entire community and we can’t let our guard down.
Given the number of cases, why are we still at Health Code Level Yellow?
Health code level decisions are based on a combination of factors, including cases and campus health environment, among other things. Investigations show that more than half of our January cases are associated with returning to campus or lack of adherence to distancing and masking protocols. Colby changed the dining program to grab-and-go only based on information obtained during contact tracing, and response teams continue to closely monitor test results and daily symptom tracking information submitted through CoVerified.
When will vaccines be available to the Colby community?
COVID-19 vaccine purchasing and distribution is a federal-state partnership. The federal government allocates vaccines to the states, and the federal CDC has issued guidelines to prioritize distribution. Maine has partnered with various healthcare providers to support vaccine distribution pursuant to its guidelines. Members of the Colby community are currently eligible for the COVID-19 vaccine based on their personal status (e.g., higher risk); individuals should consult their primary care physician for guidance on eligibility.
Based on conversations with state health officials, we do not anticipate widespread distribution of the vaccine until spring at the earliest. It is not clear at this time whether or not Colby would be offered the opportunity to conduct vaccination clinics for our students, faculty, or staff. Regardless of vaccination status, all members of the Colby community will be required to continue participating in the COVID-19 prevention strategies, including testing, masking, and social distancing.