Universal testing of entire nursing home communities has revealed higher COVID-19 positivity due to asymptomatic cases. The lessons learned from this testing data have consequences to the future of public health surveillance.
Testing remains one of our most useful tools to combat the continuing COVID-19 pandemic. Dr. Morgan Katz, a clinician and researcher specializing in infectious diseases at the Johns Hopkins Medical Institute, employed universal COVID-19 testing at long-term care facilities (LTCFs) early in the pandemic before this was a widely accepted practice. Her research shows that testing of only symptomatic residents may underestimate SARS-CoV-2 infection rates, as many people are asymptomatic and contributing to the spread of COVID-19.
Testing has a huge impact on how we make preventative recommendations, such as masking indoors and avoiding public gatherings. We need to understand what is happening in terms of community transmission to guide those recommendations. Testing data also helps hospitals prepare. Hospitalizations and deaths often lag behind an increase in case counts, so having this understanding of community transmission informed by testing data can help hospitals ensure they have emergency plans in place, prepare their COVID-19 units, acquire backup staff, or start suspending elective surgeries.
We need to include testing of asymptomatic individuals because they contribute to transmission of the virus. We saw how important it was in LTCFs. Initially, LTCFs were only testing residents who displayed symptoms for COVID-19. When we started going into these facilities and providing universal testing for everyone, we found that about 40% of the residents who tested positive would not have been identified through symptomatic testing alone. Either they were asymptomatic or pre-symptomatic at the time of that universal testing. Without the ability to identify those cases through testing, it's impossible to identify and isolate individuals who may be carrying the virus. That can be particularly devastating in a congregate living setting, and can contribute to continued transmission in the greater community as well.
You often get more reliable information by focusing on a subset of individuals. If you're looking at COVID-19 cases in a single health system with a unified electronic medical record, you're able to get a much more detailed history, such as comorbidity status, treatment history, and outcomes. That information is not available on larger state or federal registries mainly because it would be too burdensome to collect that information.
The obvious limitation is that anything you conclude from those analyses may not be generalizable to other states or across the world. You're going to see drastic differences in terms of vaccination rates across countries and even between states, and that is going to impact the results of your data. Economic factors, access to treatment, all those things make a huge difference and it makes it harder to generalize what you find in your research study in a smaller subset.
You'll see a wide variety of different case counts if you compare different data aggregators. The reason for that is we weren't requiring any specific data collection and reporting from LTCFs until the end of May 2020. The time between March and May is a black box for COVID-19 in LTCFs. Also, at that time we were really only doing symptomatic testing, so what we were capturing was probably just the tip of the iceberg, in terms of case numbers.
A lot of these facilities don't have unified electronic health records. Many of them are still working with paper records. Data reporting often relies on one individual going through their list of the residents and staff that are infected, and physically typing in the data on a daily or weekly basis. Then they have to enter the data into various databases, sometimes multiple databases on a state or federal level. There's certainly a high potential for human error.
Many experts who are familiar with the challenges in nursing homes have pushed for a single database for LTCFs to enter their information. A single, more reliable database is crucial. They shouldn't have to report to multiple databases on a weekly basis. LTCFs also need dedicated full-time infection prevention support. There should be an individual that can reliably look at this data on a daily basis in each facility. Many of these facilities have one part-time infection preventionist that does five or six other jobs, and is trying to deal with an unprecedented crisis on a daily basis. Having someone fully dedicated to that job could be really helpful.
Funding to support populated electronic health records is a dream. LTCFs certainly do not have a surplus of money to update their electronic records. They're basically drowning at this point, just trying to stay afloat. An increase of funding across the board could help support testing surveillance, infection prevention, and data management at these facilities.
Testing surveillance is our best way to monitor for developing outbreaks and transmission of infectious diseases. We use regular testing to identify cases, so that we can implement mitigation measures before widespread transmission. It's necessary for many diseases, and we've done this for years. As soon as flu season comes around, if a child comes to the clinic with respiratory symptoms, we’ll test them for flu, perform surveillance, and report on outbreaks at a local level (for example, to school administration) so that we have a measure of transmission in the area.
In terms of future surveillance for COVID-19, I think it's going to end up being similar to flu, where we will test someone immediately if they have symptoms. If you want to be part of a community, if you're doing activities with a number of other individuals, you should expect that you're going to be tested at some measure throughout that time, particularly if you're not vaccinated.