Nursing homes are high-risk COVID-19 settings with residents who are typically older and have multiple comorbidities. Testing frequently in care homes suggests that repeat testing is generally not warranted in the 90 days following initial positive test results.
A new study by the Yale School of Public Health in collaboration with the Connecticut Department of Public Health (CT DPH) has offered evidence on why residents in long-term care facilities had a significantly higher reinfection rate than people in the general population.
For the study, scientists analyzed nine months of testing data just before the roll-out of vaccines in long-term care facilities. This period allowed them to see the results in the setting of natural exposure to the virus.
They identified that 2.6% of Connecticut’s 212 nursing homes residents had one or more repeat positive SARS-CoV-2 PCR tests occurring as early as 90 days after an initial positive test. This percentage was significantly higher than other demographics, such as younger adults or community-dwelling elderly.
The more concerning fact was 12.6% of the elderly with a second positive test after 90 days died shortly after that repeat positive test. While genetic sequencing was not available, several lines of evidence supported that reinfection may have been responsible for the repeat positive tests, including the fact that 80% of those elderly had an intervening negative test.
Sunil Parikh, associate professor and the study’s lead author said, “While nursing home residents represent some of the most elderly and frail individuals in our community, we were still quite surprised at the patterns of test results and the outcomes. This was an early clue as to the less robust and waning immunity that may be seen in this vulnerable population following natural SARS-CoV-2 infection.”
The use of surveillance testing for the SARS-CoV-2 virus is a critical tool to contain outbreaks in nursing homes. While tests were hard in the early months of the pandemic, states, for example, Connecticut, had the option to conduct rapid and frequent comprehensive testing of nursing home inhabitants by mid-May 2020. The sheer number of positive tests was sobering, however, this permitted nursing homes to distinguish outbreaks, analyze information, and separate individuals who were infected, subsequently restricting these potentially explosive outbreaks.
With rising repeat COVID-19 positive tests, questions started arising: Were these residents re-infected soon after initial infection, were these false-positive tests, or were these persisting infections?
Doctoral student Jillian Armstrong said, “Together with the more transmissible Delta variant, gaps in staff vaccination coverage, and the need for boosters in these settings, this scenario should raise a concern about a renewed risk of COVID-19 outbreaks in congregate settings. Sadly, the fight is not over, and we must remain vigilant in monitoring infection rates in nursing homes and ensuring vaccination of all staff and residents.”
- Jillian N. Armstrong et al. Repeat positive SARS-CoV-2 RNA testing in nursing home residents during the initial nine months of the COVID-19 pandemic: an observational retrospective analysis. DOI: 10.1016/j.lana.2021.100054