CDC: Nursing Home Cases Suggest COVID Reinfection

A Kentucky nursing home had what appeared to be several cases of COVID-19 reinfection last year, CDC researchers found.

Five patients in a skilled nursing facility who tested positive for SARS-CoV-2 in July and August — three asymptomatic and two with mild symptoms — tested positive again in the fall, when the five developed COVID-19 symptoms, reported Alyson Cavanaugh, PhD, of the CDC, and colleagues in the Morbidity and Mortality Weekly Report. All five had repeatedly tested negative during the intervening months.

Moreover, those who had mild symptoms the first time reported “worse symptoms” the second time, and one previously asymptomatic resident required hospitalization for her respiratory symptoms and eventually died.

While COVID-19 reinfection has been reported, it has been seen as a relatively rare event, with the assumption of “some level of immunity” expected following infection, Cavanaugh and co-authors noted.

Yet the five apparent reinfections occurred among a total of 12 residents who tested positive during the second outbreak and were still living in the facility in October — suggesting that reinfection may not be so rare when exposure risk is high.

As well, the researchers wrote, “that all five patients with recurrent COVID-19 had either asymptomatic or mildly symptomatic courses during their first infections is noteworthy, suggesting the possibility that asymptomatic or mildly symptomatic initial infections do not produce a sufficiently robust immune response to prevent reinfection.”

In the first outbreak, the Kentucky facility (which was not identified) had 20 cases among patients confirmed via RT-PCR testing, while the second outbreak had 85 cases.

The five recurrent cases ranged in age from 67 to 99, and four were women. Three patients had roommates testing positive prior to their own positive tests, and the investigators attributed the other two cases to the large number of infected residents in the facility.

Each patient had more than three underlying chronic comorbidities, but none had an immunosuppressive condition or was taking immunosuppressive medication, which Cavanaugh’s group noted “might have hindered clearance of the virus or predisposed them to virus reactivation.” All had at least four negative RT-PCR tests between their two positive tests.

Interestingly, the patients who were symptomatic during the first outbreak reported gastrointestinal symptoms and nausea, while in the second outbreak, both patients reported loss of appetite and malaise.

The investigators acknowledged the possibility of false-positive tests during the first outbreak, though that was less likely during the second outbreak. They also noted that the test samples were not sequenced, making it impossible to compare isolates and know for certain if the cases were truly reinfections versus recrudescence of the initial infection.

Last Updated February 25, 2021