Patient Characteristics in Cases of Reinfection or Prolonged viral shedding in SARS-CoV-2

Yoo, R. M.; Romero, R. A.; Mabajen, J.; Mehrotra, S.; Kohane, I. S.; Sheils, N. E.

Importance: As testing options increase for COVID-19, their interpretability is challenged by the increasing variety of clinical contexts in which results are obtained. In particular, positive COVID-19 diagnostic (RT-PCR) tests that occur after a patient has seroconverted may be indicative of reinfection. However, in the absence of SARS-CoV-2 sequence data, the possibility of prolonged viral shedding may not be excluded. We highlight a testing pattern that identifies such cases and study its statistical power in identifying potential reinfection. We also study the medical records of patients that matched the pattern. Objective: To describe the frequency and demographic information of people with a testing pattern indicative of SARS-CoV-2 reinfection. Design: We examined 4.2 million test results from a large national health insurer in the United States. Specifically, we identified the pattern of a positive RT-PCR test followed by a positive IgG test, again followed by a positive RT-PCR. Setting: Data from outpatient laboratories across the United States was joined with claims data from a single large commercial insurer's administrative claims database. Participants: Study participants are those whose insurance, either commercial or Medicare, is provided by a single US based insurer. Exposures: People who received at least two positive diagnostic tests via RT-PCR for SARS-Cov-2 separated by 42 or more days with at least one serological test (IgG) indicating the presence of antibodies between diagnostic tests. Main Outcomes and Measures: Count and characteristics of people with the timeline of three tests as described in Exposures. Results: We identified 79 patients who had two positive RT-PCR tests separated by more than six weeks, with a positive IgG test in between. These patients tended to be older than those COVID-19 patients without this pattern (median age 56 vs. 42), and they exhibited comorbidities typically attributed to a compromised immune system and heart disease. Conclusions and Relevance: While the testing pattern alone was not sufficient to distinguish potential reinfection from prolonged viral shedding, we were able to identify common traits of the patients identified through the pattern.