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

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.