The Effect of Varying Interval Definitions on the Prevalence of SARS-CoV-2 Reinfections: A Retrospective Cross-Sectional Cohort Study

Abstract

Background: We assessed the SARS-CoV-2 reinfection rate in a large patient cohort, and evaluated the effect of varying time intervals between two positive tests on assumed reinfection rates using viral load data. Methods: All positive SARS-CoV-2 samples collected between 1 March 2020 and 1 August 2021 from a laboratory in the region Kennemerland, the Netherlands, were included. The reinfection rate was analyzed using different time intervals between two positive tests varying between 2 and 16 weeks. SARS-CoV-2 PCR crossing point (Cp) values were used to estimate viral loads. Results: In total, 679.513 samples were analyzed, of which 53.366 tests (7.9%) were SARS-CoV-2 positive. The number of reinfections varied between 260 (0.52%) for an interval of 2 weeks, 89 (0.19%) for 4 weeks, 52 (0.11%) for 8 weeks, and 37 (0.09%) for a minimum interval of 16 weeks between positive tests. The median Cp-value (IQR) in the second positive samples decreased when a longer interval was chosen, but stabilized from week 8 onwards. Conclusions: Although the calculated reinfection prevalence was relatively low (0.11% for the 8-week time interval), choosing a different minimum interval between two positive tests resulted in major differences in reinfection rates. As reinfection Cp-values stabilized after 8 weeks, we hypothesize this interval to best reflect novel infection rather than persistent shedding.

Phenomenology Study of Self Concept And Adaptation of Covid-19 Re-Infection Patient at Work Area of Binong Public Health Care Curug Sub District Tangerang

“…Wang et al (2021) in Asia, Europe, North America and South America found an average interval between the first Covid-19 infection and the second Covid-19 infection, an average of 76 days. Another study conducted by Pinto et al (2021) reported the characteristics of the time span of repeated infections, which were found to report 27 cases of re-infection with COVID-19, the duration between the first and second episodes was 108 days with a median of 60 days while Euser (2022) found eight weeks (2 months) between two positive PCRs can be defined for Covid-19 re-infection (Euser, 2022). Re-infection of SARS-Cov-2 is thought to occur after antibody titers decrease (Mulder et al, 2021).…”

How does the SARS-CoV-2 reinfection rate change over time? The global evidence from systematic review and meta-analysis

“…Moreover, there is still no clear global definition of SARS-CoV-2 reinfection. Some studies defined reinfection as the time interval between two positive tests needing to be more than 90 days [ 16 , 17 ], while some studies defined reinfection as the time interval only needing to be more than 30 days [ 18 , 19 ], and it was difficult to directly compare reinfection rates under different definitions with large differences [ 20 ]. Therefore, the aim of this study was to conduct a meta-analysis to describe and summarize the current reinfection rates in different regions and among diverse populations.…”