Background During the COVID-19 pandemic, a minority of index cases are associated with a majority of secondary cases suggesting that super-spreaders could drive the pandemic. We identified a phenotype in individuals with extremely high viral load who could act as super-spreaders. Methods Data were analyzed from individuals tested for SARS-CoV-2 from March 18 through August 15, 2020. Outcomes were compared using contingency table and quantile regression to test the equality of medians between the pandemic waves and by viral load groups. Results Of the 11,564 samples tested, 1,319 (11.4%) were positive for SARS-CoV-2. An increase in weekly median viral load occurred in the second wave of the SARS-CoV2 pandemic. This population was more likely to be women, outpatients, symptomatic and have an extremely high or high viral load. In patients with multiple RT-PCR positive tests, the duration of viral shedding was comparable between individuals with asymptomatic/mild and mild/moderate illness severity. Conclusions We detected a small group of individuals with extremely high SARS-CoV-2 viral load with mild illness. We believe that these individuals’ characteristics could be consistent with the super-spreader phenomenon and that greater awareness of the social dynamics of these individuals is needed to understand the spread of SARS-CoV-2.

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BackgroundSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was first reported in December 2019 in Wuhan, China, and then rapidly spread causing an unprecedented pandemic. A robust serological assay is needed to evaluate vaccine candidates and better understand the epidemiology of coronavirus disease (COVID-19).MethodsWe used the full-length spike (S) protein of SARS-CoV-2 for the development of qualitative and quantitative IgG and IgA anti-S enzyme linked immunosorbent assays (ELISA). A total of 320 sera used for assay development were comprised of pandemic sera from SARS-CoV-2 infected adults (n=51) and pre-pandemic sera (n=269) including sera from endemic human coronavirus infected adults. Reverse cumulative curves and diagnostic test statistics were evaluated to define the optimal serum dilution and OD cutoff value for IgG anti-S and IgA anti-S ELISAs. The IgG and IgA anti-S, and three functional antibodies (ACE-2 receptor blocking antibody, lentipseudovirus-S neutralizing antibody, and SARS-CoV-2 neutralizing antibody) were measured using additional SARS-CoV-2 PCR positive sera (n=76) and surveillance sera (n=25). Lastly, the IgG and IgA anti-S levels were compared in different demographic groups.ResultsThe optimal serum dilution for the qualitative IgG anti-S ELISA was at 1:1024 yielding a 99.6% specificity, 92.2% sensitivity, 92.9% positive predictive value (PPV), and 99.6% negative predictive value (NPV) at a SARS-CoV-2 seroprevalence of 5%. The optimal serum dilution for the qualitative IgA anti-S ELISA was at 1:128 yielding a 98.9% specificity, 76.5% sensitivity, 78.3% PPV, and 98.8% NPV at the same seroprevalence. Significant correlations were demonstrated between the IgG and IgA (r=0.833 for concentrations, r=0.840 for titers) as well as between IgG and three functional antibodies (r=0.811-0.924 for concentrations, r=0.795-0.917 for titers). The IgG and IgA anti-S levels were significantly higher in males than females (p<0.05), and in adults with moderate/severe symptoms than in adults with mild/moderate symptoms (p<0.001).ConclusionWe developed a highly specific and sensitive IgG anti-S ELISA assay to SARS-CoV-2 using full length S protein. The IgG anti-S antibody level was strongly associated with IgA and functional antibody levels in adults with SARS-CoV-2 infection. Gender and disease severity, rather than age, play an important role in antibody levels.

Since the start of the SARS‐CoV‐2 pandemic, it has been difficult to differentiate between SARS‐CoV‐2 re‐infection and prolonged RNA shedding. In this report, we identified patients with positive RT‐PCR results for SARS‐CoV‐2 ≥70 days apart. Clinical and laboratory data were collected and criteria were applied to discern whether the presentation was consistent with SARS‐CoV‐2 re‐infection or prolonged viral RNA shedding. Eleven individuals met the initial testing criteria, of which, seven met at least one criteria for re‐infection and four were consistent with prolonged RNA shedding. These data demonstrate the need for criteria to differentiate SARS‐CoV‐2 re‐infection from prolonged RNA shedding.

Since the start of the SARS-CoV-2 pandemic, it has been difficult to differentiate between SARS-CoV-2 re-infection and prolonged RNA shedding. In this report, we identified patients with positive rtPCR results for SARS-CoV-2 ≥70 days apart. Clinical and laboratory data were collected and criteria were applied to discern whether the presentation was consistent with SARS-CoV-2 re-infection or prolonged viral RNA shedding. Eleven individuals met the initial testing criteria, of which, seven met at least one criteria for re-infection and four were consistent with prolonged RNA shedding. These data demonstrate the need for criteria to differentiate SARS-CoV-2 re-infection from prolonged RNA shedding.