Analysis of accumulated SARS-CoV-2 seroconversion in North Carolina: The COVID-19 Community Research Partnership.

INTRODUCTION: The COVID-19 Community Research Partnership is a population-based longitudinal syndromic and sero-surveillance study. The study includes over 17,000 participants from six healthcare systems in North Carolina who submitted over 49,000 serology results. The purpose of this study is to use these serology data to estimate the cumulative proportion of the North Carolina population that has either been infected with SARS-CoV-2 or developed a measurable humoral response to vaccination. METHODS: Adult community residents were invited to participate in the study between April 2020 and February 2021. Demographic information was collected and daily symptom screen was completed using a secure, HIPAA-compliant, online portal. A portion of participants were mailed kits containing a lateral flow assay to be used in-home to test for presence of anti-SARS-CoV-2 IgM or IgG antibodies. The cumulative proportion of participants who tested positive at least once during the study was estimated. A standard Cox proportional hazards model was constructed to illustrate the probability of seroconversion over time up to December 20, 2020 (before vaccines available). A separate analysis was performed to describe the influence of vaccines through February 15, 2021. RESULTS: 17,688 participants contributed at least one serology result. 68.7% of the population were female, and 72.2% were between 18 and 59 years of age. The average number of serology results submitted per participant was 3.0 (±1.9). By December 20, 2020, the overall probability of seropositivity in the CCRP population was 32.6%. By February 15, 2021 the probability among healthcare workers and non-healthcare workers was 83% and 49%, respectively. An inflection upward in the probability of seropositivity was demonstrated around the end of December, suggesting an influence of vaccinations, especially for healthcare workers. Among healthcare workers, those in the oldest age category (60+ years) were 38% less likely to have seroconverted by February 15, 2021. CONCLUSIONS: Results of this study suggest more North Carolina residents may have been infected with SARS-CoV-2 than the number of documented cases as determined by positive RNA or antigen tests. The influence of vaccinations on seropositivity among North Carolina residents is also demonstrated. Additional research is needed to fully characterize the impact of seropositivity on immunity and the ultimate course of the pandemic.

Bacteremia in hemodialysis patients with hepatitis C.

BACKGROUND: Hepatitis C virus (HCV) infection and bacteremia are common comorbidities in hemodialysis patients. A specific relationship between HCV infection and bacteremia has not been defined; however, there is evidence of immune compromise in both HCV-infected and uremic patients, suggesting that this group may be at higher risk for infection. METHODS: We investigated risk factors and mortality associated with bacteremia in HCV-infected hemodialysis patients from the United States Renal Data System. RESULTS: During the 4-year study period, HCV was present in 2.1% of 355,084 patients initiating hemodialysis. When compared with the total population, the rate of bacteremia was significantly higher in patients with HCV (38.3% versus 21.8%). The adjusted relative risk (RR) for bacteremia was higher in HCV versus all patients (relative risk, 95% confidence interval [CI]) in the presence of methicillin-resistant Staphylococcus aureus infection (2.64, CI: 2.58-2.70 versus 2.32, CI: 2.27-2.38), HIV (1.93, CI: 1.85-2.02 versus 1.86, CI: 1.77-1.95) urinary tract infection (1.79, CI: 1.77, 1.82 versus 1.64, CI: 1.61-1.67) and cirrhosis (1.49, CI: 1.45-1.54 versus 1.29, CI: 1.25-1.34). The hazard ratio (95% CI) for death was higher in HCV versus all patients at 1.69 (CI: 1.58-1.81) versus 1.54 (CI: 1.53-1.56). CONCLUSIONS: These data indicate that several clinical covariates increase the risk of bacteremia in hemodialysis patients, with the magnitude of that risk being further increased by HCV infection. Improving outcomes in HCV-infected hemodialysis patients will likely be dependent on aggressive diagnosis and treatment of both HCV and bacteremia.