SARS-CoV-2 seropositivity among healthcare professionals in a rural state

Abstract

Objectives: We evaluated SARS-CoV-2 anti-nucleocapsid (anti-N) seroconversion and seroreversion rates, risk factors associated with SARS-CoV-2 seroconversion, and COVID-19 risk perceptions among academic healthcare center employees in a rural state.

Methods: Among employees aged ≥18 years who completed a screening survey (n = 1,377), we invited all respondents reporting previous COVID-19 (n = 85; 82 accepted) and a random selection of respondents not reporting previous COVID-19 (n = 370; 220 accepted) to participate. Participants completed surveys and provided blood samples at 3-month intervals (T0, T3, T6, T9). We used logistic regression to identify risk factors for seropositivity at T0.

Results: The cohort was primarily direct patient caregivers (205/302; 67.9%), white (278/302; 92.1%), and female (212/302; 70.2%). At T0, 86/302 (28.4%) participants were seropositive. Of the seronegative participants, 6/198 (3.0%), 6/183 (3.3%), and 14/180 (7.8%) had seroconverted at T3, T6, and T9, respectively. The overall seroreversion rate was 6.98% at T9. At T0, nursing staff (odds ratio [OR], 2.37; 95% confidence interval [CI], 1.08, 5.19) and being within six feet of a non-household member outside of work (OR, 2.91; 95% CI, 1.02, 8.33) had significantly higher odds of seropositivity. Vaccination (OR, 0.05; 95% CI, 0.02, 0.12) and face mask use (OR, 0.36; 95% CI, 0.17, 0.78) were protective.

Conclusions: The seroconversion and seroreversion rates were low among participants. Public health and infection prevention measures implemented early in the COVID-19 pandemic - vaccination, face mask use, and social distancing - were associated with significantly lower odds of SARS-CoV-2 seropositivity among participants.

Figure 1.

Seroconversions during Different Phases of the Pandemic. UIHC, University of Iowa Hospitals and Clinics. To assess COVID-19 seroconversion data in the context of vaccine availability and the circulating variants, we defined the time variable shown on the x-axis as the number of days since the first case of COVID-19 was identified in Iowa (March 8, 2020).

Figure 2.

Changes in Healthcare Professionals’ Perceptions of COVID-19 Over Time. (a). Healthcare Professionals’ Concern about Spreading COVID-19 if Infected but Asymptomatic. (b). Healthcare Professionals’ Willingness to Visit Public Places. (c). Healthcare Professionals’ Face Covering Use in Public Places Outside of Work. To assess COVID-19 sentiment data in the context of vaccine availability and the circulating variants, we defined the time variable shown on the x-axis as the number of days since the first case of COVID-19 was identified in Iowa (March 8, 2020).