Infection prevention strategies are highly protective in COVID-19 units while main risks to healthcare professionals come from coworkers and the community
Authors: Edwin S Monuki
Delia Tifrea
Keith M Madey
Donald Forthal
Wayne Chang
Lanny Hsieh
William C Wilson
Usme Khusbu
Cassiana E Bittencourt
Saahir Khan
Philip Felgner
Kathleen A Quan
Sebastian D Schubl
Aarti Jain
Rafael Assis
Suzanne King-Adelsohn
Tom Tjoa
Lynn Willis
Antonella Saturno
Sherif A Rezk
Michael J Stamos
Neil Detweiler
Bridgit O Crews
Robert Edwards
Susan S Huang
Cesar Figueroa
Shruti K Gohil
Journal: Antimicrobial resistance and infection control (2021)
Discipline: PHARMACOLOGY & TOXICOLOGY
Keywords: COVID-19 outbreaks; COVID-19 seroprevalence; Healthcare professional COVID-19 exposure; Healthcare worker COVID-19 exposure; Severe acute respiratory syndrome coronavirus-2.
Affiliations: Epidemiology and Infection Prevention Program, Irvine Health (UC Irvine Health), University of California, Irvine, USA. ., Division of Infectious Diseases, Department of Medicine, Irvine School of Medicine, University of California, 100 Theory, Suite 120, Irvine, CA, 92617, USA. ., Epidemiology and Infection Prevention Program, Irvine Health (UC Irvine Health), University of California, Irvine, USA., Pathology and Laboratory Medicine, UCI Health, Newport Beach, USA., Division of Infectious Diseases, Department of Medicine, Irvine School of Medicine, University of California, 100 Theory, Suite 120, Irvine, CA, 92617, USA., Division of Infectious Diseases, Keck School of Medicine, University of Southern California, Los Angeles, USA., Department of Surgery, Irvine School of Medicine, University of California, Irvine, USA., Division of Occupational and Environmental Medicine, Irvine School of Medicine, University of California, Irvine, USA., Department of Physiology and Biophysics, University of California, Irvine, USA., Chief Medical Officer, UC Irvine Health, Orange, USA.

Abstract:  Background: Early evaluations of healthcare professional (HCP) COVID-19 risk occurred during insufficient personal protective equipment and disproportionate testing, contributing to perceptions of high patient-care related HCP risk. We evaluated HCP COVID-19 seropositivity after accounting for community factors and coworker outbreaks. Methods: Prior to universal masking, we conducted a single-center retrospective cohort plus cross-sectional study. All HCP (1) seen by Occupational Health for COVID-like symptoms (regardless of test result) or assigned to (2) dedicated COVID-19 units, (3) units with a COVID-19 HCP outbreak, or (4) control units from 01/01/2020 to 04/15/2020 were offered serologic testing by an FDA-authorized assay plus a research assay against 67 respiratory viruses, including 11 SARS-CoV-2 antigens. Multivariable models assessed the association of demographics, job role, comorbidities, care of a COVID-19 patient, and geocoded socioeconomic status with positive serology. Results: Of 654 participants, 87 (13.3%) were seropositive; among these 60.8% (N = 52) had never cared for a COVID-19 patient. Being male (OR 1.79, CI 1.05-3.04, p = 0.03), working in a unit with a HCP-outbreak unit (OR 2.21, CI 1.28-3.81, p &lt; 0.01), living in a community with low owner-occupied housing (OR = 1.63, CI = 1.00-2.64, p = 0.05), and ethnically Latino (OR 2.10, CI 1.12-3.96, p = 0.02) were positively-associated with COVID-19 seropositivity, while working in dedicated COVID-19 units was negatively-associated (OR 0.53, CI = 0.30-0.94, p = 0.03). The research assay identified 25 additional seropositive individuals (78 [12%] vs. 53 [8%], p &lt; 0.01). Conclusions: Prior to universal masking, HCP COVID-19 risk was dominated by workplace and community exposures while working in a dedicated COVID-19 unit was protective, suggesting that infection prevention protocols prevent patient-to-HCP transmission. Prior to universal masking, HCP COVID-19 risk was dominated by workplace and community exposures while working in a dedicated COVID-19 unit was protective, suggesting that infection prevention protocols prevent patient-to-HCP transmission. 

Retracted: No

PubPeer comments:
 As highlighted by several commenters on twitter there are numerous impossible and inconsistent values in this paper which in my view warrants further explanation. In Table 1 there are multiple rows where the number of seropositive + seronegative individuals do not equal the total number of individuals including  Occupational health visit ,  Race - Black ,  Race - Other There are more possible inconsistencies in Table 1 which might be explained by missing data, but the authors have not reported the existence of any missing data nor how it was handled in the analysis. The reported standard deviation for age in the seropositive subset is 47.1, which seems improbable. In Table 2 the authors present an OR of 1.3 for Registered Nurse despite Registered Nurse being the reference category. The number of participants from the COVID-19 HCP-outbreak unit cohort is reported differently in the text (n=197) and in Table 1 (n=272). , 
 This is an interesting paper but unfortunately several of the numbers in this paper donu2019t appear to be compatible with each other. I would appreciate it if the authors could provide some clarifications to explain these discrepancies. In table 1: It is reported that there are 10 black participants, 2 black seropositive participants and 10 black seronegative participants. It is reported that there are 273 individuals in the occupational health visit cohort, but then only 52 seropositive and 166 seronegative individuals in this group are reported, leaving 55 individuals with unknown sero-status. However the total N row reports that there are no individuals with unknown sero-status. Similarly it is reported that there are 131 participants with u201cotheru201d race, 17 seropositive u201cotheru201d, 46 seronegative u201cotheru201d. This leaves 68 participants with u201cotheru201d race where the serostatus is unknown which is incompatible with the total N row reporting that there are no individuals with unknown sero-status. In Table 2: It is reported that the reference group for HCP role is Registered Nurse in the footnote. However the table presents an odds ratio of 1.29 (0.57-2.95) for the Registered Nurse category. By definition, a reference group should have an odds ratio of 1. None of the HCP role categories has an odds ratio of 1. Additionally there are some unusual findings that I would appreciate further clarification from the authors on: The reported standard deviation of age in the seropositive group is 47.1. This is remarkably high, what was the age of the oldest individual in this group? Could the authors specify how they calculated the p value for the age comparison? The paper reports it was a chi square test but no details are provided as to which age categories were used. It would help the reader if the authors provided details of the extent of missing data in the publication. Can the authors confirm that when they have calculated percentages they have included missing values in their denominator? ,