Excess risk of SARS-CoV-2 infection among in-person nonhealthcare workers in six states, September 2020-June 2021.

BACKGROUND: While the occupational risk of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection for healthcare personnel in the United States has been relatively well characterized, less information is available on the occupational risk for workers employed in other settings. Even fewer studies have attempted to compare risks across occupations and industries. Using differential proportionate distribution as an approximation, we evaluated excess risk of SARS-CoV-2 infection by occupation and industry among non-healthcare workers in six states. METHODS: We analyzed data on occupation and industry of employment from a six-state callback survey of adult non-healthcare workers with confirmed SARS-CoV-2 infection and population-based reference data on employment patterns, adjusted for the effect of telework, from the U.S. Bureau of Labor Statistics. We estimated the differential proportionate distribution of SARS-CoV-2 infection by occupation and industry using the proportionate morbidity ratio (PMR). RESULTS: Among a sample of 1111 workers with confirmed SARS-CoV-2 infection, significantly higher-than-expected proportions of workers were employed in service occupations (PMR 1.3, 99% confidence interval [CI] 1.1-1.5) and in the transportation and utilities (PMR 1.4, 99% CI 1.1-1.8) and leisure and hospitality industries (PMR 1.5, 99% CI 1.2-1.9). CONCLUSIONS: We found evidence of significant differences in the proportionate distribution of SARS-CoV-2 infection by occupation and industry among respondents in a multistate, population-based survey, highlighting the excess risk of SARS-CoV-2 infection borne by some worker populations, particularly those whose jobs require frequent or prolonged close contact with other people.

Reported Exposures Among In-Person Workers With Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Infection in 6 States, September 2020-June 2021.

BACKGROUND: Surveillance systems lack detailed occupational exposure information from workers with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. The National Institute for Occupational Safety and Health partnered with 6 states to collect information from adults diagnosed with SARS-CoV-2 infection who worked in person (outside the home) in non-healthcare settings during the 2 weeks prior to illness onset. METHODS: The survey captured demographic, medical, and occupational characteristics and work- and non-work-related risk factors for SARS-CoV-2 infection. Reported close contact with a person known or suspected to have SARS-CoV-2 infection was categorized by setting as exposure at work, exposure outside of work only, or no known exposure/did not know. Frequencies and percentages of exposure types are compared by respondent characteristics and risk factors. RESULTS: Of 1111 respondents, 19.4% reported exposure at work, 23.4% reported exposure outside of work only, and 57.2% reported no known exposure/did not know. Workers in protective service occupations (48.8%) and public administration industries (35.6%) reported exposure at work most often. More than one third (33.7%) of respondents who experienced close contact with ≥10 coworkers per day and 28.8% of respondents who experienced close contact with ≥10 customers/clients per day reported exposures at work. CONCLUSIONS: Exposure to occupational SARS-CoV-2 was common among respondents. Examining differences in exposures among different worker groups can help identify populations with the greatest need for prevention interventions. The benefits of recording employment characteristics as standard demographic information will remain relevant as new and reemerging public health issues occur.

Common Behaviors and Faults When Doffing Personal Protective Equipment for Patients With Serious Communicable Diseases.

BACKGROUND: The safe removal of personal protective equipment (PPE) can limit transmission of serious communicable diseases, but this process poses challenges to healthcare workers (HCWs). METHODS: We observed 41 HCWs across 4 Ebola treatment centers in Georgia doffing PPE for simulated patients with serious communicable diseases. Using human factors methodologies, we obtained the details, sequences, and durations of doffing steps; identified the ways each step can fail (failure modes [FMs]); quantified the riskiness of FMs; and characterized the workload of doffing steps. RESULTS: Eight doffing steps were common to all hospitals-removal of boot covers, gloves (outer and inner pairs), the outermost garment, the powered air purifying respirator (PAPR) hood, and the PAPR helmet assembly; repeated hand hygiene (eg, with hand sanitizer); and a final handwashing with soap and water. Across hospitals, we identified 256 FMs during the common doffing steps, 61 of which comprised 19 common FMs. Most of these common FMs were above average in their riskiness at each hospital. At all hospitals, hand hygiene, removal of the outermost garment, and removal of boot covers were above average in their overall riskiness. Measurements of workload revealed that doffing steps were often mentally demanding, and this facet of workload correlated most strongly with the effortfulness of a doffing step. CONCLUSIONS: We systematically identified common points of concern in protocols for doffing high-level PPE. Addressing FMs related to hand hygiene and the removal of the outermost garment, boot covers, and PAPR hood could improve HCW safety when doffing high-level PPE.We identified ways that doffing protocols for high-level personal protective equipment may fail to protect healthcare workers. Hand hygiene, removing the outermost garment, boot covers, and respirator hood harbored the greatest risk and failed in similar ways across different hospitals.

Variability in the Duration and Thoroughness of Hand Hygiene.

We observed 354 hand hygiene instances across 41 healthcare workers doffing personal protective equipment at 4 hospital-based biocontainment units. We measured the duration and thoroughness of each hand hygiene instance. Both parameters varied substantially, with systematic differences between hospitals and differences between healthcare workers accounting for much of the variance.

Human Factors Risk Analyses of a Doffing Protocol for Ebola-Level Personal Protective Equipment: Mapping Errors to Contamination.

Background: Doffing protocols for personal protective equipment (PPE) are critical for keeping healthcare workers (HCWs) safe during care of patients with Ebola virus disease. We assessed the relationship between errors and self-contamination during doffing. Methods: Eleven HCWs experienced with doffing Ebola-level PPE participated in simulations in which HCWs donned PPE marked with surrogate viruses (ɸ6 and MS2), completed a clinical task, and were assessed for contamination after doffing. Simulations were video recorded, and a failure modes and effects analysis and fault tree analyses were performed to identify errors during doffing, quantify their risk (risk index), and predict contamination data. Results: Fifty-one types of errors were identified, many having the potential to spread contamination. Hand hygiene and removing the powered air purifying respirator (PAPR) hood had the highest total risk indexes (111 and 70, respectively) and number of types of errors (9 and 13, respectively). ɸ6 was detected on 10% of scrubs and the fault tree predicted a 10.4% contamination rate, likely occurring when the PAPR hood inadvertently contacted scrubs during removal. MS2 was detected on 10% of hands, 20% of scrubs, and 70% of inner gloves and the predicted rates were 7.3%, 19.4%, 73.4%, respectively. Fault trees for MS2 and ɸ6 contamination suggested similar pathways. Conclusions: Ebola-level PPE can both protect and put HCWs at risk for self-contamination throughout the doffing process, even among experienced HCWs doffing with a trained observer. Human factors methodologies can identify error-prone steps, delineate the relationship between errors and self-contamination, and suggest remediation strategies.

Assessing Viral Transfer During Doffing of Ebola-Level Personal Protective Equipment in a Biocontainment Unit.

Background: Personal protective equipment (PPE) protects healthcare workers (HCWs) caring for patients with Ebola virus disease (EVD), and PPE doffing is a critical point for preventing viral self-contamination. We assessed contamination of skin, gloves, and scrubs after doffing Ebola-level PPE contaminated with surrogate viruses: bacteriophages MS2 and Φ6. Methods: In a medical biocontainment unit, HCWs (n = 10) experienced in EVD care donned and doffed PPE following unit protocols that incorporate trained observer guidance and alcohol-based hand rub (ABHR). A mixture of Φ6 (enveloped), MS2 (nonenveloped), and fluorescent marker was applied to 4 PPE sites, approximating body fluid viral load (Φ6, 105; MS2, 106). They performed a patient care task, then doffed. Inner gloves, face, hands, and scrubs were sampled for virus, as were environmental sites with visible fluorescent marker. Results: Among 10 HCWs there was no Φ6 transfer to inner gloves, hands, or face; 1 participant had Φ6 on scrubs at low levels (1.4 × 102). MS2 transfer (range, 101-106) was observed to scrubs (n = 2), hands (n = 1), and inner gloves (n = 7), where it was highest. Most (n = 8) had only 1 positive site. Environmental samples with visible fluorescent marker (n = 21) were negative. Conclusions: Among experienced HCWs, structured, observed doffing using ABHR protected against hand contamination with enveloped virus. Nonenveloped virus was infrequent on hands and scrubs but common on inner gloves, suggesting that inner gloves, but not necessarily ABHR, protect against hand contamination. Optimizing doffing protocols to protect against all types of viruses may require reinforcing careful handling of scrubs and good glove/hand hygiene with effective agents.

Design strategies to improve healthcare worker safety in biocontainment units: learning from ebola preparedness.

OBJECTIVE: To identify ways that the built environment may support or disrupt safe doffing of personal protective equipment (PPE) in biocontainment units (BCU). DESIGN: We observed interactions between healthcare workers (HCWs) and the built environment during 41 simulated PPE donning and doffing exercises. SETTING: The BCUs of 4 Ebola treatment facilities and 1 high-fidelity BCU mockup.ParticipantsA total of 64 HCWs (41 doffing HCWs and 15 trained observers) participated in this study. RESULTS: In each facility, we observed how the physical environment influences risky behaviors by the HCW. The environmental design impeded communication between trained observers (TOs) and HCWs because of limited window size or visual obstructions with louvers, which allowed unobserved errors. The size and configuration of the doffing area impacted HCW adherence to protocol, and lack of clear demarcation of zones resulted in HCWs inadvertently leaving the doffing area and stepping back into the contaminated areas. Lack of standard location for items resulted in equipment and supplies frequently shifting positions. Finally, different solutions for maintaining balance while removing shoe covers (ie, chair, hand grips, and step stool) had variable success. We identified the 5 key requirements that doffing areas must achieve to support safe doffing of PPE, and we developed a matrix of proposed design strategies that can be implemented to meet those requirements. CONCLUSIONS: Simple, low-cost environmental design interventions can provide structure to support and improve HCW safety in BCUs. These interventions should be implemented in both current and future BCUs.