10/25/2021 | Press release | Archived content
Considerations for State and Local Health Departments on Investigating Non-Healthcare Workplace Clusters of COVID-19
General approach to investigating a workplace cluster
When COVID-19 cases are identified in a workplace, public health authorities (PHAs) should determine if an outbreak investigation is necessary. CDC encourages collaboration between employers and health departments in the investigation of workplace exposure to COVID-19; however, the legal authority for communicable disease case investigation lies with PHAs. While workplace investigations should follow the same general approach as other outbreak investigations, specific information can be helpful to consider in the work environment. Outbreak investigations may include four components:
These components provide insight in identifying who is at risk, modes of transmission, and worker and workplace factors that contribute to disease transmission and can help inform infection prevention and control recommendations to reduce COVID-19 transmission. Because every workplace is unique, each situation will dictate which investigation components are necessary to identify appropriate controls and disrupt transmission. CDC's National Institute for Occupational Safety and Health (NIOSH), trade associations, unions, state-based occupational health programs, and academic occupational health programs can provide subject matter expertise for various industry sectors, as needed.
After COVID-19 cases are identified in a workplace, and it is determined that an outbreak investigation is warranted, a multidisciplinary investigation team should be established by the PHA, in collaboration with CDC if assistance is needed. This team may include qualified professionals with experience in the fields of:
The team may also include other relevant practitioners, agencies, or stakeholders (e.g., agricultural agencies and veterinarians in the case of food processing facility outbreaks). Cultural liaisons may also be helpful to include if the workplace has a high proportion of refugees, immigrants, or other special populations within the workforce. After a team is formed, the investigation should begin in close consultation with officials from the facility including occupational health programs and unions or other worker organizations, if present in the workplace. If no union is present, it is important to include a worker representative in the investigation process to ensure all parties receive the same information. The team should follow the basic steps for conducting any outbreak investigation, but tailor their approach to incorporate principles that apply to the individual work environment. This includes developing a comprehensive set of questions based on knowledge of the industry and COVID-19.
The investigation team can learn about job-related characteristics associated with COVID-19 by reviewing information already available from case reports and interviews. This information can then be supplemented with employee records such as rosters that include occupational information (e.g., job tenure, job title), worker interviews or surveys, and review of occupational health policies and procedures.
Workplace outbreak investigation components
As mentioned above, specific information is available to consider for workplace environment safety. Components such as exposure, engineering, and work practice assessment; epidemiologic investigation; medical record review; and employer policy and record review may be included when conducting workplace outbreak investigations. Information about each component is provided below.
Exposure, engineering, and work practice assessment
Exposure assessment should identify potential pathways of exposure, assess the presence and use of workplace controls, and evaluate the capability of an employer to effectively implement additional controls needed to prevent further COVID-19 transmission. Identifying and controlling exposures to occupational hazards is the fundamental method of protecting workers. Traditionally, a hierarchy of controls has been used to help determine ways of implementing feasible and effective control solutions. During this component of the investigation, it is critical to enlist help from industrial hygiene, engineering, and infection control professionals who understand how to evaluate the workplace and implement effective procedures based on the hierarchy of controls.
The hierarchy of controls includes:
An epidemiologic investigation in the workplace is important because it helps to better define the characteristics of workers who contracted COVID-19; it can offer insight into risk factors for transmission, prevalence, and incidence of disease within the workplace. A workplace epidemiologic investigation may include:
If an employer chooses to conduct enhanced symptom and illness monitoring, they should routinely and systematically review screening results. They should also have a referral process in place that will direct employees with signs or symptoms of CLI to the system established by local public health departments for further assessment. It is important to note that some workplaces might have a system already in place for employee monitoring, assessment, and testing. In these workplaces, employers should have systems set up to ensure all test results are reported to the appropriate PHAs to ensure proper follow up and investigation. In some cases, PHAs may have the right to access, monitor, and review all records.
Medical Record Review
Medical record review for a workplace cluster can include conducting medical records abstraction to assist with the epidemiologic component of the investigation. Individuals, organizations, and agencies that are covered entitiesexternal icon under the Health Insurance Portability and Accountability Act (HIPAA) must abide by HIPAA rules. However, HIPAA permits covered entities to disclose protected health information without authorization for specified public health purposesexternal icon . Records that PHAs may be able to access include:
Employer Policy and Record Review
Relevant occupational health and medical policies and procedures to review include:
Other employer records that may be needed to supplement the investigation include:
In some cases, PHAs may also request access to records of client interactions (e.g., appointment or site visit calendars) in order to identify non-worker workplace close contacts of cases.
After this information is collected and analyzed, the team should provide site-specific recommendations to workplace officials. These recommendations should be shared with the requester of the cluster investigation and any unions present within the workplace. The team can also provide specific training or expertise to the employer as needed. Recommendations and training should be based on best practices followed by related industries and provided by OSHA, CDC, and state and local health departments for COVID-19.