Guidance on Asymptomatic Laboratory Testing for Coronavirus Disease (COVID-19)

Source: Wildland Fire Medical and Public Health Advisory Team (MPHAT)

If fire management units or incidents decide to make expanded screening testing part of their prevention procedures to reduce the risk of COVID-19 transmission, they should consider the following criteria outlined on this page in the development and implementation of a testing strategy. These criteria will guide fire managers and safety personnel to optimize and maintain ongoing fire suppression operations. If an expanded testing strategy is needed, agency administrators and fire management should engage with their public health officials and safety program staff to most effectively implement a COVID-19 testing strategy for their fire personnel.

Many considerations outlined here and additional guidance can be found in the Federal Testing Plan for Federal Workforce.

Testing to diagnose COVID-19 is one component of a comprehensive strategy to slow and prevent the spread of COVID-19. Testing should be used in addition to practicing behaviors that reduce spread, maintaining healthy work environments and operations, and preparing for proper response when someone gets sick. Testing strategies must be carried out in a way that protects individual privacy and confidentiality and is consistent with applicable laws and regulations. In addition to state and local laws, fire managers should work with their human resources departments to ensure they follow guidance from the Equal Employment Opportunity Commission and the Americans with Disabilities Act (ADA). Home units and incident management teams are encouraged to work with state and local health officials, on determining and implementing any testing strategy.

MPHAT currently recommends prioritizing testing for individuals with signs and symptoms consistent with COVID-19 and asymptomatic individuals with recent known close contact or suspected exposure to SARS-CoV-2 (exposure being defined as within 6 feet for a total of 15 minutes or more). Testing of asymptomatic individuals without known or suspected exposure to SARS-CoV-2 for early identification of COVID-19 may be used in special settings. The MPHAT recommendations on testing for wildland fire are in alignment with CDC Interim Guidance for SARS-CoV-2 Testing in Non-Healthcare Workplaces. 

Considerations for Interpreting Test Results, Logistics Required, and Implications

• Fire managers should be aware that positive tests may not indicate an individual is infected or is contagious (false positive results). This broad-based testing strategy may impact resource availability. Before testing a large proportion of asymptomatic workers without known or suspected exposure to SARS-CoV-2, employers should have a plan in place for how they may modify infection control procedures and support infected fire personnel based on test results.
• Fire managers should consider the availability of dedicated resources and the logistics needed to conduct expanded screening testing among fire personnel. Examples of resources include trained staff to conduct tests, personal protective equipment, and physical space for conducting testing safely and ensuring privacy.
• For individuals that test positive for COVID-19, wildfire agencies should ensure procedures are in place for rapid notification, sick leave policies are flexible and consistent with public health guidance, and employees are aware of and understand these policies. In addition, employers should have policies and procedures in place to support employees through quarantine and isolation.

Expanded screening testing strategy for early identification of SARS-CoV-2 in fire camps or the workplace

Expanded screening of COVID-19 within the fire camp environment or workplaces may provide fire and safety managers useful intelligence to optimize and maintain ongoing fire suppression operations. Screening testing may not produce reliable information for individual employee related decision making.

Considerations

• Expanded screening testing of asymptomatic individuals without known or suspected exposure to SARS-CoV-2 within a specific population may be most useful in guiding an overall prevention and mitigation strategy. Testing is not a substitute for employing infection prevention strategies and must be voluntary. An expanded screening testing strategy may be considered when incident or workplace characteristics make social distancing or mask use difficult and presents high risk of widespread transmission. Below are additional risk factors to assess in the workplace or at fire camps when deciding on a testing strategy.
  • Number of personnel assigned: The more personnel at an incident, the higher the likelihood of an infected individual arriving to the incident.
  • Duration of incident: The longer the duration of the incident, the higher the likelihood of an infected individual entering the camp population.
  • Degree of personnel dispersal and social distancing discipline: The less dispersed personnel are or not adhering to social distancing recommendations at camp, the higher the likelihood of person-to-person contact and exposure to SARS-CoV-2.
  • Screening frequency: Consistent daily screening increases the opportunities for symptomatic individuals to be appropriately diagnosed and isolated. Refer to the FMB COVID-19 Screening Tool for Wildland Fire Personnel.
  • Use of masks: Masks are a simple barrier to prevent the spread of COVID-19. The greater use of masks by personnel lowers the overall camp risk of SARS-CoV-2 transmission.
  • Infection rates in the surrounding community: If transmission rates are higher in surrounding communities or areas, fire personnel may be at a higher risk of SARS-CoV-2 exposure through interaction with the public See below for CDC guidance around community indicators.
  • Positive cases already identified within the workplace or fire camp: If infections are seen across multiple crews or “modules,” then the possibility of within-camp transmission and outbreak risk is greater.
• CDC recommends the frequency of testing could be informed by the current community indicators for COVID-19 (at county level). These indicators include cumulative incidence in the past seven days and test positivity rate at the county level (described in the tables below). If the two indicators suggest different transmission levels, the higher level (more conservative) should be selected.
• Frequency of testing could also be informed by the size of the workplace, residential setting, or gathering. Since fire resources may be deployed from many locations, fire managers may need to consider multiple locations when reviewing the current community spread. In rural areas with low population density, multiple jurisdictions might need to be combined to make the indicators more useful for decision-making.

Table 1. Community Indicators at the County Level

Table 2. Potential Actions Based on Community Indicator Level

• If initial results indicate localized transmission in a selected group is high, more frequent screening of that group might be needed regardless of the community indicators.
• Testing approaches may include initial testing of all workers before entering a workplace, periodic testing of workers at regular intervals, and/or targeted testing of new workers.
• The likelihood of exposure to SARS-CoV-2 for individuals should be considered in developing a testing strategy. A targeted testing strategy should focus on employees who worked in the same area and during the same shift as symptomatic individual or asymptomatic individuals who have tested positive.
• Tests used should aim for rapid turn-around-times (e.g., less than 48 hours) to minimize post-test exposures and facilitate effective action from fire managers and public health departments.

Independent laboratory testing of fire personnel in fire camps or the workplace

State, local, territorial, and tribal health departments may be able to provide assistance on any local context or guidance impacting the workplace. However, in areas with moderate to substantial community transmission, health departments may not be able to provide assistance with determining and implementing any testing strategy in the workplace. Under such conditions, the effective implementation of a testing strategy may require fire managers and line officers to work directly with independent laboratories. Below are recommendations that should be considered when procuring services to provide testing for fire personnel.

Considerations

• Testing in the workplaces requires medical oversight and needs to be ordered by a healthcare provider.
• Testing strategies should include information on specimen collection and transport, personnel collecting samples, tracking of specimens and reporting of results.
• Samples need to be collected and handled following CDC Interim Guidelines for Collecting, Handling, and Testing Clinical Specimens for COVID-19.
• Ensure that all staff involved in specimen collection are appropriately trained and wear personal protective equipment (PPE) as appropriate.
• Testing locations should have good ventilation and space for social distancing.
• Ensure proper disposal of biohazard waste (used specimen collection materials; soiled gloves, masks, gowns, etc.).
• Understand the type of viral test and the specimen source (e.g., nasopharyngeal, anterior nares) that will be used.
  • Test must have been granted an Emergency Use Authorization by the Food and Drug Administration. Individuals tested are required to receive patient fact sheets as part of the test’s emergency use authorization.
  • For testing asymptomatic individuals without known or suspected exposure to SARS-CoV-2 viral tests should have a high sensitivity (>95%) for screening.
  • Antibody testing may not be used to diagnose infection nor to make employment related decisions (e.g. to determine if someone is immune).
• Laboratories selected should be able to quickly process large numbers of tests with rapid reporting of results (e.g., within 48 hours). This will inform infection prevention initiatives to prevent and limit transmission. Testing a large number of individuals may impact testing capacity and turn-around time of results.
• Individuals may choose to use a self-collection kit or a self-test that can be performed at home or anywhere else. These tests may be available over the counter or through a prescription. See CDC guidance for more information on how to administer a self-test and report results to your healthcare provider or health department.
• Individuals must be notified of their testing results. Testing should be carried out in a way that protects confidentiality of tested individuals that is consistent with all applicable laws and regulations.
  • All screening testing plans must include a process for the appropriate handling of medical documentation in accordance with applicable law, including provisions of the Americans with Disabilities Act applied to the Federal Government through the Rehabilitation Act of 1973 and the Privacy Act.
• Under OSHA’s recordkeeping requirements, COVID-19 is a recordable illness, and employers are responsible for recording cases of COVID-19 on Form 300 logs if the following requirements are met: (1) the case is a confirmed case of COVID-19; (2) the case is work-related (as defined by 29 CFR 1904.5); and (3) the case involves one or more relevant recording criteria (set forth in 29 CFR 1904.7).
• Even if the local health department does not conduct the testing, fire managers should coordinate how all results will be shared with the health department.

Conclusion

MPHAT recommends testing be used as one component of a comprehensive strategy to slow and prevent the spread of COVID-19 in the wildland fire community. If fire managers choose to implement expanded screening for SARS-CoV-2, the implementation of testing services should address the considerations noted above. Home units and incident management teams should collaborate with state, territorial, tribal and local health officials to determine whether and how to implement testing strategies appropriate to their circumstances. Before testing, fire managers and incident command teams should have a plan for how they will modify operations and inform additional prevention and control efforts, and support fire personnel based on test results.