Key Points

• Emergency medical service (EMS) workers appear to be at higher risk of infection when compared to firefighters and other frontline emergency personnel.
• Little research exists on infectious diseases in 911 dispatchers and telecommunicators.
• Research studies on infectious diseases in the EMS and 911 workforce have increased significantly since the beginning of the coronavirus disease 2019 (COVID-19) pandemic.
• Most research since 2006 has concentrated on the epidemiology of infections and infection risk.
• Research into the field effectiveness of N95 respirator and surgical face mask personal protective equipment (PPE) is limited, especially in the arena of airborne diseases.
• Regular hand hygiene decreases the spread of methicillin-resistant Staphylococcus aureus (MRSA).
• Standard precautions, such as gloves, decrease the chance of needlestick exposures.
• Vaccine uptake increases with the application of on-site directed clinics in the workforce, especially when combined with an active, targeted educational program with supervisor and peer support.
• Mandatory influenza vaccine programs increase the likelihood of vaccine uptake.
• Research into EMS and 911 infectious disease issues would be strengthened by a national research agenda including improved data uniformity, use of appropriate comparison groups, and comparable outcome measures.

Background and Purpose

The COVID-19 pandemic has highlighted the need for an improved understanding of infectious diseases in the EMS and 911 workforce. Public facing EMS clinicians have contact with multiple patients per day as they move through varying work environments in the field and hospital setting. Although PPE has been studied in controlled settings, research in EMS settings is more challenging. The transition of patients throughout these environments and the challenges of hand washing and PPE in the field provide opportunities for pathogens to spread from patients or co-workers to EMS clinicians. In addition, first responders, including 911 telecommunicators, are often in a communal work environment with shared eating and sleeping spaces. EMS clinicians are also at risk for needlestick injuries and blood-borne exposures to viruses such as human immunodeficiency virus (HIV) and hepatitis C, and droplet/airborne exposures to viruses such as influenza and the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

This Technical Brief aims to summarize current evidence on exposures to infectious pathogens in the EMS and 911 workforces and on interventions or practices for preventing, recognizing, and controlling occupationally acquired infectious diseases in these workforces. The Technical Brief also seeks to identify future research needs in this area. The Guiding Questions are:

1. What are the characteristics, incidence, prevalence, and severity of occupationally acquired infectious diseases and related exposures for the EMS and 911 workforces?
2. What are the characteristics and reported effectiveness (i.e., benefits and harms) of practices to prevent infectious diseases?
3. What are the characteristics and reported effectiveness (i.e., benefits and harms) of practices examined in studies of the EMS and 911 workforces to recognize and control (e.g., chemoprophylaxis, but excluding treatment) infectious diseases?
4. What are the context and implementation factors of studies with effective EMS and 911 workforce practices to prevent, recognize, and treat occupationally acquired infectious diseases? This description might include distinguishing factors such as workforce training, surveillance, protective equipment, pre- and post-exposure prophylaxis, occupational health services, preparedness for emerging infectious diseases, and program funding.
5. What future research is needed to close existing evidence gaps regarding preventing, recognizing, and treating occupationally acquired infectious diseases in the EMS and 911 workforces?

Methods

We employed methods consistent with those outlined in the Evidence-based Practice Center Program Methods Guidance (https://effectivehealthcare.ahrq.gov/topics/cer-methods-guide/overview), and we describe these in the full report. Our searches covered publication dates from January 1, 2006, to March 15, 2022. We included studies of the EMS and 911 workforces conducted in the United States. We included studies that evaluated the effectiveness of EMS and 911 workforce practices that had a comparison group. We did not include studies that evaluated firefighters or police personnel whose roles were not primarily related to medical care.

Results

In the published literature, we found 32 studies that met our inclusion criteria. Twenty-five were observational studies examining the characteristics, incidence, prevalence, and/or severity of occupationally acquired infectious diseases and related exposures in the EMS and 911 workforces. Eleven observational studies reported on the characteristics and effectiveness of infection prevention and control (IPC) practices in the EMS and 911 workforces. Some studies examined both the epidemiology of occupational infections and the interventions or practices to mitigate or prevent them. None of the studies used an experimental design.

Research into infectious diseases in the EMS and 911 workforces has increased significantly since the COVID-19 pandemic, and most of the evidence on how occupationally acquired infections differ by demographics is limited to SARS-CoV-2. The incidence, prevalence, and severity of infections generally did not differ according to demographic differences in the EMS and 911 workforces, except for an increase in hepatitis C in older workers and an increase in SARS-CoV-2 in Black non-Hispanic and other Hispanic workers when compared with white non-Hispanic workers. Compared with single-role firefighters (firefighters whose role was not primarily related to medical care), EMS workers had an increased risk of hospitalization or death from COVID-19 and a mildly increased prevalence of hepatitis C. In addition, EMS workers certified/licensed in Advanced Life Support (ALS) had an increased risk of blood exposure, fluids exposure, and needlesticks when compared to workers certified/licensed in Basic Life Support (BLS). One study found no differences in years of experience, population density, or level of care for nasal colonization with MRSA.

In the 11 observational studies on characteristics and effectiveness of IPC practices in the EMS and 911 workforces, several workforce practices were examined, including hand hygiene, standard precautions, and on-site vaccine clinics. Both daily and post-glove use hand hygiene were negatively correlated with nasal colonization of MRSA. The increased use of standard precautions such as face masks, gloves, and protective devices for resuscitation were associated with a decreased likelihood of a needlestick.

One study demonstrated that the lack of PPE and PPE breach or failure were correlated with higher SARS-CoV-2 seropositivity. Another study demonstrated that aerosol-generating procedures (AGPs), with full PPE, were not associated with SARS-CoV-2 diagnosis. Only one EMS clinician developed COVID-19 infection during the study period. No included study examined the protectiveness of N95 respirators or Powered Air-Purifying Respirators during AGPs in comparison with use of surgical masks alone or when paired with a face shield.

On-site vaccine clinics were found to be effective at improving vaccine acceptance and uptake for H1N1 influenza and seasonal influenza, especially when paired with an active program of education, social influence, and advice from supervisors. Vaccine uptake and acceptance were enhanced not only by the presence of a vaccination program, but also by accompanying educational modules and buy-in from supervisors and trusted peers. Mandatory vaccination policies for seasonal influenza and H1N1 influenza also were shown to be effective at increasing vaccine uptake amongst EMS and 911 workers. No studies on mandatory vaccination policies for SARS-CoV-2 fit within our inclusion criteria.

Limitations

The available data exhibits considerable heterogeneity in research design, methodology, and outcomes studied. Most studies in our review were observational cohort studies with a comparison group. The studies of IPC practices included in this review are limited to those having a comparison group because effectiveness of a public health intervention cannot be reliably determined without a comparison group. Although the observational studies of IPC practices generally included EMS and 911 workers representative of the target population of interest, most of the studies did not provide enough information to assess potential selection bias and confounding factors. These studies also did not provide separate information about the effectiveness of IPC practices in 911 telecommunicators and emergency dispatchers.

Implications and Conclusions

A moderate amount of evidence exists on the incidence, prevalence, and severity of occupationally acquired infections in the EMS and 911 workforce, but most of that evidence has been published in the last 2 years and mostly focuses on SARS-CoV-2. This evidence reinforces concerns about the substantial risks of numerous types of infection in the EMS and 911 workforces. A moderate amount of evidence also exists on the characteristics and effectiveness of IPC practices in the EMS and 911 workforces, offering some support for the effectiveness of hand hygiene, standard precautions, mandatory vaccination policies, and on-site vaccine clinics. However, many evidence gaps remain. More research is needed on the effectiveness of different types of IPC interventions for the full range of occupationally acquired infections in the EMS and 911 workforces. The evidence is limited by lack of experimental study designs in the EMS setting and insufficient attention to potential selection bias and confounding in observational studies. Future research could benefit from a national research agenda including the above elements and incorporating practical guidance on how to conduct studies in the highly challenging mobile environments typical of EMS work.