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COVID-19 Exposure Among First Responders in Arizona

Shukla, Vershalee MD; Lau, Christine S.M. MD; Towns, Mikayla; Mayer, Jennifer RN; Kalkbrenner, Kara; Beuerlein, Steve; Prichard, Pablo MD

Author Information
Journal of Occupational and Environmental Medicine: December 2020 - Volume 62 - Issue 12 - p 981-985
doi: 10.1097/JOM.0000000000002027
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Abstract

Learning Objectives

  • Identify issues related to the risk of COVID-19 among first responders.
  • Summarize the new findings on COVID-19 antibody testing of Arizona firefighters/EMS and police personnel, including factors likely affecting the results.
  • Discuss areas of concern and other issues related to COVID-19 among this occupational group.

Coronavirus disease (COVID-19) is an infectious disease caused by SARS-CoV-2. First identified in Wuhan, China in December 2019, the outbreak was declared a Public Health Emergency of International Concern on January 30, 2020, and recognized as a pandemic on March 11, 2020.1 The first confirmed case of COVID-19 in the United States (US) was reported on January 20, 2020. Six days later, on January 26, 2020, Arizona had their first confirmed case of COVID-19.1 By April 21, 2020, that number grew to 5251 cases and 208 deaths in Arizona.2,3 As of June 2020, that number has risen to over 70,000 cases and 1500 deaths.3 The rate of new cases is rapidly rising, and Arizona is currently one of the hot spots within the country, with one of the fastest rates of new daily cases.

Many people infected with SARS-CoV-2 will experience mild to moderate respiratory illness and recover without requiring hospitalization and medical intervention.1,4 Symptoms may take 2 to 14 days after exposure and during this time, the individual may spread the virus to other individuals.4

First responders, including firefighters, emergency medical service (EMS) personnel, and police officers, interact with the public and respond to medical related calls on a daily basis. As a result, first responders are believed to be at higher risk of being exposed to SARS-CoV-2 and COVID-19 patients without knowing it. In the state of Arizona, there have been first responders who have tested positive for SARS-CoV-2, and more have been out sick and/or self-quarantine and isolation. This in turn, places a burden on the fire and police departments. Furthermore, this pandemic has had a significant impact on the mental health and well-being of first responders. In a study by Cohen Veterans Network with 523 New York City first responders and front-line healthcare workers, during COVID-19, 55% of first responders were concerned about their overall mental health, with 54% of respondents describing themselves as anxious, 68% as concerned, 58% worn out, and 29% scared.5 Furthermore, 58% of first responders across the US say their job is putting the lives of their family at risk because of the coronavirus.5

Antibody testing for SARS-CoV-2 has been recently developed, which detects IgM and/or IgG antibodies to the coronavirus. By testing first responders for the antibodies, we can identify those who have been exposed and recovered from the illness and built up some potential immunity to the virus. This will help assess the safety protocols and procedures implemented by the fire and police departments during this pandemic, including the use of personal protective equipment (PPE). This will also help alleviate some anxiety for those responding to future calls on the front lines. First responders who test positive can also potentially donate plasma as a treatment to help other severely ill COVID-19 patients.

The aim of this study is to identify patterns in coronavirus exposure among first responders in Arizona and assess the impact of the antibody testing on their daily work as a first responder.

METHODS

This study was conducted according to Good Clinical Practice guidelines, but did not have external monitoring. Written consent to participate in the study was obtained from each individual.

Study Participants and Study Design

Inclusion criteria: All first responders (including firefighters, EMS, and police officers) age 18 and older who are members of the United Phoenix Firefighters Association Local 493 or Phoenix Law Enforcement Association or work for the Cities of Phoenix, Tempe, or Glendale were eligible to participate in this study. United Phoenix Firefighters Association Local 493 includes professional firefighters from Phoenix, Tempe, Glendale, Peoria, Surprise, and Chandler.

All eligible first responders were notified via email list serves that SARS-CoV-2 IgG antibody testing would be available to them free-of-charge. Antibody testing was available at three different test sites across Arizona over a span of 4 weeks from April 24 to May 21, 2020. When the first responders arrived to receive their antibody testing, they were asked if they wished to participate in the exposure survey. Members were given the option to receive the antibody test but not participate in the exposure survey. Participation in the study was voluntary and did not impact their ability to obtain the SARS-CoV-2 antibody test, or their employment at the fire or police station. Informed consent was obtained from those who wanted to participate. A short exposure survey was given to participants who provided informed consent. Participants were able to skip any question(s) on the survey they did not feel comfortable answering or did not wish to answer.

Results of the antibody test and data to the study surveys were confidential, and not released to their fire or police department, nor their union. Only aggregate de-identified data in summary format was released and shared with the fire and police departments.

Coronavirus Antibody Test

The RayBiotech Coronavirus (COVID-19) IgG Rapid Test Kit was utilized. This lateral flow immunoassay has a sensitivity of 90.4% and specificity of 98.3%.6 This test qualitatively detects SARS-CoV-2 IgG antibodies in human peripheral whole blood from a finger prick. The test kit uses the principle of immunochromatography, separating the components through a medium using capillary force and the specific rapid binding of antibody to antigen. This test does not cross react with other anti-nuclear antibodies (ANA), respiratory syncytial virus (RSV), influenza A or B, hepatitis C virus, or hepatitis B virus.6 All antibody testing was performed by certified emergency medical technicians (EMTs), registered nurses (RNs), or medical doctors (MDs), and all results were read and interpreted by study staff RNs and MDs. Each test was read by two study staff medical professionals.

Exposure Survey

The study survey questionnaire contained demographic information such as age, gender, and department (fire and EMS, or police) (Supplemental Digital Content 1, https://links.lww.com/JOM/A807). Clinical information regarding any medical conditions (asthma, chronic lung disease, hypertension, heart disease, diabetes, kidney disease, liver disease, cancer, or autoimmune disorders) was collected. Information regarding recent travel, contact with COVID-19 patients, symptoms, prior testing, and self-quarantine/isolation was also asked.

To assess their attitudes and views about the impact the coronavirus has had on their daily job as a first responder, the participants were asked to rate the extent to which they agree or disagree with eight statements using a Likert scale (definitely agree, somewhat agree, neither agree nor disagree, somewhat disagree, definitely disagree). Items included “I think I have already contracted the coronavirus,” “I am worried I am a carrier of the coronavirus without knowing it,” “I am worried I will become a carrier of the coronavirus without knowing it,” “I am worried about contracting the coronavirus and/or developing COVID-19,” “I have adequate personal protective equipment to protect me from contracting the coronavirus while performing work-related duties,” “Because of my high-risk job, I have taken extra precautions at home to protect my family from contracting the coronavirus,” “Having this antibody testing will help easy my anxiety about going to work and performing work-related duties,” and “Having this antibody testing will be beneficial helping me perform work-related duties.”

Statistical Analysis

Participant data was grouped into two groups—Fire/EMS versus Police. The role of firefighter and EMS are intertwined and therefore unable to be differentiated for the purpose of this study.

Categorical data was compared using the Chi-square test and continuous data were compared using Student's t-test and analysis of variance (ANOVA). Missing and unknown data were excluded from the analysis. All statistical analysis was conducted using IBM SPSS®v25 (Armonk, NY). Statistical significance was accepted at a level of P < 0.05.

RESULTS

A total of 3714 first responders were tested for SARS-CoV-2 IgG antibodies. Among these, 3326 (89.6%) provided consent to be included in the study. There were 1713 (51.0%) firefighters and 1643 (49.0%) police officers. There were 2637 (82.9%) males and 544 (17.1%) females, and an average age of 41.3 ± 9.6 years.

A total of 50 (1.50%) first responders tested positive for SARS-CoV-2 IgG antibodies (Table 1). A total of 25 (1.46%) firefighters and 25 (1.52%) police officers tested positive, with no significant difference between fire or police (P = 0.901). Among those who tested positive, 44 were male and 6 were female, with an average age of 41.4 ± 9.3 years.

TABLE 1 - Demographic Characteristics of First Responders and Those With SARS-CoV-2 IgG Antibodies
Total First RespondersN (%) IgG PositiveN (%)
Total 3,326 50 (1.50%)
Sex
 Male 2,637 (82.9%) 44 (88.0%)
 Female 544 (17.1%) 6 (12.0%)
Age
 18–24 yrs 100 (3.1%) 0 (0.0%)
 25–34 yrs 730 (22.2%) 11 (22.4%)
 35–44 yrs 1,186 (36.1%) 16 (32.7%)
 45–54 yrs 984 (30.0%) 18 (36.7%)
 55–64 yrs 266 (8.1%) 4 (8.2%)
 65 + yrs 16 (0.5%) 0 (0.0%)
Service
 Fire 1,713 (51.0%) 25 (50.0%)
 Police 1,643 (49.0%) 25 (50.0%)
City
 Phoenix 2,014 (62.8%) 29 (58.0%)
 Tempe 370 (11.5%) 13 (26.0%)
 Glendale 503 (15.7%) 5 (10.0%)
 Surprise 135 (4.2%) 0 (0.0%)
 Peoria 110 (3.4%) 2 (4.0%)
 Chandler 76 (2.4%) 1 (2.0%)

A total of 773 first responders (23.2%) had at least one underlying health condition, with the most common conditions being hypertension (10.8%) and asthma (9.6%) (Table 2). Among those who tested positive for IgG antibodies, 12 (24.0%) had at least one underlying health condition, with the most common being asthma (12.0%) and hypertension (8.0%).

TABLE 2 - Comorbidities Among First Responders and Those With SARS-CoV-2 IgG Antibodies
All First Responders (%) Fire (%) Police (%) IgG Positive (%)
Asthma 9.6 9.5 9.7 12.8
Lung disease 0.4 0.4 0.4 0.0
Hypertension 10.8 9.9 11.2 8.3
Heart disease 0.6 0.5 0.8 0.0
Diabetes 2.3 1.8 2.8 0.0
Kidney disease 0.4 0.4 0.4 2.1
Liver disease 0.2 0.1 0.2 0.0
Cancer 1.7 2.2 1.2 4.2
Autoimmune disorder 2.5 2.3 2.8 2.1

Travel and Contact History

A total of 6.3% of first responders reported travel outside the country since January 1, 2020 (Table 3). A total of 19.8% of first responders had contact with an individual confirmed to be positive for coronavirus, and 31.6% think they had contact with an individual with the virus. About 20.1% of individuals had symptoms, while 3.7% were tested, and 5.1% had to self-quarantine or isolate for possible infection.

TABLE 3 - Travel and Contact History of First Responders and Those With SARS-CoV-2 IgG Antibodies
All First Responders (%) Fire (%) Police (%) IgG Positive (%) IgG Negative (%) P-Value
Have you travelled out of the country since Jan 1, 2020? 6.3 7.1 5.1 6.3 6.3 0.985
Have you come in contact with an individual who tested positive for coronavirus? 19.8 32.7 6.7 31.3 19.5 0.043
Do you think you have come in contact with an individual who had coronavirus? 31.6 48.0 14.8 41.7 31.3 0.125
Have you had symptoms of the coronavirus/COVID-19? 20.1 19.5 20.6 29.2 19.8 0.109
Have you ever been tested for the coronavirus? 3.7 4.5 2.8 8.3 3.7 0.089
Have you had to self-quarantine/isolate for possible coronavirus? 5.1 5.3 4.9 10.4 5.0 0.087
P values refer to difference between IgG positive and IgG negative groups.COVID-19, coronavirus disease.

When comparing those who tested positive for IgG and those who tested negative for IgG, significantly more individuals who tested positive for IgG had known contact with an individual who tested positive for the virus (31.3% vs 19.5%, P = 0.043) (Table 3). There was no significant difference between those who were IgG positive and IgG negative in terms of those who had symptoms (29.2% vs 19.8%, P = 0.109), those who received testing (8.3% vs 3.7%, P = 0.089), and those who had to self-quarantine or isolate (10.4% vs 5.0%, P = 0.087). There was insufficient data to perform any subgroup analysis between fire and police for those who tested positive for SARS-CoV-2 IgG.

Exposure Survey

A total of 3104 (83.6%) first providers provided consent to the exposure survey, of which 2978 (95.9%) completed the exposure survey (Table 4). Of those who completed the survey, 20.5% of first responders either definitely or somewhat agreed with the statement “I think I have already contracted the virus.” About 15.4% agreed with the statement “I am worried I am a carrier of the coronavirus without knowing it.” About 28.8% agreed with the statement “I am worried I will become a carrier of the coronavirus without knowing it.” About 30.2% agreed with the statement “I am worried about contracting the coronavirus and/or developing COVID-19.” About 74.5% agreed with the statement “I have adequate personal protective equipment to protect me from contracting the coronavirus while performing work-related duties.” On the other hand, 12.0% disagreed with the statement, indicating a lack of PPE. 80.4% agreed with the statement “Because of my high-risk job, I have taken extra precautions at home to protect my family from contracting the coronavirus.” About 62.5% agreed with the statement “Having this antibody testing will help ease my anxiety about going to work and performing work-related duties.” About 60.2% agreed with the statement “Having this antibody testing will be beneficial to helping me perform work-related duties.”

TABLE 4 - Attitudes and Views About the Impact of COVID-19 on First Responder's Work and Personal Life (All First Responders [Fire/Police])
Definitely Agree (%) Somewhat Agree (%) Neither Agree nor Disagree (%) Somewhat Disagree (%) Definitely Disagree (%)
1. I think I have already contracted the coronavirus. 3.8 (4.3/3.4) 16.7 (16.5/16.9) 33.2 (35.4/31.4) 14.2 (15.4/13.2) 32.1 (28.4/35.1)
2. I am worried I am a carrier of the coronavirus without knowing it. 2.4 (2.5/2.2) 13.0 (13.4/12.8) 32.8 (35.1/30.9) 14.8 (15.9/13.9) 37.0 (33.1/40.2)
3. I am worried I will become a carrier of the coronavirus without knowing it. 6.2 (7.0/5.6) 22.5 (23.4/21.7) 31.1 (31.8/30.6) 12.7 (14.0/11.6) 27.5 (23.8/30.5)
4. I am worried about contracting the coronavirus and /or developing COVID-19. 7.8 (8.6/7.1) 22.4 (23.9/21.3) 29.1 (30.0/28.4) 15.4 (15.7/15.1) 25.3 (21.8/28.1)
5. I have adequate personal protective equipment to protect me from contracting the coronavirus while performing work-related duties. 44.1 (54.6/35.7) 30.4 (26.3/33.7) 13.5 (11.8/14.9) 6.0 (3.4/8.1) 6.0 (3.9/7.6)
6. Because of my high-risk job, I have taken extra precautions at home to protect my family from contracting the coronavirus. 49.3 (56.7/43.3) 31.1 (25.7/35.3) 13.5 (12.1/14.7) 2.6 (1.9/3.2) 3.5 (3.6/3.5)
7. Having this antibody testing will help ease my anxiety about going to work and performing work-related duties. 33.6 (31.7/35.1) 28.9 (27.2/30.3) 28.7 (31.7/26.2) 3.1 (2.9/3.2) 5.7 (6.5/5.2)
8. Having this antibody testing will be beneficial to helping me perform work-related duties. 33.0 (32.5/33.3) 27.6 (25.7/29.1) 31.6 (33.7/29.9) 2.4 (2.8/2.1) 5.4 (5.3/5.6)
COVID-19, coronavirus disease.

When comparing those who tested positive for IgG and those who tested negative for IgG, significantly more individuals who tested IgG positive believed they had already contracted the coronavirus, compared to those who tested negative for IgG (33.3% vs 19.9%, P = 0.038) (Table 5). No significant differences were found between antibody statuses for any of the other statements. There was insufficient data to perform any subgroup analysis between fire and police for those who tested positive for SARS-CoV-2 IgG.

TABLE 5 - Differences in Attitudes and Views About the Impact of COVID-19 on First Responder's Among Those With and Without SARS-CoV-2 IgG Antibodies
First Responders Who Definitely or Somewhat Agree With Each Statement
IgG Positive (%) IgG Negative (%) P-Value
I think I have already contracted the coronavirus. 33.3 19.9 0.038
I am worried I am a carrier of the coronavirus without knowing it. 20.5 15.5 0.387
I am worried I will become a carrier of the coronavirus without knowing it. 30.8 28.7 0.773
I am worried about contracting the coronavirus and /or developing COVID-19. 39.5 30.5 0.233
I have adequate personal protective equipment to protect me from contracting the coronavirus while performing work-related duties. 71.1 74.4 0.609
Because of my high-risk job, I have taken extra precautions at home to protect my family from contracting the coronavirus. 76.3 79.8 0.597
Having this antibody testing will help ease my anxiety about going to work and performing work-related duties. 53.8 63.1 0.235
Having this antibody testing will be beneficial to helping me perform work-related duties. 59.0 60.4 0.858
COVID-19, coronavirus disease.

DISCUSSION

The COVID-19 pandemic has had an enormous impact on the general public, but especially for frontline workers, including first responders. First responders, including firefighters, EMS personnel, and police officers, are at high risk of being exposed to SARS-CoV-2 and COVID-19 as a result of their daily interactions with the public and medical emergencies. The vague respiratory symptoms and the potential of asymptomatic carriers however, make it difficult to manage the spread of the virus. Although safety protocols have been implemented, there is still heightened anxiety among first responders. The patterns of COVID-19 exposure and immunity among first responders are currently unknown and is critical in ensuring the safety of our first responders.

The results of this study show that 1.5% of first responders in the state of Arizona have SARS-CoV-2 IgG antibodies, indicating a prior infection with the virus that causes COVID-19. During this time, positive rates from polymerase chain reaction (PCR) testing in Arizona were between 6% and 7%, and rates from serology testing in Arizona were approximately 3%. Case rates among Arizona and Maricopa at the end of the testing period were 223 per 100,000 and 204 per 100,000, respectively.

The low rates of prior infection among first responders are likely a result of the safety protocols and procedures that were implemented among fire and police stations across the state of Arizona. COVID-19 has affected the fire and police service in every facet of daily operations. In early March 2020, the fire and police services implemented changes to lesson exposures for firefighters, EMS personnel, police officers, and administrative staff. Dispatch centers started screening 911 callers for flu-like symptoms and tagging calls with “C19” if symptoms were present. These messages are then sent in the initial dispatch to the responding unit. This allows first responders to dress in the proper PPE before entering a scene. Upon responding to the scene, first responders place a surgical mask on the patient and bring the patient outside (if possible) to minimize exposures.

A majority of the first responders in this study reported having adequate access to appropriate PPE. Fire departments and EMS responding to possible COVID-19 cases must wear N95 respirators and gloves. Gowns and eye protection are also recommended. After possible COVID calls, all PPE is discarded or sanitized and decontaminated. Although N95 respirators have been in short supply, decontamination procedures are available. All vehicles and equipment are also frequently sanitized and decontaminated. Police officers have also been given masks/face coverings and have access to N95 respirators when required.

First responders who become ill with possible COVID-19 are sent home and receive testing with the nasopharyngeal or oropharyngeal swabs. Members are not allowed to return to work until they test negative for the active infection. Fire and EMS departments have also implemented a tracking system to log COVID-19 calls. Many departments have also implemented policies for its members upon returning from travels in another country, and some have mandated their members self-quarantine for 2 weeks before returning to work.

First responder non-emergency community interactions, events, and programs (including school and community events, community training classes, ride-alongs, and station visits) have also been limited. Some cities have completely suspended these events and have not yet resumed them.

Although these numbers are low, it should be noted that these antibody testing was done while the number of cases in Arizona were low and while Arizona was under a stay-at-home order, which went into effect March 31, 2020. At the start of this program, there were approximately 6000 confirmed cases across Arizona. By the end of the testing, there were approximately 15,000 confirmed cases. This study also tested only IgG antibodies, which are formed 7 to 10 days following infection. At the time this study was initiated, few rapid antibody tests for IgM were available, and none were diagnostic. Any individual who tested positive for IgM would have required a diagnostic nasopharyngeal or oropharyngeal swab, and state testing for COVID-19 was limited to those who meet Center for Disease Control and Prevention (CDC) guidelines, which excluded routine testing of asymptomatic individuals. Furthermore, this study aimed to evaluate the prevalence and exposure patterns of SARS-CoV-2 since the start of this pandemic, which required IgG testing. With the recent re-opening of the state and the relaxing of the stay-at-home orders, the number of COVID-19 cases in Arizona has increased, and the numbers are expected to rise.

Despite demonstrating low rates of prior infection among first responders in this study, there are limitations and factors which limit generalizability. Arizona as a state, has had relatively low rates of infection, compared to some other states such as New York. This allowed fire and police departments time to create and implement safety precautions and protocols. Hospitals and healthcare facilities in Arizona had adequate bed capacity and resources to manage the volume of COVID-19 patients. Furthermore, a majority of the first responders indicated they had adequate access to PPE. Other cities which had much higher counts of COVID-19 did not have adequate access to PPE, which places their first responders at higher risk of contracting the virus. Lastly, this virus is still spreading and currently, case counts in Arizona are increasing. With the recent rise in cases with the re-opening of the states, more first responders will likely contract the coronavirus and develop COVID-19. Continuous antibody testing, widespread testing with the diagnostic nasopharyngeal swabs, and contact tracing as the pandemic progresses is required to truly understand the prevalence, exposure patterns, and impact of coronavirus exposure among first responders.

CONCLUSIONS

Rates of SARS-CoV-2 IgG antibodies are low among first responders in Arizona. This is likely attributable to the strict safety protocols and procedures that were implemented among fire and police stations, including increased use of PPE, increased sanitation and disinfecting, decreased non-emergent public interactions, PCR testing for active infection among those with symptoms, and quarantining following travel or respiratory symptoms while waiting for PCR test results. The continued use of PPE and vigilance following safety protocols and precautions will remain critical as the pandemic continues and the number of COVID-19 cases rises with the re-opening of the state.

Acknowledgments

The authors would like to thank United Phoenix Firefighters Association, Phoenix Law Enforcement Association, and the Cities of Phoenix, Tempe, Glendale, Surprise, Peoria, and Chandler. Most importantly, the authors would like to recognize and thank the first responders across the state of Arizona who participated in this study, while working the front-lines and serving the communities during this pandemic.

REFERENCES

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2. CDC Centers for Disease Control and Prevention. Coronavirus Disease 2019 (COVID-19): Cases in U.S.; 2020. Available at: https://www.cdc.gov/coronavirus/2019-ncov/cases-updates/cases-in-us.html. Accessed April 13, 2020.
3. Arizona Department of Health Services. COVID-19: Arizona's Emergency Response to the COVID-19 Outbreak; 2020. Available at: https://www.azdhs.gov/preparedness/epidemiology-disease-control/infectious-disease-epidemiology/index.php#novel-coronavirus-home. Accessed May 22, 2020.
4. CDC Centers for Disease Control and Prevention. Coronavirus Disease 2019 (COVID-19): Symptoms of Coronavirus; 2020. Available at: https://www.cdc.gov/coronavirus/2019-ncov/symptoms-testing/symptoms.html. Accessed April 10, 2020.
5. Cohen Veterans Network. New survey shows COVID-19 is having a significant impact on the mental health of America's frontline healthcare providers and first responders. Available at: https://www.prnewswire.com/news-releases/new-survey-shows-covid-19-is-having-a-significant-impact-on-the-mental-health-of-americas-frontline-healthcare-providers-and-first-responders-301074693.html. Accessed June 11, 2020.
6. RayBiotech. Coronavirus (COVID-19) IgM/IgG Rapid Test; 2020. Available at: https://www.raybiotech.com/covid-19-igm-igg-rapid-test-kit/. Accessed April 14, 2020.
Keywords:

antibodies; antibody testing; coronavirus; COVID-19; first responders; pandemic; SARS-CoV-2

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