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COVID-19 in Health Care Personnel

Significance of Health Care Role, Contact History, and Symptoms in Those Who Test Positive for SARS-CoV-2 Infection

      Abstract

      Objective

      To identify significant factors that help predict whether health care personnel (HCP) will test positive for severe acute respiratory coronavirus 2 (SARS-CoV-2).

      Patients and Methods

      We conducted a prospective cohort study among 7015 symptomatic HCP from March 25, 2020, through November 11, 2020. We analyzed the associations between health care role, contact history, symptoms, and a positive nasopharyngeal swab SARS-CoV-2 polymerase chain reaction test results, using univariate and multivariable modelling.

      Results

      Of the symptomatic HCP, 624 (8.9%) were positive over the study period. On multivariable analysis, having a health care role other than physician or advanced practice provider, contact with family or community member with known or suspected coronavirus disease 2019 (COVID-19), and seven individual symptoms (cough, anosmia, ageusia, fever, myalgia, chills, and headache) were significantly associated with higher adjusted odds ratios for testing positive for SARS-CoV-2. For each increase in symptom number, the odds of testing positive nearly doubled (odds ratio, 1.93; 95% CI, 1.82 to 2.07, P<.001).

      Conclusion

      Symptomatic HCP have higher adjusted odds of testing positive for SARS-CoV-2 based on three distinct factors: (1) nonphysician/advanced practice provider role, (2) contact with a family or community member with suspected or known COVID-19, and (3) specific symptoms and symptom number. Differences among health care roles, which persisted after controlling for contacts, may reflect the influence of social determinants. Contacts with COVID-19–positive patients and/or HCP were not associated with higher odds of testing positive, supporting current infection control efforts. Targeted symptom and contact questionnaires may streamline symptomatic HCP testing for COVID-19.

      Abbreviations and Acronyms:

      APP (advanced practice provider), ASTM (American Society for Testing and Materials (formerly)), CDC (Centers for Disease Control and Prevention), COVID-19 (coronavirus disease 2019), HCP (health care personnel), IRB (institutional review board), MA (medical assistant), NP (nasopharyngeal), OR (odds ratio), PCR (polymerase chain reaction), PPE (personal protective equipment), RT-PCR (real-time polymerase chain reaction), SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2)
      Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of coronavirus disease 2019 (COVID-19), continues to surge globally. Health care personnel (HCP) are vital to the response, necessitating a healthy workforce. Sources of transmission to HCP can include patients, health care visitors, other HCP, and close contacts such as family and community members. Within each contact type, the risk of transmission may vary based on use of personal protective equipment, hand hygiene, physical distancing, aerosol exposure, ventilation management, and frequency and duration of contact. Severe acute respiratory syndrome coronavirus 2 acquisition among HCP may also be driven by social determinants, especially outside of the health care environment.
      Monitoring for COVID-19 symptoms in HCP is important for early diagnosis and isolation, preventing spread in the health care system and among vulnerable populations. However, signs and symptoms can be subtle and mimic other common respiratory viral illnesses.
      • Wang Z.
      • Deng H.
      • Ou C.
      • et al.
      Clinical symptoms, comorbidities and complications in severe and non-severe patients with COVID-19: a systematic review and meta-analysis without cases duplication.
      Therefore, health care systems have struggled to balance screening HCP for possible COVID-19, promoting illness absenteeism, and ensuring appropriate staffing for patient care, especially during surges. Data on prevalence of, and risk factors for, COVID-19 in HCP exist
      • Gomez-Ochoa S.A.
      • Franco O.H.
      • Rojas L.Z.
      • et al.
      COVID-19 in healthcare workers: a living systematic review and meta-analysis of prevalence, risk factors, clinical characteristics, and outcomes.
      • Mani N.S.
      • Budak J.Z.
      • Lan K.F.
      • et al.
      Prevalence of COVID-19 infection and outcomes among symptomatic healthcare workers in Seattle, Washington.
      • Calo F.
      • Russo A.
      • Camaioni C.
      • De Pascalis S.
      • Coppola N.
      Burden, risk assessment, surveillance and management of SARS-CoV-2 infection in health workers: a scoping review.
      • Wu M.
      • Xie C.
      • Wu R.
      • et al.
      Epidemiological and clinical characteristics of severe acute respiratory coronavirus virus 2 (SARS-CoV-2) infection among healthcare workers in Hubei Province, China.
      • Koh W.C.
      • Naing L.
      • Chaw L.
      • et al.
      What do we know about SARS-CoV-2 transmission? a systematic review and meta-analysis of the secondary attack rate and associated risk factors.
      ; however, there is little information on the relationship between (1) health care role, (2) contact history, and (3) symptoms with subsequent SARS-CoV-2 polymerase chain reaction (PCR) testing results for symptomatic HCP.
      • Lan F.Y.
      • Filler R.
      • Mathew S.
      • et al.
      COVID-19 symptoms predictive of healthcare workers' SARS-CoV-2 PCR results.
      • Van Loon N.
      • Verbrugghe M.
      • Cartuyvels R.
      • Ramaekers D.
      Diagnosis of COVID-19 based on symptomatic analysis of hospital healthcare workers in Belgium: observational study in a large Belgian tertiary care center during early COVID-19 outbreak.
      • Buonafine C.P.
      • Paiatto B.N.M.
      • Leal F.B.
      • et al.
      High prevalence of SARS-CoV-2 infection among symptomatic healthcare workers in a large university tertiary hospital in Sao Paulo, Brazil.
      • Tostmann A.
      • Bradley J.
      • Bousema T.
      • et al.
      Strong associations and moderate predictive value of early symptoms for SARS-CoV-2 test positivity among healthcare workers, the Netherlands, March 2020.
      • Ganz-Lord F.A.
      • Segal K.R.
      • Rinke M.L.
      COVID-19 symptoms, duration, and prevalence among healthcare workers in the New York metropolitan area.
      We performed a prospective cohort study of symptomatic HCP at a large, tertiary care center to determine these associations.

      Methods

      Study Design and Data Collection

      We constructed a prospective cohort of symptomatic HCP working in a large, integrated health system serving more than 600,000 patients annually in the Upper Midwest. The system employed approximately 13,000 personnel at four hospitals and more than 80 outpatient sites. Data collection took place between March 25, 2020, and November 11, 2020.
      Starting March 25, 2020, Employee Health Services offered SARS-CoV-2 nasopharyngeal swab PCR testing for any symptomatic HCP at no cost to employees. All HCP were eligible and encouraged to use the testing site if they had symptoms compatible with COVID-19. Employee Health Services–trained staff prospectively collected HCP self-reported symptoms, sociodemographics, contact history, and duration of contact using a standardized telephone survey performed at the time of testing. All data collection was performed before test results to prevent recall bias. Queried symptoms included cough, chills, shortness of breath, chest tightness, fever, anosmia (loss of smell), ageusia (loss of taste), pharyngitis (sore throat), rhinorrhea (runny nose), nasal congestion, headache, fatigue, myalgia (muscle pain), nausea and/or vomiting, and diarrhea. Ten questions focused on potential contacts with SARS-CoV-2–infected individuals including patients, health care visitors, other HCP, and family or community members. Specifically, Employee Health Services staff inquired about whether HCP had any known contact with a patient, another HCP member, or family/community member with (1) known COVID-19, (2) suspected or presumptive COVID-19 (ie, based on symptoms or clinical characteristics), or (3) a concurrent respiratory illness within the last 14 days. Contact was defined as being within 6 feet of this person who did not wear a surgical mask for any portion of the contact time. Additionally, contact with a nonmasked health care visitor was ascertained. If there was reported contact, the estimated duration was recorded (<10 minutes, 10-20 minutes, >20 minutes, or indeterminate). Additional variables included date of testing, test result, work location (inpatient, ambulatory setting, home, affiliated health care facility), and health care role. Roles were grouped as follows: (1) physician or advanced practice provider (APP); (2) nurse, medical assistant (MA), or therapist; (3) other HCP involved in direct patient care (eg, radiology technician); (4) other HCP not involved in direct patient care (eg, custodian); (5) medical/nursing trainee (eg, medical student, resident, nursing student); and (6) pharmacy. Retesting a symptomatic HCP was restricted to the following criteria: (1) those who had a previous negative test, but the symptoms had resolved completely and they now had new symptoms; (2) those who had a previous negative test whose previous symptoms had not completely resolved but have developed new symptoms or significant worsening of previous symptoms; and (3) for situations outside of the previous two, the case was discussed with employee health nurse or APP. Health care personnel included in the dataset who had more than one test over the study period were considered independent observations for each lab test-data pair. Health care personnel who tested positive were not included if they were tested again at a later period to avoid counting a single infection twice.

      Institutional COVID-19 Standards of Practice

      Throughout the study period, the health care system’s infection control measures for confirmed COVID-19 included negative pressure room isolation and donning fit-tested N-95 respirators, gowns, gloves, and face shields for room entries.
      • Lepak A.J.
      • Shirley D.K.
      • Buys A.
      • Stevens L.
      • Safdar N.
      Implementation of infection control measures to prevent healthcare-associated transmission of severe acute respiratory coronavirus virus 2 (SARS-CoV-2).
      For all other HCP-patient interactions, HCP wore surgical masks made to ASTM standards and face shield. Surgical masks were reused for up to 3 days and N-95 for 7 days. Health care personnel received in-person personal protective equipment (PPE) training and emails regarding best practices to reduce transmission. All hospital visitors were instructed to wear a mask, although some did not comply completely with this policy early in the pandemic. Universal masking of staff, patients, and visitors was instituted on April 24, 2020, and remained in effect throughout the remaining period. Hospital visitation became increasingly restricted over the study period; for a significant portion no visitors were allowed except under special circumstances such as end of life. This study was considered quality improvement and was exempt from institutional review board evaluation.

      SARS-CoV-2 Testing Methods

      Health care personnel reporting symptoms compatible with COVID-19 were referred to a single testing site. Nasopharyngeal swab samples were collected using standardized technique by trained health care staff. Samples underwent real-time PCR (RT-PCR) testing by a validated in-house RT-PCR assay using the Centers for Disease Control and Prevention (CDC)–published primer-probe design or Hologic Panther Fusion SARS-CoV-2 Assay (Hologic, Inc). All assays were performed and interpretations made according to manufacturer’s instructions for use under the emergency use authorization.

      Statistical Analysis

      We used χ2 and Fisher exact tests to summarize demographic information, HCP contact history, and symptoms. We conducted univariate logistic regression to identify factors associated with a positive SARS-CoV-2 PCR test. Factors with P values less than or equal to .05 in univariate analysis were entered into a multivariable model. We used a post-estimation odds plot with confidence intervals to graph the results of the multivariable model and robust standard error estimates.
      • Jann B.
      Plotting regression coefficients and other estimates in Stata: University of Bern Social Sciences Working Papers No. 1; Bern.
      We also constructed an unweighted symptom score (0-7) using the seven symptoms that remained positively correlated with a positive test result in our multivariable model. We created a second multivariable model to assess the association between testing positive for SARS-CoV-2 and the symptom score, controlling for factors that were statistically significant in the univariate model but excluding individual symptom variables to avoid collinearity. All analyses were conducted using STATA 16 (StataCorp, 2019. Stata Statistical Software: Release 16).

      Results

      A total of 7015 SARS-CoV-2 RT-PCR tests were performed on symptomatic HCP with 624 (8.9%) testing positive over the study period. Trends in the number of HCP tested and positivity rate paralleled regional surges, with very low prevalence and relatively lower testing volume early, a modest surge in June and July, and a substantial surge in September through November (Figure 1).
      Figure thumbnail gr1
      Figure 1Monthly numbers of health care personnel (HCP) tested for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (bars) and proportion who tested positive (dashed line) over the study period. ∗March was combined with April as testing began March 25, 2020. November encompasses results from only the first 11 days.
      Testing, demographic, contact, and symptom data stratified by HCP role are presented in Table 1. Those in the nursing, MA, or therapist group comprised the largest subset of HCP tested (n=2968, 42.3%), followed by other HCP not involved in direct patient care, physician/APP, other HCP involved in direct patient care, medical/nursing trainees, and pharmacy. The proportion of symptomatic HCP testing positive differed across health care roles. Those serving in pharmacy roles had the highest proportion of positive tests (12.6%), followed by those not involved in direct patient care (11.2%). Physicians/APPs had the smallest proportion of positive tests (4.0%).
      Table 1Cohort Characteristics Stratified by HCP Role
      APP, advanced practice provider; COVID-19, coronavirus disease 2019; HCP, health care personnel; MA, medical assistant; SARS-CoV-2, severe acute respiratory syndrome coronavirus 2.
      ,
      Values shown are n (%).
      CharacteristicTotal cohortNurse/MA/therapistOther HCP not involved in direct patient carePhysician/APPOther HCP involved in direct patient careMedial/ nursing traineePharmacy
      Symptomatic HCP701529681739910862361175
       Test positive for SARS-CoV-2624 (8.9)252 (8.5)195 (11.2)36 (4.0)86 (10.0)33 (9.1)22 (12.6)
      Work location
       Inpatient3120 (44.5)1708 (57.6)364 (20.9)367 (40.3)349 (40.5)261 (72.3)71 (40.6)
       Ambulatory3196 (45.6)1129 (38.0)981 (56.4)447 (49.1)458 (53.1)89 (24.7)92 (53.1)
       Home511 (7.3)58 (2.0)349 (20.1)36 (4.0)49 (5.7)8 (2.2)11 (6.3)
       Affiliated health care facility188 (2.7)73 (2.5)45 (2.6)60 (6.6)6 (0.7)3 (0.8)1 (0.6)
      Reported contacts with
       Patient with known COVID-19950 (13.5)506 (17.1)57 (3.3)141 (15.5)154 (17.9)86 (23.8)6 (3.4)
       Patient with suspected COVID-19746 (10.6)360 (12.1)64 (3.7)107 (11.8)149 (17.3)59 (16.3)7 (4.0)
       Patient with respiratory illness1064 (15.2)567 (19.1)69 (4.0)164 (18.0)163 (18.9)91 (25.2)10 (5.7)
       Nonmasked health care visitor879 (12.5)386 (13.0)134 (7.7)140 (15.4)137 (15.9)71 (19.7)11 (6.3)
       HCP with known COVID-19712 (10.2)350 (11.8)123 (7.1)65 (7.1)113 (13.1)35 (9.7)26 (14.9)
       HCP with suspected COVID-19284 (4.1)136 (4.6)57 (3.3)18 (2.0)51 (5.9)14 (3.9)8 (4.6)
       HCP with respiratory illness228 (3.3)105 (3.5)50 (2.9)29 (3.2)29 (3.4)12 (3.3)3 (1.7)
       Family/community member with known COVID-19847 (12.1)367 (12.4)256 (14.7)61 (6.7)110 (12.8)33 (9.1)20 (11.4)
       Family/community member with suspected COVID-19624 (8.9)232 (7.8)165 (9.5)87 (9.6)88 (10.2)30 (8.3)21 (12.0)
       Family/community member with respiratory illness747 (10.7)307 (10.3)175 (10.1)141 (15.5)71 (8.2)41 (11.4)12 (6.9)
      Contact duration
       Not recalled or applicable3531 (50.3)1346 (45.4)1082 (62.2)444 (48.8)404 (46.9)150 (41.6)105 (60.0)
      <10 min704 (10.0)309 (10.4)137 (7.9)93 (10.2)108 (12.5)47 (13.0)10 (5.7)
      10-20 min345 (4.9)147 (5.0)47 (2.7)65 (7.1)44 (5.1)34 (9.4)8 (4.6)
      >20 min2435 (34.7)1166 (39.3)473 (27.2)308 (33.9)306 (35.5)130 (36.0)52 (29.7)
      Symptoms
       Cough2926 (41.7)1189 (40.1)802 (46.1)351 (38.6)373 (43.3)132 (36.6)79 (45.1)
       Chills1445 (20.6)603 (20.3)402 (23.1)149 (16.4)189 (21.9)67 (18.6)35 (20.0)
       Shortness of breath864 (12.3)357 (12.0)280 (16.1)60 (6.6)120 (13.9)22 (6.1)25 (14.3)
       Chest tightness1218 (17.4)511 (17.2)349 (20.1)92 (10.1)193 (22.4)42 (11.6)31 (17.7)
       Fever787 (11.2)344 (11.6)227 (13.1)74 (8.1)90 (10.4)30 (8.3)22 (12.6)
       Anosmia431 (6.1)192 (6.5)113 (6.5)45 (5.0)52 (6.0)20 (5.5)9 (5.1)
       Ageusia399 (5.7)174 (5.9)113 (6.5)41 (4.5)47 (5.5)15 (4.2)9 (5.1)
       Pharyngitis4361 (62.2)1846 (62.2)1044 (60.0)583 (64.1)545 (63.2)245 (67.9)98 (56.0)
       Rhinorrhea3344 (47.7)1403 (47.3)819 (47.1)474 (52.1)411 (47.7)160 (44.3)77 (44.0)
       Nasal congestion4115 (58.7)1775 (59.8)988 (56.8)537 (59.0)505 (58.6)208 (57.6)102 (58.3)
       Headache4265 (60.8)1885 (63.5)1076 (61.9)465 (51.1)545 (63.2)197 (54.6)97 (55.4)
       Fatigue2026 (28.9)876 (29.5)560 (32.2)198 (21.8)237 (27.5)107 (29.6)48 (27.4)
       Myalgia1910 (27.2)791 (26.7)520 (29.9)221 (24.3)243 (28.2)90 (24.9)45 (25.7)
       Nausea/vomiting1172 (16.7)539 (18.2)293 (16.9)102 (11.2)152 (17.6)52 (14.4)34 (19.4)
       Diarrhea897 (12.8)381 (12.8)266 (15.3)93 (10.2)103 (12.0)34 (9.4)20 (11.4)
      a APP, advanced practice provider; COVID-19, coronavirus disease 2019; HCP, health care personnel; MA, medical assistant; SARS-CoV-2, severe acute respiratory syndrome coronavirus 2.
      b Values shown are n (%).
      The majority of HCP worked in inpatient (n=3120, 44.5%) or ambulatory settings (n=3296, 47.0%). HCP not involved in direct patient care frequently worked from home. Four thousand fourteen HCP (57.2%) reported 7080 contacts. Contact with an individual known to have COVID-19 was reported 2507 times, whereas contact with an individual suspected to have COVID-19 was reported 1654 times. Patient contacts were highest among those expected to have more patient interactions (eg, physician/APP and nurse/MA/therapist groups). Contact with another HCP with suspected or known COVID-19 was similar across health care roles. Physicians/APPs had fewer contacts with family members with known COVID-19 compared with other health care roles. When contact time could be estimated, a majority (n=2435, 69.9%) recalled spending more than 20 minutes within 6 feet of the index person. The proportion reporting this contact duration was similar across health care roles. Finally, the most common symptoms, in descending order, included pharyngitis, headache, and nasal congestion. All were reported in more than 50% of symptomatic HCP. Rhinorrhea, cough, fatigue, myalgia, chills, chest tightness, nausea/vomiting, diarrhea, shortness of breath, and fever were reported in 10% to 50% of cases; whereas loss of smell or loss of taste as a symptom were rare (<10%) (Figure 1). Symptoms were reported with similar frequency across HCP roles.

      Univariate Analysis

      On univariate analysis, all health care roles had significantly higher odds of testing positive compared with the referent physician/APP group (Table 2). Working from home and contact with a family or community member with known or suspected COVID-19 were associated with higher odds of testing positive for SARS-CoV-2. In the health care environment, contact with a patient who had a respiratory illness or nonmasked visitor was protective. Contact times longer than 20 minutes were associated with increased odds of positive test results. Nine symptoms (cough, chills, fever, anosmia, ageusia, nasal congestion, headache, fatigue, and myalgia) were associated with increased odds of testing positive for SARS-CoV-2, whereas two (pharyngitis and nausea/vomiting) were associated with decreased odds. The proportion of HCP who tested positive versus negative for SARS-CoV-2 for each symptom is shown in Figure 2.
      Table 2Odds Ratios of Testing Positive for SARS-CoV-2 PCR Test by Univariate Analysis of HCP Role, Contact History, and Symptoms
      APP, advanced practice provider; COVID-19, coronavirus disease 2019; HCP, health care personnel; MA, medical assistant; PCR, polymerase chain reaction; SARS-CoV-2, severe acute respiratory syndrome coronavirus 2.
      Tested positive (N=624) n (%)Tested negative (N=6391) n (%)Unadjusted odds ratio (95% CI)P
      Healthcare role
       Physician/APP36 (5.8)874 (13.7)Ref
       Nurse/MA/therapist252 (40.4)2716 (42.5)2.25 (1.58-3.22)<.001
      Bold values indicate statistically significant values.
       Other HCP not involved in direct patient care195 (31.3)1544 (24.2)3.07 (2.13-4.42)<.001
       Other HCP involved in direct patient care86 (13.8)776 (12.1)2.69 (1.80-4.02)<.001
       Medical/nursing trainee33 (5.3)328 (5.1)2.44 (1.50-3.98)<.001
       Pharmacy22 (3.5)153 (2.4)3.49 (2.00-6.10)<.001
      Work location
       Inpatient278 (44.6)2842 (44.5)Ref
       Ambulatory261 (41.8)2935 (45.9)0.90 (0.76-1.08).290
       Home67 (10.7)444 (6.9)1.54 (1.16-2.05).003
       Affiliated health facility18 (2.9)170 (2.7)1.08 (0.66-1.79).757
      Reported contacts with
       Patient with known COVID-1997 (15.5)853 (13.3)1.19 (0.95-1.50).13
       Patient with suspected COVID-1961 (9.8)685 (10.7)0.90 (0.68-1.19).47
       Patient with respiratory illness77 (12.3)987 (15.4)0.77 (0.60-0.99).04
       Nonmasked health care visitor58 (9.3)821 (12.9)0.69 (0.53-0.92).01
       HCP with known COVID-1969 (11.1)643 (10.1)1.11 (0.85-1.44).43
       HCP with suspected COVID-1924 (3.9)260 (4.1)0.94 (0.62-1.44).92
       HCP with respiratory illness16 (2.6)212 (3.3)0.77 (0.46-1.28).35
       Family/community member with known COVID-19212 (34.0)635 (9.9)4.66 (3.88-5.61)<.001
       Family/community member with suspected COVID-19106 (17.0)517 (8.1)2.32 (1.85-2.92)<.001
       Family/community member with respiratory illness72 (11.5)675 (10.6)1.10 (0.85-1.43).45
      Contact duration
       Not recalled or applicable245 (39.3)3286 (51.4)Ref
      <10 min37 (5.9)667 (10.4)0.74 (0.52-1.06).103
      10-20 min19 (3.0)326 (5.1)0.78 (0.48-1.26).315
      >20 min323 (51.8)2112 (33.0)2.05 (1.72-2.44)<.001
      Symptoms
       Cough417 (66.8)2509 (39.3)3.10 (2.6-3.7)<.001
       Chills234 (37.5)1211 (18.9)2.57 (2.2-3.1)<.001
       Shortness of breath88 (14.1)776 (12.1)1.19 (0.94-1.51).16
       Chest tightness117 (18.8)1101 (17.2)1.11 (0.90-1.37).34
       Fever155 (24.8)632 (9.9)3.01 (2.47-3.68)<.001
       Anosmia127 (20.3)304 (4.8)5.12 (4.08-6.42)<.001
       Ageusia123 (19.7)276 (4.3)5.43 (4.32-6.85)<.001
       Pharyngitis357 (57.2)4004 (62.7)0.80 (0.67-0.94).007
       Rhinorrhea310 (49.7)3034 (47.5)1.09 (0.93-1.29).29
       Nasal congestion417 (66.8)3698 (57.9)1.47 (1.23-1.75)<.001
       Headache453 (72.6)3812 (59.7)1.79 (1.49-2.15)<.001
       Fatigue246 (39.4)1780 (27.9)1.68 (1.42-1.99)<.001
       Myalgia286 (45.8)1624 (25.4)2.48 (2.10-2.94)<.001
       Nausea/vomiting77 (12.3)1095 (17.1)0.68 (0.53-0.87).002
       Diarrhea88 (14.1)809 (12.7)1.13 (0.89-1.44).30
      a APP, advanced practice provider; COVID-19, coronavirus disease 2019; HCP, health care personnel; MA, medical assistant; PCR, polymerase chain reaction; SARS-CoV-2, severe acute respiratory syndrome coronavirus 2.
      b Bold values indicate statistically significant values.
      Figure thumbnail gr2
      Figure 2Radar plot showing the proportion of health care personnel with each symptom stratified by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) polymerase chain reaction test result.

      Multivariable Analysis

      In multivariable analysis (Table 3), health care role remained a strong predictor of testing results, with all health care roles having significantly higher odds of testing positive for SARS-CoV-2 compared with the physician/APP group. Pharmacy had the highest odds (odds ratio [OR], 3.06; 95% CI, 1.69 to 5.52), followed by medical/nursing trainees (OR, 2.76; 95% CI, 1.63 to 4.67), other HCP not involved in direct patient care (OR, 2.21; 95% CI, 1.49 to 3.29), other HCP involved in direct patient care (OR, 2.18; 95% CI, 1.41 to 3.35), and nurse/MA/therapist group (OR, 1.79; 95% CI, 1.23 to 2.60). In the adjusted model, there was no significant difference in the odds of a positive test across work locations or contact duration, nor was there a significant difference based on contact with a patient who had a respiratory illness or contact with a nonmasked visitor. However, contact with a family or community member with known or suspected COVID-19 remained highly associated with a positive SARS-CoV-2 test (OR, 4.03; 95% CI, 3.13 to 5.18; and OR, 1.65; 95% CI, 1.24 to 2.19; respectively). Seven symptoms remained statistically significant in the multivariable model. These included, in descending order, cough, anosmia, ageusia, fever, myalgia, chills, and headache. The two symptoms that were negatively correlated were pharyngitis and nausea/vomiting.
      Table 3Odds Ratios of Testing Positive for SARS-CoV-2 PCR Test by Multivariable Analysis of HCP Role, Contact History, and Symptoms
      APP, advanced practice provider; COVID-19, coronavirus disease 2019; HCP, health care personnel; MA, medical assistant; PCR, polymerase chain reaction; SARS-CoV-2, severe acute respiratory syndrome coronavirus 2.
      Adjusted odds ratio95% CIP
      Healthcare role
       Physician/APPRef
       Nurse/MA/Therapist1.791.23-2.60.002
      Bold values indicate statistically significant values.
       Other HCP not involved in direct patient care2.211.49-3.29<.001
       Other HCP involved in direct patient care2.181.41-3.35<.001
       Medical or nursing trainee2.761.63-4.67<.001
       Pharmacy3.061.69-5.52<.001
      Work location
       InpatientRef
       Ambulatory0.840.69-1.04.108
       Home0.800.56-1.15.231
       Affiliated health facility0.860.47-1.57.625
      Reported contacts with
       Patient with respiratory illness0.790.58-1.06.120
       Nonmasked health care visitor0.750.53-1.04.084
       Family/community member with known COVID-194.033.13-5.18<.001
       Family/community member with suspected COVID-191.651.24-2.19.001
      Contact duration
       Not recalled or applicableRef
      <10 min0.790.54-1.17.236
      10-20 min0.620.37-1.05.074
      >20 min1.250.97-1.59.080
      Symptoms
       Cough2.882.36-3.50<.001
       Chills1.711.37-2.14<.001
       Fever2.341.82-3.00<.001
       Anosmia2.862.10-3.89<.001
       Ageusia2.772.02-3.78<.001
       Sore throat0.600.50-0.73<.001
       Nasal congestion1.160.94-1.42.161
       Headache1.261.02-1.55.030
       Fatigue0.930.75-1.15.480
       Myalgia1.821.48-2.24<.001
       Nausea/vomiting0.520.39-0.70<.001
      a APP, advanced practice provider; COVID-19, coronavirus disease 2019; HCP, health care personnel; MA, medical assistant; PCR, polymerase chain reaction; SARS-CoV-2, severe acute respiratory syndrome coronavirus 2.
      b Bold values indicate statistically significant values.
      We created a second multivariable model using the composite symptom score based on the seven symptoms that were associated with increased odds of testing positive in the main multivariable model (cough, anosmia, ageusia, fever, myalgia, chills, and headache). Among HCP with none of the seven symptoms, 3.1% (n=35) tested positive. More than 40% of HCP with five or more of the seven symptoms tested positive (Table 4). The odds of testing positive almost doubled (OR, 1.93; 95% CI, 1.82 to 2.07) for each additional symptom.
      Table 4Number of Symptoms, Positivity Rate, and Odds Ratio of Testing Positive Associated With Increasing Symptom Number by Multivariable Analysis
      COVID-19, coronavirus disease 2019; OR, odds ratio.
      Number of symptoms
      Symptoms included cough, chills, fever, anosmia, ageusia, headache, and myalgia.
      TotalTested positive n (%)Multivariable adjusted OR (95% CI) of test result by number of symptoms
      0111635 (3.1)For each additional symptom, adjusted
      Adjusted for health care role, contact with patient with respiratory illness, contact with nonmasked visitor, contact with family/community member with known COVID-19, contact with family/community member with suspected COVID-19, duration of contact, and work location.
      OR of testing positive was 1.94 (1.82-2.07), P<.001
      1239381 (3.4)
      21770152 (8.6)
      31009135 (13.4)
      4497127 (25.6)
      517872 (40.4)
      ≥65222 (42.3)
      a COVID-19, coronavirus disease 2019; OR, odds ratio.
      b Symptoms included cough, chills, fever, anosmia, ageusia, headache, and myalgia.
      c Adjusted for health care role, contact with patient with respiratory illness, contact with nonmasked visitor, contact with family/community member with known COVID-19, contact with family/community member with suspected COVID-19, duration of contact, and work location.

      Discussion

      We report relationships between (1) health care role, (2) contact history, and (3) symptoms and testing positive for SARS-CoV-2 in a large, prospective cohort of symptomatic HCP. The odds of a positive test differed by job role and were associated with family or community exposures, but not with exposures within the health care environment. There may be several explanations for this finding and it is important to acknowledge we could not definitively distinguish between SARS-CoV-2 infection acquired occupationally or from the community. A possibility we theorize, but could not test, was whether differences in sociodemographics and/or socioeconomic status played a role. For example, symptomatic physicians and APPs had significantly reduced odds of testing positive for SARS-CoV-2 compared with all other health care roles. The one exception to the trend was pharmacy. This may reflect the extremely high volume of interactions many pharmacy personnel have with persons who have an unknown infectious (ie, COVID-19) history, as well as PPE, hand hygiene, and physical distancing challenges that are unique to their specific work environment. Pharmacists may also work at multiple locations with variation in community SARS-CoV-2 transmission. However, pharmacy was the smallest group with a wide confidence interval around our point estimate. Therefore, the true odds may be aligned with our hypothesized socioeconomic trend and poorly estimated in our model.
      Numerous studies have reported an association between COVID-19 and social disadvantage.
      • Adhikari S.
      • Pantaleo N.P.
      • Feldman J.M.
      • Ogedegbe O.
      • Thorpe L.
      • Troxel A.B.
      Assessment of community-level disparities in coronavirus disease 2019 (COVID-19) infections and deaths in large US metropolitan areas.
      • Bassett M.T.
      • Chen J.T.
      • Krieger N.
      Variation in racial/ethnic disparities in COVID-19 mortality by age in the United States: a cross-sectional study.
      • Gross C.P.
      • Essien U.R.
      • Pasha S.
      • Gross J.R.
      • Wang S.Y.
      • Nunez-Smith M.
      Racial and ethnic disparities in population-level COVID-19 mortality.
      • Jay J.
      • Bor J.
      • Nsoesie E.O.
      • et al.
      Neighbourhood income and physical distancing during the COVID-19 pandemic in the United States.
      • Lundon D.J.
      • Mohamed N.
      • Lantz A.
      • Goltz H.H.
      • Kelly B.D.
      • Tewari A.K.
      Social determinants predict outcomes in data from a multi-ethnic cohort of 20,899 patients investigated for COVID-19.
      • Raifman M.A.
      • Raifman J.R.
      Disparities in the population at risk of severe illness from COVID-19 by race/ethnicity and income.
      • Mody A.
      • Pfeifauf K.
      • Geng E.H.
      Using lorenz curves to measure racial inequities in COVID-19 testing.
      • Lan F.Y.
      • Filler R.
      • Mathew S.
      • et al.
      Sociodemographic risk factors for COVID-19 infection among Massachusetts healthcare workers: a retrospective cohort study.
      The health care system can serve as a unique microcosm for understanding COVID-19 disparities. In our study population, all HCP received email reminders of best practices to remain safe in and out of the health care environment. Testing for symptomatic individuals was accessible and free regardless of specific job roles. Therefore, better education or access to testing is unlikely to explain the lower odds of a positive test among physicians/APPs compared with other HCP groups. Instead, we suspect physicians/APPs may have increased resources to more effectively reduce their risk of SARS-CoV-2 infection. For example, higher earning individuals may be more likely to live in detached, single-dwelling homes where distancing is feasible. They may be able to afford in-home care or education options for their dependents, which may reduce exposure risk. Lower earners may have additional risk due to second jobs or dependence on public services such as transportation. Additionally, social behaviors and interactions that are independent of economic factors may differ between these groups. Further studies incorporating income and other social determinants are necessary to examine the influence of these factors on differences in SARS-CoV-2 infection across health care roles.
      Our study and others suggest that SARS-CoV-2 transmission to HCP within the hospital environment is relatively rare if strict infection control practices are followed.
      • Lepak A.J.
      • Shirley D.K.
      • Buys A.
      • Stevens L.
      • Safdar N.
      Implementation of infection control measures to prevent healthcare-associated transmission of severe acute respiratory coronavirus virus 2 (SARS-CoV-2).
      ,
      • Lan F.Y.
      • Filler R.
      • Mathew S.
      • et al.
      Sociodemographic risk factors for COVID-19 infection among Massachusetts healthcare workers: a retrospective cohort study.
      • Lepak A.J.
      • Chen D.J.
      • Buys A.
      • Stevens L.
      • Safdar N.
      Utility of repeat nasopharyngeal SARS-CoV-2 RT-PCR testing and refinement of diagnostic stewardship strategies at a tertiary care academic center in a low-prevalence area of the United States.
      • Braun K.M.
      • Moreno G.K.
      • Bobholz M.
      • et al.
      Viral sequencing reveals healthcare personnel rarely become infected with SARS-CoV-2 through patient contact.
      • Sikkema R.S.
      • Pas S.D.
      • Nieuwenhuijse D.F.
      • et al.
      COVID-19 in health-care workers in three hospitals in the south of the Netherlands: a cross-sectional study.
      Neither patients nor HCP contacts were associated with higher odds of testing positive for SARS-CoV-2. However, HCP who had contact with a COVID-19–positive family or community member experienced a greater than four-fold increased odds of a positive test. Given that SARS-CoV-2 is highly contagious, and contact with a family or community member is not likely to occur under the same PPE standards as in the health care environment, one would expect these interactions to lead to transmission. In addition, the protective association on univariate analysis between contact with a patient with a respiratory illness and contact with a nonmasked visitor is logical when put into context. First, if HCP reported contact with a patient who had a respiratory illness, but not known or suspected COVID-19, it most often meant that the patient had a negative SARS-CoV-2 test result. Secondly, nonmasked visitors were primarily an event of the first few months of the pandemic when the local prevalence was very low and mask mandates were not strictly enforced. For the rest of study period, hospital visitation was more restrictive. Thus, the odds of HCP getting COVID-19 from either of these two contact situations should be low.
      In our cohort, many specific symptoms were associated with a symptomatic HCP testing positive for SARS-CoV-2, including cough, anosmia, ageusia, fever, myalgia, chills, and headache. We also demonstrated the importance of multiple symptoms from this group; as for each additional symptom, the odds of testing positive for SARS-CoV-2 doubled. We believe this data is helpful to health care institutions that would like to create streamlined symptom questionnaires, prioritize testing queues, and triage HCP before definitive PCR testing. However, we do not think that symptoms alone may be a substitute for testing.
      A number of other publications found similar associations between symptoms and SARS-CoV-2 testing for symptomatic HCP.
      • Lan F.Y.
      • Filler R.
      • Mathew S.
      • et al.
      COVID-19 symptoms predictive of healthcare workers' SARS-CoV-2 PCR results.
      • Van Loon N.
      • Verbrugghe M.
      • Cartuyvels R.
      • Ramaekers D.
      Diagnosis of COVID-19 based on symptomatic analysis of hospital healthcare workers in Belgium: observational study in a large Belgian tertiary care center during early COVID-19 outbreak.
      • Buonafine C.P.
      • Paiatto B.N.M.
      • Leal F.B.
      • et al.
      High prevalence of SARS-CoV-2 infection among symptomatic healthcare workers in a large university tertiary hospital in Sao Paulo, Brazil.
      • Tostmann A.
      • Bradley J.
      • Bousema T.
      • et al.
      Strong associations and moderate predictive value of early symptoms for SARS-CoV-2 test positivity among healthcare workers, the Netherlands, March 2020.
      • Ganz-Lord F.A.
      • Segal K.R.
      • Rinke M.L.
      COVID-19 symptoms, duration, and prevalence among healthcare workers in the New York metropolitan area.
      Most demonstrated the presence of fever, cough, ageusia, or anosmia are associated with a higher odds of testing positive; few have similarly shown gastrointestinal symptoms and pharyngitis may be associated with significantly lower odds. However, prior results have been hampered by: (1) limited power, with on average 752 symptomatic HCP (range, 295-1698); (2) brief study durations over relatively small portions of the pandemic period (average 7.5 weeks, all between March and June 2020); and (3) limited prevalence. The latter two may skew symptom reporting toward common mimicker illnesses that were temporally and geographically associated at that time. These limitations are not present in our study, which corroborates earlier findings.
      Despite our study’s strengths, including the size and breadth of the population, the duration of evaluation through periods of low, moderate, and high COVID-19 activity within our local community, the prospective approach to symptom and contact data collection, and equal and free access to testing, we also acknowledge limitations. Contact and symptom data are self-reported and we cannot conclusively determine all contact events. Likewise, genome sequencing was not performed routinely to link specific contacts with infection events. There is heterogeneity within some health care role groups in terms of job title, responsibilities, experience, and income. We were unable to examine specific socioeconomic status and sociodemographic factors such as race. Finally, this is a single-center cohort study, which may limit generalizability. Future studies incorporating social, behavioral, and economic determinants will be important to elucidate why we observed differences in SARS-CoV-2 infection across health care roles.

      Conclusion

      We demonstrated significant factors associated with positive SARS-CoV-2 testing in symptomatic HCP across three distinct areas: health care role, contact history, and symptoms. Our findings of different risk across HCP roles, after controlling for known contacts, reinforce the need for further investigations into COVID-19 disparities. They suggest equal education and testing will not be enough to overcome differences. Our findings emphasize that existing infection control practices limit transmission to HCP within the health care environment. Lastly, the association between seven symptoms and positive test results, as well as the increased odds of testing positive with each additional symptom, may be useful in augmenting HCP testing strategies. Whereas this study limited the analysis to HCP, it may be reasonable to apply some of our findings, including contact history with family/community members with known or suspected COVID-19 and the seven symptoms, to the screening process for other populations.

      Acknowledgments

      The authors thank Mallory Wagner and Theron Schultz for assistance in data collection for this project; and Jamie LaMantia for her editorial assistance.

      References

        • Wang Z.
        • Deng H.
        • Ou C.
        • et al.
        Clinical symptoms, comorbidities and complications in severe and non-severe patients with COVID-19: a systematic review and meta-analysis without cases duplication.
        Medicine (Baltimore). 2020; 99: e23327
        • Gomez-Ochoa S.A.
        • Franco O.H.
        • Rojas L.Z.
        • et al.
        COVID-19 in healthcare workers: a living systematic review and meta-analysis of prevalence, risk factors, clinical characteristics, and outcomes.
        Am J Epidemiol. 2021; 190: 161-175
        • Mani N.S.
        • Budak J.Z.
        • Lan K.F.
        • et al.
        Prevalence of COVID-19 infection and outcomes among symptomatic healthcare workers in Seattle, Washington.
        Clin Infect Dis. 2020; 71: 2702-2707
        • Calo F.
        • Russo A.
        • Camaioni C.
        • De Pascalis S.
        • Coppola N.
        Burden, risk assessment, surveillance and management of SARS-CoV-2 infection in health workers: a scoping review.
        Infect Dis Poverty. 2020; 9: 139
        • Wu M.
        • Xie C.
        • Wu R.
        • et al.
        Epidemiological and clinical characteristics of severe acute respiratory coronavirus virus 2 (SARS-CoV-2) infection among healthcare workers in Hubei Province, China.
        Infect Control Hosp Epidemiol. 2020; : 1-7
        • Koh W.C.
        • Naing L.
        • Chaw L.
        • et al.
        What do we know about SARS-CoV-2 transmission? a systematic review and meta-analysis of the secondary attack rate and associated risk factors.
        PLoS One. 2020; 15: e0240205
        • Lan F.Y.
        • Filler R.
        • Mathew S.
        • et al.
        COVID-19 symptoms predictive of healthcare workers' SARS-CoV-2 PCR results.
        PLoS One. 2020; 15: e0235460
        • Van Loon N.
        • Verbrugghe M.
        • Cartuyvels R.
        • Ramaekers D.
        Diagnosis of COVID-19 based on symptomatic analysis of hospital healthcare workers in Belgium: observational study in a large Belgian tertiary care center during early COVID-19 outbreak.
        J Occup Environ Med. 2021; 63: 27-31
        • Buonafine C.P.
        • Paiatto B.N.M.
        • Leal F.B.
        • et al.
        High prevalence of SARS-CoV-2 infection among symptomatic healthcare workers in a large university tertiary hospital in Sao Paulo, Brazil.
        BMC Infect Dis. 2020; 20: 917
        • Tostmann A.
        • Bradley J.
        • Bousema T.
        • et al.
        Strong associations and moderate predictive value of early symptoms for SARS-CoV-2 test positivity among healthcare workers, the Netherlands, March 2020.
        Euro Surveill. 2020; 25: 2000508
        • Ganz-Lord F.A.
        • Segal K.R.
        • Rinke M.L.
        COVID-19 symptoms, duration, and prevalence among healthcare workers in the New York metropolitan area.
        Infect Control Hosp Epidemiol. 2020; : 1-7
        • Lepak A.J.
        • Shirley D.K.
        • Buys A.
        • Stevens L.
        • Safdar N.
        Implementation of infection control measures to prevent healthcare-associated transmission of severe acute respiratory coronavirus virus 2 (SARS-CoV-2).
        Infect Control Hosp Epidemiol. 2021; 42: 229-232
        • Jann B.
        Plotting regression coefficients and other estimates in Stata: University of Bern Social Sciences Working Papers No. 1; Bern.
        University of Bern, Department of Social Sciences, Switzerland2014 ([revised September 18, 2017])
        • Adhikari S.
        • Pantaleo N.P.
        • Feldman J.M.
        • Ogedegbe O.
        • Thorpe L.
        • Troxel A.B.
        Assessment of community-level disparities in coronavirus disease 2019 (COVID-19) infections and deaths in large US metropolitan areas.
        JAMA Netw Open. 2020; 3: e2016938
        • Bassett M.T.
        • Chen J.T.
        • Krieger N.
        Variation in racial/ethnic disparities in COVID-19 mortality by age in the United States: a cross-sectional study.
        PLoS Med. 2020; 17: e1003402
        • Gross C.P.
        • Essien U.R.
        • Pasha S.
        • Gross J.R.
        • Wang S.Y.
        • Nunez-Smith M.
        Racial and ethnic disparities in population-level COVID-19 mortality.
        J Gen Intern Med. 2020; 35: 3097-3099
        • Jay J.
        • Bor J.
        • Nsoesie E.O.
        • et al.
        Neighbourhood income and physical distancing during the COVID-19 pandemic in the United States.
        Nat Hum Behav. 2020; 4: 1294-1302
        • Lundon D.J.
        • Mohamed N.
        • Lantz A.
        • Goltz H.H.
        • Kelly B.D.
        • Tewari A.K.
        Social determinants predict outcomes in data from a multi-ethnic cohort of 20,899 patients investigated for COVID-19.
        Front Public Health. 2020; 8: 571364
        • Raifman M.A.
        • Raifman J.R.
        Disparities in the population at risk of severe illness from COVID-19 by race/ethnicity and income.
        Am J Prev Med. 2020; 59: 137-139
        • Mody A.
        • Pfeifauf K.
        • Geng E.H.
        Using lorenz curves to measure racial inequities in COVID-19 testing.
        JAMA Netw Open. 2021; 4: e2032696
        • Lan F.Y.
        • Filler R.
        • Mathew S.
        • et al.
        Sociodemographic risk factors for COVID-19 infection among Massachusetts healthcare workers: a retrospective cohort study.
        Infect Control Hosp Epidemiol. 2021; : 1-23
        • Lepak A.J.
        • Chen D.J.
        • Buys A.
        • Stevens L.
        • Safdar N.
        Utility of repeat nasopharyngeal SARS-CoV-2 RT-PCR testing and refinement of diagnostic stewardship strategies at a tertiary care academic center in a low-prevalence area of the United States.
        Open Forum Infect Dis. 2020; 7: ofaa388
        • Braun K.M.
        • Moreno G.K.
        • Bobholz M.
        • et al.
        Viral sequencing reveals healthcare personnel rarely become infected with SARS-CoV-2 through patient contact.
        Clin Infect Dis. 2021; : ciab281
        • Sikkema R.S.
        • Pas S.D.
        • Nieuwenhuijse D.F.
        • et al.
        COVID-19 in health-care workers in three hospitals in the south of the Netherlands: a cross-sectional study.
        Lancet Infect Dis. 2020; 20: 1273-1280

      Linked Article

      • Reducing Community Exposure to Protect Health Care Personnel in a Pandemic Environment
        Mayo Clinic ProceedingsVol. 96Issue 9
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          Health care practices typically have an abundance of evidence-based medicine literature and best practice guidelines on which to base policies and procedures designed to prevent transmission of communicable disease. However, with the coronavirus disease 2019 (COVID-19) pandemic, things were much different. Physicians and their teams practicing in public health, employee occupational health, and infection prevention quickly found themselves asked to make recommendations and decisions to support safety in health care institutions with limited and sometimes conflicting information about severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).
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