Prevalence of SARS-CoV-2 Among Healthcare Workers in New Jersey

Overworked healthcare worker looking through a window.
Overwhelmed healthcare worker looking through a window.
Additional strategies are needed to protect workers at risk of COVID-19 infection and to identify deficiencies in current protections.

A study published in BMC Infectious Diseases investigated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection by healthcare worker status and job role during the early phases of community spread. The results show healthcare workers (HCW) had a higher prevalence of infection with the virus than non-HCW (NHCW).

Between March 24 and April 7, eligible participants from Rutgers University and its affiliated hospitals were recruited for this ongoing prospective cohort study. A total of 546 HCW and 283 NHCW with no known prior SARS-CoV-2 exposure completed prescreening and met the eligibility criteria.

The cohort was 64.1% women, and 51.6% of participants were less than 40 years of age. At least 1 chronic medical condition was reported by 34.7% of participants, and 4.5% reported to be active smokers. The group was racially diverse: 58.3% identified as White, 20.5% as Asian, 10.9% as Black, and 12.2% as Hispanic. Missing values or those identifying as “other” accounted for 10.4% of the participants.

At baseline, 40 HCW (7.3%) and 1 NHCW (0.4%) tested positive via reverse transcriptase polymerase chain reaction (RT-PCR). Of these 41 particiapnts, 14 (34.2%) reported symptoms. The absolute risk was 7.0% greater (95% CI, 4.7-9.3) for HCW. Positive tests also occurred more frequently among Black (8.9%), “other” (9.3%), and Hispanic (11.9%) participants relative to White (3.9%) and Asian participants (3.5%).

Over 71% of HCW workers reported working with at least 1 known or suspected COVID-19 patient. HCW who cared for 5 or more of these patients were more likely to be positive (24/226, 10.6%) than counterparts caring for fewer patients known to have or suspected of having COVID-19 (15/310; 4.8%).

The highest rates of observed infections occurred among nurses (11.1%) and the lowest rates were observed among attending physicians (1.8%), resident, fellow physicians (3.1%). ICU workers had lower rates of observed infections (2.2%) compared with other units. Across the 2 weeks of recruitment, positive tests increased in line with increasing cases in the hospitals and surrounding areas.

This study rapidly recruited a convenience sample, which potentially biased enrollment toward participants highly concerned about infection. Investigators could not definitely identify exposures leading to infections, and data on personal protective equipment by HCW was self-reported. Although longitudinal follow-up of the cohort is ongoing, the small number of cases at baseline and large number of potentially related factors limited statistical analysis.

Investigators concluded that during the early phases of community transmission, infection was “considerably higher in HCW compared to NHCW.” Higher rates were also found among nurses, those caring for more patients suspected or confirmed as having COVID-19, and in hospitals with higher proportions of COVID-19 patients.


Barrett ES, Horton DB, Roy J, et al. Prevalence of SARS-CoV-2 infection in previously undiagnosed health care workers in New Jersey, at the onset of the U.S. COVID-19 pandemic. BMC Infect Dis. 2020;20(1):853. doi: 10.1186/s12879-020-05587-2