Transmission risk of SARS-CoV-2 to healthcare workers – observational results of a primary care hospital contact tracing

Abstract

BACKGROUND The coronavirus disease (COVID)-19 epidemic is evolving rapidly. Healthcare workers are at increased risk for infection, and specific requirements for their protection are advisable to ensure the functioning of the basic healthcare system, including the availability of general practitioners (GPs). Understanding the transmission risk is particularly important for guiding evidence-based protective measures in the primary healthcare setting. METHODS Healthcare worker contacts of an initially undiagnosed COVID-19 case, who were without personal protective equipment, in particular not wearing facemasks, were screened with nasopharyngeal swabs and polymerase chain reaction tests for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), irrespective of respiratory symptoms or fever seven days after initial contact. The details of exposure to the index case were obtained during routine contact investigation after unintentional pathogen exposure. RESULTS Twenty-one healthcare workers reported contacts with the index case. Three healthcare workers reported respiratory symptoms (cough) or low-grade fever within 4 days. None of them tested positive for SARS-CoV-2 at the time of symptom onset. All 21 healthcare workers tested SARS-CoV-2 negative 7 days after initial index case contact, including the three healthcare workers with previous symptoms. Ten of the 21 healthcare workers reported a cumulative exposure time of >15 minutes. Longer cumulative contact times were associated with more individual contacts, reduced contact time per contact and activities with physical patient contact. The closest relative of the index patient tested SARS-CoV-2 positive 2 days after the index case presented at the hospital emergency department. CONCLUSION We found a low risk of SARS-CoV-2 transmission in a primary care setting. These findings are compatible with previous reports of the highest transmission probability in household settings with prolonged close contacts. The current protective measures for healthcare workers, including strict adherence to basic standard hygiene and facemasks, offer considerable protection during short periods of contact with symptomatic COVID-19 cases by diminishing the risk of direct and indirect transmission.

SARS-CoV-2 screening of asymptomatic healthcare workers

“…[1][2][3][4] Transmission rates within the healthcare setting have varied in the literature. [5][6][7][8] We developed this protocol to determine the SARS-CoV-2 positivity rate among asymptomatic HCWs at our institution.…”

Serology surveillance of anti-SARS-CoV-2 antibodies among asymptomatic healthcare workers in Malaysian healthcare facilities designated for COVID-19 care

“…Numerous studies have stressed the critical importance of strict adherence to IPC measures to prevent patient-to-HCW infections, [21,23,[38][39][40] but few have investigated HCW compliance with IPC measures. Interestingly, Barrett et al did not nd any signi cant association between usage of PPE and COVID-19…”

The Impact of COVID-19 on a Tertiary Care Pediatric Emergency Department

“…Parents reported to feel anxious about their children, and they did not consider nonurgent ED visits a violation of the use of healthcare system, as the ED offered rsthand evaluations within the time-frame they desired (12). However, the rapid local and international spread and the ability of this novel Coronovirus to infect a large number of hospital workers generated fears regarding the potential nosocomial transmission of this contagious disease (25,26). Citizens are likely to be more afraid than before to visit healthcare facilities due to the risk of contracting COVID-19, and the use of alternative strategies (e.g., telephone consultation) might have increased.…”