Investigation of healthcare-associated COVID-19 in a large French hospital group by whole-genome sequencing.

OBJECTIVES: Despite the quick implementation of infection prevention and control procedures and the use of personal protective equipment within healthcare facilities, many cases of nosocomial COVID-19 transmission have been reported. We aimed to estimate the frequency and impact of healthcare-associated COVID-19 (HA-COVID-19) and evaluate the contribution of whole-genome sequencing (WGS) in cluster investigation. METHODS: We estimated the frequency and mortality of HA-COVID-19 infections from September 1 to November 30, 2020, with a focus on the evolution of hospitalized community-associated COVID-19 (CA-COVID-19) cases and cases detected among healthcare workers (HCWs) within the Sorbonne University Hospital Group (Paris, France). We thoroughly examined 12 clusters through epidemiological investigations and WGS. RESULTS: Overall, 209 cases of HA-COVID-19 were reported. Evolution of HA-COVID-19 incidence closely correlated with the incidence of CA-COVID-19 and COVID-19 among HCWs. During the study period, 13.9 % of hospitalized patients with COVID-19 were infected in the hospital and the 30-day mortality rate of HA-COVID-19 was 31.5 %. Nosocomial transmission of SARS-CoV-2 led to clusters involving both patients and HCWs. WGS allowed the exclusion of one-third of cases initially assigned to a cluster. CONCLUSIONS: WGS analysis combined with comprehensive epidemiological investigations is essential to understand transmission routes and adapt the IPC response to protect both patients and HCWs.

Broad-based SARS-CoV-2 testing program for healthcare workers in a primary care hospital in France.

A broad-based SARS-CoV-2 testing program for all symptomatic healthcare workers (HCWs) was implemented in Tenon hospital, Paris, France. From February 26 to April 22, 2020, 701 symptomatic HCWs were screened, of whom 247 (35.2%) tested positive for SARS-Cov-2. Myalgia, fever, anosmia and ageusia were associated with RT-PCR positivity. Testing of HCWs is an essential step toward control of the epidemic. Further studies could establish clinical algorithms for SARS-CoV-2 diagnosis to compensate for RT-PCR test and chest CT limits or unavailability.