Healthcare workers in elderly care: a source of silent SARS-CoV-2 transmission?

ImportanceHealthcare workers (HCWs), including those with mild symptoms, may be an important source of COVID-19 within elderly care. ObjectiveTo gain insight into the spread of SARS-CoV-2 among HCWs working in elderly care settings. DesignCross-sectional study among HCWs working in elderly care in the South-East of the Netherlands, testing for SARS-CoV-2, between March 31 and April 17, 2020. SettingHCWs working in geriatric rehabilitation, somatic and psychogeriatric wards or small-scale living groups and district nursing, with a total of 5245 HCWs within 4 organisations. Participants621 HCWs with mild respiratory symptoms. Main OutcomesNumber of HCWs testing positive for SARS-CoV-2 in pharyngeal swabs, using realtime reverse-transcriptase PCR targeting the SARS-CoV-2 E-gene, N-gene, and RdRP. HCWs filled out a survey to collect information on symptoms and possible sources of infection. Results133/615 (21.6%) HCWs tested positive for SARS-CoV-2, ranging from 15.6 to 44.4% per elderly care organisation, and from 0 to 64.3% per separate location of the organizations, respectively. 74.6% of tested HCWs were nursing staff, 1.7% elderly care physicians, 20.3% other HCWs with patient contact and 3.4% HCWs without patient contact. In the univariate analysis, fever, runny or stuffy nose, anosmia, general malaise, myalgia, headache and ocular pain were associated with SARS-CoV-2 positivity, while gastro-intestinal symptoms and respiratory symptoms, other than runny or stuffy nose were not. Risk factors for SARS-CoV-2 positivity were contact with patients or colleagues with suspected or proven COVID-19. Whole genome sequencing of 22 samples in 2 facilities strongly suggests spread within facilities. Conclusions and RelevanceWe found a high SARS-CoV-2 prevalence among HCWs in nursing homes and district nursing, supporting the hypothesis of undetected spread within elderly care facilities. Structural testing of elderly care HCWs, including track and trace of contacts, should be performed to control this spread, even when only mild symptoms are present.