[Mutations in the SARS-CoV-2 genome: the emergence of variants and the impact on vaccines]

Almost two years after the introduction of SARS-CoV-2, it has become clear that the virus is unlikely to disappear any time soon. It is also clear that the virus mutates, resulting in specific variants of SARS-CoV-2. The exact implications of these variants are being investigated but it is likely that they have a selective advantage over previously circulating variants. It is possible that SARS-CoV-2 will mutate in the coming years to such an extent that existing vaccines do not offer sufficient protection against hospitalizations in the general population. At present, the protection of current vaccines against infection is observed to be reduced by the emergence of variants but remains high against hospitalizations and severe disease. Booster vaccinations are currently advised for specific risk groups where the regular vaccination schedule leads to an insufficient immune response, and are being considered for people in old age where the vaccine effectiveness is lower.

Transmission of SARS-CoV-2 among healthcare workers and patients in a teaching hospital in the Netherlands confirmed by whole-genome sequencing.

AIM: To investigate the sources of infection among healthcare workers (HCWs) and patients in a teaching hospital in the Netherlands during the early stages of the coronavirus disease 2019 (COVID-19) pandemic using epidemiological and whole-genome sequencing data. METHODS: From 3rd April to 11th May 2020, 88 HCWs and 215 patients were diagnosed with COVID-19. Whole-genome sequences were obtained for 30 HCWs and 20 patients. RESULTS: Seven and 11 sequence types were identified in HCWs and patients, respectively. Cluster A was the most common sequence type, detected in 23 (77%) HCWs; of these, 14 (61%) had direct patient contact and nine (39%) had indirect patient contact. In addition, seven patients who were not hospitalized in the COVID-19 cohort isolation ward who became positive during their admission were infected with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) cluster A. Following universal masking of all HCWs and emphasis on physical distancing during meals and breaks, no further evidence was found for patient-to-HCW or HCW-to-HCW transmission or vice versa. CONCLUSION: The finding that patients and HCWs were infected with SARS-CoV-2 cluster A suggests both HCW-to-HCW and HCW-to-patient transmission.

Why psychiatry is different - challenges and difficulties in managing a nosocomial outbreak of coronavirus disease (COVID-19) in hospital care.

OBJECTIVE: Coronavirus disease (COVID-19) was officially declared a pandemic in March 2020. Many cases of COVID-19 are nosocomial, but to the best of our knowledge, no nosocomial outbreaks on psychiatric departments of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been reported in Europe. The different nature of psychiatry makes outbreak management more difficult. This study determines which psychiatry specific factors contributed to a nosocomial outbreak taking place in a psychiatric department. This will provide possible interventions in future outbreak management. METHOD: A case series describing a nosocomial outbreak in a psychiatric department of an acute care hospital in the Netherlands between March 13, 2020 and April, 14 2020. The outbreak was analyzed by combining data from standardized interviews, polymerase chain reaction (PCR) tests and whole genome sequencing (WGS). RESULTS: The nosocomial outbreak in which 43% of staff of the psychiatric department and 19% of admitted patients were involved, was caused by healthcare worker (HCW)-to-HCW transmissions, as well as patient-to-HCW-to-patient transmission. We identified four aspects associated with the mental health care system which might have made our department more susceptible to an outbreak. CONCLUSIONS: Infection control measures designed for hospitals are not directly applicable to psychiatric departments. Psychiatric patients should be considered a high-risk group for infectious diseases and customized measures should be designed and implemented. Extra attention for psychiatric departments is necessary during a pandemic as psychiatric HCWs are less familiar with outbreak management. Clear communication and governance is crucial in correctly implementing these measures.