Management of a COVID outbreak on a hematology-oncology ward

Introduction: Within one week, 11 members of the nursing staff and one patient of the hematology-oncology tested positive for COVID-19. Transmission of SARS-COV-2 on the ward was suspected. Objectives: Description of measures to end this outbreak. Methods: Additional to standard COVID-19 precautions in our hospital, all admitted asymptomatic patients were investigated by PCRscreening on a regular basis and positive specimens were investigated via Whole Genome Sequencing (WGS). The following measures were installed: 1) Temporary closure of the ward for new admissions;2) Restriction of number of visitors to a minimum;3) Cohorting of patients and healthcare workers (HCW);4) Nursing personnel was required to change their FFP-2 mask every hour;5) Transfer of positive patients to the specialized COVID-ward, if medically safely possible. Additional measures were employed when new cases occurred despite measures: a) Pre-admission PCR-screening of new admissions;b) Critical appraisal of all non-patient-related activities of HCW and improvement where possible;c) Expansion of use of FFP-2 masks in care of asymptomatic non-COVID patients to some long-lasting non-aerosol forming close-contact procedures;d) Avoidance of the use of multiple person rooms for the non-COVID cohort as much as possible;e) Expansion of a working ban for COVID-19 positive HCW with CT-values < 30 to any positive result, as it became evident that early detected patients/HCW frequently had a high initial CT-value which decreased dramatically in follow-up samples. Results: WGS results proved the transmission of a particular SARSCOV- 2 variant (B.1.221 lineage, unique mutation A26513G) on the ward. New cases occurred for 3 weeks. After installing extra measures, the incidence of new cases declined gradually. The total outbreak eventually comprised 19 patients and 33 HCW. An important part of COVID-19 positive healthcare workers had long-lasting complaints of the infection and remained incapacitated far longer than the period that their CT-value required them to be banned from work. Therefore, extra personnel had to be recruited. Conclusion: A bundle of preventive measures was effective in controlling this outbreak. The screening of asymptomatic patients and HCW was very helpful in ending it. (Figure Presented).