Identifying Patient Zero – The use of genomic sequencing in conjunction with epidemiological data in a hospital outbreak of COVID-19
Ms Rebecca McNamara1, Dr Norelle Sherry2, Professor Rhonda L Stuart1
1Monash Health, Clayton, Australia, 2University of Melbourne at the Doherty Institute, Melbourne, Australia
Background:
The transmissibility of SARS-CoV-2, the virus which causes COVID-19, has been a key factor in the acquisition of hospital-acquired COVID-19 in both patients and healthcare workers. Given the silent nature of transmission, the identification of nosocomial spread can be challenging within the hospital setting. The use of genomic sequencing in conjunction with epidemiological data allows further insight into the transmission of COVID-19. We outline this use in an acute medical ward of a tertiary health service.
Method:
Nine positive cases of COVID-19 were identified within a 30-bed acute general medical ward over a 1 month period and extensive contact tracing was completed by the Infection Prevention and Epidemiology team. Phylogenetic analysis of these 9 cases in addition to other potential attributable positives cases identified within the hospital were completed.
Results:
Contact tracing identified 7 COVID-19 positive staff who had cared for a COVID 19 positive patient. These patients had required extensive care and physical contact due to cognitive impairment. One patient was deemed a ‘super spreader’ and the likely source of staff exposure, however epidemiological data was unable to determine ‘patient zero’. Genomic sequencing of positive cases within the hospital within the month of the outbreak and the month prior uncovered 2 positive cases that provided the missing link and identified the chain of transmission and ‘patient zero’.
Conclusion:
The use of genomic sequencing when combined with epidemiological data aids identification of the transmission pathway of SARs-CoV-2, and allows for quality improvement implementation processes to occur.
Biography:
Rebecca has been working as a Clinical Nurse Consultant in Infection Prevention and Epidemiology at Monash Health since 2018. She has a background in Emergency Nursing and has completed a Masters of Advanced Clinical Nursing through Monash University. Rebecca’s interests include outbreak investigation, aseptic technique and prevention of Healthcare Associated Infections (HAIs).