Updated Oct. 16 at 6:35 p.m. This will be our final update regarding the COVID-19 cluster.
Our Infection Control team is confident that the COVID-19 cluster, identified on Sept. 22 and involving Braunwald Tower 16A and 14CD, has been contained. In total, we had 57 cases potentially connected to the cluster, including 42 employees and 15 patients. We have not had any new potentially contagious cases on the units that were affected since Oct. 3. We have run whole genome sequencing of all cases to confirm the infections are related. We anticipate that the case numbers may change slightly as results are returned.
In response to the cluster, we tested all inpatients for COVID-19 every three days. This was in addition to testing all patients upon admission and for daily symptom screening per hospital policy. We contacted all potentially exposed staff and tested them. We tested those in the highest risk groups every three days. Staff who were symptomatic and/or tested positive were not permitted to return to work until they met return-to-work criteria. We contacted all patients discharged from the affected units to arrange testing for them. We also tested the HVAC systems and performed a thorough cleaning of the affected areas.
Additionally, we made COVID-19 testing available to all staff on the main campus. Since Friday, Sept. 25, we performed 10,840 tests on 7,999 unique employees and received 10,319 results. Of these results, 58 were positive. Of these 58 positive results, 42 were deemed likely associated with the cluster, 14 were not associated with the cluster and two are being investigated further. Through this testing, we were able to determine that there is an extremely low prevalence of COVID-19 in the Brigham community (0.18 percent) compared to the prevalence in the surrounding community, which is 0.8 percent (this is the test positivity rate amongst asymptomatic MGB patients).
Our Infection Control team identified multiple possible factors that contributed to the cluster, including a highly infectious source patient, several individuals with very high viral loads, inconsistencies in patient masking and the use of eye protection among providers, and a lack of physical distancing among staff while eating.
The cluster did not impact any other areas of the hospital or our outpatient clinics, and our experience over the past few months demonstrates that we can create and maintain a safe environment by adhering to all of the elements of our Safe Care Commitment and our infection control policies. In addition, in response to this outbreak, we are: