Low-threshold SARS-CoV-2 testing facility for hospital staff: Prevention of COVID-19 outbreaks?

BACKGROUND

The ongoing global SARS-CoV-2 pandemic has caused over 4.7 million infections greatly challenging healthcare workers (HCW) and medical institutions worldwide. The SARS-CoV-2 pandemic has shown to significantly impact mental and physical health of HCW. Thus, implementation of testing facilities supporting HCW are urgently needed.

METHODS

A low-threshold SARS-CoV-2 testing facility was introduced at the University Hospital Bonn, Germany, in March 2020. Irrespective of clinical symptoms employees were offered a voluntary and free SARS-CoV-2 test. Furthermore, employees returning from SARS-CoV-2 risk regions and employees after risk contact with SARS-CoV-2 infected patients or employees were tested for SARS-CoV-2 infection. Pharyngeal swabs were taken and reverse transcription polymerase chain reaction for detection of SARS-CoV-2 was performed, test results being available within 24 h. Profession, symptoms and reason for SARS-CoV-2 testing of employees were recorded.

RESULTS

Between 9th March and April 30, 2020, a total of 1510 employees were tested for SARS-CoV-2 infection. 1185 employees took advantage of the low-threshold testing facility. One percent (n = 11) were tested positive for SARS-CoV-2 infection, 18% being asymptomatic, 36% showing mild and 36% moderate/severe symptoms (missing 10%). Furthermore, of 56 employees returning from SARS-CoV-2 risk regions, 18% (10/56) were tested SARS-CoV-2 positive. After risk contact tracking by the hospital hygiene 6 patient-to-employee transmissions were identified in 163 employees with contact to 55 SARS-CoV-2 positive patients.

CONCLUSION

In the absence of easily accessible public SARS-CoV-2 testing facilities low-threshold SARS-CoV-2 testing facilities in hospitals with rapid testing resources help to identify SARS-CoV-2 infected employees with absent or mild symptoms, thus stopping the spread of infection in vulnerable hospital environments. High levels of professional infection prevention training and implementation of specialized wards as well as a perfectly working hospital hygiene network identifying and tracking risk contacts are of great importance in a pandemic setting.

The emergence of a C/EBPalpha mutation in the clonal evolution of MDS towards secondary AML

Recently, mutations in the transcription factor CCAAT/ enhancer binding protein alpha (C/EBPalpha) have been described in acute myeloid leukemia (AML). We performed a mutational analysis of the C/EBPalpha gene in the myelodysplastic syndromes and AML with antecedent MDS. No mutations were found in patients with refractory anemia (0/27), refractory anemia with ringed sideroblasts (0/7), refractory anemia with excess of blasts (RAEB 0/16) or chronic myelomonocytic leukemia (CMML 0/5). One out of 13 patients with RAEB-T/AML secondary to MDS showed a mutation in the C/EBPalpha gene. In this patient a 4 bp insertion disrupted codon 69 in one allele. This novel +1 frame shift is predicted to result in a truncated protein of 107 amino acids. However, the dominant protein translated was the C/EBPalpha isoform p30, which was previously shown to inhibit the DNA-binding and transactivation properties of C/EBPalpha p42. Interestingly this mutation could not be detected at diagnosis in the initial RAEB and RAEB-T stage. The mutation appeared at relapse after chemotherapy for RAEB-T. We conclude that the C/EBPalpha mutation was not essential for the initial blast accumulation. The emergence of a bast clone carrying a C/EBPalpha mutation at relapse indicates that this mutation may confer a growth advantage in a myeloid cell with an established differentiation block.