Treatment outcomes of COVID-19 patients in Hong Kong's first designated infection control centre and the impact of emergent SARS-CoV-2 mutant strains from imported cases

ABSTRACT

Background and Aims: The North Lantau Hospital Hong Kong Infection Control Centre (HKICC) was established in February 2021 as a designated hospital to combat the coronavirus disease 2019 (COVID-19) in Hong Kong, during which an increase in emergent mutant strains of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) raised concerns pertinent to increased transmissibility and disease severity. We aim to describe the treatment outcomes of SARS-CoV-2 infection in HKICC, and to evaluate the impact of mutant strains in imported cases. Methods: Consecutive patients with COVID-19 admitted to HKICC from February to April 2021 were identified with their clinical features and treatment outcomes evaluated. Clinical features of mutant strains and wild-type strains were compared. Results: of 513 COVID-19 patients treated in HKICC (mean age 38 years, 45.2% male), 238 (46.4 %) were imported. The incidence of hypoxemia was 3.1% (16/513). All patients were discharged successfully with a median length of stay of 10 days (IQR 6-13). All mutant strains were imported with an incidence of 47.9% (114/238), N501Y mutation was most frequently found (111/114, 97.4%). Among imported cases, strains with N501Y mutation alone were associated with more cough (16.5% vs 6.5%, p=0.022), but had similar incidence of hypoxemia and length of stay, compared with wild-type strains. Conclusion: HKICC successfully contributed to combating COVID-19 pandemic in Hong Kong. Imported cases with N501Y mutation alone presented with more cough, but had similar incidence of hypoxemia and length of stay, compared with wild-type strains. Further studies to evaluate the impact of other mutant strains are warranted.