Perceptions of healthcare workers in high-risk areas of a Singapore hospital during COVID-19: a cross-sectional study.

Introduction: There is worldwide concern over the psycho-emotional impact of COVID-19 on healthcare workers (HCWs). This study aimed to elicit HCWs' perceptions of the adequacy of protective measures in high-risk clinical areas and the factors associated with these perceptions. Methods: This was a cross-sectional study conducted in April 2020. An anonymous electronic survey was sent via email to operating theatre (OT) and intensive care unit (ICU) staff of Sengkang General Hospital, Singapore. Results: Of the 358 eligible participants, 292 (81.6%) responded to the survey. 93.2% of the participants felt that precautionary measures at work were sufficient and 94.9% acknowledged that adequate training was provided. More than 60% of the participants opined that their chances of contracting COVID-19 were moderate to high. Female gender, nursing occupation and duration of service <10 years were significantly associated with increased fear of contracting COVID-19, less control over occupational exposure and lower perceived need to care for COVID-19 patients. Having young children at home did not significantly affect these perceptions. The most important ICU precautions were availability of personal protective equipment outside the rooms of COVID-19 positive patients (95.3%) and having visitor restrictions (95.3%). The most important OT measures were having a dedicated OT for COVID-19 positive patients (91.2%) and having simulation as part of protocol familiarisation (91.7%). Conclusion: Overall, there was high confidence in the adequacy of COVID-19 protective measures to prevent healthcare transmission in Singapore. The pandemic had a lower degree of psycho-emotional impact on HCWs here as compared to other countries.

Widely heterogeneous humoral and cellular immunity after mild SARS-CoV-2 infection in a homogeneous population of healthy young men.

BACKGROUND: We studied humoral and cellular responses against SARS-CoV-2 longitudinally in a homogeneous population of healthy young/middle-aged men of South Asian ethnicity with mild COVID-19. METHODS: In total, we recruited 994 men (median age: 34 years) post-COVID-19 diagnosis. Repeated cross-sectional surveys were conducted between May 2020 and January 2021 at six time points - day 28 (n = 327), day 80 (n = 202), day 105 (n = 294), day 140 (n = 172), day 180 (n = 758), and day 280 (n = 311). Three commercial assays were used to detect anti-nucleoprotein (NP) and neutralizing antibodies. T cell response specific for Spike, Membrane and NP SARS-CoV-2 proteins was tested in 85 patients at day 105, 180, and 280. RESULTS: All serological tests displayed different kinetics of progressive antibody reduction while the frequency of T cells specific for different structural SARS-CoV-2 proteins was stable over time. Both showed a marked heterogeneity of magnitude among the studied cohort. Comparatively, cellular responses lasted longer than humoral responses and were still detectable nine months after infection in the individuals who lost antibody detection. Correlation between T cell frequencies and all antibodies was lost over time. CONCLUSION: Humoral and cellular immunity against SARS-CoV-2 is induced with differing kinetics of persistence in those with mild disease. The magnitude of T cells and antibodies is highly heterogeneous in a homogeneous study population. These observations have implications for COVID-19 surveillance, vaccination strategies, and post-pandemic planning.