Re-examine the transfusion transmitted risk of SARS-CoV-2 virus during a major COVID-19 outbreak in 2022.

INTRODUCTION: Although no case of COVID-19 transmission through transfusion has been reported, blood transfusion service (BTS) continues to implement pre-donation and post-donation measures to minimise the risk. In year 2022, when local healthcare system was badly impacted by a major outbreak, it opened an opportunity to re-examine the viraemia risk in these asymptomatic donors. MATERIALS AND METHODS: Records were retrieved from blood donors who reported COVID-19 after donation and follow-up was also made for recipients who received their blood. Blood samples at donation were tested for SARS-CoV-2 viraemia by single-tube nested real-time RT-PCR assay designed to detect most SARS-CoV-2 variants including the prevailing delta and omicron variants. RESULTS: From 1 January to 15 August 2022, the city with 7.4 M inhabitants recorded 1 187 844 COVID-19 positive cases and 125 936 successful blood donations were received. 781 donors reported to the BTS after donation with 701 being COVID-19 related (including close contact and symptoms respiratory tract infection). 525 COVID-19 were positive at the time of call back or follow-up. Of the 701 donations, they were processed into 1480 components with 1073 discarded upon donors' call back. For remaining 407 components, no recipient was found to have adverse event or COVID-19 positive. 510 samples from the above 525 COVID-19 positive donors were available and all tested negative for SARS-CoV-2 RNA. DISCUSSION: With the negative SARS-CoV-2 RNA in blood donation samples and follow up data in transfusion recipients, the risk of transfusion transmitted COVID-19 appears negligible. However, current measures remains important in securing blood safety with ongoing surveillance of their effectiveness.

Development of a prediction score (ThyroCOVID) for identifying abnormal thyroid function in COVID-19 patients.

PURPOSE: Thyroid dysfunction in COVID-19 carries clinical and prognostic implications. In this study, we developed a prediction score (ThyroCOVID) for abnormal thyroid function (TFT) on admission amongst COVID-19 patients. METHODS: Consecutive COVID-19 patients admitted to Queen Mary Hospital were prospectively recruited during July 2020-May 2021. Thyroid-stimulating hormone (TSH), free thyroxine (fT4) and free triiodothyronine (fT3) were measured on admission. Multivariable logistic regression analysis was performed to identify independent determinants of abnormal TFTs. ThyroCOVID was developed based on a clinical model with the lowest Akaike information criteria. RESULTS: Five hundred and forty six COVID-19 patients were recruited (median age 50 years, 45.4% men, 72.9% mild disease on admission). 84 patients (15.4%) had abnormal TFTs on admission. Patients with abnormal TFTs were more likely to be older, have more comorbidities, symptomatic, have worse COVID-19 severity, higher SARS-CoV-2 viral loads and more adverse profile of acute-phase reactants, haematological and biochemical parameters. ThyroCOVID consisted of five parameters: symptoms (malaise), comorbidities (ischaemic heart disease/congestive heart failure) and laboratory parameters (lymphocyte count, C-reactive protein, and SARS-CoV-2 cycle threshold values). It was able to identify abnormal TFT on admission with an AUROC of 0.73 (95% CI 0.67-0.79). The optimal cut-off of 0.15 had a sensitivity of 75.0%, specificity of 65.2%, negative predictive value of 93.5% and positive predictive value of 28.1% in identifying abnormal TFTs on admission amongst COVID-19 patients. CONCLUSION: ThyroCOVID, a prediction score to identify COVID-19 patients at risk of having abnormal TFT on admission, was developed based on a cohort of predominantly non-severe COVID-19 patients.

A prospective study of the impact of glycaemic status on clinical outcomes and anti-SARS-CoV-2 antibody responses among patients with predominantly non-severe COVID-19

OBJECTIVE: We aimed to evaluate the impact of glycaemic status on clinical outcomes and anti-SARS-CoV-2 antibody (Ab) response among patients with predominantly non-severe COVID-19, highly relevant to the current COVID-19 vaccination programme. METHODS: We included consecutive adults admitted to Queen Mary Hospital for COVID-19 from July 2020 to May 2021. Glycaemic status was defined by HbA1c on admission: normoglycaemia (<5.7%), prediabetes (5.7-6.4%) and diabetes (≥6.5% or known diabetes). Clinical deterioration was defined by radiological progression, new oxygen requirement, intensive care unit admission, or death. COVID-19 survivors had Ab measurements at 1-month, 2-month, 3- month and 6-month post-discharge, with a live SARS-CoV-2-based microneutralization assay which correlated well with anti-SARS-CoV-2 receptor binding domain IgG (≥1:20 defined as positive). RESULTS: Among 605 patients (age 50.2 - 17.1 years;45.1% men;96.9% non-severe COVID-19), 325 had normoglycaemia, 185 had prediabetes and 95 had diabetes. 74 had clinical deterioration (12.2%): 16 required intensive care and 4 died. Clinical deterioration was more likely with worse glycaemic status (P < 0.001) and higher HbA1c (OR 1.403, P < 0.001). Older age (P < 0.001), higher viral loads (P < 0.001), higher C-reactive protein (CRP) (P < 0.001) and symptomatic presentation (P = 0.008), but not glycaemic status/HbA1c, independently predicted clinical deterioration. 314 patients had Ab measured upon follow-up (1-month: 295;2-month: 227;3-month: 207;6-month: 122). Ab titres were comparable across glycaemic status throughout follow-up period. CRP (P = 0.003), but not glycaemic status/HbA1c, was the only positive independent determinant of Ab levels. Rate of decline of Ab titre was comparable across glycaemic status, and did not correlate with HbA1c. Furthermore, most patients remained Ab-positive throughout follow-up (1-month: 94.9%, 2-month: 93.8%, 3-month: 87.4%, 6-month 80.3%), similar across glycaemic status. CONCLUSION: Worse glycaemic status was associated with a higher chance of clinical deterioration in COVID-19, contributed by older age, more severe inflammation and higher viral loads. Importantly, glycaemic status did not adversely influence the Ab response.

Combating the coronavirus disease 2019 pandemic in the HONG KONG hospital authority paediatric infectious disease centre

Since the coronavirus disease 2019 (COVID-19) outbreak in late December 2019, and escalation of the public hospital infectious disease outbreak response level to the highest "emergency" level three days after two COVID-19 cases were diagnosed on 22 January 2020, all public hospitals implemented a series of isolation policies, rescheduled clinical services and mobilised resources to support frontline clinical staff. This article reviewed these multi-level policies adopted in the Department of Paediatrics and Adolescent Medicine, Princess Margaret Hospital, which have ensured that the healthcare system was not overwhelmed and frontline staff was not over-stressed and infected.

From SARS coronavirus to novel animal and human coronaviruses

In 2003, severe acute respiratory syndrome coronavirus (SARS-CoV) caused one of the most devastating epidemics known to the developed world. There were two important lessons from this epidemic. Firstly, coronaviruses, in addition to influenza viruses, can cause severe and rapidly spreading human infections. Secondly, bats can serve as the origin and natural animal reservoir of deadly human viruses. Since then, researchers around the world, especially those in Asia where SARS-CoV was first identified, have turned their focus to find novel coronaviruses infecting humans, bats, and other animals. Two human coronaviruses, HCoV-HKU1 and HCoV-NL63, were identified shortly after the SARS-CoV epidemic as common causes of human respiratory tract infections. In 2012, a novel human coronavirus, now called Middle East respiratory syndrome coronavirus (MERS-CoV), has emerged in the Middle East to cause fatal human infections in three continents. MERS-CoV human infection is similar to SARS-CoV in having a high fatality rate and the ability to spread from person to person which resulted in secondary cases among close contacts including healthcare workers without travel history to the Middle East. Both viruses also have close relationships with bat coronaviruses. New cases of MERS-CoV infection in humans continue to occur with the origins of the virus still unknown in many cases. A multifaceted approach is necessary to control this evolving MERS-CoV outbreak. Source identification requires detailed epidemiological studies of the infected patients and enhanced surveillance of MERS-CoV or similar coronaviruses in humans and animals. Early diagnosis of infected patients and appropriate infection control measures will limit the spread in hospitals, while social distancing strategies may be necessary to control the outbreak in communities if it remained uncontrolled as in the SARS epidemic. FAU - To, Kelvin K. W.

Factors affecting stability and infectivity of SARS-CoV-2.

BACKGROUND: In late 2019, a novel human coronavirus - severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) - emerged in Wuhan, China. This virus has caused a global pandemic involving more than 200 countries. SARS-CoV-2 is highly adapted to humans and readily transmits from person-to-person. AIM: To investigate the infectivity of SARS-CoV-2 under various environmental and pH conditions. The efficacies of various laboratory virus inactivation methods and home disinfectants against SARS-CoV-2 were investigated. METHODS: The residual virus in dried form or in solution was titrated on to Vero E6 cells on days 0, 1, 3, 5 and 7 after incubation at different temperatures. Viral viability was determined after treatment with various disinfectants and pH solutions at room temperature (20-25oC). FINDINGS: SARS-CoV-2 was able to retain viability for 3-5 days in dried form or 7 days in solution at room temperature. SARS-CoV-2 could be detected under a wide range of pH conditions from pH 4 to pH 11 for several days, and for 1-2 days in stool at room temperature but lost 5 logs of infectivity. A variety of commonly used disinfectants and laboratory inactivation procedures were found to reduce viral viability effectively. CONCLUSION: This study demonstrated the stability of SARS-CoV-2 on environmental surfaces, and raises the possibility of faecal-oral transmission. Commonly used fixatives, nucleic acid extraction methods and heat inactivation were found to reduce viral infectivity significantly, which could ensure hospital and laboratory safety during the SARS-CoV-2 pandemic.