Significantly Lower Case-fatality Ratio of Coronavirus Disease 2019 (COVID-19) than Severe Acute Respiratory Syndrome (SARS) in Hong Kong-A Territory-Wide Cohort Study

Risk prediction of advanced colorectal neoplasia among diabetic patients: A derivation and validation study

Background and Aim

Colorectal cancer (CRC) is the third most common cancer in the world. This study devises and validates a clinical scoring system for risk prediction of advanced colorectal neoplasia (ACN) to guide colonoscopy evaluation among diabetic patients.

Methods

We identified 55 964 diabetic patients who received colonoscopies from a large database in a Chinese population (2008-2018). We recruited a derivation cohort based on random sampling. The risk factors of CRC evaluated by univariate analysis were examined for ACN, defined as advanced adenoma, CRC, or any combination thereof using binary logistic regression analysis. We used the adjusted odds ratios (aORs) for independent risk factors to devise a risk score, ranging from 0 to 6: 0-4 "average risk" (AR) and 5-6 "high risk" (HR). The other subjects acted as an independent validation cohort.

Results

The prevalence of ACN in both the derivation and validation cohorts was 2.0%. Using the scoring system constructed, 78.5% and 21.5% of patients in the validation cohort were classified as AR and HR, respectively. The prevalence of ACN in the AR and HR groups was 1.5% and 4.1%, respectively. Individuals in the HR group had a 2.78-fold increased prevalence of ACN than the AR group. The concordance (c-) statistics was 0.70, implying a good discriminatory capability of the risk score to stratify high-risk individuals who should consider colonoscopy.

Conclusion

The clinical risk scoring system based on age, gender, smoking, presence of hypertension, and use of aspirin is useful for ACN risk prediction among diabetic patients.

COVID-19-Induced Diabetes Mellitus: Comprehensive Cellular and Molecular Mechanistic Insights

Despite evidence demonstrating the risks of developing diabetes mellitus because of SARS-CoV-2, there is, however, insufficient scientific data available to elucidate the relationship between diabetes mellitus and COVID-19. Research indicates that SARS-CoV-2 infection is associated with persistent damage to organ systems due to the systemic inflammatory response. Since COVID-19 is known to induce these conditions, further investigation is necessary to fully understand its long-term effects on human health. Consequently, it is essential to consider the effect of the COVID-19 pandemic when predicting the prevalence of diabetes mellitus in the future, especially since the incidence of diabetes mellitus was already on the rise before the pandemic. Additional research is required to fully comprehend the impact of SARS-CoV-2 infection on glucose tolerance and insulin sensitivity. Therefore, this article delves deeper into the current literature and links the perceived relationship between SARS-CoV-2 and diabetes. In addition, the article highlights the necessity for further research to fully grasp the mechanisms that SARS-CoV-2 utilises to induce new-onset diabetes. Where understanding and consensus are reached, therapeutic interventions to prevent the onset of diabetes could be proposed. Lastly, we propose advocating for the regular screening of diabetes and pre-diabetes, particularly for the high-risk population with a history of COVID-19 infection.

Recurrence rates of advanced colorectal neoplasia (ACN) in subjects with baseline ACN followed up at different surveillance intervals

BACKGROUND

Current clinical guidelines recommend that a baseline finding of advanced colorectal neoplasia (ACN) should be followed-up within 1-3 years.

AIM

We compared the recurrence rate of ACN at 1 year vs. 3 years among individuals with ACN detected and polypectomised at baseline colonoscopy.

METHODS

We extracted data from eligible patients in a Chinese population database from 2008 to 2018. The outcome variables included recurrence of advanced adenoma and advanced neoplasia, respectively, at follow-up colonoscopy. Binary logistic regression modeling was constructed to examine the association between length of surveillance and the outcome variables, controlling for risk factors of colorectal cancer, including age, gender, smoking, alcohol drinking, body mass index and chronic diseases.

RESULTS

We included 147,270 subjects who have received a baseline colonoscopy from our dataset. They were aged 69.3 years and 59.7% of them were male subjects. The crude 1-year and 3-year recurrence rate of ACN was 7.57% and 7.74%. From a binary logistic regression model, individuals with surveillance colonoscopy performed at 3 years did not have significantly higher recurrence rate of ACN than those followed-up at 1 year.

CONCLUSIONS

No statistically significantly difference in recurrence of ACN between individuals who received workup at 1vs. 3 years. These findings support a 3-year surveillance period after baseline ACN was polypectomised.

Comparison of the 12-month impact of COVID-19 and SARS on physiological capacity and health-related quality of life

BACKGROUND

Little is known about the differences in medium to long-term recovery on spirometry, 6-minute walking distance (6MWD) and health-related quality of life (HRQoL) between COVID-19 and SARS.

METHODS

We performed a 12-month prospective study on COVID-19 survivors. The changes in dynamic lung volumes at spirometry (%predicted FEV1, %predicted FVC), 6MWD and HRQoL at 1-3, 6 to 12 months were compared against a historical cohort of SARS survivors using the same study protocol. The residual radiological changes in HRCT in COVID-19 survivors were correlated with their functional capacity.

RESULTS

108 COVID-19 survivors of various disease severity (asymptomatic 2.9%, mild 33.3%, moderate 47.2%, severe 8.3%, critical 8.3%) were recruited. When compared with 97 SARS survivors, 108 COVID-19 survivors were older (48.1 ± 16.4 vs. 36.1 ± 9.5 years, p < 0.001) and required less additional support during hospitalization; with lower dynamic lung volumes, shorter 6MWD and better physical component score. Both groups of survivors had comparable changes in these parameters at subsequent follow-ups. Both COVID-19 and SARS survivors had similar mental component score (MCS) at 6 and 12 months. COVID-19 survivors initially experienced less (between-group difference, -3.1, 95% confidence interval [CI] -5.5 to -0.7, p = 0.012) and then more improvement (between-group difference 2.9, 95%, CI 0.8 to 5.1, p = 0.007) than SARS survivors in the MCS at 1-3 to 6 months and 6 to 12 months respectively. Forty (44.0%) out of 91 COVID-19 survivors had residual abnormalities on HRCT at 12 months, with a negative correlation between the severity scores of parenchymal changes and 6MWD (r=-0.239, p < 0.05).

CONCLUSIONS

COVID-19 survivors demonstrated a similar recovery speed in dynamic lung volumes and exercise capacity, but different paces of psychological recovery as SARS survivors in the convalescent phase. The severity of parenchymal changes in HRCT is negatively correlated with the 6MWD of COVID-19 survivors.

TRIAL REGISTRATION

This prospective study was registered at ClinicalTrials.gov on 2 November 2020 (Identifier: NCT04611243).

Prediction algorithm for gastric cancer in a general population: A validation study

BACKGROUND

Worldwide, gastric cancer is a leading cause of cancer incidence and mortality. This study aims to devise and validate a scoring system based on readily available clinical data to predict the risk of gastric cancer in a large Chinese population.

METHODS

We included a total of 6,209,697 subjects aged between 18 and 70 years who have received upper digestive endoscopy in Hong Kong from 1997 to 2018. A binary logistic regression model was constructed to examine the predictors of gastric cancer in a derivation cohort (n = 4,347,224), followed by model evaluation in a validation cohort (n = 1,862,473). The algorithm's discriminatory ability was evaluated as the area under the curve (AUC) of the mathematically constructed receiver operating characteristic (ROC) curve.

RESULTS

Age, male gender, history of Helicobacter pylori infection, use of proton pump inhibitors, non-use of aspirin, non-steroidal anti-inflammatory drugs (NSAIDs), and statins were significantly associated with gastric cancer. A scoring of ≤8 was designated as "average risk (AR)". Scores at 9 or above were assigned as "high risk (HR)". The prevalence of gastric cancer was 1.81% and 0.096%, respectively, for the HR and LR groups. The AUC for the risk score in the validation cohort was 0.834, implying an excellent fit of the model.

CONCLUSIONS

This study has validated a simple, accurate, and easy-to-use scoring algorithm which has a high discriminatory capability to predict gastric cancer. The score could be adopted to risk stratify subjects suspected as having gastric cancer, thus allowing prioritized upper digestive tract investigation.

Aggravated pneumonia and diabetes in SARS-CoV-2 infected diabetic mice

Multiple clinical and epidemiological studies have shown an interconnection between coronavirus disease 2019 (COVID-19) and diabetes, but experimental evidence is still lacking. Understanding the interplay between them is important because of the global health burden of COVID-19 and diabetes. We found that C57BL/6J mice were susceptible to the alpha strain of SARS-CoV-2. Moreover, diabetic C57BL/6J mice with leptin receptor gene deficiency (db/db mice) showed a higher viral load in the throat and lung and slower virus clearance in the throat after infection than C57BL/6J mice. Histological and multifactor analysis revealed more advanced pulmonary injury and serum inflammation in SARS-CoV-2 infected diabetic mice. Moreover, SARS-CoV-2 infected diabetic mice exhibited more severe insulin resistance and islet cell loss than uninfected diabetic mice. By RNA sequencing analysis, we found that diabetes may reduce the collagen level, suppress the immune response and aggravate inflammation in the lung after infection, which may account for the greater susceptibility of diabetic mice and their more severe lung damage after infection. In summary, we successfully established a SARS-CoV-2 infected diabetic mice model and demonstrated that diabetes and COVID-19 were risk factors for one another.

Evolution of SARS-CoV-2 Variants: Implications on Immune Escape, Vaccination, Therapeutic and Diagnostic Strategies

The COVID-19 pandemic caused by SARS-CoV-2 is associated with a lower fatality rate than its SARS and MERS counterparts. However, the rapid evolution of SARS-CoV-2 has given rise to multiple variants with varying pathogenicity and transmissibility, such as the Delta and Omicron variants. Individuals with advanced age or underlying comorbidities, including hypertension, diabetes and cardiovascular diseases, are at a higher risk of increased disease severity. Hence, this has resulted in an urgent need for the development of better therapeutic and preventive approaches. This review describes the origin and evolution of human coronaviruses, particularly SARS-CoV-2 and its variants as well as sub-variants. Risk factors that contribute to disease severity and the implications of co-infections are also considered. In addition, various antiviral strategies against COVID-19, including novel and repurposed antiviral drugs targeting viral and host proteins, as well as immunotherapeutic strategies, are discussed. We critically evaluate strategies of current and emerging vaccines against SARS-CoV-2 and their efficacy, including immune evasion by new variants and sub-variants. The impact of SARS-CoV-2 evolution on COVID-19 diagnostic testing is also examined. Collectively, global research and public health authorities, along with all sectors of society, need to better prepare against upcoming variants and future coronavirus outbreaks.

Incidence of Viral Rebound After Treatment With Nirmatrelvir-Ritonavir and Molnupiravir

Importance

Some patients treated with nirmatrelvir-ritonavir have experienced rebound of COVID-19 infections and symptoms; however, data are scarce on whether viral rebound also occurs in patients with COVID-19 receiving or not receiving molnupiravir.

Objective

To examine the incidence of viral rebound in patients with COVID-19 who were treated with the oral antiviral agents nirmatrelvir-ritonavir and molnupiravir.

Design, Setting, and Participants

This cohort study identified 41 255 patients with COVID-19 who were hospitalized from January 1, 2022, to March 31, 2022, in Hong Kong and assessed 12 629 patients with serial cycle threshold (Ct) values measured. Patients were followed up until the occurrence of the clinical end point of interest, death, date of data retrieval (July 31, 2022), or up to 30 days of follow-up, whichever came first.

Exposures

Molnupiravir or nirmatrelvir-ritonavir treatment.

Main Outcomes and Measures

Viral rebound, defined as a Ct value greater than 40 that decreased to 40 or less.

Results

Of 12 629 patients (mean [SD] age, 65.4 [20.9] years; 6624 [52.5%] male), 11 688 (92.5%) were oral antiviral nonusers, 746 (5.9%) were molnupiravir users, and 195 (1.5%) were nirmatrelvir-ritonavir users. Compared with nonusers, oral antiviral users were older, had more comorbidities, and had lower complete vaccination rates. The mean (SD) baseline Ct value was slightly higher in nirmatrelvir-ritonavir users (22.2 [6.0]) than nonusers (21.0 [5.4]) and molnupiravir users (20.9 [5.4]) (P = .04). Viral rebound occurred in 68 nonusers (0.6%), 2 nirmatrelvir-ritonavir users (1.0%), and 6 molnupiravir users (0.8%). Among 76 patients with viral rebound, 12 of 68 nonusers, 1 of 6 molnupiravir users, and neither of the nirmatrelvir-ritonavir users died of COVID-19.

Conclusions and Relevance

In this cohort study, viral rebound was uncommon in patients taking molnupiravir or nirmatrelvir-ritonavir and was not associated with increased risk of mortality. Given these findings, novel oral antivirals should be considered as a treatment for more patients with COVID-19 in the early phase of the infection.

Impact of the Use of Oral Antiviral Agents on the Risk of Hospitalization in Community Coronavirus Disease 2019 Patients (COVID-19)

BACKGROUND

We examined the effectiveness of molnupiravir and nirmatrelvir/ritonavir in reducing hospitalization and deaths in a real-world cohort of nonhospitalized patients with coronavirus disease 2019 (COVID-19).

METHODS

This was a territory-wide retrospective cohort study in Hong Kong. Nonhospitalized COVID-19 patients who attended designated outpatient clinics between 16 February and 31 March 2022 were identified. Patients hospitalized on the day of the first clinic appointment or used both oral antivirals were excluded. The primary endpoint was hospitalization. The secondary endpoint was a composite of intensive care unit admission, invasive mechanical ventilation use, and/or death.

RESULTS

Of 93 883 patients, 83 154 (88.6%), 5808 (6.2%), and 4921 (5.2%) were oral antiviral nonusers, molnupiravir users, and nirmatrelvir/ritonavir users, respectively. Compared with nonusers, oral antiviral users were older and had more comorbidities, lower complete vaccination rate, and more hospitalizations in the previous year. Molnupiravir users were older and had more comorbidities, lower complete vaccination rate, and more hospitalizations in the previous year than nirmatrelvir/ritonavir users. At a median follow-up of 30 days, 1931 (2.1%) patients were hospitalized and 225 (0.2%) patients developed the secondary endpoint. After propensity score weighting, nirmatrelvir/ritonavir use (weighted hazard ratio 0.79; 95% confidence interval [CI], 0.65-0.95; P = .011) but not molnupiravir use (weighted hazard ratio 1.17; 95% CI, 0.99-1.39; P = .062) was associated with a reduced risk of hospitalization than nonusers. The use of molnupiravir or nirmatrelvir/ritonavir was not associated with a lower risk of the secondary endpoint as compared with nonusers.

CONCLUSION

Use of nirmatrelvir/ritonavir but not molnupiravir was associated with a reduced risk of hospitalization in real-world nonhospitalized patients with COVID-19.

No increased risk of flare in ulcerative colitis patients in corticosteroid-free remission after stopping 5-aminosalicylic acid: A territory-wide population-based study

BACKGROUND AND AIM

Whether 5-aminosalicylic acid (ASA) can be stopped in patients with stable ulcerative colitis (UC) remains unclear. We aimed to examine whether 5-ASA can be safely withdrawn in UC patients who have been in corticosteroid-free clinical remission for ≥ 1 year.

METHODS

This is a retrospective cohort study using territory-wide healthcare database in Hong Kong. Primary outcome was development of UC flare, defined as new corticosteroid use or UC-related hospitalizations within 5 years. UC patients on oral 5-ASA ≥ 2 g daily for ≥ 1 year with C-reactive protein (CRP) < 10 mg/dL and no 5-ASA dosage escalation, UC-related hospitalization or corticosteroid use in the past year were included. Patients on biological agents were excluded. Patients were classified as "stopping" if 5-ASA was withdrawn for ≥ 90 days within follow-up period. We performed multivariable Cox regression models adjusting for demographics, blood parameters and immunosuppressants used. Adjusted hazard ratio (aHR) with 95% confidence interval (CI) was reported comparing stopping and continuous-use groups.

RESULTS

A total of 1408 patients were included with a median follow-up duration of 41.8 months (interquartile range [IQR]: 17.2-60.0 months). Stopping 5-ASA was not associated with an increased risk of UC flare (aHR 0.91; 95% CI 0.64-1.31; P = 0.620). A higher CRP levels at the time of stopping 5-ASA (aHR 1.15; 95% CI: 1.01-1.30; P = 0.037) were associated with increased risk of flare.

CONCLUSION

Stopping 5-ASA in UC patients in corticosteroid-free remission for ≥ 1 year was not associated with increased risk of flare. Future prospective trials should evaluate the role of stopping 5-ASA in stable UC patients.

Predictors and microbiology of respiratory and bloodstream bacterial infection in patients with COVID-19: living rapid review update and meta-regression

Background

The prevalence of bacterial infection in patients with COVID-19 is low, however, empiric antibiotic use is high. Risk stratification may be needed to minimize unnecessary empiric antibiotic use.

Objective

To identify risk factors and microbiology associated with respiratory and bloodstream bacterial infection in patients with COVID-19.

Data sources

We searched MEDLINE, OVID Epub and EMBASE for published literature up to 5 February 2021.

Study eligibility criteria

Studies including at least 50 patients with COVID-19 in any healthcare setting.

Methods

We used a validated ten-item risk of bias tool for disease prevalence. The main outcome of interest was the proportion of COVID-19 patients with bloodstream and/or respiratory bacterial co-infection and secondary infection. We performed meta-regression to identify study population factors associated with bacterial infection including healthcare setting, age, comorbidities and COVID-19 medication.

Results

Out of 33 345 studies screened, 171 were included in the final analysis. Bacterial infection data were available from 171 262 patients. The prevalence of co-infection was 5.1% (95% CI 3.6–7.1%) and secondary infection was 13.1% (95% CI 9.8–17.2%). There was a higher odds of bacterial infection in studies with a higher proportion of patients in the intensive care unit (ICU) (adjusted OR 18.8, 95% CI 6.5–54.8). Female sex was associated with a lower odds of secondary infection (adjusted OR 0.73, 95% CI 0.55–0.97) but not co-infection (adjusted OR 1.05, 95% CI 0.80–1.37). The most common organisms isolated included Staphylococcus aureus, coagulase-negative staphylococci and Klebsiella species.

Conclusions

While the odds of respiratory and bloodstream bacterial infection are low in patients with COVID-19, meta-regression revealed potential risk factors for infection, including ICU setting and mechanical ventilation. The risk for secondary infection is substantially greater than the risk for co-infection in patients with COVID-19. Understanding predictors of co-infection and secondary infection may help to support improved antibiotic stewardship in patients with COVID-19.

Diabetes, hypertension, body mass index, smoking and COVID-19-related mortality: a systematic review and meta-analysis of observational studies

OBJECTIVES

We conducted a systematic literature review and meta-analysis of observational studies to investigate the association between diabetes, hypertension, body mass index (BMI) or smoking with the risk of death in patients with COVID-19 and to estimate the proportion of deaths attributable to these conditions.

METHODS

Relevant observational studies were identified by searches in the PubMed, Cochrane library and Embase databases through 14 November 2020. Random-effects models were used to estimate summary relative risks (SRRs) and 95% CIs. Certainty of evidence was assessed using the Cochrane methods and the Grading of Recommendations, Assessment, Development and Evaluations framework.

RESULTS

A total of 186 studies representing 210 447 deaths among 1 304 587 patients with COVID-19 were included in this analysis. The SRR for death in patients with COVID-19 was 1.54 (95% CI 1.44 to 1.64, I2=92%, n=145, low certainty) for diabetes and 1.42 (95% CI 1.30 to 1.54, I2=90%, n=127, low certainty) for hypertension compared with patients without each of these comorbidities. Regarding obesity, the SSR was 1.45 (95% CI 1.31 to 1.61, I2=91%, n=54, high certainty) for patients with BMI ≥30 kg/m2 compared with those with BMI <30 kg/m2 and 1.12 (95% CI 1.07 to 1.17, I2=68%, n=25) per 5 kg/m2 increase in BMI. There was evidence of a J-shaped non-linear dose-response relationship between BMI and mortality from COVID-19, with the nadir of the curve at a BMI of around 22-24, and a 1.5-2-fold increase in COVID-19 mortality with extreme obesity (BMI of 40-45). The SRR was 1.28 (95% CI 1.17 to 1.40, I2=74%, n=28, low certainty) for ever, 1.29 (95% CI 1.03 to 1.62, I2=84%, n=19) for current and 1.25 (95% CI 1.11 to 1.42, I2=75%, n=14) for former smokers compared with never smokers. The absolute risk of COVID-19 death was increased by 14%, 11%, 12% and 7% for diabetes, hypertension, obesity and smoking, respectively. The proportion of deaths attributable to diabetes, hypertension, obesity and smoking was 8%, 7%, 11% and 2%, respectively.

CONCLUSION

Our findings suggest that diabetes, hypertension, obesity and smoking were associated with higher COVID-19 mortality, contributing to nearly 30% of COVID-19 deaths.

TRIAL REGISTRATION NUMBER

CRD42020218115.

Glucose-lowering drugs and outcome from COVID-19 among patients with type 2 diabetes mellitus: a population-wide analysis in Hong Kong

OBJECTIVES

To investigate the association between baseline use of glucose-lowering drugs and serious clinical outcome among patients with type 2 diabetes.

DESIGN

Territory-wide retrospective cohort of confirmed cases of COVID-19 between January 2020 and February 2021.

SETTING

All public health facilities in Hong Kong.

PARTICIPANTS

1220 patients with diabetes who were admitted for confirmed COVID-19.

PRIMARY AND SECONDARY OUTCOME MEASURES

Composite clinical endpoint of intensive care unit admission, requirement of invasive mechanical ventilation and/or in-hospital death.

RESULTS

In this cohort (median age 65.3 years, 54.3% men), 737 (60.4%) patients were treated with metformin, 385 (31.6%) with sulphonylureas, 199 (16.3%) with dipeptidyl peptidase-4 (DPP-4) inhibitors and 273 (22.4%) with insulin prior to admission. In multivariate Cox regression, use of metformin and DPP-4 inhibitors was associated with reduced incidence of the composite endpoint relative to non-use, with respective HRs of 0.51 (95% CI 0.34 to 0.77, p=0.001) and 0.46 (95% CI 0.29 to 0.71, p<0.001), adjusted for age, sex, diabetes duration, glycated haemoglobin (HbA1c), smoking, comorbidities and drugs. Use of sulphonylureas (HR 1.55, 95% CI 1.07 to 2.24, p=0.022) and insulin (HR 6.34, 95% CI 3.72 to 10.78, p<0.001) were both associated with increased hazards of the composite endpoint.

CONCLUSIONS

Users of metformin and DPP-4 inhibitors had fewer adverse outcomes from COVID-19 compared with non-users, whereas insulin and sulphonylurea might predict a worse prognosis.

Association between Vitamin D Status and Risk of Developing Severe COVID-19 Infection: A Meta-Analysis of Observational Studies

OBJECTIVE

The relationship between 25-hydroxyvitamin D3 (25(OH)D), the surrogate marker for vitamin D₃, serum concentration and COVID-19 has come to the forefront as a potential pathway to improve COVID-19 outcomes. The current evidence remains unclear on the impact of vitamin D status on the severity and outcomes of COVID-19 infection. To explore possible association between low 25(OH)D levels and risk of developing severe COVID-19 (i.e. need for invasive mechanical ventilation, the length of hospital stay, total deaths). We also aimed to understand the relationship between vitamin D insufficiency and elevated inflammatory and cardiac biomarkers.

METHODS

We conducted a comprehensive electronic literature search for any original research study published up to March 30, 2021. For the purpose of this review, low vitamin D status was defined as a range of serum total 25(OH)D levels of <10 to <30 ng/ml. Two independent investigators assessed study eligibility, synthesized evidence, analyzed, critically examined, and interpreted herein.

RESULTS

Twenty-four observational studies containing 3637 participants were included in the meta-analysis. The mean age of the patients was 61.1 years old; 56% were male. Low vitamin D status was statistically associated with higher risk of death (RR, 1.60 (95% CI, 1.10-2.32), higher risk of developing severe COVID-19 pneumonia (RR: 1.50; 95% CI, 1.10-2.05). COVID-19 patients with low vitamin D levels had a greater prevalence of hypertension and cardiovascular diseases, abnormally high serum troponin and peak D-dimer levels, as well as elevated interleukin-6 and C-reactive protein than those with serum 25(OH)D levels ≥30 ng/ml.

CONCLUSIONS

In this meta-analysis, we found a potential increased risk of developing severe COVID-19 infection among patients with low vitamin D levels. There are plausible biological mechanisms supporting the role of vitamin D in COVID-19 severity. Randomized controlled trials are needed to test for potential beneficial effects of vitamin D in COVID-19 outcomes.

Hospital mortality in patients with rare diseases during pandemics: lessons learnt from the COVID-19 and SARS pandemics

BACKGROUND

The threat and experience of pandemics occur differently for different groups. The rare disease population is at particular risk of being further marginalised during pandemics. In this study, our objective was to assess the hospital mortality patterns in the rare disease and the general populations during the coronavirus disease of 2019 (COVID-19) and severe acute respiratory syndrome (SARS) pandemics in Hong Kong.

METHODS

All admission records during the COVID-19 pandemic (January 23-August 23, 2020) and SARS pandemic (March 11-June 30, 2003) were extracted from the local public healthcare database. Patients with rare diseases were identified using one or more of the 1084 10th version International Classification of Diseases and Related Health Problems (ICD-10) codes cross-referenced with 467 ORPHAcodes. Hospital mortality patterns were compared in patients with and without COVID-19/SARS infection. Admission records during the same period in 2019 and 2002 were retrieved for comparison.

RESULTS

During the COVID-19 pandemic, 407,219 patients were admitted to one or more of the 43 public hospitals in Hong Kong, of which, 13,894 were patients with rare diseases (3.4%). A total of 4381 and 77 patients from the general and rare disease populations were infected with COVID-19. Rare disease patients had an adjusted 3.4 times odds of COVID-19-related hospital mortality compared with that of the general population (95% C.I. 1.24-9.41). COVID-19-related mortality was almost exclusively seen in patients ≥ 60 years. While age-related increase in mortality was also observed for the general population during the SARS pandemic, the pattern observed in the rare disease population was significantly different, with a 12.5 times higher SARS-related mortality observed in rare disease patients ≤ 18 years than those in the general population (12.5% vs 1.0%). Patients admitted during the same pandemic periods without coronavirus infection had a significantly higher hospital mortality compared with those admitted one year before the pandemic (p < 0.001).

CONCLUSION

This population-based study demonstrated the differential impacts of the COVID-19 and SARS pandemics on the rare disease population. In the era of budget and resource scarcity, this study warrants cautious healthcare planning, with consideration of the rare disease population in healthcare prioritisation.

Differential Impacts of Multimorbidity on COVID-19 Severity across the Socioeconomic Ladder in Hong Kong: A Syndemic Perspective

The severity of COVID-19 infections could be exacerbated by the epidemic of chronic diseases and underlying inequalities in social determinants of health. Nonetheless, there is scanty evidence in regions with a relatively well-controlled outbreak. This study examined the socioeconomic patterning of COVID-19 severity and its effect modification with multimorbidity in Hong Kong. 3074 local COVID-19 cases diagnosed from 5 July to 31 October 2020 were analyzed and followed up until 30 November 2020. Data on residential addresses, socio-demographic background, COVID-19 clinical conditions, and pre-existing chronic diseases of confirmed cases were retrieved from the Centre for Health Protection and the Hospital Authority. Results showed that, despite an independent adverse impact of multimorbidity on COVID-19 severity (aOR = 2.35 [95% CI = 1.72-3.19]), it varied across the socioeconomic ladder, with no significant risk among those living in the wealthiest areas (aOR = 0.80 [0.32-2.02]). Also, no significant association of the area-level income-poverty rate with severe COVID-19 was observed. In conclusion, the socioeconomic patterning of severe COVID-19 was mild in Hong Kong. Nonetheless, socioeconomic position interacted with multimorbidity to determine COVID-19 severity with a mitigated risk among the socioeconomically advantaged. Plausible explanations include the underlying socioeconomic inequalities in chronic disease management and the equity impact of the public-private dual-track healthcare system.

Type-I interferon signatures in SARS-CoV-2 infected Huh7 cells

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that causes Coronavirus disease 2019 (COVID-19) has caused a global health emergency. A key feature of COVID-19 is dysregulated interferon-response. Type-I interferon (IFN-I) is one of the earliest antiviral innate immune responses following viral infection and plays a significant role in the pathogenesis of SARS-CoV-2. In this study, using a proteomics-based approach, we identified that SARS-CoV-2 infection induces delayed and dysregulated IFN-I signaling in Huh7 cells. We demonstrate that SARS-CoV-2 is able to inhibit RIG-I mediated IFN-β production. Our results also confirm the recent findings that IFN-I pretreatment is able to reduce the susceptibility of Huh7 cells to SARS-CoV-2, but not post-treatment. Moreover, senescent Huh7 cells, in spite of showing accentuated IFN-I response were more susceptible to SARS-CoV-2 infection, and the virus effectively inhibited IFIT1 in these cells. Finally, proteomic comparison between SARS-CoV-2, SARS-CoV, and MERS-CoV revealed a distinct differential regulatory signature of interferon-related proteins emphasizing that therapeutic strategies based on observations in SARS-CoV and MERS-CoV should be used with caution. Our findings provide a better understanding of SARS-CoV-2 regulation of cellular interferon response and a perspective on its use as a treatment. Investigation of different interferon-stimulated genes and their role in the inhibition of SARS-CoV-2 pathogenesis may direct novel antiviral strategies.

SARS-CoV-2 infection dynamics in Denmark, February through October 2020: Nature of the past epidemic and how it may develop in the future

BACKGROUND

Initially, the relative sizes of the asymptomatic and the symptomatic infected populations were not known for the COVID-19 pandemic and neither was the actual fatality rate. Therefore it was not clear either how the pandemic would impact the healthcare system. As a result it was initially predicted that the COVID-19 epidemic in Denmark would overwhelm the healthcare system and thus both the diagnosis and treatment of other hospital patients were compromised for an extended period.

AIM

To develop a mathematical model, which includes both asymptomatic and symptomatic infected persons, for early estimation of the epidemic's course, its Infection Fatality Rate and the healthcare system load in Denmark, both retrospectively and prospectively.

METHODS

The SEIRS (Susceptible-Exposed-Infected-Recovered-Susceptible) model including deaths outside hospitals and separate assessments of symptomatic and asymptomatic cases (based on seroprevalence) with different immunological memories. Optimal model parameters are in part identified by Monte Carlo based Least Square Error methods while micro-outbreaks are modeled by noise and explored in Monte Carlo simulations. Estimates for infected population sizes are obtained by using a quasi steady state method.

RESULTS

The calculations and simulations made by the model were shown to fit with the observed development of the COVID-19 epidemic in Denmark. The antibody prevalence in the general population in May 2020 was 1.37%, which yields a relative frequency of symptomatic and asymptomatic cases of 1 to 5.2. Due to the large asymptomatic population, the Infection Mortality Rate was only 0.4%. However, with no non-pharmacological restrictions the COVID-19 death toll was calculated to have more than doubled the national average yearly deaths within a year. The transmission rate ℜ0 was 5.4 in the initial free epidemic period, 0.4 in the lock-down period and 0.8-1.0 in the successive re-opening periods through August 2020. The large asymptomatic population made the termination of the epidemic difficult and micro-outbreaks occurred when the country re-opened. The estimated infected population size July 15 to August 15 was 2,100 and 12,200 for October 1-20, 2020.

CONCLUSIONS

The results of the model show, that COVID-19 has a low Infection Fatality Rate because the majority of infected persons are either asymptomatic or with few symptoms. A minority of the infected persons, therefore, requires hospitalization. That means that for a given infection pressure of both symptomatic and asymptomatic infected there will be a lower pressure on the capacity of the health care system than previously predicted. Further the epidemic will be difficult to terminate since about 84% of the infected individuals are asymptomatic but still contagious. The model may be useful if a major infection wave occurs in the autumn-winter season as it could make robust estimates both for the scale of an ongoing expanding epidemic and for the expected load on the healthcare system. The simulation may also be useful to evaluate different testing strategies based on estimated infected population sizes. The model can be adjusted and scaled to other regions and countries, which is illustrated with Spain and USA.