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1.
Commun Med (Lond) ; 2: 53, 2022.
Article in English | MEDLINE | ID: covidwho-1947555

ABSTRACT

Background: The adaptive immune responses of COVID-19 patients contributes to virus clearance, restoration of health and protection from re-infection. The patterns of and the associated characteristics with longitudinal neutralising antibody (NAb) response following SARS-CoV-2 infection are important in their potential association with the population risks of re-infection. Methods: This is a longitudinal study with blood samples and clinical data collected in adults aged 18 or above following diagnosis of SARS-CoV-2 infection. NAb levels were measured by the SARS-CoV-2 surrogate virus neutralisation test (sVNT). Anonymous clinical and laboratory data were matched with surveillance data for each subject for enabling analyses and applying latent class mixed models for trajectory delineation. Logistic regression models were performed to compare the characteristics between the identified classes. Results: In 2020-2021, 368 convalescent patients in Hong Kong are tested for NAb. Their seroconversion occur within 3 months in 97% symptomatic patients, the level of which are maintained at 97% after 9 months. The NAb trajectories of 200 symptomatic patients are classified by the initial response and subsequent trend into high-persistent and waning classes in latent class mixed models. High-persistent (15.5%) class patients are older and most have chronic illnesses. Waning class patients (84.5%) are largely young adults who are mildly symptomatic including 2 who serorevert after 10 months. Conclusions: Characteristic sub-class variabilities in clinical pattern are noted especially among patients with waning NAb. The heterogeneity of the NAb trajectory patterns and their clinical association can be important for informing vaccination strategy to prevent re-infection.

2.
Ecotoxicol Environ Saf ; 241: 113740, 2022 Aug.
Article in English | MEDLINE | ID: covidwho-1944829

ABSTRACT

Air and surface contamination of the SARS-CoV-2 have been reported by multiple studies. However, the evidence is limited for the change of environmental contamination of this virus in the surrounding of patients with COVID-19 at different time points during the course of disease and under different conditions of the patients. Therefore, this study aims to understand the risk factors associated with the appearance of SARS-CoV-2 through the period when the patients were staying in the isolation wards. In this study, COVID-19 patients admitted to the isolation wards were followed up for up to 10 days for daily collection of air and surface samples in their surroundings. The positivity rate of the environmental samples at different locations was plotted, and multiple multi-level mixed-effect logistic regressions were used to examine the association between the positivity of environmental samples and their daily health conditions and environmental factors. It found 6.6 % of surface samples (133/2031 samples) and 2.1 % of air samples (22/1075 samples) were positive, and the positivity rate reached to peak during 2-3 days after admission to the ward. The virus was more likely to present at bedrail, patients' personal items and medical equipment, while less likely to be detected in the air outside the range of 2 m from the patients. It also revealed that higher positivity rate is associated with lower environmental temperature, fever and cough at the day of sampling, lower Ct values of latest test for respiratory tract samples, and pre-existing respiratory or cardiovascular conditions. The finding can be used to guide the hospital infection control strategies by identifying high-risk areas and patients. Extra personal hygiene precautions and equipment for continuously environmental disinfection can be used for these high-risk areas and patients to reduce the risk of hospital infection.


Subject(s)
COVID-19 , Cross Infection , Air Microbiology , COVID-19/epidemiology , COVID-19/prevention & control , Cross Infection/prevention & control , Disinfection , Environment , Equipment Contamination , Hospitals , Humans , Infection Control , SARS-CoV-2
3.
Seminars in Nephrology ; 2022.
Article in English | ScienceDirect | ID: covidwho-1937145

ABSTRACT

The Covid-19 pandemic caused by the severe acute respiratory syndrome coronavirus (SARS-CoV-2) has faced the transplant community with unprecedented clinical challenges in a highly vulnerable patient category. These were associated with many uncertainties for patients and healthcare professionals and prompted many ethical debates regarding safe delivery of kidney transplantation. In this paper, we highlight some of the most important ethical questions that were raised during the pandemic and attempt to analyse ethical arguments in the light of core principles of medical ethics to either suspend or continue kidney transplantation, to mandate vaccination in transplant patients and transplant candidates, and finally healthcare providers. We have come up with frameworks to deal responsibly with these ethical challenges, and formulated recommendations to cope with the issues imposed on patients and transplant professionals.

4.
J Hazard Mater ; 436: 129152, 2022 08 15.
Article in English | MEDLINE | ID: covidwho-1851499

ABSTRACT

Although airborne transmission has been considered as a possible route for the spread of SARS-CoV-2, the role that aerosols play in SARS-CoV-2 transmission is still controversial. This study evaluated the airborne transmission of SARS-CoV-2 in COVID-19 isolation wards at Prince of Wales Hospital in Hong Kong by both on-site sampling and numerical analysis. A total of 838 air samples and 1176 surface samples were collected, and SARS-CoV-2 RNA was detected using the RT-PCR method. Testing revealed that 2.3% of the air samples and 9.3% of the surface samples were positive, indicating that the isolation wards were contaminated with the virus. The dispersion and deposition of exhaled particles in the wards were calculated by computational fluid dynamics (CFD) simulations. The calculated accumulated number of particles collected at the air sampling points was closely correlated with the SARS-CoV-2 positive rates from the field sampling, which confirmed the possibility of airborne transmission. Furthermore, three potential intervention strategies, i.e., the use of curtains, ceiling-mounted air cleaners, and periodic ventilation, were numerically investigated to explore effective control measures in isolation wards. According to the results, the use of ceiling-mounted air cleaners is effective in reducing the airborne transmission of SARS-CoV-2 in such wards.


Subject(s)
COVID-19 , SARS-CoV-2 , Aerosols , COVID-19/epidemiology , Hospitals , Humans , RNA, Viral
5.
Nephrology (Carlton) ; 2022 Apr 08.
Article in English | MEDLINE | ID: covidwho-1784718

ABSTRACT

Peritoneal dialysis (PD) first policy has been established in Hong Kong since 1985. After 35 years of practice, the PD first policy in Hong Kong has influenced many countries around the world including governments, health ministries, nephrologists and renal nurses on the overall health policy structure and clinical practice in treating kidney failure patients using PD as an important dialysis modality. In 2021, the International Association of Chinese Nephrologists and the Hong Kong Society of Nephrology jointly held a symposium celebrating the 35 years of PD first policy in Hong Kong. In that symposium, experts and opinion leaders from around the world have shared their perspectives on how the PD first policy has grown and how it has affected PD and home dialysis practice globally. The advantages of PD during COVID-19 pandemic were highlighted and the use of telemedicine as an important adjunct was discussed in treating kidney failure patients to improve the overall quality of care. Barriers to PD and the need for sustainability of PD first policy were also emphasized. Overall, the knowledge awareness of PD as a home dialysis for patients, families, care providers and learners is a prerequisite for the success of PD first. A critical mass of PD regional hubs is needed for training and mentorship. Importantly, the alignment of policy and clinical goals are enablers of PD first program.

6.
J Gastroenterol Hepatol ; 37(5): 823-831, 2022 May.
Article in English | MEDLINE | ID: covidwho-1685355

ABSTRACT

BACKGROUND AND AIM: Gut dysbiosis is associated with immune dysfunction and severity of COVID-19. Whether targeting dysbiosis will improve outcomes of COVID-19 is unknown. This study aimed to assess the effects of a novel gut microbiota-derived synbiotic formula (SIM01) as an adjuvant therapy on immunological responses and changes in gut microbiota of hospitalized COVID-19 patients. METHODS: This was an open-label, proof-of-concept study. Consecutive COVID-19 patients admitted to an infectious disease referral center in Hong Kong were given a novel formula of Bifidobacteria strains, galactooligosaccharides, xylooligosaccharide, and resistant dextrin (SIM01). The latter was derived from metagenomic databases of COVID-19 patients and healthy population. COVID-19 patients who were admitted under another independent infectious disease team during the same period without receiving SIM01 acted as controls. All patients received standard treatments for COVID-19 according to the hospital protocol. We assessed antibody response, plasma proinflammatory markers, nasopharyngeal SARS-CoV-2 viral load, and fecal microbiota profile from admission up to week 5. RESULTS: Twenty-five consecutive COVID-19 patients received SIM01 for 28 days; 30 patients who did not receive the formula acted as controls. Significantly more patients receiving SIM01 than controls developed SARS-CoV-2 IgG antibody (88% vs 63.3%; P = 0.037) by Day 16. One (4%) and 8 patients (26.7%) in the SIM01 and control group, respectively, failed to develop positive IgG antibody upon discharge. At week 5, plasma levels of interleukin (IL)-6, monocyte chemoattractant protein-1 (MCP-1), macrophage colony-stimulating factor (M-CSF), tumor necrosis factor (TNF-α), and IL-1RA reduced significantly in the SIM01 but not in the control group. There was a significant negative correlation of nasopharyngeal SARS-CoV-2 viral load and SIM01 intervention. Metagenomic analysis showed that bacterial species in SIM01 formula were found in greater abundance leading to enrichment of commensal bacteria and suppression of opportunistic pathogens in COVID-19 patients by week 4 and week 5. CONCLUSIONS: This proof-of-concept study suggested that the use of a novel gut microbiota-derived synbiotic formula, SIM01, hastened antibody formation against SARS-CoV-2, reduced nasopharyngeal viral load, reduced pro-inflammatory immune markers, and restored gut dysbiosis in hospitalised COVID-19 patients.


Subject(s)
COVID-19 , Gastrointestinal Microbiome , Synbiotics , Bacteria , COVID-19/therapy , Dysbiosis , Humans , Immunoglobulin G , Pilot Projects , SARS-CoV-2
7.
Gut ; 70(4): 698-706, 2021 04.
Article in English | MEDLINE | ID: covidwho-1024254

ABSTRACT

OBJECTIVE: Although COVID-19 is primarily a respiratory illness, there is mounting evidence suggesting that the GI tract is involved in this disease. We investigated whether the gut microbiome is linked to disease severity in patients with COVID-19, and whether perturbations in microbiome composition, if any, resolve with clearance of the SARS-CoV-2 virus. METHODS: In this two-hospital cohort study, we obtained blood, stool and patient records from 100 patients with laboratory-confirmed SARS-CoV-2 infection. Serial stool samples were collected from 27 of the 100 patients up to 30 days after clearance of SARS-CoV-2. Gut microbiome compositions were characterised by shotgun sequencing total DNA extracted from stools. Concentrations of inflammatory cytokines and blood markers were measured from plasma. RESULTS: Gut microbiome composition was significantly altered in patients with COVID-19 compared with non-COVID-19 individuals irrespective of whether patients had received medication (p<0.01). Several gut commensals with known immunomodulatory potential such as Faecalibacterium prausnitzii, Eubacterium rectale and bifidobacteria were underrepresented in patients and remained low in samples collected up to 30 days after disease resolution. Moreover, this perturbed composition exhibited stratification with disease severity concordant with elevated concentrations of inflammatory cytokines and blood markers such as C reactive protein, lactate dehydrogenase, aspartate aminotransferase and gamma-glutamyl transferase. CONCLUSION: Associations between gut microbiota composition, levels of cytokines and inflammatory markers in patients with COVID-19 suggest that the gut microbiome is involved in the magnitude of COVID-19 severity possibly via modulating host immune responses. Furthermore, the gut microbiota dysbiosis after disease resolution could contribute to persistent symptoms, highlighting a need to understand how gut microorganisms are involved in inflammation and COVID-19.


Subject(s)
Bacteria , COVID-19 , Dysbiosis , Gastrointestinal Microbiome/immunology , Gastrointestinal Tract , Immunity , SARS-CoV-2 , Adult , Bacteria/genetics , Bacteria/immunology , Bacteria/isolation & purification , C-Reactive Protein/analysis , COVID-19/blood , COVID-19/diagnosis , COVID-19/epidemiology , COVID-19/immunology , Cytokines/analysis , DNA, Bacterial/isolation & purification , Dysbiosis/epidemiology , Dysbiosis/etiology , Dysbiosis/immunology , Dysbiosis/virology , Female , Gastrointestinal Tract/immunology , Gastrointestinal Tract/microbiology , Gastrointestinal Tract/virology , Hong Kong , Humans , Male , SARS-CoV-2/immunology , SARS-CoV-2/isolation & purification , Severity of Illness Index , Transferases/analysis
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