Opportunistic Respiratory Pathogens in Symptomatic Non- Covid-19 Adults during a Presumptive Influenza Season

Intro: It is hypothesized that metagenomics could contribute to the effective sentinel surveillance of emerging infections to identify plausible cause of respiratory symptoms in the population. Method(s): This study forms part of a longitudinal household cohort study involving the collection of respiratory symptoms and vaccination history in Hong Kong. As a pilot, selected households were provided with swab collection kit for collecting nasopharyngeal and throat samples when there was an influenza-like illness (ILI) during a 4-month presumptive period of the year's winter influenza season. Sequence-Independent Single Primer Amplification (SISPA) and nanopore metagenomic sequencing were performed. After basecalling, demultiplexing, and quality filtering, taxonomic classification was done. Unclassified and host reads were removed and only taxon with over 0.1% abundance were included in the analysis. Finding(s): Between December 2021 and April 2022, of 101 collection kits delivered, 36 (36%) participants returned the samples. Two (6%) had previous COVID-19 diagnosis and almost all (97%) received at least one dose of COVID-19 vaccination. Metagenomics sequencing was performed on 13 samples collected from participants when ILI was present. Of the 1,592,219 reads obtained, 5308 taxa were identified and 136 had over 0.1% abundance, including 128 bacteria, 6 fungi, and 1 virus, which was a bacteriophage. The five most abundant genera of bacteria included Neisseria (19%), Streptococcus (10%), Haemophilus (9%), Veillonella (3%), and Rothia (3%). Haemophilus parainfluenzae was the most abundant species with 97,542 (6%) reads, followed by Neisseria meningitides (5%). Other bacteria identified included Rothia mucilaginosa, Acinetobacter baumannii, Lautropia mirabilis, Veillonella atypica, Streptococcus salivarius, and Streptococcus pneumonia. Inter-participant abundance profile was significantly different (p<0.001). Conclusion(s): The absence of viral infections identified echoed the extremely low proportion (3/21986, or 0.01%) of respiratory specimens testing positive for influenza virus by the government laboratory during the same period. The metagenomic profile could be useful for identifying the likely ILI-causing pathogen.Copyright © 2023

Antibody responses to SARS-CoV-2 vaccination outperform responses induced by natural infection in patients with IBD receiving immunosuppressive medications: A report from the ICARUS-IBD consortium

Background: The effects of immunosuppressive medications on immune responses to COVID-19 vaccination in patients with inflammatory bowel diseases (IBD) have been reported. However there is little data on immune responses in naturally infected SARS-CoV-2 patients compared with vaccination. We compared in a longitudinal study SARS-CoV-2 antibody and T cell responses in naturally-infected vs. vaccinated IBD patients Methods: 110 IBD patients enrolled at the Icahn School of Medicine at Mount Sinai were prospectively followed with serial blood collection between May 2020, and February 2022. Samples were screened by ELISA to determine seropositivity, and stratified by infection, vaccination status, and IBD medications. Subsequently, ELISA-based inhibition assay and pseudotyped SARS-CoV-2 microneutralization assays were used to determine the inhibition and neutralization capacity of the seropositive individuals for wild type (WT) delta variant (Dv) and Omicron. Cellular responses were measured by IFN-gamma ELIspot using nucleocapsid and spike peptide libraries Results: Overall, 64 patients had Crohn's Disease and 46 had Ulcerative Colitis (UC), 69 were naturally infected. Only Anti-TNF (N=52), Ustekinumab (N=16), and Vedolizumab (VDZ) (N=33) treatment groups were considered. Only US-available vaccinations were included. Double-vaccinated IBD patients showed greater neutralizing responses to SARS-CoV-2 WT and Dv than naturally-infected individuals (p=0.0003, p=0.0025). Moreover, double-vaccinated individuals had greater neutralizing reactions against WT than DV (p 0.017) and Omicron (p 0.001) variants. Following natural infection, there were no differences between treatment groups in neutralization response, however those double-vaccinated on anti-TNF had lower neutralization than VDZ (p=0.008). Neutralization responses were maintained for a period of 8 months following natural infection and double vaccination SARS-CoV-2 spike T cell responses were significantly higher in naturally infected (p=0.009) and double vaccinated individuals (p=0.005) with no significant differences between treatment groups (p<0.999) Conclusion(s): After a second vaccine dose, IBD patients showed stronger neutralizing antibody titers than naturally infected patients. Those on anti-TNF exhibited lower neutralizing responses than VDZ. T-cell responses were similar in infected and double-vaccinated subjects after vaccination or infection. These data imply COVID-19 immunization provides additional serological protection over natural infection.

Antibiotic use for respiratory tract infections among older adults living in long-term care facilities: a systematic review and meta-analysis.

BACKGROUND: Antibiotics are commonly prescribed for respiratory tract infections (RTIs) among older adults in long-term care facilities (LTCFs), and this contributes to the emergence of antimicrobial resistance. The objective of this study was to determine the antibiotic prescribing rate for RTIs among LTCF residents, and to analyse the antibiotic consumption patterns with the AwaRe monitoring tool, developed by the World Health Organization. METHODS: MEDLINE, EMBASE and CINAHL were searched from inception to March 2022. Original articles reporting antibiotic use for RTIs in LTCFs were included in this review. Study quality was assessed using the Joanna Briggs Institute's Critical Appraisal Checklist for Prevalence Data. A random-effects meta-analysis was employed to calculate the pooled estimates. Subgroup analysis was conducted by type of RTI, country, and study start year. RESULTS: In total, 47 articles consisting of 50 studies were included. The antibiotic prescribing rate ranged from 21.5% to 100% (pooled estimate 69.8%, 95% confidence interval 55.2-82.6%). The antibiotic prescribing rate for lower respiratory tract infections (LRTIs) was higher than the rates for viral and general RTIs. Compared with Italy, France and the USA, the Netherlands had lower antibiotic use for LRTIs. A proportion of viral RTIs were treated with antibiotics, and all the antibiotics were from the Watch group. Use of antibiotics in the Access group was higher in the Netherlands, Norway, Switzerland and Slovenia compared with the USA and Australia. CONCLUSION: The antibiotic prescribing rate for RTIs in LTCFs was high, and AWaRe antibiotic use patterns varied by type of RTI and country. Improving antibiotic use may require coordination efforts.

Neutralising antibody titers and COVID outcomes in cancer patients

Background: Cancer patients are at high risk of severe COVID infection and recommended at least three doses of SARS-CoV2 mRNA vaccines. Various anti-neoplastic treatments may affect long-term vaccine immunogenicity. Methods: Patients with solid or haematological cancer were recruited from two Singapore hospitals between July 2021 and March 2022. GenScript cPASS surrogate virus neutralisation assays measured antibody responses, which were correlated with clinical outcomes obtained from medical records and national mandatory-reporting databases. Results: In total, 273 patients were recruited (40 with haematological malignancies and the rest solid tumours). Two-hundred and four patients (74.7%) were receiving active cancer therapy: 98 (35.9%) receiving systemic chemotherapy and the rest targeted or immunotherapy. All patients were seronegative at baseline. After receiving one, two and three doses of SARS-CoV-2-mRNA vaccination, seroconversion rate was 35.2%, 79.4% and 92.4% respectively. After three doses, patients on active treatment for haematological malignancies had lower antibodies (57.3%±46.2) as compared to patients on immunotherapy (94.1%±9.56, p<0.05) and chemotherapy (92.8%±18.1, p<0.05). SARS-CoV-2 infection was reported in 77 (28.2%) patients of which 18 were severe. Conclusion: This study demonstrates high immunogenicity of three doses of vaccines and protection against severe infection in cancer patients.

A Community-Designed Qr Code-Based Animation Helps Patients Prepare for Endoscopies

Aim: Conventionally, patients are gathered to watch an introductory video at the clinic before endoscopic investigations take place. This may arouse practical issues under the COVID pandemic. Our centre, in collaboration with students from a local secondary school, has designed a set of animations which patients can easily access to with a QR code using their own mobile devices, so as to avoid patient gathering and increase their flexibility to read the information. This study aims to evaluate patients' perception of the QR code-based introductory animations of esophagogastroduodenoscopy (OGD) and colonoscopy (CLN). Method(s): A QR code linking to the animation was attached to the appointment sheet. Patients were asked to watch the animation with their own mobile devices before the endoscopy. A questionnaire with 5 questions was distributed after completion of their procedures. Result(s): A total of 144 patients undergoing OGD and CLN were recruited in May-June, 2022 at Tin Shui Wai Hospital. The response rate was 91.7%. Positive feedback was received. 12 patients (8.3%) did not gain access to the animation. A majority of patients agreed or totally agreed that the animation offered them more flexibility to understand the procedures before their OGD (75.4%) and CLN (79.1%). The QR code-based animation was deemed easy-to-use (80.3%), appealing (78.0%) and educational (81.0%). Conclusion(s): With increasing accessibility to mobile devices, patient education in preparation for medical procedures is no longer confined to the hospital setting. QR code-based animation is shown to be an effective and welcoming tool to prepare patients for endoscopies.

Trans-continental analysis of over, 2000 Inflammatory Bowel Disease patients implicates geography, disease type, and exposure to immunosuppression as drivers of SARS-CoV-2 seroprevalence: data from the ICARUS-IBD Consortium

Background IBD patients on immune-modulatory therapies are considered high-risk for SARS-CoV-2 infection. Direct comparisons of serological responses to SARS-CoV-2 infection in IBD patients across different continents and medications are lacking. We performed SARS-CoV-2 sero-surveillance of IBD patients prior to vaccination at seven large tertiary centres in Asia, Europe, and North America. Methods Clinical data and sera were collected from, 2,213 IBD patients receiving routine care at institutions in Belgium, Canada, Hong Kong, India, Japan, the United Kingdom, and the United States between, 26 May, 2020 and, 24 September, 2021 (Table, 1). Sera were taken prior to vaccination. Clinical data were collected through patient questionnaires and medical records. Antibody reactivity to the SARS-CoV-2 spike protein was assessed using the Roche SARS-CoV-2 anti-spike total antibody and/or Siemens Healthineers COV2T anti-spike total antibody assays, which showed, 99.4% concordance. Univariate analysis was performed to evaluate association between individual variables and sero-status. Results The pre-vaccination seroprevalence of antibodies to SARS-CoV-2 in IBD patient varied widely according to location from, 0% in Hong Kong to, 57.9% in New Delhi, India (p<0.001). Rates in Europe and North America were similar (range, 3.57%-8.94%). Overall, SARS-CoV-2 seroprevalence appears to be equal to or less than local populations (Table, 2). Seroprevalence rates were associated with IBD type (7.8% CD, 12.4% UC, 15% IBD-U, p<0.001), smoking status (p<0.001), and history of COVID diagnosis (p<0.001) or COVID hospitalization (p=0.001), and any IMM (p<0.001). (Table, 3). Whilst there were no significant differences in seroprevalence between patients receiving infliximab (IFX), vedolizumab (VDZ), and ustekinumab (UST), antibody levels were attenuated in patients on IFX monotherapy and combination therapy (both p=0.002) and VDZ (p=0.02), compared with no medications (Figure 1). Conclusion We confirm in diverse poulations that exposure to biologics or immunomodulators, type of disease, and smoking status are associated with seroprevalence and antibody levels. We show for the first time the dominant influence of geographical location on sero-status in these patients. These observations should be considered as we look towards post-vaccination data to help stratify patients for clinical guidelines on SARS-CoV-2 vaccination.

TRANS-CONTINENTAL ANALYSIS OF OVER 2,000 INFLAMMATORY BOWEL DISEASE PATIENTS IMPLICATES GEOGRAPHY, DISEASE TYPE, AND EXPOSURE TO IMMUNOSUPPRESSION AS DRIVERS OF SARS-COV-2 SEROPREVALENCE

Background: IBD patients on immune-modulatory therapies are considered high-risk for SARS-CoV-2 infection. Direct comparisons of serological responses to SARS-CoV-2 infection in IBD patients across different continents and medications are lacking. We performed SARSCoV- 2 sero-surveillance of IBD patients prior to vaccination at seven large tertiary centres in Asia, Europe, and North America. Methods: Clinical data and sera were collected from 2,241 IBD patients receiving routine care at institutions in Belgium, Canada, Hong Kong, India, Japan, United Kingdom, and the United States between May 2020 and September 2021 (Table 1). Sera were taken prior to vaccination. Clinical data were collected from patient questionnaires and medical records. Antibody reactivity to the SARS-CoV-2 spike protein was assessed using the Roche SARS-CoV-2 anti-spike total antibody and/or Siemens Healthineers COV2T anti-spike total antibody assays, which showed 99.4% concordance. We performed univariate analysis to evaluate association between variables and sero-status. Results: The pre-vaccination seroprevalence of antibodies to SARS-CoV-2 in IBD patient varied widely according to location from 0% in Hong Kong, China, to 57.9% in New Delhi, India. Rates in Europe and North America were similar (range 3.6%-8.9%). Overall, SARSCoV- 2 seroprevalence appears to be equal to or less than local populations (Table 1). Seroprevalence rates were associated with IBD type (Crohn's disease 7.8%, ulcerative colitis 12.4%, IBD-unclassified 15.0%, p<0.001), smoking status (p<0.001), and history of COVID diagnosis (p<0.001) or COVID hospitalization (p=0.001), and any immunomodulator (IMM) (p<0.001) (Table 1). Infection as indicated by seropositivity in the absence of known COVID infection occurred in 7.3% of patients. Whilst there were no significant differences in seroprevalence between patients receiving anti-tumor necrosis factor (anti-TNF) medications, vedolizumab (VDZ), and ustekinumab (UST), antibody levels were attenuated in patients on anti-TNF monotherapy (p=0.002), anti-TNF + IMM combination therapy (p=0.002), and VDZ (p=0.02), compared with no medications (Figure 1). Conclusion: We confirm in diverse populations that exposure to anti-TNFs, vedolizumab and immunomodulators, type of disease, and smoking status are associated with seroprevalence and antibody levels. We show for the first time the dominant influence of geographical location on sero-status in these patients. These observations should be considered as we look towards post-vaccination data to help stratify patients for clinical guidelines on SARS-CoV-2 vaccination. (Table Presented) Table 1. Seroprevalence of total anti-SARS-CoV-2 spike antibodies in IBD patients by ICARUS centre with non-IBD controls noted for New Delhi, India, and publicly reported local seroprevalence and by selected patient characteristics.(Figure Presented) Figure 1. Antibody levels by medication group.

BOTH VEDOLIZUMAB AND ANTI-TNF THERAPY ARE ASSOCIATED WITH ATTENUATION OF SEROLOGICAL AND NEUTRALIZING RESPONSES TO SARS-COV-2 INFECTION IN INFLAMMATORY BOWEL DISEASE

Introduction: More adverse clinical outcomes following SARS-CoV-2 infection are reported in patients treated with infliximab/thiopurines (IFX/THIO), compared with biological monotherapy with anti-TNF or vedolizumab (VDZ). VDZ has been associated with a heightened and more durable serological response after infection and vaccination, compared to IFX. However, whether IBD patients on VDZ have a fully intact systemic response to SARS- CoV2 remains unknown. We explored the serological and functional neutralizing response after SARS-CoV-2 infection in IBD patients treated with VDZ, IFX or IFX/THIO compared to true healthy controls to guide treatment decisions and vaccination strategies. Methods: Serum from 640 IBD patients attending routine infusions in Oxford and London (May to December 2020) was screened by the Abbott assay for SARS-CoV-2 nucleocapsid (N) antibodies. Serum from seropositive patients was compared to seropositive health care workers (Table 1). Antibody reactivity to the SARS-CoV-2 wild type (WT) strain receptor-binding domain (RBD), full-length spike, and N was assayed by IgG/IgA ELISA over time as well as by IgG MSD V-PLEX ELISA at the time of seropositivity. A pseudotyped SARS-CoV-2 virus microneutralization assay was used to detect neutralizing antibodies to the WT, and an ELISA-based inhibition assay to compare differential inhibition of the WT vs. delta variant (DV) SARS-CoV-2 RBD-ACE2 interaction. Results: All IBD patients showed significantly reduced IgG antibody responses compared to healthy controls to all SARS-CoV-2 antigens, using MSD V-PLEX (Figure 1A-C). The greatest reduction in IgG response by ELISA was observed in patients treated with IFX/THIO (p=0.00019), whereas IgG response over time declined significantly faster in the IFX treated group (p=0.019). IgA responses were significantly reduced in the IFX/THIO group compared to healthy controls (p=0.009), but not in the IFX or VDZ group. The rate of decline in these monotherapy groups was not significantly different to healthy controls. Compared to healthy controls, functional SARS-CoV-2 neutralization was reduced in each treatment group (Figure 1D), with the greatest effect in patients receiving IFX/THIO (p=0.00000091). Neutralizing capacity to the DV was significantly reduced in 68.1% of IBD patients (30/44, p=0.0005). Conclusion: Both IFX and VDZ are associated with significantly reduced IgG responses to multiple SARS-CoV-2 antigens, and with impaired functional SARS-CoV-2 neutralizing antibody capacity, compared to healthy individuals. However, whilst IgG and neutralization responses are reduced in IBD patients on biological monotherapy, these findings were most pronounced in the combination treatment group. As neutralizing antibody responses are associated with protection, these observations may impact on decision-making regarding treatment and vaccination strategies.(Table Presented)(Figure Presented)

Functional viral neutralisation responses after SARS-CoV-2 infection in Inflammatory Bowel Disease patients receiving infusion therapies: Report from the ICARUS-IBD Consortium

Background: Recent data have highlighted adverse clinical outcomes in IBD patients treated with infliximab/thiopurines (IFX/ THIO) upon infection with SARS-CoV-2, as well as attenuated serological responses after infection and vaccination in patients treated with IFX. To provide mechanistic insight, we explored the serological and functional anti-viral response after infection in IBD patients treated with VDZ, IFX or IFX/THIO compared to healthy controls to guide clinical decision-making regarding treatment and vaccination strategies. Methods: Serum from 640 IBD patients attending routine infusions in Oxford and London in May to December 2020 was screened for anti-SARS-CoV-2 antibody responses by the Abbott assay. Serum from seropositive patients was compared to seropositive health care workers (Table 1). Antibody reactivity to the SARS-CoV-2 wild type strain receptor-binding domain (RBD), full-length spike, and nucleocapsid was assayed by IgG/IgA ELISA over time as well as by IgG high-throughput MSD V-PLEX ELISA at the time of seropositivity. A pseudotyped SARS-CoV-2 virus microneutralization assay was used to detect neutralising antibodies to the wild type, and an ELISA-based inhibition assay to compare differential inhibition of the wild type vs. delta variant SARS-CoV-2 RBD-ACE2 interaction. Results: All IBD patients showed significantly reduced IgG antibody responses compared to healthy controls for all SARS-CoV-2 antigens, using MSD V-PLEX ELISA (Figure 1). The greatest reduction in IgG response by ELISA was observed in individuals treated with IFX/THIO (p=0.00019), whereas IgG response over time declined significantly faster in the IFX treated group (p=0.019). IgA responses were significantly reduced in the IFX/THIO group compared to healthy controls (p=0.009), but not in the IFX or VDZ monotherapy group. The rate of decline in these monotherapy groups was also not significantly different to healthy controls. Functional SARS-CoV-2 neutralisation was significantly lower in all IBD patients compared to healthy controls, with the greatest reduction in patients receiving IFX/THIO (Figure 2A;p=0.00000091). The delta variant inhibition capacity was significantly reduced in 68.1% of IBD patients (30/44, Figure 2B;p=0.0005). Conclusion: IFX/THIO is associated with significantly lower IgA and IgG responses, and with impaired functional SARS-CoV-2 neutralising antibody capacity, compared to healthy individuals. Whilst IgG and neutralisation responses are reduced in each group of IBD patients, these findings were most pronounced in the combination treatment group. As neutralising antibody responses are associated with protection, this observation may impact on decision-making regarding treatment and vaccination/antiviral strategies.

Women authorship in gastroenterology sustained during early COVID-19 pandemic

Introduction: Prior data indicate that within procedural specialties, women may be less likely to be first and senior authors of manuscripts during the COVID-19 pandemic, especially for studies pertaining to the pandemic. Women are more likely faced with challenges of balancing work and other duties such as household responsibilities and childcare, especially for those who are mothers. The purpose of this study was to determine the gender distribution of authorship of manuscripts in high-impact gastroenterology and hepatology journals during the early part of the COVID-19 pandemic. Methods: Manuscripts published between March 1, 2019 to January 1, 2020 and March 1, 2020 to January 1, 2021 in 16 high-impact gastroenterology and hepatology journals were identified using bibliometric data. Genders of first authors and senior authors were determined by matching first names with a predicted gender using a validated multinational database (Genderize.io). Number of women and men first and senior authors, and whether the manuscript was related to COVID-19 were recorded. Comparisons between female first and senior authorship of manuscripts from 2019 and 2020 were analyzed using Fisher exact testing. Results: In 2019, women were first authors of 777 (27.4%) manuscripts and senior authors of 546 (18.4%) manuscripts. In 2020, women were first authors of 999 (28.5%) manuscripts and senior authors of 646 (17.7%) manuscripts. There were no statistically significant differences of women first or senior authorship from 2019 to 2020. During the pandemic, women were first authors of 902 (28.9%) non-COVID-19 related manuscripts and 97 (25.7%) COVID-19 related manuscripts. Women were senior authors of 586 (18.0%) non-COVID-19 related manuscripts and 60 (15.6%) COVID-19 related manuscripts. There were no statistically significant differences of women authorship between non-COVID and COVID related manuscripts. Conclusion: The frequency and proportion of women first and senior authorship in 2020 was comparable to that in 2019. Women maintained scientific productivity in gastroenterology regarding publications in high-impact gastroenterology journals, despite facing increased challenges during the early part of the COVID-19 pandemic..

Outcomes in COVID-19 patients with and without preexisting chronic liver disease: A retrospective study

Background: Many patients with COVID-19 also present with liver injury, in addition to respiratory symptoms. There is concern that COVID-19 could lead to more severe clinical outcomes in patients with comorbid chronic liver disease and vice versa. Evaluation of demographic data and the clinical COVID-19 disease course in this subset of patients is warranted due to the rapid and severe nature of the virus. Methods: A retrospective cohort study was conducted on patients infected with COVID-19, with and without chronic liver disease, from March 22nd, 2020, to August 1, 2020. A randomized list of 450 patients without (NLD) and 225 patients with chronic liver disease (LD) was compiled and matched on age, gender, and BMI into 150 patient pairs. Six patients were disqualified for not meeting inclusion criteria, resulting in a final number of 147 patients in each cohort. Demographic, clinical, and laboratory data was collected at baseline and post-COVID-19 infection. Descriptive statistics and bivariate analyses were also conducted. IRB approval was obtained prior to the data collection process. Results: Our cohort averaged 59.32 years of age, were 48.98% male and 51.02% female, and had an average BMI of 31.27. The most common causes of chronic liver disease were non-alcoholic fatty liver disease (62.59%) and Hepatitis C (20.41%). Patients with cirrhosis made up 15.65% of the cohort. LD patients were more likely to have comorbidities like hypertension and hyperlipidemia. NLD patients were more likely to have respiratory symptoms than LD patients, who were more likely to have GI symptoms. In a comparison of laboratory results, the LD group had statistically significantly higher baseline and follow up AST levels compared to the NLD group. However, post COVID-19 infection, both groups had a statistically significant increase in AST. NLD patients also had statistically significant increases in creatinine and ALT compared to baseline. Overall mortality rate in the cohort of 294 patients was 10.54%, with a higher mortality in the NLD group, albeit not statistically significant. The incidence of mortality for patients with cirrhosis was 10%. Conclusion: This study found that LD patients were more likely to experience GI symptoms than respiratory symptoms, which were more common in NLD patients. Both groups developed increased liver enzymes post-COVID infection. LD patients were more likely to have metabolic disease as expected, given NAFLD as the main underlying liver disease. Though LD patients had these comorbidities, there was no statistically significant difference in rate of hospitalization, ICU admissions, or mortality between the groups. This could possibly be explained by the high rate of obesity in both groups (average BMI 31). There was also a small percentage of patients with cirrhosis, the majority of whom were well compensated. Further studies are needed to determine the risk of COVID-19 in patients with chronic liver disease and cirrhosis.

How are family doctors serving the Hong Kong community during the COVID-19 outbreak? A survey of HKCFP members.

INTRODUCTION: This study evaluated the preparedness of family doctors during the early phase of the coronavirus disease 2019 (COVID-19) outbreak in Hong Kong. METHODS: All members of the Hong Kong College of Family Physicians were invited to participate in a cross-sectional online survey using a 20-item questionnaire to collect information on practice preparedness for the COVID-19 outbreak through an email followed by a reminder SMS message between 31 January 2020 and 3 February 2020. RESULTS: Of 1589 family doctors invited, 491 (31%) participated in the survey, including 242 (49%) from private sector. In all, 98% surveyed doctors continued to provide clinical services during the survey period, but reduced clinic service demands were observed in 45% private practices and 24% public clinics. Almost all wore masks during consultation and washed hands between or before patient contact. Significantly more private than public doctors (80% vs 26%, P<0.001) experienced difficulties in stocking personal protective equipment (PPE); more public doctors used guidelines to manage suspected patients. The main concern of the respondents was PPE shortage. Respondents appealed for effective public health interventions including border control, quarantine measures, designated clinic setup, and public education. CONCLUSION: Family doctors from public and private sectors demonstrated preparedness to serve the community from the early phase of the COVID-19 outbreak with heightened infection control measures and use of guidelines. However, there is a need for support from local health authorities to secure PPE supply and institute public health interventions.

Inferring super-spreading from transmission clusters of COVID-19 in Hong Kong, Japan, and Singapore.

Super-spreading events in an outbreak can change the nature of an epidemic. Therefore, it is useful for public health teams to determine whether an ongoing outbreak has any contribution from such events, which may be amenable to interventions. We estimated the basic reproductive number (R0) and the dispersion factor (k) from empirical data on clusters of epidemiologically linked coronavirus disease 2019 (COVID-19) cases in Hong Kong, Japan and Singapore. This allowed us to infer the presence or absence of super-spreading events during the early phase of these outbreaks. The relatively large values of k implied that large cluster sizes, compatible with super-spreading, were unlikely.