Unintended Consequence: Influenza plunges with public health response to COVID-19 in Singapore

Impact of COVID-19 national response on primary care utilisation in Singapore: an interrupted time-series analysis

Since the start of the pandemic, many national responses, such as nationwide lockdowns, have been implemented to curb the spread of COVID-19. We aim to assess the impact of Singapore's national responses on primary care utilisation. We performed an interrupted time series using acute and chronic primary care data of 3 168 578 visits between 1 September 2019 and 31 August 2020 over four periods: before any measures were put in place, during Disease Outbreak Response System Condition (DORSCON) Orange, when Circuit Breaker was instituted, and when Circuit Breaker was lifted. We found significant mean reductions in acute and chronic primary care visits immediately following DORSCON Orange and Circuit Breaker. DORSCON Orange was associated with - 2020 mean daily visits (95% CI - 2890 to - 1150). Circuit Breaker was associated with a further - 2510 mean daily visits (95% CI - 3660 to - 1360). Primary care utilisation for acute visits remained below baseline levels even after the Circuit Breaker was lifted. These significant reductions were observed in both acute and chronic visits, with acute visits experiencing a steeper drop during DORSCON Orange. Understanding the impact of COVID-19 measures on primary care utilisation will be useful for future public health planning.

Impact of the coronavirus disease 2019 pandemic on the diversity of notifiable infectious diseases: a case study in Shanghai, China

The outbreak of coronavirus disease 2019 (COVID-19) has not only posed significant challenges to public health but has also impacted every aspect of society and the environment. In this study, we propose an index of notifiable disease outbreaks (NDOI) to assess the impact of COVID-19 on other notifiable diseases in Shanghai, China. Additionally, we identify the critical factors influencing these diseases using multivariate statistical analysis. We collected monthly data on 34 notifiable infectious diseases (NIDs) and corresponding environmental and socioeconomic factors (17 indicators) from January 2017 to December 2020. The results revealed that the total number of cases and NDOI of all notifiable diseases decreased by 47.1% and 52.6%, respectively, compared to the period before the COVID-19 pandemic. Moreover, the COVID-19 pandemic has led to improved air quality as well as impacted the social economy and human life. Redundancy analysis (RDA) showed that population mobility, particulate matter (PM2.5), atmospheric pressure, and temperature were the primary factors influencing the spread of notifiable diseases. The NDOI is beneficial in establishing an early warning system for infectious disease epidemics at different scales. Furthermore, our findings also provide insight into the response mechanisms of notifiable diseases influenced by social and environmental factors.

Impact of influenza immunity on the mortality among older adults hospitalized with COVID-19: a retrospective cohort study

It has been suggested that the outcomes of coronavirus disease 2019 (COVID-19) are better in individuals having recently received an influenza vaccine than in non-vaccinated individuals. We hypothesized that this association depends on the humoral responses against influenza viruses. We aim to assess the relationship between the humoral immunity against influenza and the 3-month all-cause mortality among hospitalized older patients with COVID-19. We performed an exploratory retrospective study of older patients (aged 65 and over) hospitalized for confirmed COVID-19 between November 2020 and June 2021. Previous humoral responses to influenza viruses were assessed using a hemagglutination inhibition assay on routinely collected blood samples. The study's primary outcome was the 3-month all-cause mortality, and the secondary outcomes were severe COVID-19 (oxygen requirement ≥ 6 L/min or ventilatory support) and complications (kidney or heart failure, thrombosis and bacterial infection). In the cohort of 95 patients with COVID-19, immunity against influenza vaccine subtypes/lineages was not significantly associated with 3-month all-cause mortality, with an OR [95%CI] of 0.22 [0.02-1.95] (p = 0.174) for the H1N1pdm09 subtype, 0.21 [0.03-1.24] (p = 0.081) for A/Hong Kong/2671/2019 H3N2 subtype, 1.98 [0.51-8.24] (p = 0.329) for the B/Victoria lineage, and 1.82 [0.40-8.45] (p = 0.437) for the B/Yamagata lineage. Immunity against influenza vaccine subtypes/lineages was also not significantly associated with severity and complication. Immunity against influenza subtypes/lineages included in the 2020-2021 vaccine was not associated with a lower 3-month all-cause mortality among COVID-19 hospitalized patients.Trial registration: The study was approved by a hospital committee with competency for research not requiring approval by an institutional review board (Tours University Medical Center, Tours, France: reference: 2021_015). All patients give the informed consent.

SARS-CoV-2 Related Viral Respiratory Co-Infections: A Narrative Review

Background

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is the new coronavirus originating from Wuhan, China, responsible for the illness known as coronavirus disease 2019 (COVID-19). Early experience and the recent literature have shown that co-infection of SARS-CoV-2 with another respiratory virus might occur. Similar symptoms of acute respiratory infections (ARIs) and COVID-19 represent a challenge for diagnostic and therapeutic efficacy and may modify COVID-19 outcomes.

Materials and Methods

We reviewed the literature on the epidemic pattern and major learning points on important aspects of SARS-CoV-2-related viral respiratory co-infections during the COVID-19 pandemic. Databases such as PubMed, Scopus, Science Direct, and Google Scholar were used to conduct a comprehensive search.

Results

The circulation of respiratory viruses changed as the COVID-19 epidemic continues. Phenomena like viral interference, resource competition, and differences in virus-host range might explain why simultaneous viral respiratory infections have seemed to vanish with the spread of SARS-CoV-2.

Conclusion

Key research to be conducted during this pandemic should include the simultaneous screening of other respiratory pathogens with many available commercial platforms for transmission containment and appropriate clinical management.

Sharp decline in rates of community respiratory viral detection among patients at the National Institutes of Health Clinical Center during the coronavirus disease 2019 (COVID-19) pandemic

OBJECTIVES

To analyze the frequency and rates of community respiratory virus infections detected in patients at the National Institutes of Health Clinical Center (NIHCC) between January 2015 and March 2021, comparing the trends before and during the coronavirus disease 2019 (COVID-19) pandemic.

METHODS

We conducted a retrospective study comparing frequency and rates of community respiratory viruses detected in NIHCC patients between January 2015 and March 2021. Test results from nasopharyngeal swabs and washes, bronchoalveolar lavages, and bronchial washes were included in this study. Results from viral-challenge studies and repeated positives were excluded. A quantitative data analysis was completed using cross tabulations. Comparisons were performed using mixed models, applying the Dunnett correction for multiplicity.

RESULTS

Frequency of all respiratory pathogens declined from an annual range of 0.88%-1.97% between January 2015 and March 2020 to 0.29% between April 2020 and March 2021. Individual viral pathogens declined sharply in frequency during the same period, with no cases of influenza A/B orparainfluenza and 1 case of respiratory syncytial virus (RSV). Rhino/enterovirusdetection continued, but with a substantially lower frequency of 4.27% between April 2020 and March 2021, compared with an annual range of 8.65%-18.28% between January 2015 and March 2020.

CONCLUSIONS

The decrease in viral respiratory infections detected in NIHCC patients during the pandemic was likely due to the layered COVID-19 prevention and mitigation measures implemented in the community and the hospital. Hospitals should consider continuing the use of nonpharmaceutical interventions in the future to prevent nosocomial transmission of respiratory viruses during times of high community viral load.

Online HOPE intervention on help-seeking attitudes and intentions among young adults in Singapore: A randomized controlled trial and process evaluation

INTRODUCTION

Despite the high prevalence of mental health disorders, professional help seeking was often unsought, worsening impairments in overall functioning among those who experienced them.

AIM

This study aimed to evaluate the online HOPE intervention on help-seeking attitudes and intentions among young adults 18 to 24 years old in a University in Singapore. The study also described the process evaluation of the online HOPE intervention.

METHOD

The study adopted a parallel two arms RCT. Outcome measurements measured at baseline, post-test and two-month follow-up were (1) recognition of depression, (2) barriers of help-seeking, (3) help-seeking intentions (4) attitudes about interventions, help sources, medications and (5) participants' perceptions about the intervention.

RESULTS

At post-test, intervention group had significantly lower acknowledgement of depression as stress. At two months, control group was significantly more concerned about side effects of medications. There were no significant differences in all barriers of help-seeking between groups, pre and post intervention. The intervention group had greater acknowledgement of antidepressants, tranquilisers and antipsychotics. Thematic analysis revealed four main themes.

DISCUSSION

There was high baseline recognition of depression. Improvements in help-seeking intentions were partially attributed to decreased help-seeking barriers.

IMPLICATION FOR PRACTICE

The online HOPE intervention could be promptly implemented for young adults to enhance the identification of mental health disorders, early help-seeking and recovery. Nurses played an important role in patient education, and online interventions are especially crucial during this Covid period which mandated social distancing. [NCT04266119].

Choice of SARS-CoV-2 diagnostic test: challenges and key considerations for the future

A plethora of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) diagnostic tests are available, each with different performance specifications, detection methods, and targets. This narrative review aims to summarize the diagnostic technologies available and how they are best selected to tackle SARS-CoV-2 infection as the pandemic evolves. Seven key settings have been identified where diagnostic tests are being deployed: symptomatic individuals presenting for diagnostic testing and/or treatment of COVID-19 symptoms; asymptomatic individuals accessing healthcare for planned non-COVID-19-related reasons; patients needing to access emergency care (symptom status unknown); patients being discharged from healthcare following hospitalization for COVID-19; healthy individuals in both single event settings (e.g. airports, restaurants, hotels, concerts, and sporting events) and repeat access settings (e.g. workplaces, schools, and universities); and vaccinated individuals. While molecular diagnostics remain central to SARS-CoV-2 testing strategies, we have offered some discussion on the considerations for when other tools and technologies may be useful, when centralized/point-of-care testing is appropriate, and how the various additional diagnostics can be deployed in differently resourced settings. As the pandemic evolves, molecular testing remains important for definitive diagnosis, but increasingly widespread point-of-care testing is essential to the re-opening of society.

Estimation of Excess Deaths Associated With the COVID-19 Pandemic in Istanbul, Turkey

Background and Objectives

The official number of daily cases and deaths are the most prominent indicators used to plan actions against the COVID-19 pandemic but are insufficient to see the real impact. Official numbers vary due to testing policy, reporting methods, etc. Therefore, critical interventions are likely to lose their effectiveness and better-standardized indicators like excess deaths/mortality are needed. In this study, excess deaths in Istanbul were examined and a web-based monitor was developed.

Methods

Daily all-cause deaths data between January 1, 2015- November 11, 2021 in Istanbul is used to estimate the excess deaths. Compared to the pre-pandemic period, the % increase in the number of deaths was calculated as the ratio of excess deaths to expected deaths (P-Scores). The ratio of excess deaths to official figures (T) was also examined.

Results

The total number of official and excess deaths in Istanbul are 24.218 and 37.514, respectively. The ratio of excess deaths to official deaths is 1.55. During the first three death waves, maximum P-Scores were 71.8, 129.0, and 116.3% respectively.

Conclusion

Excess mortality in Istanbul is close to the peak scores in Europe. 38.47% of total excess deaths could be considered as underreported or indirect deaths. To re-optimize the non-pharmaceutical interventions there is a need to monitor the real impact beyond the official figures. In this study, such a monitoring tool was created for Istanbul. The excess deaths are more reliable than official figures and it can be used as a gold standard to estimate the impact more precisely.

Dual impacts of the COVID-19 nonpharmaceutical interventions on other infectious diseases

1.

COVID nonpharmaceutical interventions (NPIs) impacted on other infectious diseases.

2.

The impacts on 36 infectious diseases in China were calculated.

3.

COVID NPIs increased the incidences of some infectious diseases.

4.

COVID NPIs reduced the incidences of some other infectious diseases.

5.

The impacts were calculated with optimized methods.

It is complicated: Potential short- and long-term impact of coronavirus disease 2019 (COVID-19) on antimicrobial resistance—An expert review

As of December 2021, the coronavirus disease 2019 (COVID-19) pandemic has claimed millions of deaths and caused disruptions in health systems around the world. The short- and long-term effects of COVID-19 on antimicrobial resistance (AMR), which was already a global threat before the pandemic, are manifold and complex. In this expert review, we summarize how COVID-19 might be affecting AMR in the short term (by influencing the key determinants antibiotic use, infection control practices and international/local mobility) and which additional factors might play a role in the long term. Whereas reduced outpatient antibiotic use in high-income countries, increased awareness for hand hygiene, and reduced mobility have likely mitigated the emergence and spread of AMR in the short term, factors such as overuse of antibiotics in COVID-19 patients, shortage of personal protective equipment, lack of qualified healthcare staff, and patient overcrowding have presumably facilitated its propagation. Unsurprisingly, international and national AMR surveillance data for 2020 show ambiguous trends. Although disruptions in antibiotic stewardship programs, AMR surveillance and research might promote the spread of AMR, other developments could prove beneficial to the cause in the long term. These factors include the increased public awareness for infectious diseases and infection control issues, the strengthening of the One Health perspective as outlined by the Centers for Disease Control and Prevention, and the unprecedented number of international research collaborations and platforms. These factors could even serve as leverage and provide opportunities to better combat AMR in the future.

Fending off Delta - Hospital measures to reduce nosocomial transmission of COVID-19

Objectives

Following the emergence of the Delta variant of SARS-CoV-2 in Singapore, our hospital experienced a Delta-linked ward cluster. In this study, we review the enhanced strategies in preventing nosocomial transmission of COVID-19 following widespread community transmission of the Delta variant.

Methods

We conducted a cohort study on exposures to unexpected COVID-19 cases for which contact tracing was initiated from June 2021 to October 2021. Strategies evaluated included upgraded personal protective equipment (PPE) and rostered routine testing (RRT) for staff and patients, surveillance of staff with acute respiratory illness (ARI), and expanded quarantining and testing for contacts of identified cases.

Results

From 193 unexpected COVID-19 exposures, 2,573 staff, 542 patients, and 128 visitor contacts were traced. Four staff contacts subsequently had SARS-CoV-2 infection. Two were likely from exposure in community settings, whereas 2 had exposure to the same COVID-19 positive staff in the hospital, forming the only hospital cluster. One inpatient had a nosocomial infection, possibly from visitors. The SARS-CoV-2 detection rate among staff was 0.3% (of 11,200 staff) from biweekly RRT and 2.5% (of 3,675 staff) from ARI surveillance.

Conclusion

Enhanced hospital measures, including upgraded PPE and RRT for staff and patients, staff sickness surveillance, and more rigorous management of contacts of COVID-19 cases, were likely to have reduced nosocomial transmission amid the Delta variant.

Population Decline in COPD Admissions During the COVID-19 Pandemic Associated with Lower Burden of Community Respiratory Viral Infections

BACKGROUND

The Coronavirus disease 2019 (COVID-19) pandemic has led to widespread implementation of public health measures, such as stay-at-home orders, social distancing, and masking mandates. In addition to decreasing spread of severe acute respiratory syndrome coronavirus 2, these measures also impact the transmission of seasonal viral pathogens, which are common triggers of chronic obstructive pulmonary disease (COPD) exacerbations. Whether reduced viral prevalence mediates reduction in COPD exacerbation rates is unknown.

METHODS

We performed retrospective analysis of data from a large, multicenter health care system to assess admission trends associated with community viral prevalence and with initiation of COVID-19 pandemic control measures. We applied difference-in-differences analysis to compare season-matched weekly frequency of hospital admissions for COPD prior to and after implementation of public health measures for COVID-19. Community viral prevalence was estimated using regional Centers for Disease Control and Prevention test positivity data and correlated to COPD admissions.

RESULTS

Data involving 4422 COPD admissions demonstrated a season-matched 53% decline in COPD admissions during the COVID-19 pandemic, which correlated to community viral burden (r = 0.73; 95% confidence interval, 0.67-0.78) and represented a 36% greater decline over admission frequencies observed in other medical conditions less affected by respiratory viral infections (incidence rate ratio 0.64; 95% confidence interval, 0.57-0.71, P < .001). The post-COVID-19 decline in COPD admissions was most pronounced in patients with fewer comorbidities and without recurrent admissions.

CONCLUSION

The implementation of public health measures during the COVID-19 pandemic was associated with decreased COPD admissions. These changes are plausibly explained by reduced prevalence of seasonal respiratory viruses.

One Year on: An Overview of Singapore's Response to COVID-19-What We Did, How We Fared, How We Can Move Forward

Background—One year has passed since the first COVID-19 case in Singapore. This scoping review commemorates Singaporean researchers that have expanded the knowledge on this novel virus. We aim to provide an overview of healthcare-related articles published in peer-reviewed journals, authored by the Singapore research community about COVID-19 during the first year of the pandemic. Methods—This was reported using the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) protocol. It included healthcare-related articles about COVID-19 published between 23 January 2020 and 22 January 2021 with a Singapore-affiliated author. MEDLINE, Embase, Scopus, Web of Science, CINAHL, PsycINFO, Google Scholar, and local journals were searched. The articles were screened independently by two reviewers. Results—The review included 504 articles. Most of the articles narrated the changes to hospital practice (210), while articles on COVID-19 pathology (94) formed most of the non-narrative papers. Publications on public health (61) and the indirect impacts to clinical outcomes (45) were other major themes explored by the research community. The remaining articles detailed the psychological impact of the pandemic (35), adaptations of medical education (30), and narratives of events (14). Conclusion—Amidst a resurgence of community cases involving variant COVID-19 strains, the resources from the research community will provide valuable guidance to navigate these uncertain times.

The COVID-19 epidemic and other notifiable infectious diseases in China

Many infection control measures have been implemented to prevent the spread of SARS-CoV-2 during COVID-19 pandemic. We aimed to investigate the impact of COVID-19 epidemic on the other notifiable infectious diseases in China, including respiratory infectious diseases, diseases transmitted through the digestive tract and animal-borne diseases. Compared with 2019, the overall decline rate of respiratory infectious diseases in 2020 is the highest (60–90%), and the diseases transmitted by the digestive tract and animal-borne diseases are similar at 20–30%. Both hepatitis and sexually transmitted diseases decreased significantly in February, and there were basically no significant changes in other months compared with previous years. The series of measures taken by China government to prevent the spread of SARS-CoV-2 are also very effective in preventing the spread of respiratory infectious diseases. But they also have a certain degree of prevention against notifiable infectious diseases spread by other routes.

Diagnostic performance of COVID-19 serological assays during early infection: A systematic review and meta-analysis of 11 516 samples

OBJECTIVE

The use of coronavirus disease 2019 (COVID-19) serological testing to diagnose acute infection or determine population seroprevalence relies on understanding assay accuracy during early infection. We aimed to evaluate the diagnostic performance of serological testing in COVID-19 by providing summary sensitivity and specificity estimates with time from symptom onset.

METHODS

A systematic search of Ovid MEDLINE, Embase, Cochrane Central Register of Controlled Trials (CENTRAL) and PubMed was performed up to May 13, 2020. All English language, original peer-reviewed publications reporting the diagnostic performance of serological testing vis-à-vis virologically confirmed SARS-CoV-2 infection were included.

RESULTS

Our search yielded 599 unique publications. A total of 39 publications reporting 11 516 samples from 8872 human participants met eligibility criteria for inclusion in our study. Pooled percentages of IgM and IgG seroconversion by Day 7, 14, 21, 28 and after Day 28 were 37.5%, 73.3%, 81.3%, 72.3% and 73.3%, and 35.4%, 80.6%, 93.3%, 84.4% and 98.9%, respectively. By Day 21, summary estimate of IgM sensitivity was 0.872 (95% CI: 0.784-0.928) and specificity 0.973 (95% CI: 0.938-0.988), while IgG sensitivity was 0.913 (95% CI: 0.823-0.959) and specificity 0.960 (95% CI: 0.919-0.980). On meta-regression, IgM and IgG test accuracy was significantly higher at Day 14 using enzyme-linked immunosorbent assay (ELISA) compared to other methods.

CONCLUSIONS

Serological assays offer imperfect sensitivity for the diagnosis of acute SARS-CoV-2 infection. Estimates of population seroprevalence during or shortly after an outbreak will need to adjust for the delay between infection, symptom onset and seroconversion.

The impact of the coronavirus disease 2019 epidemic on notifiable infectious diseases in Taiwan: A database analysis

Introduction

The impact of the COVID-19 pandemic on the incidence of notifiable infectious diseases (NIDs) in Taiwan remains unclear.

Materials and methods

The number of cases of NID (n = 42) between January and September 2019 and 2020 were obtained from the open database from Taiwan Centers for Disease Control.

Results

The number of NID cases was 21,895 between January and September 2020, which was lower than the number of cases during the same period in 2019 (n = 24,469), with a decline in incidence from 102.9 to 91.7 per 100,000 people in 2019 and 2020, respectively. Fourteen airborne/droplet, 11 fecal-oral, seven vector-borne, and four direct-contact transmitted NID had an overall reduction of 2700 (−28.1%), 156 (−23.0%), 557 (−54.8%), and 73 (−45.9%) cases, respectively, from 2019 to 2020. Similar trends were observed for the changes in incidence, which were 11.5 (−28.4%), 6.7 (−23.4%), 2.4 (−55.0%), and 0.3 (−46.2%) per 100,000 people for airborne/droplet, fecal-oral, vector-borne, and direct-contact transmitted NID, respectively. In addition, all the 38 imported NID showed a reduction of 632 (−73.5%) cases from 2019 to 2020. In contrast, 4 sexually transmitted diseases (STDs) showed an increase of 903 (+7.2%) cases from 2019 to 2020, which was attributed to the increase in gonorrhea (from 3220 to 5028). The overall incidence of STDs increased from 52.5 to 56.0 per 100,000 people, with a percentage change of +6.7%.

Conclusion

This study demonstrated a collateral benefit of COVID-19 prevention measures for various infectious diseases, except STDs, in Taiwan, during the COVID-19 epidemic.

Cloth masks in public places: an essential intervention to prevent COVID-19 in Brazil

There is increasing evidence that the use of masks is an indispensable protective measure against COVID-19, given the high transmissibility of the new coronavirus through the respiratory system, including by asymptomatic individuals. The use of cloth masks in public places has been established as a protective measure to be adopted alongside social distancing and hand hygiene. This narrative review aims to systematize the scientific evidence that informs the widespread use of cloth masks as a preventive measure against COVID-19 and to describe the evolution of positions contrary to or in favor of its use outside the home, in view of the advance of the new coronavirus pandemic globally. The scientific articles, technical notes, governmental decrees and other documents analyzed indicate that widespread use of masks has the potential to reduce the spread of the new coronavirus. We recommend that the Brazilian government adopt strategies to increase the supply of reusable cloth masks to the public, especially to vulnerable populations and to support studies on the impact of this measure to control the pandemic in the country. Finally, it is imperative to ensure that use of masks does not exacerbate stigmatization of racial groups that already face prejudice.

The unintended consequences of COVID-19 mitigation measures matter: practical guidance for investigating them

BACKGROUND

COVID-19 has led to the adoption of unprecedented mitigation measures which could trigger many unintended consequences. These unintended consequences can be far-reaching and just as important as the intended ones. The World Health Organization identified the assessment of unintended consequences of COVID-19 mitigation measures as a top priority. Thus far, however, their systematic assessment has been neglected due to the inattention of researchers as well as the lack of training and practical tools.

MAIN TEXT

Over six years our team has gained extensive experience conducting research on the unintended consequences of complex health interventions. Through a reflexive process, we developed insights that can be useful for researchers in this area. Our analysis is based on key literature and lessons learned reflexively in conducting multi-site and multi-method studies on unintended consequences. Here we present practical guidance for researchers wishing to assess the unintended consequences of COVID-19 mitigation measures. To ensure resource allocation, protocols should include research questions regarding unintended consequences at the outset. Social science theories and frameworks are available to help assess unintended consequences. To determine which changes are unintended, researchers must first understand the intervention theory. To facilitate data collection, researchers can begin by forecasting potential unintended consequences through literature reviews and discussions with stakeholders. Including desirable and neutral unintended consequences in the scope of study can help minimize the negative bias reported in the literature. Exploratory methods can be powerful tools to capture data on the unintended consequences that were unforeseen by researchers. We recommend researchers cast a wide net by inquiring about different aspects of the mitigation measures. Some unintended consequences may only be observable in subsequent years, so longitudinal approaches may be useful. An equity lens is necessary to assess how mitigation measures may unintentionally increase disparities. Finally, stakeholders can help validate the classification of consequences as intended or unintended.

CONCLUSION

Studying the unintended consequences of COVID-19 mitigation measures is not only possible but also necessary to assess their overall value. The practical guidance presented will help program planners and evaluators gain a more comprehensive understanding of unintended consequences to refine mitigation measures.

Coronavirus Disease 2019 (COVID-19): The Singapore Experience. A Review of the First Eight Months

As of 27 October 2020, there have been 57,980 confirmed cases of COVID-19 in Singapore, with 28 fatalities. To summarise the Singapore experience in managing and containing COVID-19 based on available published data and from relevant sources, a review of literature using research databases such as PubMed and OVID Medline, along with non-peer-reviewed articles and other sources, was conducted with the search terms ‘COVID-19’ and ‘Singapore’. Research conducted in Singapore has provided insight into the clinical manifestations and period of infectivity of COVID-19, demonstrated evidence of pre-symptomatic transmission, linked infection clusters using serological tools, and highlighted aspects of hospital-based environmental contamination. It has also provided guidance for diagnostic testing and has described immune and virologic correlates with disease severity. Evidence of effectiveness of containment measures such as early border control, rigorous contact training, and calibrated social distancing measures have also been demonstrated. Singapore’s multipronged strategy has been largely successful at containing COVID-19 and minimising fatalities, but the risk of re-emergence is high. Keywords: Epidemiology, management, prevention, transmission

COMOKIT: A Modeling Kit to Understand, Analyze, and Compare the Impacts of Mitigation Policies Against the COVID-19 Epidemic at the Scale of a City

Since its emergence in China, the COVID-19 pandemic has spread rapidly around the world. Faced with this unknown disease, public health authorities were forced to experiment, in a short period of time, with various combinations of interventions at different scales. However, as the pandemic progresses, there is an urgent need for tools and methodologies to quickly analyze the effectiveness of responses against COVID-19 in different communities and contexts. In this perspective, computer modeling appears to be an invaluable lever as it allows for the in silico exploration of a range of intervention strategies prior to the potential field implementation phase. More specifically, we argue that, in order to take into account important dimensions of policy actions, such as the heterogeneity of the individual response or the spatial aspect of containment strategies, the branch of computer modeling known as agent-based modeling is of immense interest. We present in this paper an agent-based modeling framework called COVID-19 Modeling Kit (COMOKIT), designed to be generic, scalable and thus portable in a variety of social and geographical contexts. COMOKIT combines models of person-to-person and environmental transmission, a model of individual epidemiological status evolution, an agenda-based 1-h time step model of human mobility, and an intervention model. It is designed to be modular and flexible enough to allow modelers and users to represent different strategies and study their impacts in multiple social, epidemiological or economic scenarios. Several large-scale experiments are analyzed in this paper and allow us to show the potentialities of COMOKIT in terms of analysis and comparison of the impacts of public health policies in a realistic case study.