Case fatality risk of influenza A (H1N1pdm09): a systematic review

Unleashing the global potential of public health: A framework for future pandemic response

Public health emergencies, especially pandemics, need to be managed globally, and on several levels, emphasizing the importance of leadership, communication, and synchronization of measures, data, and management plans in contrast to the management of the Coronavirus-19 pandemic, which illustrated diverse strategies employed by various nations. This paper aims to review and discuss whether globalized diseases in a globalized world should be managed by globalized public health. Using a systematic literature search, followed by a non-systematic literature review, selected studies were grouped into topics, and analyzed, using content analysis to enhance the conclusive results. The results present a roadmap towards a re-envisioned framework highlighting key areas of focus: data-driven decision-making, robust technology infrastructure, global cooperation, and ongoing public health education, as part of a coordinated global response. This article reveals the weaknesses of current pandemic management systems and recommends new steps to further strengthen the management of future pandemics.

Exploring the Process of Policy Overreaction: The COVID-19 Lockdown Decisions

Policy overreaction is a common phenomenon, especially in complex and emergency situations where politicians are led to make decisions fast. In these emergency decisions, emotions run generally high and cognitive processes are often impaired. The conditions of policy overreaction are in place as emotions overwhelm decision makers' rational processes. Drawing on the response patterns of three countries to the COVID-19 pandemic, we develop a process model of policy overreaction which describes the effects of negative emotions and institutional isomorphism on policy decision-making. Our model highlights four critical stages: negative emotions buildup, propagation of fear, isomorphic decision-making, and leading to an intractable crisis. This article shows precisely how the cascading effect of negative emotions, particularly fear, is contagious and spreads to generate crowd effects, which bend considerably policy makers' ability to make rational decisions. Our theory provides a better understanding of the process by which policy overreaction takes place.

Race and Sex Differences in Vital Signs Associated with COVID-19 and Flu Diagnoses in Mississippi

Early detection of viral infections, such as COVID-19 and flu, have potential to reduce risk of morbidity, mortality, and disease transmission through earlier intervention strategies. For example, detecting changes in vital signs have the potential to more rapidly diagnose respiratory virus diseases. The objective of this study was to utilize the University of Mississippi Medical Center's extensive clinical database (EPIC) to investigate associations between temperature, pulse rate, blood pressure (BP), and respiration rate in COVID-19 and flu diagnosed patients. Data from 1,363 COVID-19 (March 3, 2020, to February 27, 2021) and 507 flu (October 1, 2017, to September 30, 2018) diagnosed patients with reported demographic dimensions (age, first race, and sex) and office visit dimensions (BMI, diastolic BP, pulse rate, respiration rate, systolic BP, and temperature) was obtained, including day of diagnosis and additional encounter visits 60 days before and after first unique diagnosis. Patients with COVID-19 or flu were disproportionately obese, with 93% of COVID-19 and 79% of flu patients with BMI ≥ 30. Most striking, Black women 50-64 years of age disproportionately carried the burden of disease. At the time of diagnosis, temperature was significantly increased for all patients, yet pulse rate was only significantly increased for flu diagnosis, and BP was not significantly different in either. Our findings show the need for more complete demographic and office visit dimension data from patients during epidemic and pandemic events and support further studies needed to understand association between vital signs and predicting respiratory disease.

Role of Necroptosis in Central Nervous System Diseases

Necroptosis is a type of precisely regulated necrotic cell death activated in caspase-deficient conditions. Multiple factors initiate the necroptotic signaling pathway, including toll-like receptor 3/4, tumor necrosis factor (TNF), dsRNA viruses, and T cell receptors. Presently, TNF-induced necroptosis via the phosphorylation of three key proteins, receptor-interacting protein kinase 1, receptor-interacting protein kinase 3, and mixed lineage kinase domain-like protein, is the best-characterized process. Necroptosis induced by Z-DNA-binding protein 1 (ZBP-1) and toll/interleukin-1 receptor (TIR)-domain-containing adapter-inducing interferon (TRIF) plays a significant role in infectious diseases, such as influenza A virus, Zika virus, and herpesvirus infection. An increasing number of studies have demonstrated the close association of necroptosis with multiple diseases, and disrupting necroptosis has been confirmed to be effective for treating (or managing) these diseases. The central nervous system (CNS) exhibits unique physiological structures and immune characteristics. Necroptosis may occur without the sequential activation of signal proteins, and the necroptosis of supporting cells has more important implications in disease development. Additionally, necroptotic signals can be activated in the absence of necroptosis. Here, we summarize the role of necroptosis and its signal proteins in CNS diseases and characterize typical necroptosis regulators to provide a basis for the further development of therapeutic strategies for treating such diseases. In the present review, relevant information has been consolidated from recent studies (from 2010 until the present), excluding the patents in this field.

The danger of the single storyline obfuscating the complexities of managing SARS-CoV-2/COVID-19

Chimamanda Ngozi Adichie showed how a single story is limited and thereby distorts the true nature of an issue. During this COVID-19 pandemic there have been, at least, three consecutive single stories-the 'lethal threat' story, followed by the 'economic threat' story, and finally the 'vaccine miracle' story. None of these single stories can convincingly and permanently capture the dynamics of the pandemic. This is because countries experienced different morbidity and mortality patterns, different socioeconomic disadvantage, age and vulnerability of population, timing and level of lockdown with economic variability, and, despite heavy promotion, vaccines were beset with a significant and variable degree of hesitancy. Lack of transparency, coherence and consistency of pandemic management-arising from holding on to single storylines-showed the global deficiency of public health policy and planning, an underfunding of (public) health and social services, and a growing distrust in governments' ability to manage crises effectively. Indeed, the global management has increased already large inequities, and little has been learnt to address the growing crises of more infectious and potentially more lethal virus mutations. Holding onto single stories prevents the necessary learnings to understand and manage the complexities of 'wicked' problems, whereas listening to the many stories provides insights and pathways to do so effectively as well as efficiently.

COVID-19: Past, present and future

Not available.

Multi-attribute COVID-19 policy evaluation under deep uncertainty

Mitigating the impacts of COVID-19 comes with the evaluation of tradeoffs. However, the exact magnitude of the tradeoffs being made cannot be known ahead of time. There are three major concerns to balance: life, liberty, and economy. Here, we create a multi-attribute utility function including those three attributes and provide reasonable bounds on the weights of each. No one set of weights on the utility function can be considered "correct." Furthermore, the outcomes of each mitigation strategy are deeply uncertain. Not only do we need to take into account the characteristics of the disease, but we also need to take into account the efficacy of the mitigation strategies and how each outcome would be evaluated. To handle this, we use Robust Decision Making methods to simulate plausible outcomes for various strategies and evaluate those outcomes using different weights on the multi-attribute utility function. The simulation is done with a compartmental epidemiological model combined with a simple economic model and a model of liberty costs. Rather than trying to optimize likely outcomes for a particular version of the utility function, we find which strategies are robust across a wide range of plausible scenarios even when there is disagreement about how to weigh the competing values of life, liberty, and economy.

Ecological Barrier Deterioration Driven by Human Activities Poses Fatal Threats to Public Health due to Emerging Infectious Diseases

The coronavirus disease 2019 (COVID-19) and concerns about several other pandemics in the 21st century have attracted extensive global attention. These emerging infectious diseases threaten global public health and raise urgent studies on unraveling the underlying mechanisms of their transmission from animals to humans. Although numerous works have intensively discussed the cross-species and endemic barriers to the occurrence and spread of emerging infectious diseases, both types of barriers play synergistic roles in wildlife habitats. Thus far, there is still a lack of a complete understanding of viral diffusion, migration, and transmission in ecosystems from a macro perspective. In this review, we conceptualize the ecological barrier that represents the combined effects of cross-species and endemic barriers for either the natural or intermediate hosts of viruses. We comprehensively discuss the key influential factors affecting the ecological barrier against viral transmission from virus hosts in their natural habitats into human society, including transmission routes, contact probability, contact frequency, and viral characteristics. Considering the significant impacts of human activities and global industrialization on the strength of the ecological barrier, ecological barrier deterioration driven by human activities is critically analyzed for potential mechanisms. Global climate change can trigger and expand the range of emerging infectious diseases, and human disturbances promote higher contact frequency and greater transmission possibility. In addition, globalization drives more transmission routes and produces new high-risk regions in city areas. This review aims to provide a new concept for and comprehensive evidence of the ecological barrier blocking the transmission and spread of emerging infectious diseases. It also offers new insights into potential strategies to protect the ecological barrier and reduce the wide-ranging risks of emerging infectious diseases to public health.

Does the Prosperity of a Country Play a Role in COVID-19 Outcomes?

OBJECTIVE

This study aims to clarify the association between prosperity and the coronavirus disease (COVID-19) outcomes and its impact on the future management of pandemics.

METHODS

This is an observational study using information from 2 online registries. The numbers of infected individuals and deaths and the prosperity rank of each country were obtained from worldometer.info and the Legatum Institute's Prosperity Index, respectively.

RESULTS

There is a combination of countries with high and low prosperity on the list of COVID-19-infected countries. The risk of the virus pandemic seems to be more extensive in countries with high prosperity. A Spearman's rho test confirmed a significant correlation between prosperity, the number of COVID-19 cases, and the number of deaths at the 99% level.

CONCLUSION

New emerging pandemics affect all nations. In order to increase the likelihood of successfully managing future events, it is important to consider preexisting health security, valid population-based management approaches, medical decision-making, communication, continuous assessment, triage, treatment, early and complete physical distancing strategies, and logistics. These elements cannot be taught on-site and on occasion. There is a need for innovative and regular educational activities for all stakeholders committed to safeguarding our future defense systems concerning diagnostic, protection, treatment, and rehabilitation in pandemics, as well as other emergencies.

Changes in infectivity, severity and vaccine effectiveness against delta COVID-19 variant ten months into the vaccination program: The Israeli case

We present epidemiological data to examine trends in COVID-19 incidence, morbidity and mortality in Israel as well as changes in vaccine effectiveness, and discuss the impact of the delta variant and the third, "booster", vaccine. A retrospective-archive study was conducted from February 27th 2020 to October 16th, 2021. Data were obtained from the Israeli Ministry of Health's open COVID 19 database, including PCR-confirmed cases, number hospitalized - including severe cases, death rate, all by age and vaccination status, case fatality rate and changing effectiveness of the vaccine. After three COVID waves, confirmed cases rose from under 30 new daily cases in mid-June to a high of 11,000 in early September 2021. Severe hospitalized cases and death rates were lower than in previous waves and largely restricted to those not fully vaccinated. In the first three months of the vaccination campaign, non-vaccinated population demonstrated much higher morbidity rates. Four months after vaccination began, this gap was attenuated, with low rates of infection and hospitalization in all groups. The gap was regained following uptake of the third vaccine. Data from the fourth wave show reduced hospitalizations and mortality compared to previous waves and suggest that this may be related to high vaccine coverage. These trends suggest that countries with high vaccination might adopt a more permissive approach towards COVID even in the face of new variants.

An in-depth analysis of 10 epidemiological terminologies used in the context of COVID-19

AIM

In this paper, we explore the contextual use of 10 epidemiological terminologies, their significance, and interpretation/misinterpretation in explaining various aspects of the 2019 novel coronavirus disease (COVID-19) pandemic.

METHODS AND RESULTS

We first establish the different purposes of the terms 'pandemic' and 'Public Health Emergency of International Concern.' We then discuss the confusion caused by using the 'case fatality rate' as opposed to 'infection fatality rate' during the pandemic and the uncertainty surrounding the limited usefulness of identifying someone as 'pre-symptomatic.' We highlight the ambiguity in the 'positivity rate' and the need to be able to generate data on 'excess mortality' during public health emergencies. We discuss the relevance of 'association and causation' in the context of the facemask controversy that existed at the start of the pandemic. We point out how the accepted epidemiological practice of discussing 'herd immunity' in the context of vaccines has been twisted to suit the political motive of a public health approach. Given that a high proportion of COVID-19 cases are asymptomatic, we go on to show how COVID-19 has blurred the lines between 'screening/diagnosis' and 'quarantine/isolation,' while giving birth to the new terminology of 'community quarantine.'

CONCLUSIONS

Applying the lessons learned from COVID-19 to better understand the above terminologies will help health professionals communicate effectively, strengthen the scientific agenda of epidemiology and public health, and support and manage future outbreaks efficiently.

The SARS-CoV-2 pandemic: remaining uncertainties in our understanding of the epidemiology and transmission dynamics of the virus, and challenges to be overcome

Great progress has been made over the past 18 months in scientific understanding of the biology, epidemiology and pathogenesis of SARS-CoV-2. Extraordinary advances have been made in vaccine development and the execution of clinical trials of possible therapies. However, uncertainties remain, and this review assesses these in the context of virus transmission, epidemiology, control by social distancing measures and mass vaccination and the effect on all of these on emerging variants. We briefly review the current state of the global pandemic, focussing on what is, and what is not, well understood about the parameters that control viral transmission and make up the constituent parts of the basic reproductive number R 0. Major areas of uncertainty include factors predisposing to asymptomatic infection, the population fraction that is asymptomatic, the infectiousness of asymptomatic compared to symptomatic individuals, the contribution of viral transmission of such individuals and what variables influence this. The duration of immunity post infection and post vaccination is also currently unknown, as is the phenotypic consequences of continual viral evolution and the emergence of many viral variants not just in one location, but globally, given the high connectivity between populations in the modern world. The pattern of spread of new variants is also examined. We review what can be learnt from contact tracing, household studies and whole-genome sequencing, regarding where people acquire infection, and how households are seeded with infection since they constitute a major location for viral transmission. We conclude by discussing the challenges to attaining herd immunity, given the uncertainty in the duration of vaccine-mediated immunity, the threat of continued evolution of the virus as demonstrated by the emergence and rapid spread of the Delta variant, and the logistics of vaccine manufacturing and delivery to achieve universal coverage worldwide. Significantly more support from higher income countries (HIC) is required in low- and middle-income countries over the coming year to ensure the creation of community-wide protection by mass vaccination is a global target, not one just for HIC. Unvaccinated populations create opportunities for viral evolution since the net rate of evolution is directly proportional to the number of cases occurring per unit of time. The unit for assessing success in achieving herd immunity is not any individual country, but the world.

Human Influenza Epidemiology

Influenza virus infections are common in people of all ages. Epidemics occur in the winter months in temperate locations and at varying times of the year in subtropical and tropical locations. Most influenza virus infections cause mild and self-limiting disease, and around one-half of all infections occur with a fever. Only a small minority of infections lead to serious disease requiring hospitalization. During epidemics, the rates of influenza virus infections are typically highest in school-age children. The clinical severity of infections tends to increase at the extremes of age and with the presence of underlying medical conditions, and impact of epidemics is greatest in these groups. Vaccination is the most effective measure to prevent infections, and in recent years influenza vaccines have become the most frequently used vaccines in the world. Nonpharmaceutical public health measures can also be effective in reducing transmission, allowing suppression or mitigation of influenza epidemics and pandemics.

COVID-19 Pandemic: Public Health Risk Assessment and Risk Mitigation Strategies

A newly emerged respiratory viral disease called severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is also known as pandemic coronavirus disease (COVID-19). This pandemic has resulted an unprecedented global health crisis and devastating impact on several sectors of human lives and economies. Fortunately, the average case fatality ratio for SARS-CoV-2 is below 2%, much lower than that estimated for MERS (34%) and SARS (11%). However, COVID-19 has a much higher transmissibility rate, as evident from the constant increase in the count of infections worldwide. This article explores the reasons behind how COVID-19 was able to cause a global pandemic crisis. The current outbreak scenario and causes of rapid global spread are examined using recent developments in the literature, epidemiological features relevant to public health awareness, and critical perspective of risk assessment and mitigation strategies. Effective pandemic risk mitigation measures have been established and amended against COVID-19 diseases, but there is still much scope for upgrading execution and coordination among authorities in terms of organizational leadership's commitment and diverse range of safety measures, including administrative control measures, engineering control measures, and personal protective equipment (PPE). The significance of containment interventions against the COVID-19 pandemic is now well established; however, there is a need for its effective execution across the globe, and for the improvement of the performance of risk mitigation practices and suppression of future pandemic crises.

Using secondary cases to characterize the severity of an emerging or re-emerging infection

The methods to ascertain cases of an emerging infectious disease are typically biased toward cases with more severe disease, which can bias the average infection-severity profile. Here, we conducted a systematic review to extract information on disease severity among index cases and secondary cases identified by contact tracing of index cases for COVID-19. We identified 38 studies to extract information on measures of clinical severity. The proportion of index cases with fever was 43% higher than for secondary cases. The proportion of symptomatic, hospitalized, and fatal illnesses among index cases were 12%, 126%, and 179% higher than for secondary cases, respectively. We developed a statistical model to utilize the severity difference, and estimate 55% of index cases were missed in Wuhan, China. Information on disease severity in secondary cases should be less susceptible to ascertainment bias and could inform estimates of disease severity and the proportion of missed index cases.

An Eight-Year Profile of Children with Influenza A(H1N1) in a Large Hospital in India

As influenza virus A(H1N1) continues to circulate, reports from India have documented mainly respiratory involvement in children. This retrospective chart review of children at a medical college found that from August 2009 to July 2017, 855 children aged 3 months to 15 years had H1N1 influenza of whom 310 (36.3%) were admitted and 29 (9.4% admissions) died. In 2009-12, 76.5% patients presented in August-October but from 2015 to 2017, 89.3% came in January-March. The proportion of under-fives increased from 54.0% in 2009-10 to 77.7% in 2015-17. Among admitted children, 82.6% were under 5 years, 96.1% had respiratory symptoms and 11% had seizures. Six children had encephalopathy of whom four died; two survivors had severe neurological sequelae. Other features included gastroenteritis, otitis media, myositis and hepatitis. Complications included shock (10.7%) and acute respiratory distress syndrome (6.1%). Evidence of bacterial/fungal infection was present in 71 (22.9%). Oxygen was required by 123 children (39.7%), high-dependency/intensive care by 47 (15.2%), 17 (5.5%) received high-flow oxygen and 29 (9.4%) required mechanical ventilation. There were no significantly increased odds of needing intensive care or of dying in children with underlying diseases or among different age groups but those with underlying central nervous system (CNS) diseases had higher odds of needing high-dependency/intensive care [odds ratio (OR) 2.35, p = 0.046]. Significantly, children with CNS symptoms had nearly seven times higher odds of needing mechanical ventilation (OR 6.85, p < 0.001) and over three times higher odds of dying (OR 3.31, p = 0.009). Lay summaryH1N1 Influenza ("swine flu") emerged as a global pandemic in 2009 and continues to affect children all over the world. This review of records from a medical college hospital in southern India found that 855 children aged 3 months to 15 years came with H1N1 influenza over 8 years from August 2009 to July 2017. In 2009-12, over three-quarters of them presented in the rainy season but from 2015-17, almost 90% came in the winter and spring, suggesting a change in the seasonality of the outbreaks, which could impact the choice of dates for annual influenza vaccination. The proportion under 5 years of age increased from 54% in 2009-10 to 78% in 2015-17, suggesting possible immunity in children exposed to earlier outbreaks. Over a third of the children needed admission of whom almost 40% needed oxygen, one-sixth needed high-dependency/intensive care and 1 in 11 admitted children died, emphasizing the severity of this disease. While most children had respiratory symptoms, all organs of the body were affected; 11% of those admitted had seizures and 6 had encephalitis. Children admitted with central nervous system symptoms had an almost 7-fold higher risk of needing high-dependency/intensive care and an over 3-fold higher risk of dying.

Primary Pandemic Prevention

Over the last few decades, hundreds of human pathogens have emerged at a rate unprecedented in human history. Emerged from where? Mostly from animals. The AIDS virus is blamed on the butchering of primates in the African bushmeat trade, we created mad cow disease when we turned cows into carnivores and cannibals, and SARS and COVID-19 have been traced back to the exotic wild animal trade. Our last pandemic, swine flu in 2009, arose not from some backwater wet market in Asia, however. It was largely made-in-the-USA on pig production operations in the United States. In this new Age of Emerging Diseases, there are now billions of animals overcrowded and intensively confined in filthy factory farms for viruses to incubate and mutate within. Today's industrial farming practices have given viruses billions more spins at pandemic roulette. How can we stop the emergence of pandemic viruses in the first place? Whenever possible, treat the cause. The largest and oldest association of public health professionals in the world, the American Public Health Association, has called for a moratorium on factory farming for nearly two decades. Indeed, factory farms are a public health menace. In addition to discontinuing the intensive confinement practices of animal agriculture, we should continue to research, develop, and invest in innovative plant-based and cultivated meat technologies to move away from raising billions of feathered and curly-tailed test tubes for viruses with pandemic potential to mutate within.

Estimating case fatality risk of severe Yellow Fever cases: systematic literature review and meta-analysis

BACKGROUND

Case fatality risk (CFR), commonly referred to as a case fatality ratio or rate, represents the probability of a disease case being fatal. It is often estimated for various diseases through analysis of surveillance data, case reports, or record examinations. Reported CFR values for Yellow Fever vary, offering wide ranges. Estimates have not been found through systematic literature review, which has been used to estimate CFR of other diseases. This study aims to estimate the case fatality risk of severe Yellow Fever cases through a systematic literature review and meta-analysis.

METHODS

A search strategy was implemented in PubMed and Ovid Medline in June 2019 and updated in March 2021, seeking reported severe case counts, defined by fever and either jaundice or hemorrhaging, and the number of those that were fatal. The searches yielded 1,133 studies, and title/abstract review followed by full text review produced 14 articles reporting 32 proportions of fatal cases, 26 of which were suitable for meta-analysis. Four studies with one proportion each were added to include clinical case data from the recent outbreak in Brazil. Data were analyzed through an intercept-only logistic meta-regression with random effects for study. Values of the I2 statistic measured heterogeneity across studies.

RESULTS

The estimated CFR was 39 % (95 % CI: 31 %, 47 %). Stratifying by continent showed that South America observed a higher CFR than Africa, though fewer studies reported estimates for South America. No difference was seen between studies reporting surveillance data and studies investigating outbreaks, and no difference was seen among different symptom definitions. High heterogeneity was observed across studies.

CONCLUSIONS

Approximately 39 % of severe Yellow Fever cases are estimated to be fatal. This study provides the first systematic literature review to estimate the CFR of Yellow Fever, which can provide insight into outbreak preparedness and estimating underreporting.

Clinical and laboratory signs of haemophagocytic lymphohistiocytosis associated with pandemic influenza A (H1N1) infection in patients needing extracorporeal membrane oxygenation: A retrospective observational study

BACKGROUND

Severe pandemic influenza has been associated with the hyperinflammatory condition secondary haemophagocytic lymphohistiocytosis (HLH).

OBJECTIVES

To determine the frequency, degree, character and possible cause of influenza-associated HLH in critically ill patients with severe acute respiratory distress syndrome due to influenza A (H1N1) infection requiring extracorporeal membrane oxygenation (ECMO) support at our hospital.

DESIGN

A retrospective observational study.

PATIENTS AND SETTING

Medical data were retrieved retrospectively from 11 consenting patients of thirteen adults infected with pandemic influenza A (H1N1) 2009 requiring ECMO between July 2009 and January 2010 at the ECMO Centre of Karolinska University Hospital, Stockholm, Sweden. All patients were evaluated for HLH using HLH-2004 criteria and HScore.

RESULTS

Eleven patients (median age 31 years) were included in the study and all survived. All patients showed signs of multiple organ dysfunction and pronounced inflammation, more severe in the four patients with HLH who had significantly higher peak serum concentrations of ferritin (P = 0.024), alkaline phosphatase (P = 0.012) and gamma-glutamyl transferase (P = 0.024), lower concentration of albumin (P = 0.0086) and more frequently hepatomegaly (P = 0.048). Abnormal lymphocyte cytotoxicity (lytic units <10) and a low proportion of natural killer (NK) cells were observed in three of four patients with HLH. Notably, we found a significant inverse correlation between serum ferritin concentration and NK cell and cytotoxic T lymphocyte percentages (rs = -0.74, P = 0.0013 and rs = -0.79, P = 0.0025, respectively). One HLH patient received HLH-directed cytotoxic therapy, another intravenous immunoglobulin and the other two no specific HLH-directed therapy.

CONCLUSION

Critically ill patients, including healthy young adults, with pandemic influenza may develop HLH and should be monitored for signs of hyperinflammation and increasing organ dysfunction, and evaluated promptly for HLH because HLH-directed therapy may then be beneficial. The association of low NK percentages with hyperferritinaemia may suggest a role for reduced NK cell numbers, possibly also cytotoxic T lymphocytes, and subsequently reduced lymphocyte cytotoxicity, in the pathogenesis of hyperinflammation and secondary HLH.

Asymptomatic Transmission and the Infection Fatality Risk for COVID-19: Implications for School Reopening

Asymptomatic infection occurs for numerous respiratory viral diseases, including influenza and coronavirus disease 2019 (COVID-19). We seek to clarify confusion in 3 areas: age-specific risks of transmission and/or disease; various definitions for the COVID-19 "mortality rate," each useful for specific purposes; and implications for student return strategies from preschool through university settings.

Human security as biosecurity Reconceptualizing national security threats in the time of COVID-19

Research within security studies has struggled to determine whether infectious disease (ID) represents an existential threat to national and international security. With the emergence of SARS-CoV-2 (COVID-19), it is imperative to reexamine the relationship between ID and global security. This article addresses the specific threat to security from COVID-19, asking, "Is COVID-19 a threat to national and international security?" To investigate this question, this article uses two theoretical approaches: human security and biosecurity. It argues that COVID-19 is a threat to global security by the ontological crisis posed to individuals through human security theory and through high politics, as evidenced by biosecurity. By viewing security threats through the lens of the individual and the state, it becomes clear that ID should be considered an international security threat. This article examines the relevant literature and applies the theoretical framework to a case study analysis focused on the United States.

COVID-19: Rethinking the Lockdown Groupthink

The Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has caused the Coronavirus Disease 2019 (COVID-19) worldwide pandemic in 2020. In response, most countries in the world implemented lockdowns, restricting their population's movements, work, education, gatherings, and general activities in attempt to "flatten the curve" of COVID-19 cases. The public health goal of lockdowns was to save the population from COVID-19 cases and deaths, and to prevent overwhelming health care systems with COVID-19 patients. In this narrative review I explain why I changed my mind about supporting lockdowns. The initial modeling predictions induced fear and crowd-effects (i.e., groupthink). Over time, important information emerged relevant to the modeling, including the lower infection fatality rate (median 0.23%), clarification of high-risk groups (specifically, those 70 years of age and older), lower herd immunity thresholds (likely 20-40% population immunity), and the difficult exit strategies. In addition, information emerged on significant collateral damage due to the response to the pandemic, adversely affecting many millions of people with poverty, food insecurity, loneliness, unemployment, school closures, and interrupted healthcare. Raw numbers of COVID-19 cases and deaths were difficult to interpret, and may be tempered by information placing the number of COVID-19 deaths in proper context and perspective relative to background rates. Considering this information, a cost-benefit analysis of the response to COVID-19 finds that lockdowns are far more harmful to public health (at least 5-10 times so in terms of wellbeing years) than COVID-19 can be. Controversies and objections about the main points made are considered and addressed. Progress in the response to COVID-19 depends on considering the trade-offs discussed here that determine the wellbeing of populations. I close with some suggestions for moving forward, including focused protection of those truly at high risk, opening of schools, and building back better with a economy.

Do not neglect SARS-CoV-2 hospitalization and fatality risks in the middle-aged adult population

Objectives

This study aimed at estimating the SARS-CoV-2 infection hospitalization (IHR) and infection fatality ratios (IFR) in France.

Patients and methods

A serosurvey was conducted in 9782 subjects from the two French regions with the highest incidence of COVID-19 during the first wave of the pandemic and coupled with surveillance data.

Results

IHR and IFR were 2.7% and 0.49% overall. Both were higher in men and increased exponentially with age. The relative risks of hospitalization and death were 2.1 (95% CI: 1.9-2.3) and 3.8 (2.4-4.2) per 10-year increase, meaning that IHR and IFR approximately doubled every 10 and 5 years, respectively. They were dramatically high in the very elderly (80-90 years: IHR: 26%, IFR: 9.2%), and also substantial in younger adults (40-50 years: IHR: 0.98%, IFR: 0.042%).

Conclusions

These findings support the need for comprehensive preventive measures to help reduce the spread of the virus, even in young or middle-aged adults.

Biosafety Requirements for Autopsies of Patients with COVID-19: Example of a BSL-3 Autopsy Facility Designed for Highly Pathogenic Agents

Information obtained from autopsies of patients infected with high-risk pathogens is an important pillar in managing a proper response to pandemics, particular in the early phase. This is due to the fact that autopsy allows efficient evaluation of comorbidities for risk assessment, as well as identification of key pathophysiological and molecular mechanisms in organs driving the severity of disease which might be important targets for therapeutic interventions. In the case of patients who have died of infection with unknown pathogens, isolation and culture of pathogens from the affected organs is another important opportunity for a proper response to (re)emerging infectious diseases. However, the situation of COVID-19 demonstrated that there were concerns about performing autopsies because of biosafety risks. In this review we compare requirements for biosafety level 3 (BSL-3) laboratories from the European Commission and the World Health Organization and summarize specific recommendations for postmortem analysis of COVID-19-deceased patients from the Centers for Disease Control and Prevention. Furthermore, we describe in detail a BSL-3 facility with enhanced protection of personnel and an environment that has been designed for performing autopsies, biobanking of collected tissue specimens, and culture of pathogens in cases of high-risk pathogen infections and report on the experience obtained in operating this facility in the context of COVID-19.

Repeated cross-sectional sero-monitoring of SARS-CoV-2 in New York City

In late 2019, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was first detected in China and has since caused a pandemic of coronavirus disease 2019 (COVID-19). The first case of COVID-19 in New York City was officially confirmed on 1 March 2020 followed by a severe local epidemic¹. Here, to understand seroprevalence dynamics, we conduct a retrospective, repeated cross-sectional analysis of anti-SARS-CoV-2 spike antibodies in weekly intervals from the beginning of February to July 2020 using more than 10,000 plasma samples from patients at Mount Sinai Hospital in New York City. We describe the dynamics of seroprevalence in an 'urgent care' group, which is enriched in cases of COVID-19 during the epidemic, and a 'routine care' group, which more closely represents the general population. Seroprevalence increased at different rates in both groups; seropositive samples were found as early as mid-February, and levelled out at slightly above 20% in both groups after the epidemic wave subsided by the end of May. From May to July, seroprevalence remained stable, suggesting lasting antibody levels in the population. Our data suggest that SARS-CoV-2 was introduced in New York City earlier than previously documented and describe the dynamics of seroconversion over the full course of the first wave of the pandemic in a major metropolitan area.

COVID-19 and Major Organ Thromboembolism: Manifestations in Neurovascular and Cardiovascular Systems

COVID-19, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has been shown to cause multisystemic damage. We undertook a systematic literature review and comprehensive analysis of a total of 55 articles on arterial and venous thromboembolism in COVID-19 and articles on previous pandemics with respect to thromboembolism and compared the similarities and differences between them. The presence of thrombosis in multiple organ systems points to thromboembolism being an integral component in the pathogenesis of this disease. Thromboembolism is likely to be the main player in the morbidity and mortality of COVID -19 in which the pulmonary system is most severely affected. We also hypothesize that D-dimer values could be used as an early marker for prognostication of disease as it has been seen to be raised even in the pre-symptomatic stage. This further strengthens the notion that thromboembolism prevention is necessary. We also examined literature on the neurovascular and cardiovascular systems, as the manifestation of thromboembolic phenomenon in these two systems varied, suggesting different pathophysiology of damage. Further research into the role of thromboembolism in COVID-19 is important to advance the understanding of the virus, its effects and to tailor treatment accordingly to prevent further casualties from this pandemic.

SARS-CoV-2 in wastewater: State of the knowledge and research needs

The ongoing global pandemic of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been a Public Health Emergency of International Concern, which was officially declared by the World Health Organization. SARS-CoV-2 is a member of the family Coronaviridae that consists of a group of enveloped viruses with single-stranded RNA genome, which cause diseases ranging from common colds to acute respiratory distress syndrome. Although the major transmission routes of SARS-CoV-2 are inhalation of aerosol/droplet and person-to-person contact, currently available evidence indicates that the viral RNA is present in wastewater, suggesting the need to better understand wastewater as potential sources of epidemiological data and human health risks. Here, we review the current knowledge related to the potential of wastewater surveillance to understand the epidemiology of COVID-19, methodologies for the detection and quantification of SARS-CoV-2 in wastewater, and information relevant for human health risk assessment of SARS-CoV-2. There has been growing evidence of gastrointestinal symptoms caused by SARS-CoV-2 infections and the presence of viral RNA not only in feces of infected individuals but also in wastewater. One of the major challenges in SARS-CoV-2 detection/quantification in wastewater samples is the lack of an optimized and standardized protocol. Currently available data are also limited for conducting a quantitative microbial risk assessment (QMRA) for SARS-CoV-2 exposure pathways. However, modeling-based approaches have a potential role to play in reducing the impact of the ongoing COVID-19 outbreak. Furthermore, QMRA parameters obtained from previous studies on relevant respiratory viruses help to inform risk assessments of SARS-CoV-2. Our understanding on the potential role of wastewater in SARS-CoV-2 transmission is largely limited by knowledge gaps in its occurrence, persistence, and removal in wastewater. There is an urgent need for further research to establish methodologies for wastewater surveillance and understand the implications of the presence of SARS-CoV-2 in wastewater.

Fundamental protective mechanisms of face masks against droplet infections

Many governments have instructed the population to wear simple mouse-and-nose covers or surgical face masks to protect themselves from droplet infection with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in public. However, the basic protection mechanisms and benefits of these masks remain controversial. Therefore, the aim of this work is to show from a fluid physics point of view under which circumstances these masks can protect against droplet infection. First of all, we show that the masks protect people in the surrounding area quite well, since the flow resistance of the face masks effectively prevents the spread of exhaled air, e.g. when breathing, speaking, singing, coughing and sneezing. Secondly, we provide visual evidence that typical household materials used by the population to make masks do not provide highly efficient protection against respirable particles and droplets with a diameter of 0.3-2 μm as they pass through the materials largely unfiltered. According to our tests, only vacuum cleaner bags with fine dust filters show a comparable or even better filtering effect than commercial particle filtering FFP2/N95/KN95 half masks. Thirdly, we show that even simple mouse-and-nose covers made of good filter material cannot reliably protect against droplet infection in contaminated ambient air, since most of the air flows through gaps at the edge of the masks. Only a close-fitting, particle-filtering respirator offers good self-protection against droplet infection. Nevertheless, wearing simple homemade or surgical face masks in public is highly recommended if no particle filtrating respiratory mask is available. Firstly, because they protect against habitual contact of the face with the hands and thus serve as self-protection against contact infection. Secondly, because the flow resistance of the masks ensures that the air remains close to the head when breathing, speaking, singing, coughing and sneezing, thus protecting other people if they have sufficient distance from each other. However, if the distance rules cannot be observed and the risk of inhalation-based infection becomes high because many people in the vicinity are infectious and the air exchange rate is small, improved filtration efficiency masks are needed, to take full advantage of the three fundamental protective mechanisms these masks provide.

The dynamic effects of infectious disease outbreaks: The case of pandemic influenza and human coronavirus

Pandemic influenza is a regularly recurring form of infectious disease; this work analyses its economic effects. Like many other infectious diseases influenza pandemics are usually of short, sharp duration. Human coronavirus is a less regularly recurring infectious disease. The human coronavirus pandemic of 2019 (COVID-19) has presented with seemingly high transmissibility and led to extraordinary socioeconomic disruption due to severe preventative measures by governments. To understand and compare these events, epidemiological and economic models are linked to capture the transmission of a pandemic from regional populations to regional economies and then across regional economies. In contrast to past pandemics, COVID-19 is likely to be of longer duration and more severe in its economic effects given the greater uncertainty surrounding its nature. The analysis indicates how economies are likely to be affected due to the risk-modifying behaviour in the form of preventative measures taken in response to the latest novel pandemic virus.

How previous epidemics enable timelier COVID-19 responses: an empirical study using organisational memory theory

INTRODUCTION

There has been little systematic exploration into what affects timeliness of epidemic response, despite the potential for earlier responses to be more effective. Speculations have circulated that previous exposure to major epidemics helped health systems respond more quickly to COVID-19. This study leverages organisational memory theory to test whether health systems with any, more severe, or more recent exposure to major epidemics enacted timelier COVID-19 policy responses.

METHODS

A data set was constructed cataloguing 846 policies across 178 health systems in total, 37 of which had major epidemics within the last 20 years. Hypothesis testing used OLS regressions with World Health Organization region fixed effects, controlling for several health system expenditure and political variables.

RESULTS

Results show that exposure to any major epidemics was associated with providing earlier response in the following policy categories: all policies, surveillance/response, distancing, and international travel policies. The effect was about 6-10 days earlier response. The significance of this variable was largely nullified with the addition of the other two independent variables. Neither total cases nor years since previous epidemics showed no statistical significance.

CONCLUSION

This study suggests that health systems may learn from past major epidemics. Policymakers ought to institutionalise lessons from COVID-19. Future studies can examine specific generalisable lessons and whether timelier responses correlated with lower health and economic impacts.

SARS-CoV-2 pandemic: An overview

By the end of May 2020, SARS-CoV-2 pandemic caused more than 350,000 deaths worldwide. In the first months, there have been uncertainties on almost any area: infection transmission route, virus origin and persistence in the environment, diagnostic tests, therapeutic approach, high-risk subjects, lethality, and containment policies. We provide an updated summary of the current knowledge on the pandemic, discussing the available evidence on the effectiveness of the adopted mitigation strategies.

Potential COVID-19 Outbreak in Fire Camp: Modeling Scenarios and Interventions

The global COVID-19 pandemic will pose unique challenges to the management of wildland fire in 2020. Fire camps may provide an ideal setting for the transmission of SARS-CoV-2, the virus that causes COVID-19. However, intervention strategies can help minimize disease spread and reduce the risk to the firefighting community. We developed a COVID-19 epidemic model to highlight the risks posed by the disease during wildland fire incidents. Our model accounts for the transient nature of the population on a wildland fire incident, which poses unique risks to the management of communicable diseases in fire camps. We used the model to assess the impact of two types of interventions: the screening of a firefighter arriving on an incident, and social distancing measures. Our results suggest that both interventions are important to mitigate the risks posed by the SARS-CoV-2 virus. However, screening is relatively more effective on short incidents, whereas social distancing is relatively more effective during extended campaigns. We conclude with a discussion of model limitations and potential extensions to the model.

COVID-19 human challenge studies: ethical issues

COVID-19 poses an extraordinary threat to global public health and an effective vaccine could provide a key means of overcoming this crisis. Human challenge studies involve the intentional infection of research participants and can accelerate or improve vaccine development by rapidly providing estimates of vaccine safety and efficacy. Human challenge studies of low virulence coronaviruses have been done in the past and human challenge studies with severe acute respiratory syndrome coronavirus 2 have been proposed. These studies of coronaviruses could provide considerable benefits to public health; for instance, by improving and accelerating vaccine development. However, human challenge studies of severe acute respiratory syndrome coronavirus 2 in particular might be controversial, in part, for ethical reasons. The ethical issues raised by such studies thus warrant early consideration involving, for example, broad consultation with the community. This Personal View provides preliminary analyses of relevant ethical considerations regarding human challenge studies of severe acute respiratory syndrome coronavirus 2, including the potential benefits to public health and to participants, the risks and uncertainty for participants, and the third-party risks (ie, to research staff and the wider community). We argue that these human challenge studies can reasonably be considered ethically acceptable insofar as such studies are accepted internationally and by the communities in which they are done, can realistically be expected to accelerate or improve vaccine development, have considerable potential to directly benefit participants, are designed to limit and minimise risks to participants, and are done with strict infection control measures to limit and reduce third-party risks.

COVID-19 Healthcare Planning: Predicting Mortality and the Role of the Herd Immunity Barrier in the General Population

Using a mathematical model for COVID-19 incorporating data on excess of mortality compared to the corresponding period of the previous year obtained from the daily monitoring of mortality in Spain (MoMo), the prediction of total number of casualties in Spain for the first outbreak has been computed. From this figure, and following a stepwise meta-analysis of available reports, the case fatality rate (CFR) and the infectious case fatality rate (IFR) for the outbreak have been estimated. As the impact of age on these rates is notable, it is proposed to include an age-related adjusted fatality ratio in future comparative analyses between studies, calculated by adjusting the results by risk ratio to a reference age band (e.g., 60–69). From the casualty figures, and the corresponding CFR and IFR ratios, the forecast of serologically positive cases in the general Spanish population has been estimated at approximately 1% (0.87–1.3%) of the samples. If the data are confirmed by the ongoing study of the Carlos III Institute, until a vaccine is found, the immunity acquired in the general population after the infectious outbreak is far from the 65–70% herd immunity required as a barrier for COVID-19.

An analysis of International Health Regulations Emergency Committees and Public Health Emergency of International Concern Designations

INTRODUCTION

Nine events have been assessed for potential declaration of a Public Health Emergency of International Concern (PHEIC). A PHEIC is defined as an extraordinary event that constitutes a public health risk to other states through international spread and requires a coordinated international response. The WHO Director-General convenes Emergency Committees (ECs) to provide their advice on whether an event constitutes a PHEIC. The EC rationales have been criticised for being non-transparent and contradictory to the International Health Regulations (IHR). This first comprehensive analysis of EC rationale provides recommendations to increase clarity of EC decisions which will strengthen the IHR and WHO's legitimacy in future outbreaks.

METHODS

66 EC statements were reviewed from nine public health outbreaks of influenza A, Middle East respiratory syndrome coronavirus, polio, Ebola virus disease, Zika, yellow fever and coronavirus disease-2019. Statements were analysed to determine which of the three IHR criteria were noted as contributing towards the EC's justification on whether to declare a PHEIC and what language was used to explain the decision.

RESULTS

Interpretation of the criteria were often vague and applied inconsistently. ECs often failed to describe and justify which criteria had been satisfied.

DISCUSSION

Guidelines must be developed for the standardised interpretation of IHR core criteria. The ECs must clearly identify and justify which criteria have contributed to their rationale for or against PHEIC declaration.

CONCLUSION

Striving for more consistency and transparency in EC justifications would benefit future deliberations and provide more understanding and support for the process.

COVID-19: Was wir wissen können

Die Ausarbeitung seiner Logik-Vorlesungen hatte Immanuel Kant an Gottlob Benjamin Jäsche übertragen, welcher im Jahr 1800 ein Handbuch dazu veröffentlichte. Dieser Niederschrift verdanken wir die einprägsame Formulierung: „ Das Feld der Philosophie […] läßt sich auf folgende Fragen bringen: 1) Was kann ich wissen? – 2) Was soll ich tun? 3) Was darf ich hoffen? 4) Was ist der Mensch? “ 1 . Diese Frage nach dem berechtigten Wissen-Können hat nicht nur Immanuel Kant und seine Zeitgenossen beschäftigt, sondern ist eine Kernfrage von den Anfängen der Philosophie bis zu modernen heutigen Wissenschaftstheorien 2 . Die damit verbundene Skepsis – exemplifiziert durch den Empirismus David Humes – unterbrach nach eigenen Angaben Immanuel Kants seinen „dogmatischen Schlummer“ und gab seinem Denken „eine ganz andere Richtung“ 3 .

COVID-19: A Risk Assessment Perspective

COVID-19 is a newly emerging viral respiratory disease first identified in Wuhan, China, in December 2019. The disease is caused by the coronavirus SARS-CoV-2, which is related to the viruses that cause SARS and MERS. While the case fatality ratio for COVID-19 (5%) is far lower than that for SARS (11%) and MERS (34%), COVID-19 is spreading relatively uncontrolled at this time across the globe. In contrast, SARS appears to be contained, and MERS is controlled. This paper will explore why COVID-19 is able to progress to a global pandemic that affects our daily lives to an extent not known in recent history. The COVID-19 outbreak and spread will be examined based on the current literature, using a researcher's perspective of risk assessment and risk mitigation; this approach will be related to public health.

Impact of influenza vaccine-modified infectivity on attack rate, case fatality ratio and mortality

Generally, vaccines are designed to provide protection against infection (susceptibility), disease (symptoms and transmissibility), and/or complications. In a recent study of influenza vaccination, it was observed that vaccinated yet infected individuals experienced increased transmission levels. In this paper, using a mathematical model of infection and transmission, we study the impact of vaccine-modified effects, including susceptibility and infectivity, on important epidemiological outcomes of an immunization program. The balance between vaccine-modified susceptibility, infectivity and recovery needed in preventing an influenza outbreak, or in mitigating the health outcomes of the outbreak is studied using the SIRV-type of disease transmission model. We also investigate the impact of influenza vaccination program on the infection risk of vaccinated and non-vaccinated individuals.

Effect of changing case definitions for COVID-19 on the epidemic curve and transmission parameters in mainland China: a modelling study

BACKGROUND

When a new infectious disease emerges, appropriate case definitions are important for clinical diagnosis and for public health surveillance. Tracking case numbers over time is important to establish the speed of spread and the effectiveness of interventions. We aimed to assess whether changes in case definitions affected inferences on the transmission dynamics of coronavirus disease 2019 (COVID-19) in China.

METHODS

We examined changes in the case definition for COVID-19 in mainland China during the first epidemic wave. We used exponential growth models to estimate how changes in the case definitions affected the number of cases reported each day. We then inferred how the epidemic curve would have appeared if the same case definition had been used throughout the epidemic.

FINDINGS

From Jan 15 to March 3, 2020, seven versions of the case definition for COVID-19 were issued by the National Health Commission in China. We estimated that when the case definitions were changed, the proportion of infections being detected as cases increased by 7·1 times (95% credible interval [CrI] 4·8-10·9) from version 1 to 2, 2·8 times (1·9-4·2) from version 2 to 4, and 4·2 times (2·6-7·3) from version 4 to 5. If the fifth version of the case definition had been applied throughout the outbreak with sufficient testing capacity, we estimated that by Feb 20, 2020, there would have been 232 000 (95% CrI 161 000-359 000) confirmed cases in China as opposed to the 55 508 confirmed cases reported.

INTERPRETATION

The case definition was initially narrow and was gradually broadened to allow detection of more cases as knowledge increased, particularly milder cases and those without epidemiological links to Wuhan, China, or other known cases. These changes should be taken into account when making inferences on epidemic growth rates and doubling times, and therefore on the reproductive number, to avoid bias.

FUNDING

Health and Medical Research Fund, Hong Kong.

Epidemiology and phylogenetic analysis of respiratory viruses from 2012 to 2015 - A sentinel surveillance report from union territory of Puducherry, India

Background

Acute respiratory infections (ARI) are the most common illnesses affecting people of all ages worldwide. Viruses contribute to 30–70% of acute respiratory infections. Identification of these respiratory viruses is not given high priority except influenza; however, the knowledge about prevalence of non-influenza viruses, their seasonal pattern and genetic evolution have significant epidemiological value.

Methods

As a part of National Influenza-like illness surveillance programme, respiratory specimens were collected children and adults with symptoms of ILI or ARI, between January 2012 and March 2015 (including SARI cases). Real-time PCR was done to identify 13 respiratory viruses. Sequencing was done for representative isolates of each virus using ABI 3730 Genetic Analyzer.

Results

During the study period between January 2012 and March 2015, a total of 648 patients with symptoms of ARI were included in this study. The mean age of the patients was 20.2 years (SD = 19.13, median = 18); 292 (45.1%) were children (≤13 years) and 356 (54.9%) were adults. Respiratory viruses were identified in 44% (287/648) of all patients. Influenza accounted for the maximum number of cases- 179/648 (27.6%). Among the non-influenza viruses, RSV predominated with 34 cases (5.2%), followed by HMPV 24 (3.7%) and PIV-3 20 (3%). Four patients died due to INF A/H1N1 (2012-2, 2015-2) as a result of acute respiratory distress syndrome (ARDS) (CFR 3.7%). Among the non-influenza viruses, no particular seasonality pattern was observed over the different months of the study period.

Conclusion

Antibiotic usage in treating acute respiratory infections empirically is not justified as nearly half of ARI are due to viruses; nearly 28% of them were due to influenza viruses. Among the non-influenza viruses, RSV predominated, followed by HMPV. This study is based on an active influenza surveillance initiated after 2009 pandemic influenza outbreak, in the Union territory of Puducherry which has contributed significantly to the knowledge of the burden of influenza and non-influenza viruses among children and adults. Such surveillance network has paved the way for better diagnosis and timely therapeutic interventions.

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First data on the epidemiology of respiratory viruses from this region after 1974.

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First study to report corona virus, HCoV OC43 from India, and only the second Indian study to document corona virus, HCoV229E. This study is the first study to analyse the genetic sequence of HCoV-229E and OC-43.

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Influenza accounted for the maximum number of cases in the study population, 27%; four patients died of Acute respiratory distress syndrome (ARDS) due to influenza A/H1N1; CFR- 3.7%.

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Among the non-influenza viruses, RSV pre-dominated followed HMPV and PIV-3. No deaths were reported due to non-influenza viral ARI. RSV was detected almost equally in adults and children.

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Distinct pattern was observed in seasonality of influenza viruses but not for non-influenza viruses.

Serological assays for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), March 2020

BackgroundThe ongoing coronavirus disease (COVID-19) pandemic has major impacts on health systems, the economy and society. Assessing infection attack rates in the population is critical for estimating disease severity and herd immunity which is needed to calibrate public health interventions. We have previously shown that it is possible to achieve this in real time to impact public health decision making.AimOur objective was to develop and evaluate serological assays applicable in large-scale sero-epidemiological studies.MethodsWe developed an ELISA to detect IgG and IgM antibodies to the receptor-binding domain (RBD) of the spike protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We evaluated its sensitivity and specificity in combination with confirmatory microneutralisation (MN) and 90% plaque reduction neutralisation tests (PRNT90) in 51 sera from 24 patients with virologically confirmed COVID-19 and in age-stratified sera from 200 healthy controls.ResultsIgG and IgM RBD ELISA, MN and PRNT90 were reliably positive after 29 days from illness onset with no detectable cross-reactivity in age-stratified controls. We found that PRNT90 tests were more sensitive in detecting antibody than MN tests carried out with the conventional 100 tissue culture infectious dose challenge. Heparinised plasma appeared to reduce the infectivity of the virus challenge dose and may confound interpretation of neutralisation test.ConclusionUsing IgG ELISA based on the RBD of the spike protein to screen sera for SARS-CoV-2 antibody, followed by confirmation using PRNT90, is a valid approach for large-scale sero-epidemiology studies.

Estimating clinical severity of COVID-19 from the transmission dynamics in Wuhan, China

As of 29 February 2020 there were 79,394 confirmed cases and 2,838 deaths from COVID-19 in mainland China. Of these, 48,557 cases and 2,169 deaths occurred in the epicenter, Wuhan. A key public health priority during the emergence of a novel pathogen is estimating clinical severity, which requires properly adjusting for the case ascertainment rate and the delay between symptoms onset and death. Using public and published information, we estimate that the overall symptomatic case fatality risk (the probability of dying after developing symptoms) of COVID-19 in Wuhan was 1.4% (0.9-2.1%), which is substantially lower than both the corresponding crude or naïve confirmed case fatality risk (2,169/48,557 = 4.5%) and the approximator1 of deaths/deaths + recoveries (2,169/2,169 + 17,572 = 11%) as of 29 February 2020. Compared to those aged 30-59 years, those aged below 30 and above 59 years were 0.6 (0.3-1.1) and 5.1 (4.2-6.1) times more likely to die after developing symptoms. The risk of symptomatic infection increased with age (for example, at ~4% per year among adults aged 30-60 years).

Emergence of a novel human coronavirus threatening human health

In late December 2019, a cluster of patients with ‘atypical pneumonia’ of unknown etiology was reported in Wuhan, China. A novel human coronavirus, now provisionally called ‘SARS-CoV-2’, was identified as the cause of this disease, now named ‘COVID-19’.

Core Minimal Datasets to Advance Clinical Research for Priority Epidemic Diseases

The Ebola virus disease outbreak in west Africa has prompted significant progress in responding to the clinical needs of patients affected by emerging infectious disease outbreaks. Among the noteworthy successes of vaccine trials, and the commendable efforts to implement clinical treatment trials during Ebola outbreaks, we should also focus on strengthening the collection and curation of epidemiological and observational data that can improve the conception and design of clinical research.

Age-Stratified Risk of Critical Illness in Young Children Presenting to the Emergency Department with Suspected Influenza

OBJECTIVE

To investigate the risk of critical illness by age group among young children without a chronic condition presenting to the emergency department (ED) with suspected influenza.

STUDY DESIGN

Retrospective study of patients aged <2 years presenting to the ED with suspected influenza (defined by diagnostic codes for influenza or influenza-like illness) from 2009 to 2017 in 49 hospitals in the Pediatric Health Information System. Patients with chronic conditions were excluded. The main clinical outcomes were intensive care unit (ICU) admission, ventilatory support, vasopressor administration, and mortality, which were compared independently by age group (<3 months, 3 to <6 months, 6 to <12 months, and 12 to <24 months). To compare outcomes by age, we estimated the prevalence of each outcome by age group after fitting logistic regression models to control for demographic differences between groups.

RESULTS

A total of 55 986 children were studied. Overall admission and ICU admission rates were 20% and 2%, respectively. After adjustment for demographic variables, infants aged <3 months had higher rates of ICU admission (2.7%; 95% CI, 2.0%-3.3%; P < .001 compared with other age groups) and ventilatory support (2.5%; 95% CI, 1.9%-3.2%; P < .001 compared with other age groups); however, there were no differences in vasopressor administration. The overall case fatality rate was low (0.007%) and thus could not be compared across age groups.

CONCLUSIONS

Infants aged <3 months with suspected influenza are at greatest risk for critical illness. Although critical illness is uncommon, these findings should be incorporated into acute management decisions, including the need for specified outpatient follow-up or hospitalization, and public health efforts should focus on prevention and disease-modifying interventions in this high-risk population.