Scope and extent of healthcare-associated Middle East respiratory syndrome coronavirus transmission during two contemporaneous outbreaks in Riyadh, Saudi Arabia, 2017

Super-spreaders of novel coronaviruses that cause SARS, MERS and COVID-19: A systematic review

PURPOSE

Most index cases with novel coronavirus infections transmit disease to just one or two other individuals, but some individuals "super-spread"-they infect many secondary cases. Understanding common factors that super-spreaders may share could inform outbreak models, and be used to guide contact tracing during outbreaks.

METHODS

We searched in MEDLINE, Scopus, and preprints to identify studies about people documented as transmitting pathogens that cause SARS, MERS, or COVID-19 to at least nine other people. We extracted data to describe them by age, sex, location, occupation, activities, symptom severity, any underlying conditions, disease outcome and undertook quality assessment for outbreaks published by June 2021.

RESULTS

The most typical super-spreader was a male age 40+. Most SARS or MERS super-spreaders were very symptomatic, the super-spreading occurred in hospital settings and frequently the individual died. In contrast, COVID-19 super-spreaders often had very mild disease and most COVID-19 super-spreading happened in community settings.

CONCLUSIONS

SARS and MERS super-spreaders were often symptomatic, middle- or older-age adults who had a high mortality rate. In contrast, COVID-19 super-spreaders tended to have mild disease and were any adult age. More outbreak reports should be published with anonymized but useful demographic information to improve understanding of super-spreading, super-spreaders, and the settings in which super-spreading happens.

Genetically Engineered Live-Attenuated Middle East Respiratory Syndrome Coronavirus Viruses Confer Full Protection against Lethal Infection

There are no approved vaccines against the life-threatening Middle East respiratory syndrome coronavirus (MERS-CoV). Attenuated vaccines have proven their potential to induce strong and long-lasting immune responses. We have previously described that severe acute respiratory syndrome coronavirus (SARS-CoV) envelope (E) protein is a virulence factor. Based on this knowledge, a collection of mutants carrying partial deletions spanning the C-terminal domain of the E protein (rMERS-CoV-E*) has been generated using a reverse genetics system. One of these mutants, MERS-CoV-E*Δ2in, was attenuated and provided full protection in a challenge with virulent MERS-CoV after a single immunization dose. The MERS-CoV-E*Δ2in mutant was stable as it maintained its attenuation after 16 passages in cell cultures and has been selected as a promising vaccine candidate.IMPORTANCE The emergence of the new highly pathogenic human coronavirus SARS-CoV-2 that has already infected more than 80 million persons, killing nearly two million of them, clearly indicates the need to design efficient and safe vaccines protecting from these coronaviruses. Modern vaccines can be derived from virus-host interaction research directed to the identification of signaling pathways essential for virus replication and for virus-induced pathogenesis, in order to learn how to attenuate these viruses and design vaccines. Using a reverse genetics system developed in our laboratory, an infectious cDNA clone of MERS-CoV was engineered. Using this cDNA, we sequentially deleted several predicted and conserved motifs within the envelope (E) protein of MERS-CoV, previously associated with the presence of virulence factors. The in vitro and in vivo evaluation of these deletion mutants highlighted the relevance of predicted linear motifs in viral pathogenesis. Two of them, an Atg8 protein binding motif (Atg8-BM), and a forkhead-associated binding motif (FHA-BM), when deleted, rendered an attenuated virus that was evaluated as a vaccine candidate, leading to full protection against challenge with a lethal dose of MERS-CoV. This approach can be extended to the engineering of vaccines protecting against the new pandemic SARS-CoV-2.

Coronavirus-associated kidney outcomes in COVID-19, SARS, and MERS: a meta-analysis and systematic review

OBJECTIVES

A meta-analysis and systematic review was conducted on kidney-related outcomes of three recent pandemics: SARS, MERS, and COVID-19, which were associated with potentially fatal acute respiratory distress syndrome (ARDS).

METHODS

A search of all published studies until 16 June 2020 was performed. The incidence/prevalence and mortality risk of acute and chronic renal events were evaluated, virus prevalence, and mortality in preexisting hemodialysis patients was investigated.

RESULTS

A total of 58 eligible studies involving 13452 hospitalized patients with three types of coronavirus infection were included. The reported incidence of new-onset acute kidney injury (AKI) was 12.5% (95% CI: 7.6%-18.3%). AKI significantly increased the mortality risk (OR = 5.75, 95% CI 3.75-8.77, p < 0.00001) in patients with coronavirus infection. The overall rate of urgent-start kidney replacement therapy (urgent-start KRT) use was 8.9% (95% CI: 5.0%-13.8%) and those who received urgent-start KRT had a higher risk of mortality (OR = 3.43, 95% CI 2.02-5.85, p < 0.00001). Patients with known chronic kidney disease (CKD) had a higher mortality than those without CKD (OR = 1.97, 95% CI 1.56-2.49, p < 0.00001). The incidence of coronavirus infection was 7.7% (95% CI: 4.9%-11.1%) in prevalent hemodialysis patients with an overall mortality rate of 26.2% (95% CI: 20.6%-32.6%).

CONCLUSIONS

Primary kidney involvement is common with coronavirus infection and is associated with significantly increased mortality. The recognition of AKI, CKD, and urgent-start KRT as major risk factors for mortality in coronavirus-infected patients are important steps in reducing future mortality and long-term morbidity in hospitalized patients with coronavirus infection.

Ventilation Techniques and Risk for Transmission of Coronavirus Disease, Including COVID-19: A Living Systematic Review of Multiple Streams of Evidence

BACKGROUND

Mechanical ventilation is used to treat respiratory failure in coronavirus disease 2019 (COVID-19).

PURPOSE

To review multiple streams of evidence regarding the benefits and harms of ventilation techniques for coronavirus infections, including that causing COVID-19.

DATA SOURCES

21 standard, World Health Organization-specific and COVID-19-specific databases, without language restrictions, until 1 May 2020.

STUDY SELECTION

Studies of any design and language comparing different oxygenation approaches in patients with coronavirus infections, including severe acute respiratory syndrome (SARS) or Middle East respiratory syndrome (MERS), or with hypoxemic respiratory failure. Animal, mechanistic, laboratory, and preclinical evidence was gathered regarding aerosol dispersion of coronavirus. Studies evaluating risk for virus transmission to health care workers from aerosol-generating procedures (AGPs) were included.

DATA EXTRACTION

Independent and duplicate screening, data abstraction, and risk-of-bias assessment (GRADE for certainty of evidence and AMSTAR 2 for included systematic reviews).

DATA SYNTHESIS

123 studies were eligible (45 on COVID-19, 70 on SARS, 8 on MERS), but only 5 studies (1 on COVID-19, 3 on SARS, 1 on MERS) adjusted for important confounders. A study in hospitalized patients with COVID-19 reported slightly higher mortality with noninvasive ventilation (NIV) than with invasive mechanical ventilation (IMV), but 2 opposing studies, 1 in patients with MERS and 1 in patients with SARS, suggest a reduction in mortality with NIV (very-low-certainty evidence). Two studies in patients with SARS report a reduction in mortality with NIV compared with no mechanical ventilation (low-certainty evidence). Two systematic reviews suggest a large reduction in mortality with NIV compared with conventional oxygen therapy. Other included studies suggest increased odds of transmission from AGPs.

LIMITATION

Direct studies in COVID-19 are limited and poorly reported.

CONCLUSION

Indirect and low-certainty evidence suggests that use of NIV, similar to IMV, probably reduces mortality but may increase the risk for transmission of COVID-19 to health care workers.

PRIMARY FUNDING SOURCE

World Health Organization. (PROSPERO: CRD42020178187).

Surveillance and Testing for Middle East Respiratory Syndrome Coronavirus, Saudi Arabia, March 2016–March 2019

During March 2016–March 2019, a total of 200,936 suspected cases of Middle East respiratory syndrome coronavirus infection were identified in Saudi Arabia; infections were confirmed in 698 cases (0.3% [0.7/100,000 population per year]). Continued surveillance is necessary for early case detection and timely infection control response.

Coronaviridae-Old friends, new enemy!

Coronaviridae is a family of single‐stranded positive enveloped RNA viruses. This article aimed to review the history of these viruses in the last 60 years since their discovery to understand what lessons can be learned from the past. A review of the PubMed database was carried out, describing taxonomy, classification, virology, genetic recombination, host adaptation, and main symptoms related to each type of virus. SARS‐CoV‐2 is responsible for the ongoing global pandemic, and SARS‐CoV and MERS‐CoV were responsible for causing severe respiratory illness and regional epidemics in the past while the four other strains of CoVs (229‐E OC43, NL63, and HKU1) circulate worldwide and normally only cause mild upper respiratory tract infections. Given the enormous diversity of coronavirus viruses in wildlife and their continuous evolution and adaptation to humans, future outbreaks would undoubtedly occur. Restricting or banning all trade in wild animals in wet markets would be a necessary measure to reduce future zoonotic infections.

Middle East respiratory syndrome

The Middle East respiratory syndrome coronavirus (MERS-CoV) is a lethal zoonotic pathogen that was first identified in humans in Saudi Arabia and Jordan in 2012. Intermittent sporadic cases, community clusters, and nosocomial outbreaks of MERS-CoV continue to occur. Between April 2012 and December 2019, 2499 laboratory-confirmed cases of MERS-CoV infection, including 858 deaths (34·3% mortality) were reported from 27 countries to WHO, the majority of which were reported by Saudi Arabia (2106 cases, 780 deaths). Large outbreaks of human-to-human transmission have occurred, the largest in Riyadh and Jeddah in 2014 and in South Korea in 2015. MERS-CoV remains a high-threat pathogen identified by WHO as a priority pathogen because it causes severe disease that has a high mortality rate, epidemic potential, and no medical countermeasures. This Seminar provides an update on the current knowledge and perspectives on MERS epidemiology, virology, mode of transmission, pathogenesis, diagnosis, clinical features, management, infection control, development of new therapeutics and vaccines, and highlights unanswered questions and priorities for research, improved management, and prevention.

Enablers of, and barriers to, optimal glove and mask use for routine care in the emergency department: an ethnographic study of Australian clinicians

Background

The risk of healthcare-acquired infection increases during outbreaks of novel infectious diseases. Emergency department (ED) clinicians are at high risk of exposure to both these and common communicable diseases. Personal protective equipment (PPE) is recommended to protect clinicians from acquiring, or becoming vectors of, infection, yet compliance is typically sub-optimal. Little is known about factors that influence use of PPE—specifically gloves and masks—during routine care in the ED.

Methods

This was an ethnographic study, incorporating documentation review, field observations and interviews. The theoretical domains framework (TDF) was used to aid thematic analysis and identify relevant enablers of and barriers to optimal PPE use.

Results

Thirty-one behavioural themes were identified that influenced participants’ use of masks and gloves. There were significant differences, namely: more reported enablers of glove use vs more barriers to mask use. Reasons included more positive unit culture towards glove use, and lower perception of risk via facial contamination.

Conclusion

Emerging infectious diseases, spread (among other routes) by respiratory droplets, have caused global outbreaks. Emergency clinicians should ensure that, as with gloves, the use of masks is incorporated into routine cares where appropriate. Further research which examines items of PPE independently is warranted.

The Middle East Respiratory Syndrome (MERS)

The Middle East respiratory syndrome (MERS) is a novel lethal zoonotic disease of humans caused by the MERS coronavirus (MERS-CoV). Although MERS is endemic to the Middle East, travelers have exported MERS-CoV on return to their home countries. Clinical manifestations range from mild to severe acute respiratory disease and death. The elderly, immunocompromised, and those with chronic comorbid liver, lung, and hepatic conditions have a high mortality rate. There is no specific treatment. Person-to-person spread causes hospital and household outbreaks, and thus improved compliance with internationally recommended infection control protocols and rapid implementation of infection control measures are required.

Middle East Respiratory Syndrome Coronavirus, Saudi Arabia, 2017-2018

We characterized exposures and demographics of Middle East respiratory syndrome coronavirus cases reported to the Saudi Arabia Ministry of Health during July 1-October 31, 2017, and June 1-September 16, 2018. Molecular characterization of available specimens showed that circulating viruses during these periods continued to cluster within lineage 5.

Comparison of Serologic Assays for Middle East Respiratory Syndrome Coronavirus

Middle East respiratory syndrome coronavirus (MERS-CoV) was detected in humans in 2012. Since then, sporadic outbreaks with primary transmission through dromedary camels to humans and outbreaks in healthcare settings have shown that MERS-CoV continues to pose a threat to human health. Several serologic assays for MERS-CoV have been developed globally. We describe a collaborative study to investigate the comparability of serologic assays for MERS-CoV and assess any benefit associated with the introduction of a standard reference reagent for MERS-CoV serology. Our study findings indicate that, when possible, laboratories should use a testing algorithm including >2 tests to ensure correct diagnosis of MERS-CoV. We also demonstrate that the use of a reference reagent greatly improves the agreement between assays, enabling more consistent and therefore more meaningful comparisons between results.

Middle East respiratory syndrome coronavirus in the last two years: Health care workers still at risk

BACKGROUND

An important emerging respiratory virus is the Middle East respiratory syndrome coronavirus (MERS-CoV). MERS-CoV had been associated with a high case fatality rate especially among severe cases.

METHODS

This is a retrospective analysis of reported MERS-CoV cases between December 2016 and January 2019, as retrieved from the World Health Organization. The aim of this study is to examine the epidemiology of reported cases and quantify the percentage of health care workers (HCWs) among reported cases.

RESULTS

There were 403 reported cases with a majority being men (n = 300; 74.4%). These cases were reported from Lebanon, Malaysia, Oman, Qatar, Saudi Arabia, and United Arab Emirates. HCWs represented 26% and comorbidities were reported among 71% of non-HCWs and 1.9% among HCWs (P < .0001). Camel exposure and camel milk ingestion were reported in 64% each, and the majority (97.8%) of those with camel exposures had camel milk ingestion. There were 58% primary cases and 42% were secondary cases. The case fatality rate was 16% among HCWs compared with 34% among other patients (P = .001). The mean age ± SD was 47.65 ± 16.28 for HCWs versus 54.23 ± 17.34 for non-HCWs (P = .001).

CONCLUSIONS

MERS-CoV infection continues to have a high case fatality rate and a large proportion of patients were HCWs. Further understanding of the disease transmission and prevention mainly in health care settings are needed.

Comparative Analysis of Eleven Healthcare-Associated Outbreaks of Middle East Respiratory Syndrome Coronavirus (Mers-Cov) from 2015 to 2017

Since its emergence in 2012, 2,260 cases and 803 deaths due to Middle East respiratory syndrome coronavirus (MERS-CoV) have been reported to the World Health Organization. Most cases were due to transmission in healthcare settings, sometimes causing large outbreaks. We analyzed epidemiologic and clinical data of laboratory-confirmed MERS-CoV cases from eleven healthcare-associated outbreaks in the Kingdom of Saudi Arabia and the Republic of Korea between 2015–2017. We quantified key epidemiological differences between outbreaks. Twenty-five percent (n = 105/422) of MERS cases who acquired infection in a hospital setting were healthcare personnel. In multivariate analyses, age ≥65 (OR 4.8, 95%CI: 2.6–8.7) and the presence of underlying comorbidities (OR: 2.7, 95% CI: 1.3–5.7) were associated with increased mortality whereas working as healthcare personnel was protective (OR 0.07, 95% CI: 0.01–0.34). At the start of these outbreaks, the reproduction number ranged from 1.0 to 5.7; it dropped below 1 within 2 to 6 weeks. This study provides a comprehensive characterization of MERS HCA-outbreaks. Our results highlight heterogeneities in the epidemiological profile of healthcare-associated outbreaks. The limitations of our study stress the urgent need for standardized data collection for high-threat respiratory pathogens, such as MERS-CoV.

Clinician perceptions of respiratory infection risk; a rationale for research into mask use in routine practice

Outbreaks of emerging and re-emerging infectious diseases are global threats to society. Planning for, and responses to, such events must include healthcare and other measures based on current evidence. An important area of infection prevention and control (IPC) is the optimal use of personal protective equipment (PPE) by healthcare workers (HCWs), including masks for protection against respiratory pathogens. Appropriate mask use during routine care is a forerunner to best practice in the event of an outbreak. However, little is known about the influences on decisions and behaviours of HCWs with respect to protective mask use when providing routine care. In this paper we argue that there is a need for more research to provide a better understanding of the decision-making and risk-taking behaviours of HCWs in respect of their use of masks for infectious disease prevention. Our argument is based on the ongoing threat of emerging infectious diseases; a need to strengthen workforce capability, capacity and education; the financial costs of healthcare and outbreaks; and the importance of social responsibility and supportive legislation in planning for global security. Future research should examine HCWs' practices and constructs of risk to provide new information to inform policy and pandemic planning.

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Emerging and remerging infectious diseases continue to pose a threat to human health and global security.

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Outbreaks of respiratory infection result in human and economic costs including staff illness and wider societal disruption.

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Clinicians' use of personal protective equipment is critical to reducing the risk of transmission of infectious disease.

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Training in the use of PPE should take account of clinicians' and patients' perceptions of risk.

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Individual and societal responsibility towards infection prevention may influence clinicians' use of protective masks.

MERS-CoV as an emerging respiratory illness: A review of prevention methods

INTRODUCTION

Middle East Respiratory Coronavirus Virus (MERS-CoV) first emerged from Saudi Arabia in 2012 and has since been recognized as a significant human respiratory pathogen on a global level.

METHODS

In this narrative review, we focus on the prevention of MERS-CoV. We searched PubMed, Embase, Cochrane, Scopus, and Google Scholar, using the following terms: 'MERS', 'MERS-CoV', 'Middle East respiratory syndrome' in combination with 'prevention' or 'infection control'. We also reviewed the references of each article to further include other studies or reports not identified by the search.

RESULTS

As of Nov 2019, a total of 2468 laboratory-confirmed cases of MERS-CoV were diagnosed mostly from Middle Eastern regions with a mortality rate of at least 35%. A major outbreak that occurred outside the Middle East (in South Korea) and infections reported from 27 countries. MERS-CoV has gained recognition as a pathogen of global significance. Prevention of MERS-CoV infection is a global public health priority. Healthcare facility transmission and by extension community transmission, the main amplifier of persistent outbreaks, can be prevented through early identification and isolation of infected humans. While MERS-CoV vaccine studies were initially hindered by multiple challenges, recent vaccine development for MERS-CoV is showing promise.

CONCLUSIONS

The main factors leading to sustainability of MERS-CoV infection in high risk courtiers is healthcare facility transmission. MERS-CoV transmission in healthcare facility mainly results from laps in infection control measures and late isolation of suspected cases. Preventive measures for MERS-CoV include disease control in camels, prevention of camel to human transmission.