A scenario-based evaluation of the Middle East respiratory syndrome coronavirus and the Hajj

SEIR Model to address the impact of face masks amid COVID-19 pandemic

Early in the pandemic of coronavirus disease 2019 (COVID-19), face masks were used extensively by the general public in several Asian countries. The lower transmission rate of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in Asian countries compared with Western countries suggested that the wider community use of face masks has the potential to decrease transmission of SARS-CoV-2. A risk assessment model named Susceptible, Exposed, Infectious, Recovered (SEIR) model is used to quantitatively evaluate the potential impact of community face masks on SARS-CoV-2 reproduction number (R₀ ) and peak number of infectious persons. For a simulated population of one million, the model showed a reduction in R₀ of 49% and 50% when 60% and 80% of the population wore masks, respectively. Moreover, we present a modified model that considers the effect of mask-wearing after community vaccination. Interestingly mask-wearing still provided a considerable benefit in lowering the number of infectious individuals. The results of this research are expected to help public health officials in making prompt decisions involving resource allocation and crafting legislation.

Application of a Risk Analysis Tool to Middle East Respiratory Syndrome Coronavirus (MERS-CoV) Outbreak in Saudi Arabia

The Grunow-Finke assessment tool (GFT) is an accepted scoring system for determining likelihood of an outbreak being unnatural in origin. Considering its high specificity but low sensitivity, a modified Grunow-Finke tool (mGFT) has been developed with improved sensitivity. The mGFT has been validated against some past disease outbreaks, but it has not been applied to ongoing outbreaks. This study is aimed to score the outbreak of Middle East respiratory syndrome coronavirus (MERS-CoV) in Saudi Arabia using both the original GFT and mGFT. The publicly available data on human cases of MERS-CoV infections reported in Saudi Arabia (2012-2018) were sourced from the FluTrackers, World Health Organization, Saudi Ministry of Health, and published literature associated with MERS outbreaks investigations. The risk assessment of MERS-CoV in Saudi Arabia was analyzed using the original GFT and mGFT criteria, algorithms, and thresholds. The scoring points for each criterion were determined by three researchers to minimize the subjectivity. The results showed 40 points of total possible 54 points using the original GFT (likelihood: 74%), and 40 points of a total possible 60 points (likelihood: 67%) using the mGFT, both tools indicating a high likelihood that human MERS-CoV in Saudi Arabia is unnatural in origin. The findings simply flag unusual patterns in this outbreak, but do not prove unnatural etiology. Proof of bioattacks can only be obtained by law enforcement and intelligence agencies. This study demonstrated the value and flexibility of the mGFT in assessing and predicting the risk for an ongoing outbreak with simple criteria.

Exploring Australian Hajj Tour Operators' Knowledge and Practices Regarding Pilgrims' Health Risks: A Qualitative Study

Background

Travel agents are known to be one of the main sources of health information for pilgrims, and their advice is associated with positive health behaviors.

Objective

This study aimed to investigate travel agents’ health knowledge, what health advice they provide to the pilgrims, and their sources of health information.

Methods

In-depth interviews were conducted among specialist Hajj travel agents in Sydney, Australia. Thematic analysis was undertaken.

Results

Of the 13 accredited Hajj travel agents, 9 (69%) were interviewed. A high level of awareness regarding gastrointestinal infections, standard hygiene methods, and the risk of injury was noted among the participants and was included in advice provided to pilgrims. However, very limited knowledge and provision of advice about the risk of respiratory infections was identified. Knowledge of the compulsory meningococcal vaccine was high, and all participated travel agents reported influenza vaccine (a recommended vaccine) as a second “compulsory” vaccine for Hajj visas. Conversely, participants reported very limited knowledge about other recommended vaccines for Hajj. The Ministry of Hajj website and personal Hajj experience were the main sources of information.

Conclusions

This study identifies a potential path for novel health promotion strategies to improve health knowledge among Hajj travel agents and subsequently among Hajj pilgrims.

Asymptomatic Middle East Respiratory Syndrome Coronavirus (MERS-CoV) infection: Extent and implications for infection control: A systematic review

Background

The Middle East Respiratory Syndrome Coronavirus (MERS-CoV) emerged in 2012 and attracted an international attention as the virus caused multiple healthcare associated outbreaks. There are reports of the role of asymptomatic individuals in the transmission of MERS-CoV, however, the exact role is not known.

Method

The MEDLINE/PubMed and Scopus databases were searched for relevant papers published till August 2018 describing asymptomatic MERS-CoV infection.

Results

A total of 10 papers were retrieved and included in the final analysis and review. The extent of asymptomatic MERS infection had increased with change in the policy of testing asymptomatic contacts. In early cases in April 2012–October 2013, 12.5% were asymptomatic among 144 PCR laboratory-confirmed MERS-CoV cases while in 2014 the proportion rose to 25.1% among 255 confirmed cases. The proportion of asymptomatic cases reported among pediatric confirmed MERS-CoV cases were higher (41.9%–81.8%). Overall, the detection rate of MERS infection among asymptomatic contacts was 1-3.9% in studies included in this review. Asymptomatic individuals were less likely to have underlying condition compared to fatal cases. Of particular interest is that most of the identified pediatric cases were asymptomatic with no clear explanation.

Conclusions

The proportion of asymptomatic MERS cases were detected with increasing frequency as the disease progressed overtime. Those patients were less likely to have comorbid disease and may contribute to the transmission of the virus.

A systematic review of emerging respiratory viruses at the Hajj and possible coinfection with Streptococcus pneumoniae

Background

The annual Hajj to the Kingdom of Saudi Arabia attracts millions of pilgrims from around the world. International health community's attention goes towards this mass gathering and the possibility of the development of any respiratory tract infections due to the high risk of acquisition of respiratory viruses.

Method

We searched MEDLINE/PubMed and Scopus databases for relevant papers describing the prevalence of respiratory viruses among Hajj pilgrims.

Results

The retrieved articles were summarized based on the methodology of testing for these viruses. A total of 31 studies were included in the quantitative/qualitative analyses. The main methods used for the diagnosis of most common respiratory viruses were polymerase chain reaction (PCR), culture and enzyme-linked immunosorbent assay (ELISA). Influenza, rhinovirus and parainfluenza were the most common viruses detected among pilgrims. Coronaviruses other than MERS-CoV were also detected among pilgrims. The acquisition of MERS-CoV remains very limited and systematic screening of pilgrims showed no infections.

Conclusions

Well conducted multinational follow-up studies using the same methodology of testing are necessary for accurate surveillance of respiratory viral infections among Hajj pilgrims. Post-Hajj cohort studies would further evaluate the impact of the Hajj on the acquisition of respiratory viruses.

MERS-CoV: Understanding the Latest Human Coronavirus Threat

Human coronaviruses cause both upper and lower respiratory tract infections in humans. In 2012, a sixth human coronavirus (hCoV) was isolated from a patient presenting with severe respiratory illness. The 60-year-old man died as a result of renal and respiratory failure after admission to a hospital in Jeddah, Saudi Arabia. The aetiological agent was eventually identified as a coronavirus and designated Middle East respiratory syndrome coronavirus (MERS-CoV). MERS-CoV has now been reported in more than 27 countries across the Middle East, Europe, North Africa and Asia. As of July 2017, 2040 MERS-CoV laboratory confirmed cases, resulting in 712 deaths, were reported globally, with a majority of these cases from the Arabian Peninsula. This review summarises the current understanding of MERS-CoV, with special reference to the (i) genome structure; (ii) clinical features; (iii) diagnosis of infection; and (iv) treatment and vaccine development.

Mass Gatherings and the Spread of Respiratory Infections. Lessons from the Hajj

The mass gathering of people is a potential source for developing, propagating, and disseminating infectious diseases on a global scale. Of the illnesses associated with mass gatherings, respiratory tract infections are the most common, the most easily transmitted, and the most likely to be spread widely beyond the site of the meeting by attendees returning home. Many factors contribute to the spread of these infections during mass gatherings, including crowding, the health of the attendees, and the type and location of meetings. The annual Hajj in the Kingdom of Saudi Arabia is the largest recurring single mass gathering in the world. Every year more than 10 million pilgrims attend the annual Hajj and Umrah. Attendees assemble in confined areas for several days. People with a wide range of age, health, susceptibility to illness, and hygiene sophistication come in close contact, creating an enormous public health challenge. Controlling respiratory infections at the Hajj requires surveillance, rapid diagnostic testing, and containment strategies. Although the Hajj is without equal, other mass gatherings can generate similar hazards. The geographic colocalization of the Zika virus epidemic and the 2016 Summer Olympic Games in Brazil is a current example of great concern. The potential of international mass gatherings for local and global calamity calls for greater global attention and research.

Middle East respiratory syndrome in children. Dental considerations

As of January 2016, 1,633 laboratory-confirmed cases of Middle East Respiratory Syndrome Coronavirus (MERS-CoV) infection and 587 MERS-related deaths have been reported by the World Health Organization globally. Middle East Respiratory Syndrome Coronavirus may occur sporadically in communities or may be transmitted within families or hospitals. The number of confirmed MERS-CoV cases among healthcare workers has been increasing. Middle East Respiratory Syndrome Coronavirus may also spread through aerosols generated during various dental treatments, resulting in transmission between patients and dentists. As MERS-CoV cases have also been reported among children, pediatric dentists are at risk of MERS-CoV infection. This review discusses MERS-CoV infection in children and healthcare workers, especially pediatric dentists, and considerations pertaining to pediatric dentistry. Although no cases of MERS-CoV transmission between a patient and a dentist have yet been reported, the risk of MERS-CoV transmission from an infected patient may be high due to the unique work environment of dentists (aerosol generation).

Comparative epidemiology of Middle East respiratory syndrome coronavirus (MERS-CoV) in Saudi Arabia and South Korea

MERS-CoV infection emerged in the Kingdom of Saudi Arabia (KSA) in 2012 and has spread to 26 countries. However, 80% of all cases have occurred in KSA. The largest outbreak outside KSA occurred in South Korea (SK) in 2015. In this report, we describe an epidemiological comparison of the two outbreaks. Data from 1299 cases in KSA (2012-2015) and 186 cases in SK (2015) were collected from publicly available resources, including FluTrackers, the World Health Organization (WHO) outbreak news and the Saudi MOH (MOH). Descriptive analysis, t-tests, Chi-square tests and binary logistic regression were conducted to compare demographic and other characteristics (comorbidity, contact history) of cases by nationality. Epidemic curves of the outbreaks were generated. The mean age of cases was 51 years in KSA and 54 years in SK. Older males (⩾70 years) were more likely to be infected or to die from MERS-CoV infection, and males exhibited increased rates of comorbidity in both countries. The epidemic pattern in KSA was more complex, with animal-to-human, human-to-human, nosocomial and unknown exposure, whereas the outbreak in SK was more clearly nosocomial. Of the 1186 MERS cases in KSA with reported risk factors, 158 (13.3%) cases were hospital associated compared with 175 (94.1%) in SK, and an increased proportion of cases with unknown exposure risk was found in KSA (710, 59.9%). In a globally connected world, travel is a risk factor for emerging infections, and health systems in all countries should implement better triage systems for potential imported cases of MERS-CoV to prevent large epidemics.

Risk of global spread of Middle East respiratory syndrome coronavirus (MERS-CoV) via the air transport network

BACKGROUND

Middle East respiratory syndrome coronavirus (MERS-CoV) emerged from the Kingdom of Saudi Arabia (KSA) in 2012 and has since spread to 26 countries. All cases reported so far have either been in the Middle East or linked to the region through passenger air travel, with the largest outbreak outside KSA occurring in South Korea. Further international spread is likely due to the high travel volumes of global travel, as well as the occurrence of large annual mass gathering such as the Haj and Umrah pilgrimages that take place in the region.

METHODS

In this study, a transport network modelling framework was used to quantify the risk of MERS-CoV spreading internationally via air travellers. All regions connected to MERS-CoV affected countries via air travel are considered, and the countries at highest risk of travel-related importations of MERS-CoV were identified, ranked and compared with actual spread of MERS cases.

RESULTS

The model identifies all countries that have previously reported a travel acquired case to be in the top 50 at-risk countries. India, Pakistan and Bangladesh are the highest risk countries which have yet to report a case, and should be prepared for the possibility of (pilgrims and general) travellers returning infected with MERS-CoV. In addition, the UK, Egypt, Turkey and the USA are at risk of more cases.

CONCLUSIONS

We have demonstrated a risk-analysis approach, using travel patterns, to prioritize countries at highest risk for MERS-CoV importations. In order to prevent global outbreaks such as the one seen in South Korea, it is critical for high-risk countries to be prepared and have appropriate screening and triage protocols in place to identify travel-related cases of MERS-CoV. The results from the model can be used by countries to prioritize their airport and hospital screening and triage protocols.

Middle East respiratory syndrome coronavirus: review of the current situation in the world

This article reviews the current epidemiology and clinical presentation of Middle East Respiratory Syndrome Coronavirus (MERS-CoV) infection and describes the preparedness plan of several countries. The MERS-CoV was first reported in 2012 and has since infected more than 1600 patients in 26 countries, mostly in Saudi Arabia and the Middle East. The epidemiology of the infection is compatible with multiple introductions of the virus into humans from an animal reservoir, probably dromedary camels. The clinical presentation ranges from no symptoms to severe pneumonitis and respiratory failure. Most confirmed cases so far were part of MERS-CoV clusters in hospital settings, affecting mainly middle-aged men and patients with a chronic disease or immuno-suppressed status. There is no vaccine or anti-viral medication available. Viral epidemics can occur anywhere in today's "global village". MERS-CoV is a relatively new virus, and this work is intended to add to the still-sparse data on its epidemiology, modes of transmission, natural history, and clinical features as well as to describe the preparedness plan for MERS-CoV infection in several countries. Effective national and international preparedness plans are essential to predict and control outbreaks, improve patient management, and ensure global health security.

Middle East respiratory syndrome coronavirus (MERS-CoV): what lessons can we learn?

The Middle East Respiratory Coronavirus (MERS-CoV) was first isolated from a patient who died with severe pneumonia in June 2012. As of 19 June 2015, a total of 1,338 MERS-CoV infections have been notified to the World Health Organization (WHO). Clinical illness associated with MERS-CoV ranges from mild upper respiratory symptoms to rapidly progressive pneumonia and multi-organ failure. A significant proportion of patients present with non-respiratory symptoms such as headache, myalgia, vomiting and diarrhoea. A few potential therapeutic agents have been identified but none have been conclusively shown to be clinically effective. Human to human transmission is well documented, but the epidemic potential of MERS-CoV remains limited at present. Healthcare-associated clusters of MERS-CoV have been responsible for the majority of reported cases. The largest outbreaks have been driven by delayed diagnosis, overcrowding and poor infection control practices. However, chains of MERS-CoV transmission can be readily interrupted with implementation of appropriate control measures. As with any emerging infectious disease, guidelines for MERS-CoV case identification and surveillance evolved as new data became available. Sound clinical judgment is required to identify unusual presentations and trigger appropriate control precautions. Evidence from multiple sources implicates dromedary camels as natural hosts of MERS-CoV. Camel to human transmission has been demonstrated, but the exact mechanism of infection remains uncertain. The ubiquitously available social media have facilitated communication and networking amongst healthcare professionals and eventually proved to be important channels for presenting the public with factual material, timely updates and relevant advice.

Middle East respiratory syndrome coronavirus (MERS-CoV): what lessons can we learn?

The Middle East Respiratory Coronavirus (MERS-CoV) was first isolated from a patient who died with severe pneumonia in June 2012. As of 19 June 2015, a total of 1,338 MERS-CoV infections have been notified to the World Health Organization (WHO). Clinical illness associated with MERS-CoV ranges from mild upper respiratory symptoms to rapidly progressive pneumonia and multi-organ failure. A significant proportion of patients present with non-respiratory symptoms such as headache, myalgia, vomiting and diarrhoea. A few potential therapeutic agents have been identified but none have been conclusively shown to be clinically effective. Human to human transmission is well documented, but the epidemic potential of MERS-CoV remains limited at present. Healthcare-associated clusters of MERS-CoV have been responsible for the majority of reported cases. The largest outbreaks have been driven by delayed diagnosis, overcrowding and poor infection control practices. However, chains of MERS-CoV transmission can be readily interrupted with implementation of appropriate control measures. As with any emerging infectious disease, guidelines for MERS-CoV case identification and surveillance evolved as new data became available. Sound clinical judgment is required to identify unusual presentations and trigger appropriate control precautions. Evidence from multiple sources implicates dromedary camels as natural hosts of MERS-CoV. Camel to human transmission has been demonstrated, but the exact mechanism of infection remains uncertain. The ubiquitously available social media have facilitated communication and networking amongst healthcare professionals and eventually proved to be important channels for presenting the public with factual material, timely updates and relevant advice.

Middle East respiratory syndrome: obstacles and prospects for vaccine development

The recent emergence of Middle East respiratory syndrome (MERS) highlights the need to engineer new methods for expediting vaccine development against emerging diseases. However, several obstacles prevent pursuit of a licensable MERS vaccine. First, the lack of a suitable animal model for MERS complicates the in vivo testing of candidate vaccines. Second, due to the low number of MERS cases, pharmaceutical companies have little incentive to pursue MERS vaccine production as the costs of clinical trials are high. In addition, the timeline from bench research to approved vaccine use is 10 years or longer. Using novel methods and cost-saving strategies, genetically engineered vaccines can be produced quickly and cost-effectively. Along with progress in MERS animal model development, these obstacles can be circumvented or at least mitigated.

Middle East respiratory syndrome coronavirus "MERS-CoV": current knowledge gaps

The Middle East respiratory syndrome coronavirus (MERS-CoV) that causes a severe lower respiratory tract infection in humans is now considered a pandemic threat to the Gulf region. Since its discovery in 2012, MERS-CoV has reached 23 countries affecting about 1100 people, including a dozen children, and claiming over 400 lives. Compared to SARS (severe acute respiratory syndrome), MERS-CoV appears to kill more people (40% versus 10%), more quickly, and is especially more severe in those with pre-existing medical conditions. Most MERS-CoV cases (>85%) reported thus far have a history of residence in, or travel to the Middle East. The current epidemiology is characterised by slow and sustained transmission with occasional sparks. The dromedary camel is the intermediate host of MERS-CoV, but the transmission cycle is not fully understood. In this current review, we have briefly summarised the latest information on the epidemiology, clinical features, diagnosis, treatment and prevention of MERS-CoV especially highlighting the knowledge gaps in its transmission dynamics, diagnosis and preventive strategy.

The discrepant epidemiology of Middle East respiratory syndrome coronavirus (MERS-CoV)

The Middle East respiratory syndrome coronavirus (MERS-CoV) is a newly emerged infection in humans affecting the Arabian Peninsula, Europe, and North Africa. The source and persistence of the infection in humans remains unknown. The aim of this paper was to apply a risk analysis approach to the epidemiology of MERS-CoV and to understand the source of ongoing infections. The epidemiology of MERS-CoV was reviewed and compared to SARS. Each observed feature of MERS-CoV epidemiology was summarized and fitted to either an epidemic or one of two sporadic scenarios (either animal or deliberate release). As of May 2014, MERS-CoV has infected over 681 people and killed a further 204 over 2 years. In contrast, there were 8,273 cases and 775 deaths from SARS within 8 months. MERS-CoV has a more sporadic pattern unlike the clear epidemic pattern seen with SARS, and an unusual concentration of cases in the Middle East, without epidemics in other countries to which it has spread. SARS, with a higher reproductive number (R0), was eliminated from humans within 8 months of emerging, yet MERS-CoV, with a low R0 has persisted in humans over a far more prolonged period. This is at odds with the expected behavior of a virus with a low R0, which theoretically should not persist unless there are ongoing introductions of infection into humans, and poses the question “what is the source of continuing infections in humans?” A hospital outbreak in Al Ahsa, the Kingdom of Saudi Arabia (KSA), had a classic epidemic pattern with some human-to-human transmission. However, 3 different strains were identified in that outbreak, an unexpected and unexplained finding for what appears to be a single source outbreak. Since this outbreak in April 2013, there has been a large increase in new cases, mainly in KSA in April and May 2014, with no corresponding epidemics in other countries. Yet MERS-CoV was present in KSA over several mass gatherings (which predispose to epidemics), including the Hajj pilgrimage, without an epidemic arising. Furthermore, although the virus has been identified in bats and camels, the mode of ongoing transmission to humans remains uncertain. Although some cases appear to be transmitted from human to human, and a few have animal or camel exposure, many cases have no history of contact with either animals or human cases. A high proportion of asymptomatic or otherwise undetected cases have been postulated as an explanation for the unusual epidemiology, yet active surveillance does not support this. When the observed data were fitted to different disease patterns, the features of MERS-CoV fit better with a sporadic pattern, with evidence for either deliberate release or an animal source. There are many discrepancies in the observed epidemiology of MERS-CoV, which better fits a sporadic than an epidemic pattern. Possible explanations of the unusual features of the epidemiology include human-to-human transmission with a large proportion of undetected cases; or sporadic ongoing infections from a non-human source; or a combination of both. Possible sources of ongoing sporadic infection in humans include animals (camels appear the most likely source), or deliberate release. The latter could explain 3 strains being present in a single hospital outbreak. Genetic testing should be conducted to determine whether the virus is evolving to be more transmissible. Better ascertainment of mild or asymptomatic cases is also needed. Finally, the discrepant epidemiology warrants critical analysis of all possible explanations, and involvement of all stakeholders in biosecurity, and deliberate release must be seriously considered and at least acknowledged as a possibility.