Middle East respiratory syndrome: A new global threat

The outbreak of Middle East respiratory syndrome (MERS) is reported from Saudi Arabia and the Republic of Korea. It is a respiratory disease caused by coronavirus. Camels are considered as a source for MERS transmission in humans, although the exact source is unknown. Human-to-human transmission is reported in the community with droplet and contact spread being the possible modes. Most patients without any underlying diseases remain asymptomatic or develop mild clinical disease, but some patients require critical care for mechanical ventilation, dialysis and other organ support. MERS is a disease with pandemic potential and awareness, and surveillance can prevent such further outbreaks.

Evaluation of Patients under Investigation for MERS-CoV Infection, United States, January 2013-October 2014

Middle East respiratory syndrome (MERS) cases continue to be reported from the Middle East. Evaluation and testing of patients under investigation (PUIs) for MERS are recommended. In 2013-2014, two imported cases were detected among 490 US PUIs. Continued awareness is needed for early case detection and implementation of infection control measures.

Lack of Transmission among Close Contacts of Patient with Case of Middle East Respiratory Syndrome Imported into the United States, 2014

In May 2014, a traveler from the Kingdom of Saudi Arabia was the first person identified with Middle East respiratory syndrome coronavirus (MERS-CoV) infection in the United States. To evaluate transmission risk, we determined the type, duration, and frequency of patient contact among health care personnel (HCP), household, and community contacts by using standard questionnaires and, for HCP, global positioning system (GPS) tracer tag logs. Respiratory and serum samples from all contacts were tested for MERS-CoV. Of 61 identified contacts, 56 were interviewed. HCP exposures occurred most frequently in the emergency department (69%) and among nurses (47%); some HCP had contact with respiratory secretions. Household and community contacts had brief contact (e.g., hugging). All laboratory test results were negative for MERS-CoV. This contact investigation found no secondary cases, despite case-patient contact by 61 persons, and provides useful information about MERS-CoV transmission risk. Compared with GPS tracer tag recordings, self-reported contact may not be as accurate.

Human-Bat Interactions in Rural West Africa

Because some bats host viruses with zoonotic potential, we investigated human-bat interactions in rural Ghana during 2011-2012. Nearly half (46.6%) of respondents regularly visited bat caves; 37.4% had been bitten, scratched, or exposed to bat urine; and 45.6% ate bat meat. Human-bat interactions in rural Ghana are frequent and diverse.

Middle East Respiratory Syndrome-Coronavirus Infection: A Case Report of Serial Computed Tomographic Findings in a Young Male Patient

Radiologic findings of Middle East respiratory syndrome (MERS), a novel coronavirus infection, have been rarely reported. We report a 30-year-old male presented with fever, abdominal pain, and diarrhea, who was diagnosed with MERS. A chest computed tomographic scan revealed rapidly developed multifocal nodular consolidations with ground-glass opacity halo and mixed consolidation, mainly in the dependent and peripheral areas. After treatment, follow-up imaging showed that these abnormalities markedly decreased but fibrotic changes developed.

Treatment strategies for Middle East respiratory syndrome coronavirus

Middle East respiratory syndrome coronavirus (MERS-CoV), an emerging infectious disease of growing global importance, has caused severe acute respiratory disease in more than 1600 people, resulting in almost 600 deaths. The high case fatality rate, growing geographic distribution and vaguely defined epidemiology of this novel pathogen have created an urgent need for effective public health countermeasures, including safe and effective treatment strategies. Despite the relatively few numbers of cases to date, research and development of MERS-CoV therapeutic candidates is advancing quickly. This review surveys the landscape of these efforts and assesses their potential for use in affected populations.

Quantifying spatiotemporal heterogeneity of MERS-CoV transmission in the Middle East region: A combined modelling approach

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We modelled MERS epidemic in the Middle East region up to September 2014.

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We assessed spatiotemporal variation in zoonotic and human transmission.

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Spring 2014 wave showed a 17-fold and 3-fold increase in the above transmissions.

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Zoonotic transmission has a larger spatial heterogeneity than human transmission.

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Human transmission is more frequent than expected (75% of cases vs. 34%).

MERS coronavirus cases notified in the Middle East region since the identification of the virus in 2012 have displayed variations in time and across geography. Through a combined modelling approach, we estimate the rates of generation of cases along the zoonotic and human-to-human transmission routes and assess their spatiotemporal heterogeneity. We consider all cases notified to WHO from March 2012 to mid-September 2014. We use a stochastic modelling of the time series of case incidence in the Middle East region to estimate time- and space-dependent zoonotic and human-to-human transmission parameters. The model also accounts for possible lack of identification of secondary transmissions among notified cases. This approach is combined with the analysis of imported cases out of the region to assess the rate of underreporting of cases. Out of a total of 32 possible models, based on different parameterisation and scenario considered, the best-fit model is characterised by a large heterogeneity in time and across space for both zoonotic and human-to-human transmission. The variation in time that occurred during Spring 2014 led to a 17-fold and 3-fold increase in the two transmissions, respectively, bringing the reproductive rate to values above 1 during that period for all regions under study. The model suggests that 75% of MERS-CoV cases are secondary cases (human-to-human transmission), which is substantially higher than the 34% of reported cases with an epidemiological link to another case. Overall, estimated reporting rate is 0.26. Our findings show a higher level of spatial heterogeneity in zoonotic transmission compared to human-to-human, highlighting the strong environmental component of the epidemic. Since sporadic introductions are predicted to be a small proportion of notified cases and are responsible for triggering secondary transmissions, a more comprehensive understanding of zoonotic source and path of transmission could be critical to limit the epidemic spread.

Lack of middle East respiratory syndrome coronavirus transmission from infected camels

To determine risk for Middle East respiratory syndrome coronavirus transmission from camels to humans, we tested serum from 191 persons with various levels of exposure to an infected dromedary herd. We found no serologic evidence of human infection, suggesting that zoonotic transmission of this virus from dromedaries is rare.

Clinical implications of and lessons learnt from external assessment of Mers-CoV diagnostics

With the emergence of new viral infections, it is necessary to set up new target-specific assays, based on existing molecular techniques such as real-time PCR, as quickly as possible. Without these diagnostic tools, the geographical spread of new infections, follow-up of the disease outbreak and analysis of the pathogenesis of the disease are not possible. Therefore, the genomic information of the emerging pathogen, diagnostic protocols and standards allowing quality control need to be available in a few days. This can only be implemented with good quality experienced laboratories having suitable infrastructure to establish in-house assays. Even though these molecular tools are available quickly, challenges still remain with what sample types to select for a proper diagnostic value.

Clinical imaging research of the first Middle East respiratory syndrome in China

Middle East respiratory syndrome is a viral respiratory illness caused by a novel human beta-coronavirus. Based on the first case of Middle East respiratory syndrome found in China, a clinical research in combination with radiological findings was studied. Fever was the main clinical manifestation of this patient, and the primary imaging findings were basically the same as viral pneumonia. Differential imaging diagnosis on the basis of epidemiological and experimental pathogen detection is helpful for clinical diagnosis of MERS, even in distinguishing from SARS and pneumonia caused by H7N9 avian influenza.

Costly Lessons From the 2015 Middle East Respiratory Syndrome Coronavirus Outbreak in Korea

Since the Middle East respiratory syndrome (MERS) outbreak in the Republic of Korea (hereafter Korea) began on May 11, 2015, a total of 186 persons have been infected by the MERS coronavirus, 38 of whom have died. With this number, Korea becomes second only to the Kingdom of Saudi Arabia in the ranking of cumulative MERS cases. In this paper Korea's unique experience of an outbreak of MERS will be summarized and discussed briefly.

Critical care medicine for emerging Middle East respiratory syndrome: Which point to be considered?

The Middle East respiratory syndrome (MERS) is a new emerging respiratory tract infection. This coronavirus infection is firstly reported from the Middle East, and it becomes threat for the global public health at present due to its existence in a remote area such as USA and Korea. The concern on the management of the patients is very important. Since most of the patients can develop severe respiratory illness and critical care management is needed, the issue on critical care for MERS is the topic to be discussed in critical medicine.

Anti-infective immunoadhesins from plants

Immunoadhesins are recombinant proteins that combine the ligand-binding region of a receptor or adhesion molecule with immunoglobulin constant domains. All FDA-approved immunoadhesins are designed to modulate the interaction of a human receptor with its normal ligand, such as Etanercept (Enbrel(®) ), which interferes with the binding of tumour necrosis factor (TNF) to the TNF-alpha receptor and is used to treat inflammatory diseases such as rheumatoid arthritis. Like antibodies, immunoadhesins have long circulating half-lives, are readily purified by affinity-based methods and have the avidity advantages conferred by bivalency. Immunoadhesins that incorporate normal cellular receptors for viruses or bacterial toxins hold great, but as yet unrealized, potential for treating infectious disease. As decoy receptors, immunoadhesins have potential advantages over pathogen-targeted monoclonal antibodies. Planet Biotechnology has specialized in developing anti-infective immunoadhesins using plant expression systems. An immunoadhesin incorporating the cellular receptor for anthrax toxin, CMG2, potently blocks toxin activity in vitro and protects animals against inhalational anthrax. An immunoadhesin based on the receptor for human rhinovirus, ICAM-1, potently blocks infection of human cells by one of the major causes of the common cold. An immunoadhesin targeting the MERS coronavirus is in an early stage of development. We describe here the unique challenges involved in designing and developing immunoadhesins targeting infectious diseases in the hope of inspiring further research into this promising class of drugs.

Middle East respiratory syndrome: current status and future prospects for vaccine development

The outbreaks of Middle East respiratory syndrome (MERS) previously in Middle East and recently in South Korea have raised serious concerns worldwide, reinforcing the importance of developing effective and safe vaccines against MERS-coronavirus (MERS-CoV). A number of vaccine candidates have been developed on the basis of viral vectors, recombinant proteins, DNAs, nanoparticles, and recombinant MERS-CoV, and some of them have shown efficacy in laboratory animals. However, the paucity of financial support has made it difficult to transfer effective candidates from the preclinical stage to clinical trials. Here, we summarize currently available MERS vaccine candidates and illustrate strategies for future development, with the aim of provoking government agencies and Big Pharma to invest more funds for developing efficacious and safe MERS vaccines.

Middle East Respiratory Syndrome Coronavirus Outbreak in the Republic of Korea, 2015

Objectives

The outbreak of Middle East respiratory syndrome coronavirus (MERS-CoV) infection in the Republic of Korea started from the index case who developed fever after returning from the Middle East. He infected 26 cases in Hospital C, and consecutive nosocomial transmission proceeded throughout the nation. We provide an epidemiologic description of the outbreak, as of July 2015.

Methods

Epidemiological research was performed by direct interview of the confirmed patients and reviewing medical records. We also analyzed the incubation period, serial interval, the characteristics of superspreaders, and factors associated with mortality. Full genome sequence was obtained from sputum specimens of the index patient.

Results

A total of 186 confirmed patients with MERS-CoV infection across 16 hospitals were identified in the Republic of Korea. Some 44.1% of the cases were patients exposed in hospitals, 32.8% were caregivers, and 13.4% were healthcare personnel. The most common presenting symptom was fever and chills. The estimated incubation period was 6.83 days and the serial interval was 12.5 days. A total of 83.2% of the transmission events were epidemiologically linked to five superspreaders, all of whom had pneumonia at presentation and contacted hundreds of people. Older age [odds ratio (OR) = 4.86, 95% confidence interval (CI) 1.90–12.45] and underlying respiratory disease (OR = 4.90, 95% CI 1.64–14.65) were significantly associated with mortality. Phylogenetic analysis showed that the MERS-CoV of the index case clustered closest with a recent virus from Riyadh, Saudi Arabia.

Conclusion

A single imported MERS-CoV infection case imposed a huge threat to public health and safety. This highlights the importance of robust preparedness and optimal infection prevention control. The lessons learned from the current outbreak will contribute to more up-to-date guidelines and global health security.

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.

An update on Middle East respiratory syndrome: 2 years later

Middle East respiratory syndrome coronavirus (MERS-CoV) was first recognized in 2012 and since then has resulted in cases in 23 countries in four continents. The majority of these cases were reported from the Kingdom of Saudi Arabia. The disease caused a spectrum of illness, from asymptomatic to severe and possibly fatal disease. Recent studies showed that the transmission of MERS-CoV among family contacts remains relatively low. Currently, there are no approved vaccines or therapeutics for MERS-CoV.

Human infection with MERS coronavirus after exposure to infected camels, Saudi Arabia, 2013

We investigated a case of human infection with Middle East respiratory syndrome coronavirus (MERS-CoV) after exposure to infected camels. Analysis of the whole human-derived virus and 15% of the camel-derived virus sequence yielded nucleotide polymorphism signatures suggestive of cross-species transmission. Camels may act as a direct source of human MERS-CoV infection.

MERS coronaviruses in dromedary camels, Egypt

We identified the near-full-genome sequence (29,908 nt, >99%) of Middle East respiratory syndrome coronavirus (MERS-CoV) from a nasal swab specimen from a dromedary camel in Egypt. We found that viruses genetically very similar to human MERS-CoV are infecting dromedaries beyond the Arabian Peninsula, where human MERS-CoV infections have not yet been detected.

Middle East Respiratory Syndrome Coronavirus: What Do We Know?

Middle East respiratory syndrome coronavirus is a viral respiratory infection initially reported in the Saudi Arabian peninsula in 2012. This epidemic has crossed from Middle Eastern countries into many European and Asian countries. Recently, the United States and United Kingdom have also been impacted. Although there is very little information about its transmission, it is important for the advanced practice nurse to be updated on the current information provided by the Centers for Disease Control and World Health Organization. This report addresses the risks, symptoms, diagnosis, and implications related to Middle East respiratory syndrome coronavirus.

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Very little information is known on MERS-CoV, a new viral respiratory epidemic.

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Usually found in bats and camels. Zoonotic transmission is suggested.

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Recent travelers or contact with travelers from the Arabian Peninsula are at risk.

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Initial flu-like symptoms may progress to pneumonia and become fatal.

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Diagnosis is confirmed with PCR testing. Standard precautions should be maintained.

Antibodies against MERS coronavirus in dromedary camels, United Arab Emirates, 2003 and 2013

Camels were infected with this virus >10 years before the first human cases.

Middle East respiratory syndrome coronavirus (MERS-CoV) has caused an ongoing outbreak of severe acute respiratory tract infection in humans in the Arabian Peninsula since 2012. Dromedary camels have been implicated as possible viral reservoirs. We used serologic assays to analyze 651 dromedary camel serum samples from the United Arab Emirates; 151 of 651 samples were obtained in 2003, well before onset of the current epidemic, and 500 serum samples were obtained in 2013. Recombinant spike protein–specific immunofluorescence and virus neutralization tests enabled clear discrimination between MERS-CoV and bovine CoV infections. Most (632/651, 97.1%) camels had antibodies against MERS-CoV. This result included all 151 serum samples obtained in 2003. Most (389/651, 59.8%) serum samples had MERS-CoV–neutralizing antibody titers >1,280. Dromedary camels from the United Arab Emirates were infected at high rates with MERS-CoV or a closely related, probably conspecific, virus long before the first human MERS cases.

Contact investigation for imported case of Middle East respiratory syndrome, Germany

No evidence was found for nosocomial transmission of this coronavirus.

On March 19, 2013, a patient from United Arab Emirates who had severe respiratory infection was transferred to a hospital in Germany, 11 days after symptom onset. Infection with Middle East respiratory syndrome coronavirus (MERS-CoV) was suspected on March 21 and confirmed on March 23; the patient, who had contact with an ill camel shortly before symptom onset, died on March 26. A contact investigation was initiated to identify possible person-to-person transmission and assess infection control measures. Of 83 identified contacts, 81 were available for follow-up. Ten contacts experienced mild symptoms, but test results for respiratory and serum samples were negative for MERS-CoV. Serologic testing was done for 53 (75%) of 71 nonsymptomatic contacts; all results were negative. Among contacts, the use of FFP2/FFP3 face masks during aerosol exposure was more frequent after MERS-CoV infection was suspected than before. Infection control measures may have prevented nosocomial transmission of the virus.

Middle East respiratory syndrome coronavirus: implications for health care facilities

Background

Middle East respiratory syndrome coronavirus (MERS-CoV) is a novel coronavirus that causes a severe respiratory disease with high case fatality rate. Starting in March 2014, a dramatic increase of cases has occurred in the Arabian Peninsula, many of which were acquired in health care settings. As of May 9, 2014, 536 laboratory-confirmed cases and 145 deaths have been reported globally.

Methods

Review of publicly available data about MERS-CoV health care–associated transmission.

Results

We identified 11 events of possible or confirmed health care–associated transmission with high morbidity and mortality, mainly among patients with comorbidities. Health care workers are also frequently affected; however, they tend to have milder symptoms and better prognosis. Gaps in infection control were noted in all events. Currently, health care–associated outbreaks are playing a pivotal role in the evolution of the MERS-CoV epidemic in countries in the Arabian Peninsula.

Conclusion

There is a need to increase infection control capacity in affected areas and areas at increased risk of being affected to prevent transmission in health care settings. Vaccines and antiviral agents are urgently needed. Overall, our knowledge about the epidemiologic characteristics of MERS-CoV that impact health care transmission is very limited. As the MERS-CoV epidemic continues to evolve, issues concerning best infection control measures will arise, and studies to better define their effectiveness in real life are needed.

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Health care–associated transmission plays a pivotal role in the Middle East respiratory syndrome coronavirus epidemic.

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Gaps in infection control were noted in all health care–associated events.

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There is a need to increase infection control capacity.

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Studies about the effectiveness of infection control measures are needed.

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Vaccines and antiviral agents against Middle East respiratory syndrome coronavirus are urgently needed.

Birth and pathogenesis of rogue respiratory viruses

Emerging infectious diseases of zoonotic origin are shaping today's infectious disease field more than ever. In this article, we introduce and review three emerging zoonotic viruses. Novel hantaviruses emerged in the Americas in the mid-1990s as the cause of severe respiratory infections, designated hantavirus pulmonary syndrome, with case fatality rates of around 40%. Nipah virus emerged a few years later, causing respiratory infections and encephalitis in Southeast Asia, with case fatality rates ranging from 40% to more than 90%. A new coronavirus emerged in 2012 on the Arabian Peninsula with a clinical syndrome of acute respiratory infections, later designated as Middle East respiratory syndrome (MERS), and an initial case fatality rate of more than 40%. Our current state of knowledge on the pathogenicity of these three severe, emerging viral infections is discussed.

Hospital-associated outbreak of Middle East respiratory syndrome coronavirus: a serologic, epidemiologic, and clinical description

BACKGROUND

In April 2012, the Jordan Ministry of Health investigated an outbreak of lower respiratory illnesses at a hospital in Jordan; 2 fatal cases were retrospectively confirmed by real-time reverse transcription polymerase chain reaction (rRT-PCR) to be the first detected cases of Middle East respiratory syndrome (MERS-CoV).

METHODS

Epidemiologic and clinical characteristics of selected potential cases were assessed through serum blood specimens, medical record reviews, and interviews with surviving outbreak members, household contacts, and healthcare personnel. Cases of MERS-CoV infection were identified using 3 US Centers for Disease Control and Prevention serologic tests for detection of anti-MERS-CoV antibodies.

RESULTS

Specimens and interviews were obtained from 124 subjects. Seven previously unconfirmed individuals tested positive for anti-MERS-CoV antibodies by at least 2 of 3 serologic tests, in addition to 2 fatal cases identified by rRT-PCR. The case-fatality rate among the 9 total cases was 22%. Six subjects were healthcare workers at the outbreak hospital, yielding an attack rate of 10% among potentially exposed outbreak hospital personnel. There was no evidence of MERS-CoV transmission at 2 transfer hospitals having acceptable infection control practices.

CONCLUSIONS

Novel serologic tests allowed for the detection of otherwise unrecognized cases of MERS-CoV infection among contacts in a Jordanian hospital-associated respiratory illness outbreak in April 2012, resulting in a total of 9 test-positive cases. Serologic results suggest that further spread of this outbreak to transfer hospitals did not occur. Most subjects had no major, underlying medical conditions; none were on hemodialysis. Our observed case-fatality rate was lower than has been reported from outbreaks elsewhere.

Hospital-associated outbreak of Middle East respiratory syndrome coronavirus: a serologic, epidemiologic, and clinical description

BACKGROUND

In April 2012, the Jordan Ministry of Health investigated an outbreak of lower respiratory illnesses at a hospital in Jordan; 2 fatal cases were retrospectively confirmed by real-time reverse transcription polymerase chain reaction (rRT-PCR) to be the first detected cases of Middle East respiratory syndrome (MERS-CoV).

METHODS

Epidemiologic and clinical characteristics of selected potential cases were assessed through serum blood specimens, medical record reviews, and interviews with surviving outbreak members, household contacts, and healthcare personnel. Cases of MERS-CoV infection were identified using 3 US Centers for Disease Control and Prevention serologic tests for detection of anti-MERS-CoV antibodies.

RESULTS

Specimens and interviews were obtained from 124 subjects. Seven previously unconfirmed individuals tested positive for anti-MERS-CoV antibodies by at least 2 of 3 serologic tests, in addition to 2 fatal cases identified by rRT-PCR. The case-fatality rate among the 9 total cases was 22%. Six subjects were healthcare workers at the outbreak hospital, yielding an attack rate of 10% among potentially exposed outbreak hospital personnel. There was no evidence of MERS-CoV transmission at 2 transfer hospitals having acceptable infection control practices.

CONCLUSIONS

Novel serologic tests allowed for the detection of otherwise unrecognized cases of MERS-CoV infection among contacts in a Jordanian hospital-associated respiratory illness outbreak in April 2012, resulting in a total of 9 test-positive cases. Serologic results suggest that further spread of this outbreak to transfer hospitals did not occur. Most subjects had no major, underlying medical conditions; none were on hemodialysis. Our observed case-fatality rate was lower than has been reported from outbreaks elsewhere.

Synthesizing data and models for the spread of MERS-CoV, 2013: key role of index cases and hospital transmission

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Transmission models for the MERS-CoV outbreak during April–October 2013.

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MERS-CoV transmission models with index and secondary cases.

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MERS-CoV transmission models with community and hospital compartments.

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Calibration of MERS-CoV transmission models using MCMC methods.

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Data indicate a strong support for R  < 1 in the first stage of the outbreak in 2013.

The outbreak of Middle East respiratory syndrome coronavirus (MERS-CoV) has caused 209 deaths and 699 laboratory-confirmed cases in the Arabian Peninsula as of June 11, 2014. Preparedness efforts are hampered by considerable uncertainty about the nature and intensity of human-to-human transmission, with previous reproduction number estimates ranging from 0.4 to 1.5. Here we synthesize epidemiological data and transmission models for the MERS-CoV outbreak during April–October 2013 to resolve uncertainties in epidemic risk, while considering the impact of observation bias. We match the progression of MERS-CoV cases in 2013 to a dynamic transmission model that incorporates community and hospital compartments, and distinguishes transmission by zoonotic (index) cases and secondary cases. When observation bias is assumed to account for the fact that all reported zoonotic cases are severe, but only ∼57% of secondary cases are symptomatic, the average reproduction number of MERS-CoV is estimated to be 0.45 (95% CI:0.29–0.61). Alternatively, if these epidemiological observations are taken at face value, index cases are estimated to transmit substantially more effectively than secondary cases, (R_i = 0.84 (0.58-1.20) vs R_s = 0.36 (0.24–0.51)). In both scenarios the relative contribution of hospital-based transmission is over four times higher than that of community transmission, indicating that disease control should be focused on hospitalized patients.

Adjusting previously published estimates for observation bias confirms a strong support for the average R < 1 in the first stage of the outbreak in 2013 and thus, transmissibility of secondary cases of MERS-CoV remained well below the epidemic threshold. More information on the observation process is needed to clarify whether MERS-CoV is intrinsically weakly transmissible between people or whether existing control measures have contributed meaningfully to reducing the transmissibility of secondary cases. Our results could help evaluate the progression of MERS-CoV in recent months in response to changes in disease surveillance, control interventions, or viral adaptation.

Replicative Capacity of MERS Coronavirus in Livestock Cell Lines

Replicative capacity of Middle East respiratory syndrome coronavirus (MERS-CoV) was assessed in cell lines derived from livestock and peridomestic small mammals on the Arabian Peninsula. Only cell lines originating from goats and camels showed efficient replication of MERS-CoV. These results provide direction in the search for the intermediate host of MERS-CoV.

The pattern of Middle East respiratory syndrome coronavirus in Saudi Arabia: a descriptive epidemiological analysis of data from the Saudi Ministry of Health

Purpose

This study describes the epidemiology of Middle East respiratory syndrome coronavirus (MERS-CoV) in Saudi Arabia.

Patients and methods

Epidemiological analysis was performed on data from all MERS-CoV cases recorded by the Saudi Ministry of Health between June 6, 2013 and May 14, 2014. The frequency of cases and deaths was calculated and adjusted by month, sex, age group, and region. The average monthly temperature and humidity of infected regions throughout the year was also calculated.

Results

A total of 425 cases were recorded over the study period. The highest number of cases and deaths occurred between April and May 2014. Disease occurrence among men (260 cases [62%]) was higher than in women (162 cases [38%]), and the case fatality rate was higher for men (52%) than for women (23%). In addition, those in the 45–59 years and ≥60 years age groups were most likely to be infected, and the case fatality rate for these people was higher than for other groups. The highest number of cases and deaths were reported in Riyadh (169 cases; 43 deaths), followed by Jeddah (156 cases; 36 deaths) and the Eastern Region (24 cases; 22 deaths). The highest case fatality rate was in the Eastern Region (92%), followed by Medinah (36%) and Najran (33%). MERS-CoV infection actively causes disease in environments with low relative humidity (<20%) and high temperature (15°C–35°C).

Conclusion

MERS-CoV is considered an epidemic in Saudi Arabia. The frequency of cases and deaths is higher among men than women, and those above 45 years of age are most affected. Low relative humidity and high temperature can enhance the spread of this disease in the entire population. Further analytical studies are required to determine the source and mode of infection in Saudi Arabia.

From SARS to MERS: crystallographic studies on coronaviral proteases enable antiviral drug design

This review focuses on the important contributions that macromolecular crystallography has made over the past 12 years to elucidating structures and mechanisms of the essential proteases of coronaviruses, the main protease (M(pro) ) and the papain-like protease (PL(pro) ). The role of X-ray crystallography in structure-assisted drug discovery against these targets is discussed. Aspects dealt with in this review include the emergence of the SARS coronavirus in 2002-2003 and of the MERS coronavirus 10 years later and the origins of these viruses. The crystal structure of the free SARS coronavirus M(pro) and its dependence on pH is discussed, as are efforts to design inhibitors on the basis of these structures. The mechanism of maturation of the enzyme from the viral polyprotein is still a matter of debate. The crystal structure of the SARS coronavirus PL(pro) and its complex with ubiquitin is also discussed, as is its orthologue from MERS coronavirus. Efforts at predictive structure-based inhibitor development for bat coronavirus M(pro) s to increase the preparedness against zoonotic transmission to man are described as well. The paper closes with a brief discussion of structure-based discovery of antivirals in an academic setting.

Geographic distribution of MERS coronavirus among dromedary camels, Africa

We found serologic evidence for the circulation of Middle East respiratory syndrome coronavirus among dromedary camels in Nigeria, Tunisia, and Ethiopia. Circulation of the virus among dromedaries across broad areas of Africa may indicate that this disease is currently underdiagnosed in humans outside the Arabian Peninsula.

Middle East respiratory syndrome coronavirus in bats, Saudi Arabia

The source of human infection with Middle East respiratory syndrome coronavirus remains unknown. Molecular investigation indicated that bats in Saudi Arabia are infected with several alphacoronaviruses and betacoronaviruses. Virus from 1 bat showed 100% nucleotide identity to virus from the human index case-patient. Bats might play a role in human infection.

Current advancements and potential strategies in the development of MERS-CoV vaccines

Middle East respiratory syndrome (MERS) is a newly emerging infectious disease caused by a novel coronavirus, MERS-coronavirus (MERS-CoV), a new member in the lineage C of β-coronavirus (β-CoV). The increased human cases and high mortality rate of MERS-CoV infection make it essential to develop safe and effective vaccines. In this review, the current advancements and potential strategies in the development of MERS vaccines, particularly subunit vaccines based on MERS-CoV spike (S) protein and its receptor-binding domain (RBD), are discussed. How to improve the efficacy of subunit vaccines through novel adjuvant formulations and routes of administration as well as currently available animal models for evaluating the in vivo efficacy of MERS-CoV vaccines are also addressed. Overall, these strategies may have important implications for the development of effective and safe vaccines for MERS-CoV in the future.

Performance and clinical validation of the RealStar MERS-CoV Kit for detection of Middle East respiratory syndrome coronavirus RNA

Background

A highly pathogenic human coronavirus causing respiratory disease emerged in the Middle East region in 2012. In-house molecular diagnostic methods for this virus termed Middle East respiratory syndrome coronavirus (MERS-CoV) allowed sensitive MERS-CoV RNA detection in patient samples. Fast diagnosis is important to manage human cases and trace possible contacts.

Objectives

The aim of this study was to improve the availability of existing nucleic acid amplification-based diagnostic methods for MERS-CoV infections by providing a real-time RT-PCR kit, including an internal control and two target regions recommended by the World Health Organization (WHO). And to validate this kit (RealStar^® MERS-CoV RT-PCR kit 1.0, Altona Diagnostics GmbH, Hamburg, Germany) using clinical samples of one MERS-CoV case from Munich and respiratory samples of patients with other respiratory diseases.

Study design

An internal amplification control was included into the RT-PCR assays targeting the genomic region upstream of the Envelope gene (upE) and within open reading frame (ORF) 1A. Based on these assays, a ready-to-use real-time RT-PCR kit featuring both the upE and ORF1A assays was developed, validated and compared to the established in-house versions.

Results

The performance of both RT-PCR assays included in the kit is comparable to the in-house assays. They show high analytical sensitivity (upE: 5.3 copies/reaction; ORF1A: 9.3 copies/reaction), no cross-reactivity with other respiratory pathogens and detected MERS-CoV RNA in patient samples in almost the same manner as the in-house versions.

Conclusion

The kit is a valuable tool for assisting in the rapid diagnosis, patient management and epidemiology of suspected MERS-CoV cases.

Stillbirth during infection with Middle East respiratory syndrome coronavirus

We conducted an epidemiologic investigation among survivors of an outbreak of Middle East respiratory syndrome coronavirus (MERS-CoV) infection in Jordan. A second-trimester stillbirth occurred during the course of an acute respiratory illness that was attributed to MERS-CoV on the basis of exposure history and positive results of MERS-CoV serologic testing. This is the first occurrence of stillbirth during an infection with MERS-CoV and may have bearing upon the surveillance and management of pregnant women in settings of unexplained respiratory illness potentially due to MERS-CoV. Future prospective investigations of MERS-CoV should ascertain pregnancy status and obtain further pregnancy-related data, including biological specimens for confirmatory testing.

Clinical management and infection control of SARS: lessons learned

The outbreak of severe acute respiratory syndrome (SARS) in 2003 was the first emergence of an important human pathogen in the 21st century. Responding to the epidemic provided clinicians with extensive experience in diagnosing and treating a novel respiratory viral disease. In this article, we review the experience of the SARS epidemic, focusing on measures taken to identify and isolate patients, prevent the transmission of infection to healthcare workers and develop effective therapies. Lessons learned from the SARS epidemic will be especially important in responding to the current emergence of another highly pathogenic human coronavirus, the agent of Middle East respiratory syndrome (MERS), and to the recently emerging H7N9 influenza A virus in China. This paper forms part of a symposium in Antiviral Research on "From SARS to MERS: 10years of research on highly pathogenic human coronaviruses."

From SARS to MERS: 10 years of research on highly pathogenic human coronaviruses

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We review the outbreak of severe acute respiratory syndrome (SARS) in 2002–2003 and antiviral treatment of patients.

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We review efforts towards the rational design of anti-SARS therapeutics.

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We present a comprehensive list of all available 3-dimensional structures of coronavirus proteins.

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We discuss the emerging MERS coronavirus and review the few antivirals available for treatment.

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We critically discuss which lessons have been learned from SARS and which are yet to be learned.

This article introduces a series of invited papers in Antiviral Research marking the 10th anniversary of the outbreak of severe acute respiratory syndrome (SARS), caused by a novel coronavirus that emerged in southern China in late 2002. Until that time, coronaviruses had not been recognized as agents causing severe disease in humans, hence, the emergence of the SARS-CoV came as a complete surprise. Research during the past ten years has revealed the existence of a diverse pool of coronaviruses circulating among various bat species and other animals, suggesting that further introductions of highly pathogenic coronaviruses into the human population are not merely probable, but inevitable. The recent emergence of another coronavirus causing severe disease, Middle East respiratory syndrome (MERS), in humans, has made it clear that coronaviruses pose a major threat to human health, and that more research is urgently needed to elucidate their replication mechanisms, identify potential drug targets, and develop effective countermeasures. In this series, experts in many different aspects of coronavirus replication and disease will provide authoritative, up-to-date reviews of the following topics:

– clinical management and infection control of SARS;

– reservoir hosts of coronaviruses;

– receptor recognition and cross-species transmission of SARS-CoV;

– SARS-CoV evasion of innate immune responses;

– structures and functions of individual coronaviral proteins;

– anti-coronavirus drug discovery and development; and

– the public health legacy of the SARS outbreak.

Each article will be identified in the last line of its abstract as belonging to the series “From SARS to MERS: 10 years of research on highly pathogenic human coronaviruses.”

Receptor recognition and cross-species infections of SARS coronavirus

Receptor recognition is a major determinant of the host range, cross-species infections, and pathogenesis of the severe acute respiratory syndrome coronavirus (SARS-CoV). A defined receptor-binding domain (RBD) in the SARS-CoV spike protein specifically recognizes its host receptor, angiotensin-converting enzyme 2 (ACE2). This article reviews the latest knowledge about how RBDs from different SARS-CoV strains interact with ACE2 from several animal species. Detailed research on these RBD/ACE2 interactions has established important principles on host receptor adaptations, cross-species infections, and future evolution of SARS-CoV. These principles may apply to other emerging animal viruses, including the recently emerged Middle East respiratory syndrome coronavirus (MERS-CoV). This paper forms part of a series of invited articles in Antiviral Research on "From SARS to MERS: 10years of research on highly pathogenic human coronaviruses".