Serologic Evidence for MERS-CoV Infection in Dromedary Camels, Punjab, Pakistan, 2012-2015

Dromedary camels from Africa and Arabia are an established source for zoonotic Middle East respiratory syndrome coronavirus (MERS-CoV) infection among humans. In Pakistan, we found specific neutralizing antibodies in samples from 39.5% of 565 dromedaries, documenting significant expansion of the enzootic range of MERS-CoV to Asia.

Estimation of Severe Middle East Respiratory Syndrome Cases in the Middle East, 2012-2016

Using data from travelers to 4 countries in the Middle East, we estimated 3,250 (95% CI 1,300-6,600) severe cases of Middle East respiratory syndrome occurred in this region during September 2012-January 2016. This number is 2.3-fold higher than the number of laboratory-confirmed cases recorded in these countries.

Contact Tracing for Imported Case of Middle East Respiratory Syndrome, China, 2015

Confirmation of an imported case of infection with Middle East respiratory syndrome coronavirus in China triggered intensive contact tracing and mandatory monitoring. Using a hotline and surveillance video footage was effective for tracing all 110 identified contacts. Contact monitoring detected no secondary transmission of infection in China.

Feasibility of Using Convalescent Plasma Immunotherapy for MERS-CoV Infection, Saudi Arabia

Efficacy testing will be challenging because of the small pool of donors with sufficiently high antibody titers.

We explored the feasibility of collecting convalescent plasma for passive immunotherapy of Middle East respiratory syndrome coronavirus (MERS-CoV) infection by using ELISA to screen serum samples from 443 potential plasma donors: 196 patients with suspected or laboratory-confirmed MERS-CoV infection, 230 healthcare workers, and 17 household contacts exposed to MERS-CoV. ELISA-reactive samples were further tested by indirect fluorescent antibody and microneutralization assays. Of the 443 tested samples, 12 (2.7%) had a reactive ELISA result, and 9 of the 12 had reactive indirect fluorescent antibody and microneutralization assay titers. Undertaking clinical trials of convalescent plasma for passive immunotherapy of MERS-CoV infection may be feasible, but such trials would be challenging because of the small pool of potential donors with sufficiently high antibody titers. Alternative strategies to identify convalescent plasma donors with adequate antibody titers should be explored, including the sampling of serum from patients with more severe disease and sampling at earlier points during illness.

Zero Transmission of Middle East Respiratory Syndrome: Lessons Learned From Thailand

New emerging pathogens can quickly become a global health threat in this era. A number of Middle East respiratory syndrome (MERS) outbreaks have been linked to healthcare facilities. The healthcare-associated transmission of Middle East respiratory syndrome coronavirus (MERS-CoV) has been attributed to overcrowding, delayed diagnosis, and the breakdown of infection control systems. Strict infection control precautions and a well-prepared hospital system may have contributed to no nosocomial transmission occurring during the treatment of MERS-CoV infections imported to Thailand. The recent outbreaks of MERS and previous emerging infections provide valuable lessons to be learned. Continuous vigilance and strengthening of infection control systems will shape the capacity to prevent and control MERS-CoV or new emerging disease transmission.

Toward Developing a Preventive MERS-CoV Vaccine-Report from a Workshop Organized by the Saudi Arabia Ministry of Health and the International Vaccine Institute, Riyadh, Saudi Arabia, November 14-15, 2015

Middle East respiratory syndrome (MERS) remains a serious international public health threat. With the goal of accelerating the development of countermeasures against MERS coronavirus (MERS-CoV), funding agencies, nongovernmental organizations, and researchers across the world assembled in Riyadh, Saudi Arabia, on November 14-15, 2015, to discuss vaccine development challenges. The meeting was spearheaded by the Saudi Ministry of Health and co-organized by the International Vaccine Institute, South Korea. Accelerating the development of a preventive vaccine requires a better understanding of MERS epidemiology, transmission, and pathogenesis in humans and animals. A combination of rodent and nonhuman primate models should be considered in evaluating and developing preventive and therapeutic vaccine candidates. Dromedary camels should be considered for the development of veterinary vaccines. Several vaccine technology platforms targeting the MERS-CoV spike protein were discussed. Mechanisms to maximize investment, provide robust data, and affect public health are urgently needed.

Genetic Characteristics of Coronaviruses from Korean Bats in 2016

Bats have increasingly been recognized as the natural reservoir of severe acute respiratory syndrome (SARS), coronavirus, and other coronaviruses found in mammals. However, little research has been conducted on bat coronaviruses in South Korea. In this study, bat samples (332 oral swabs, 245 fecal samples, 38 urine samples, and 57 bat carcasses) were collected at 33 natural bat habitat sites in South Korea. RT-PCR and sequencing were performed for specific coronavirus genes to identify the bat coronaviruses in different bat samples. Coronaviruses were detected in 2.7% (18/672) of the samples: 13 oral swabs from one species of the family Rhinolophidae, and four fecal samples and one carcass (intestine) from three species of the family Vespertiliodae. To determine the genetic relationships of the 18 sequences obtained in this study and previously known coronaviruses, the nucleotide sequences of a 392-nt region of the RNA-dependent RNA polymerase (RdRp) gene were analyzed phylogenetically. Thirteen sequences belonging to SARS-like betacoronaviruses showed the highest nucleotide identity (97.1-99.7%) with Bat-CoV-JTMC15 reported in China. The other five sequences were most similar to MERS-like betacoronaviruses. Four nucleotide sequences displayed the highest identity (94.1-95.1%) with Bat-CoV-HKU5 from Hong Kong. The one sequence from a carcass showed the highest nucleotide identity (99%) with Bat-CoV-SC2013 from China. These results suggest that careful surveillance of coronaviruses from bats should be continued, because animal and human infections may result from the genetic variants present in bat coronavirus reservoirs.

Adaptive evolution influences the infectious dose of MERS-CoV necessary to achieve severe respiratory disease

We recently established a mouse model (288–330^+/+) that developed acute respiratory disease resembling human pathology following infection with a high dose (5 × 10⁶ PFU) of mouse-adapted MERS-CoV (icMERSma1). Although this high dose conferred fatal respiratory disease in mice, achieving similar pathology at lower viral doses may more closely reflect naturally acquired infections. Through continued adaptive evolution of icMERSma1 we generated a novel mouse-adapted MERS-CoV (maM35c4) capable of achieving severe respiratory disease at doses between 10³ and 10⁵ PFU. Novel mutations were identified in the maM35c4 genome that may be responsible for eliciting etiologies of acute respiratory distress syndrome at 10–1000 fold lower viral doses. Importantly, comparative genetics of the two mouse-adapted MERS strains allowed us to identify specific mutations that remained fixed through an additional 20 cycles of adaptive evolution. Our data indicate that the extent of MERS-CoV adaptation determines the minimal infectious dose required to achieve severe respiratory disease.

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Mouse-adapted MERS-CoV can elicit severe respiratory disease at doses ranging 10³–10⁵ PFU.

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Novel mutations in MERS-CoV may be associated with severe respiratory disease.

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The extent of MERS-CoV adaptation determines the minimal effective dose to elicit respiratory disease.

An Opportunistic Pathogen Afforded Ample Opportunities: Middle East Respiratory Syndrome Coronavirus

The human coronaviruses (CoV) include HCoV-229E, HCoV-OC43, HCoV-NL63, and HCoV-HKU1, some of which have been known for decades. The severe acute respiratory syndrome (SARS) CoV briefly emerged into the human population but was controlled. In 2012, another novel severely human pathogenic CoV—the Middle East Respiratory Syndrome (MERS)-CoV—was identified in the Kingdom of Saudi Arabia; 80% of over 2000 human cases have been recorded over five years. Targeted research remains key to developing control strategies for MERS-CoV, a cause of mild illness in its camel reservoir. A new therapeutic toolbox being developed in response to MERS is also teaching us more about how CoVs cause disease. Travel-related cases continue to challenge the world’s surveillance and response capabilities, and more data are needed to understand unexplained primary transmission. Signs of genetic change have been recorded, but it remains unclear whether there is any impact on clinical disease. How camels came to carry the virus remains academic to the control of MERS. To date, human-to-human transmission has been inefficient, but virus surveillance, characterisation, and reporting are key to responding to any future change. MERS-CoV is not currently a pandemic threat; it is spread mainly with the aid of human habit and error.

Structurally Guided Removal of DeISGylase Biochemical Activity from Papain-Like Protease Originating from Middle East Respiratory Syndrome Coronavirus

Middle East respiratory syndrome coronavirus (MERS-CoV) is an emerging human pathogen that is the causative agent for Middle East respiratory syndrome (MERS). With MERS outbreaks resulting in over 35% fatalities and now spread to 27 countries, MERS-CoV poses a significant ongoing threat to global human health. As part of its viral genome, MERS-CoV encodes a papain-like protease (PLpro) that has been observed to act as a deubiquitinase and deISGylase to antagonize type I interferon (IFN-I) immune pathways. This activity is in addition to its viral polypeptide cleavage function. Although the overall impact of MERS-CoV PLpro function is observed to be essential, difficulty has been encountered in delineating the importance of its separate functions, particularly its deISGylase activity. As a result, the interface of MERS-CoV and human interferon-stimulated gene product 15 (hISG15) was probed with isothermal calorimetry, which suggests that the C-terminal domain of hISG15 is principally responsible for interactions. Subsequently, the structure of MERS-CoV PLpro was solved to 2.4 Å in complex with the C-terminal domain of hISG15. Utilizing this structural information, mutants were generated that lacked appreciable deISGylase activity but retained wild-type deubiquitinase and peptide cleavage activities. Hence, this provides a new platform for understanding viral deISGylase activity within MERS-CoV and other CoVs.IMPORTANCE Coronaviruses, such as Middle East respiratory syndrome coronavirus (MERS-CoV), encode a papain-like protease (PLpro) that possesses the ability to antagonize interferon immune pathways through the removal of ubiquitin and interferon-stimulated gene product 15 (ISG15) from target proteins. The lack of CoV proteases with attenuated deISGylase activity has been a key obstacle in delineating the impact between deubiquitinase and deISGylase activities on viral host evasion and pathogenesis. Here, biophysical techniques revealed that MERS-CoV PLpro chiefly engages human ISG15 through its C-terminal domain. The first structure of MERS-CoV PLpro in complex with this domain exposed the interface between these two entities. Employing these structural insights, mutations were employed to selectively remove deISGylase activity with no appreciable impact on its other deubiquitinase and peptide cleavage biochemical properties. Excitingly, this study introduces a new tool to probe the pathogenesis of MERS-CoV and related viruses through the removal of viral deISGylase activity.

Retrospective, epidemiological cluster analysis of the Middle East respiratory syndrome coronavirus (MERS-CoV) epidemic using open source data

The Middle East respiratory syndrome coronavirus (MERS-CoV) is caused by a novel coronavirus discovered in 2012. Since then, 1806 cases, including 564 deaths, have been reported by the Kingdom of Saudi Arabia (KSA) and affected countries as of 1 June 2016. Previous literature attributed increases in MERS-CoV transmission to camel breeding season as camels are likely the reservoir for the virus. However, this literature review and subsequent analysis indicate a lack of seasonality. A retrospective, epidemiological cluster analysis was conducted to investigate increases in MERS-CoV transmission and reports of household and nosocomial clusters. Cases were verified and associations between cases were substantiated through an extensive literature review and the Armed Forces Health Surveillance Branch's Tiered Source Classification System. A total of 51 clusters were identified, primarily nosocomial (80·4%) and most occurred in KSA (45·1%). Clusters corresponded temporally with the majority of periods of greatest incidence, suggesting a strong correlation between nosocomial transmission and notable increases in cases.

MERS, SARS and other coronaviruses as causes of pneumonia

Human coronaviruses (HCoVs) have been considered to be relatively harmless respiratory pathogens in the past. However, after the outbreak of the severe acute respiratory syndrome (SARS) and emergence of the Middle East respiratory syndrome (MERS), HCoVs have received worldwide attention as important pathogens in respiratory tract infection. This review focuses on the epidemiology, pathogenesis and clinical characteristics among SARS-coronaviruses (CoV), MERS-CoV and other HCoV infections.

The sample of choice for detecting Middle East respiratory syndrome coronavirus in asymptomatic dromedary camels using real-time reversetranscription polymerase chain reaction

The newly identified Middle East respiratory syndrome coronavirus (MERS-CoV), which causes severe respiratory disease, particularly in people with comorbidities, requires further investigation. Studies in Qatar and elsewhere have provided evidence that dromedary camels are a reservoir for the virus, but the exact modes of transmission of MERS-CoV to humans remain unclear. In February 2014, an assessment was made of the suitability and sensitivity of different types of sample for the detection of MERSCoV by real-time reverse-transcription polymerase chain reaction (RT-PCR) for three gene targets: UpE (upstream of the E gene), the N (nucleocapsid) gene and open reading frame (ORF) 1a. Fifty-three animals presented for slaughter were sampled. A high percentage of the sampled camels (79% [95% confidence interval 66.9-91.5%, standard error 0.0625]; 42 out of 53) were shown to be shedding MERS-CoV at the time of slaughter, yet all the animals were apparently healthy. Among the virus-positive animals, nasal swabs were most often positive (97.6%). Oral swabs were the second most frequently positive (35.7%), followed by rectal swabs (28.5%). In addition, the highest viral load, expressed as a cycle threshold (Ct) value of 11.27, was obtained from a nasal swab. These findings lead to the conclusion that nasal swabs are the candidate sample of choice for detecting MERS-CoV using RT-PCR technology in apparently healthy camels.

A multi-faceted approach of a nursing led education in response to MERS-CoV infection

Background

The emergence of the Middle East respiratory syndrome-coronavirus (MERS-CoV) resulted in multiple healthcare associated outbreaks. In response, we developed a nurse-led program to screen and triage patients with MERS-CoV infection.

Methods

A formal educational program was implemented to ensure a standardized approach to care planning and delivery. The essential skills that were included were the use of Personal Protective Equipment (PPE) including gown, gloves, head cover and N95 mask, hand hygiene, the practice of donning and doffing and the collection of MERS-CoV nasopharyngeal specimens.

Results

A core group of nurses were identified from high-risk units. The education program consisted of four skill-days. Nurses were assigned a pre-course work from Mosby’s Nursing Skills, an online skill module, donning and doffing of PPE, and the process for obtaining a nasopharyngeal swab. The skill lab incorporated multiple methods such group discussion, watching an on-line video, and a simulated demonstration and practice on a mannequin. In total, 450 nurses attended the Nasopharyngeal Skills Day and 1000 nurses received training. Donning and doffing PPE and N95 mask fit testing has become an annual mandatory competency requirement for staff in nursing and clinical services.

Conclusion

The application of specified protocols minimizes the risks of cross infection, placing emphasis on patient and staff safety as well as expediting the patient to definitive treatment. Nurse educators have an instrumental role in training nurses and other healthcare providers on the specifics needed to identify, contain and manage patient presenting with MERS-CoV.

Structural Insights into the Interaction of Coronavirus Papain-Like Proteases and Interferon-Stimulated Gene Product 15 from Different Species

Severe acute respiratory syndrome coronavirus (SARS-CoV) and Middle East respiratory syndrome coronavirus (MERS-CoV) encode multifunctional papain-like proteases (PLPs) that have the ability to process the viral polyprotein to facilitate RNA replication and antagonize the host innate immune response. The latter function involves reversing the post-translational modification of cellular proteins conjugated with either ubiquitin (Ub) or Ub-like interferon-stimulated gene product 15 (ISG15). Ub is known to be highly conserved among eukaryotes, but surprisingly, ISG15 is highly divergent among animals. The ramifications of this sequence divergence to the recognition of ISG15 by coronavirus PLPs at a structural and biochemical level are poorly understood. Therefore, the activity of PLPs from SARS-CoV, MERS-CoV, and mouse hepatitis virus was evaluated against seven ISG15s originating from an assortment of animal species susceptible, and not, to certain coronavirus infections. Excitingly, our kinetic, thermodynamic, and structural analysis revealed an array of different preferences among PLPs. Included in these studies is the first insight into a coronavirus PLP's interface with ISG15 via SARS-CoV PLpro in complex with the principle binding domain of human ISG15 (hISG15) and mouse ISG15s (mISG15s). The first X-ray structure of the full-length mISG15 protein is also reported and highlights a unique, twisted hinge region of ISG15 that is not conserved in hISG15, suggesting a potential role in differential recognition. Taken together, this new information provides a structural and biochemical understanding of the distinct specificities among coronavirus PLPs observed and addresses a critical gap of how PLPs can interact with ISG15s from a wide variety of species.

Hematologic, hepatic, and renal function changes in hospitalized patients with Middle East respiratory syndrome coronavirus

Background

There are no longitudinal data on the changes in hematologic, hepatic, and renal function findings in patients with Middle East respiratory syndrome coronavirus (MERS‐CoV) infection.

Methods

This is a retrospective cohort study of 16 MERS‐CoV patients, to describe the hematological, hepatic, and renal findings of patients with MERS‐CoV.

Results

During the 21 days of observation, there was no significant change in the hepatic panel or creatinine tests. There was a significant increase in the mean ± SD of the white blood cell count from 8.3 ± 4.6 to 14.53 ± 7 (P value = 0.001) and an increase in mean ± SD of the absolute neutrophil count from 6.33 ± 4.2 to 12 ± 5.5 (P value = 0.015). Leukocytosis was observed in 31% (5/16) of the patients on day 1 and in 80% (4/5) on day 21. Transient leukopenia developed in 6% (1/16) of the patients on day 1 and in 13% (1/8) on day 8. None of the patients had neutropenia. Lymphopenia was a prominent feature with a rate of 44% (7/16) of the patients on day 1 and 60% (3/5) on day 21. Lymphocytosis was not a feature of MERS‐CoV infection. Thrombocytopenia developed in 31% (5/16) of the patients on day 1 and 40% (2/5) on day 21. Thrombocytosis was not a prominent feature and was observed in 6% (1/16) of the patients on day 1 and 17% (1/6) on day 9.

Conclusions

Patients with MERS‐CoV infection showed variable hematologic parameters over time. Lymphocytosis and neutropenia were not features of MERS‐CoV infection.

Livestock Susceptibility to Infection with Middle East Respiratory Syndrome Coronavirus

Middle East respiratory syndrome (MERS) cases continue to be reported, predominantly in Saudi Arabia and occasionally other countries. Although dromedaries are the main reservoir, other animal species might be susceptible to MERS coronavirus (MERS-CoV) infection and potentially serve as reservoirs. To determine whether other animals are potential reservoirs, we inoculated MERS-CoV into llamas, pigs, sheep, and horses and collected nasal and rectal swab samples at various times. The presence of MERS-CoV in the nose of pigs and llamas was confirmed by PCR, titration of infectious virus, immunohistochemistry, and in situ hybridization; seroconversion was detected in animals of both species. Conversely, in sheep and horses, virus-specific antibodies did not develop and no evidence of viral replication in the upper respiratory tract was found. These results prove the susceptibility of llamas and pigs to MERS-CoV infection. Thus, the possibility of MERS-CoV circulation in animals other than dromedaries, such as llamas and pigs, is not negligible.

Outbreak of Middle East respiratory syndrome coronavirus in Saudi Arabia: a retrospective study

BACKGROUND

The Middle East respiratory syndrome (MERS) is proposed to be a zoonotic disease. Dromedary camels have been implicated due to reports that some confirmed cases were exposed to camels. Risk factors for MERS coronavirus (MERS-CoV) infections in humans are incompletely understood. This study aimed to describe the demographic characteristics, mortality rate, clinical manifestations and comorbidities with confirmed cases of MERS-CoV.

METHODS

Retrospective chart review were performed to identify all laboratory-confirmed cases of MERS-CoV in Saudi Arabia who reported to the Ministry of Health (MOH) of Saudi Arabia and WHO between April 23, 2014 and August 31, 2015. Patients' charts were also reviewed for demographic information, mortality, comorbidities, clinical presentations, health care facility and presented with descriptive and comparative statistics using non parametric binomial test and Chi-square test.

RESULTS

Confirmed cases of male patients (61.1%) exceeded those of female patients (38.9%). Infections among Saudi patients (62.6%) exceeded those among non-Saudi patients (37.4%; P = 0.001). The majority of the patients were aged 21-40 years (37.4%) or 41-60 years (35.8%); 43 (22.6%) were aged >61 years, and (8) 4.2% were aged 0-20 years. There was a difference in mortality between confirmed MERS-CoV cases (63.7% alive versus 36.3% dead cases, respectively). Furthermore, fever with cough and shortness of breath (SOB) (n = 39; 20.5%), fever with cough (n = 29; 15.3%), fever (n = 18; 9.5%), and fever with SOB (n = 13; 6.8%), were the most common clinical manifestations associated with confirmed MERS-CoV cases.

CONCLUSION

MERS-CoV is considered an epidemic in Saudi Arabia. The results of the present study showed that the frequency of cases is higher among men than women, in Saudi patients than non-Saudi, and those between 21 to 60 years are most affected. Further studies are required to improve the surveillance associated with MERS-CoV to get definite and clear answers and better understanding of the MERS-CoV outbreak as well the source, and route of infection transmission in Saudi Arabia.

Neurological Complications during Treatment of Middle East Respiratory Syndrome

Background and Purpose

Middle East respiratory syndrome (MERS) has a high mortality rate and pandemic potential. However, the neurological manifestations of MERS have rarely been reported since it first emerged in 2012.

Methods

We evaluated four patients with laboratory-confirmed MERS coronavirus (CoV) infections who showed neurological complications during MERS treatment. These 4 patients were from a cohort of 23 patients who were treated at a single designated hospital during the 2015 outbreak in the Republic of Korea. The clinical presentations, laboratory findings, and prognoses are described.

Results

Four of the 23 admitted MERS patients reported neurological symptoms during or after MERS-CoV treatment. The potential diagnoses in these four cases included Bickerstaff's encephalitis overlapping with Guillain-Barré syndrome, intensive-care-unit-acquired weakness, or other toxic or infectious neuropathies. Neurological complications did not appear concomitantly with respiratory symptoms, instead being delayed by 2–3 weeks.

Conclusions

Neuromuscular complications are not rare during MERS treatment, and they may have previously been underdiagnosed. Understanding the neurological manifestations is important in an infectious disease such as MERS, because these symptoms are rarely evaluated thoroughly during treatment, and they may interfere with the prognosis or require treatment modification.

Resource impact of managing suspected Middle East respiratory syndrome patients in a UK teaching hospital

Clinical challenges exist in the management of hospitalized patients returning to the UK with potential Middle East respiratory syndrome coronavirus (MERS-CoV) infection, particularly with its clinical overlap with influenza, as demonstrated in this case-series and cost-analysis review of returning Hajj pilgrims. These patients were hospitalized with acute febrile respiratory illness, initially managed as potential MERS-CoV infections, but were eventually diagnosed with influenza. Additional costs were small, yet enhanced infection prevention measures created significant burdens on isolation rooms and staff time. Planning for predictable events such as Hajj is important for resource management. Here, in-house MERS-CoV diagnostic testing would have facilitated earlier diagnosis and discharge.

Clinical determinants of the severity of Middle East respiratory syndrome (MERS): a systematic review and meta-analysis

Background

While the risk of severe complications of Middle East respiratory syndrome (MERS) and its determinants have been explored in previous studies, a systematic analysis of published articles with different designs and populations has yet to be conducted. The present study aimed to systematically review the risk of death associated with MERS as well as risk factors for associated complications.

Methods

PubMed and Web of Science databases were searched for clinical and epidemiological studies on confirmed cases of MERS. Eligible articles reported clinical outcomes, especially severe complications or death associated with MERS. Risks of admission to intensive care unit (ICU), mechanical ventilation and death were estimated. Subsequently, potential associations between MERS-associated death and age, sex, underlying medical conditions and study design were explored.

Results

A total of 25 eligible articles were identified. The case fatality risk ranged from 14.5 to 100%, with the pooled estimate at 39.1%. The risks of ICU admission and mechanical ventilation ranged from 44.4 to 100% and from 25.0 to 100%, with pooled estimates at 78.2 and 73.0%, respectively. These risks showed a substantial heterogeneity among the identified studies, and appeared to be the highest in case studies focusing on ICU cases. We identified older age, male sex and underlying medical conditions, including diabetes mellitus, renal disease, respiratory disease, heart disease and hypertension, as clinical predictors of death associated with MERS. In ICU case studies, the expected odds ratios (OR) of death among patients with underlying heart disease or renal disease to patients without such comorbidities were 0.6 (95% Confidence Interval (CI): 0.1, 4.3) and 0.6 (95% CI: 0.0, 2.1), respectively, while the ORs were 3.8 (95% CI: 3.4, 4.2) and 2.4 (95% CI: 2.0, 2.9), respectively, in studies with other types of designs.

Conclusions

The heterogeneity for the risk of death and severe manifestations was substantially high among the studies, and varying study designs was one of the underlying reasons for this heterogeneity. A statistical estimation of the risk of MERS death and identification of risk factors must be conducted, particularly considering the study design and potential biases associated with case detection and diagnosis.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-016-3881-4) contains supplementary material, which is available to authorized users.

Association between Severity of MERS-CoV Infection and Incubation Period

We analyzed data for 170 patients in South Korea who had laboratory-confirmed infection with Middle East respiratory syndrome coronavirus. A longer incubation period was associated with a reduction in the risk for death (adjusted odds ratio/1-day increase in incubation period 0.83, 95% credibility interval 0.68–1.03).

The critical care response to a hospital outbreak of Middle East respiratory syndrome coronavirus (MERS-CoV) infection: an observational study

Background

Middle East respiratory syndrome coronavirus (MERS-CoV) has caused several hospital outbreaks, including a major outbreak at King Abdulaziz Medical City, a 940-bed tertiary-care hospital in Riyadh, Saudi Arabia (August–September 2015). To learn from our experience, we described the critical care response to the outbreak.

Methods

This observational study was conducted at the Intensive Care Department which covered 5 ICUs with 60 single-bedded rooms. We described qualitatively and, as applicable, quantitatively the response of intensive care services to the outbreak. The clinical course and outcomes of healthcare workers (HCWs) who had MERS were noted.

Results

Sixty-three MERS patients were admitted to 3 MERS-designated ICUs during the outbreak (peak census = 27 patients on August 25, 2015, and the last new case on September 13, 2015). Most patients had multiorgan failure. Eight HCWs had MERS requiring ICU admission (median stay = 28 days): Seven developed acute respiratory distress syndrome, four were treated with prone positioning, four needed continuous renal replacement therapy and one had extracorporeal membrane oxygenation. The hospital mortality of ICU MERS patients was 63.4 % (0 % for the HCWs). In response to the outbreak, the number of negative-pressure rooms was increased from 14 to 38 rooms in 3 MERS-designated ICUs. Patients were managed with a nurse-to-patient ratio of 1:0.8. Infection prevention practices were intensified. As a surrogate, surface disinfectant and hand hygiene gel consumption increased by ~30 % and 17 N95 masks were used per patient/day on average. Family visits were restricted to 2 h/day. Although most ICU staff expressed concerns about acquiring MERS, all reported to work normally. During the outbreak, 27.0 % of nurses and 18.4 % of physicians working in the MERS-designated ICUs reported upper respiratory symptoms, and were tested for MERS-CoV. Only 2/196 (1.0 %) ICU nurses and 1/80 (1.3 %) physician tested positive, had mild disease and recovered fully. The total sick leave duration was 138 days for nurses and 30 days for physicians.

Conclusions

Our hospital outbreak of MERS resulted in 63 patients requiring organ support and prolonged ICU stay with a high mortality rate. The ICU response required careful facility and staff management and proper infection control and prevention practices.

Persistence of Antibodies against Middle East Respiratory Syndrome Coronavirus

To determine how long antibodies against Middle East respiratory syndrome coronavirus persist, we measured long-term antibody responses among persons serologically positive or indeterminate after a 2012 outbreak in Jordan. Antibodies, including neutralizing antibodies, were detectable in 6 (86%) of 7 persons for at least 34 months after the outbreak.

Viral RNA in Blood as Indicator of Severe Outcome in Middle East Respiratory Syndrome Coronavirus Infection

We evaluated the diagnostic and clinical usefulness of blood specimens to detect Middle East respiratory syndrome coronavirus infection in 21 patients from the 2015 outbreak in South Korea. Viral RNA was detected in blood from 33% of patients at initial diagnosis, and the detection preceded a worse clinical course.

Microevolution of Outbreak-Associated Middle East Respiratory Syndrome Coronavirus, South Korea, 2015

During the 2015 Middle East respiratory syndrome coronavirus outbreak in South Korea, we sequenced full viral genomes of strains isolated from 4 patients early and late during infection. Patients represented at least 4 generations of transmission. We found no evidence of changes in the evolutionary rate and no reason to suspect adaptive changes in viral proteins.

Variations in Spike Glycoprotein Gene of MERS-CoV, South Korea, 2015

An outbreak of nosocomial infections with Middle East respiratory syndrome coronavirus occurred in South Korea in May 2015. Spike glycoprotein genes of virus strains from South Korea were closely related to those of strains from Riyadh, Saudi Arabia. However, virus strains from South Korea showed strain-specific variations.

Multifacility Outbreak of Middle East Respiratory Syndrome in Taif, Saudi Arabia

Middle East respiratory syndrome (MERS) coronavirus (MERS-CoV) is a novel respiratory pathogen first reported in 2012. During September 2014-January 2015, an outbreak of 38 cases of MERS was reported from 4 healthcare facilities in Taif, Saudi Arabia; 21 of the 38 case-patients died. Clinical and public health records showed that 13 patients were healthcare personnel (HCP). Fifteen patients, including 4 HCP, were associated with 1 dialysis unit. Three additional HCP in this dialysis unit had serologic evidence of MERS-CoV infection. Viral RNA was amplified from acute-phase serum specimens of 15 patients, and full spike gene-coding sequencing was obtained from 10 patients who formed a discrete cluster; sequences from specimens of 9 patients were closely related. Similar gene sequences among patients unlinked by time or location suggest unrecognized viral transmission. Circulation persisted in multiple healthcare settings over an extended period, underscoring the importance of strengthening MERS-CoV surveillance and infection-control practices.

Surveillance of the Middle East respiratory syndrome (MERS) coronavirus (CoV) infection in healthcare workers after contact with confirmed MERS patients: incidence and risk factors of MERS-CoV seropositivity

Given the mode of transmission of Middle East respiratory syndrome (MERS), healthcare workers (HCWs) in contact with MERS patients are expected to be at risk of MERS infections. We evaluated the prevalence of MERS coronavirus (CoV) immunoglobulin (Ig) G in HCWs exposed to MERS patients and calculated the incidence of MERS-affected cases in HCWs. We enrolled HCWs from hospitals where confirmed MERS patients had visited. Serum was collected 4 to 6 weeks after the last contact with a confirmed MERS patient. We performed an enzyme-linked immunosorbent assay (ELISA) to screen for the presence of MERS-CoV IgG and an indirect immunofluorescence test (IIFT) to confirm MERS-CoV IgG. We used a questionnaire to collect information regarding the exposure. We calculated the incidence of MERS-affected cases by dividing the sum of PCR-confirmed and serology-confirmed cases by the number of exposed HCWs in participating hospitals. In total, 1169 HCWs in 31 hospitals had contact with 114 MERS patients, and among the HCWs, 15 were PCR-confirmed MERS cases in study hospitals. Serologic analysis was performed for 737 participants. ELISA was positive in five participants and borderline for seven. IIFT was positive for two (0.3%) of these 12 participants. Among the participants who did not use appropriate personal protective equipment (PPE), seropositivity was 0.7% (2/294) compared to 0% (0/443) in cases with appropriate PPE use. The incidence of MERS infection in HCWs was 1.5% (17/1169). The seroprevalence of MERS-CoV IgG among HCWs was higher among participants who did not use appropriate PPE.

Predicting the international spread of Middle East respiratory syndrome (MERS)

Background

The Middle East respiratory syndrome (MERS) associated coronavirus has been imported via travelers into multiple countries around the world. In order to support risk assessment practice, the present study aimed to devise a novel statistical model to quantify the country-level risk of experiencing an importation of MERS case.

Methods

We analyzed the arrival time of each reported MERS importation around the world, i.e., the date on which imported cases entered a specific country, which was modeled as a dependent variable in our analysis. We also used openly accessible data including the airline transportation network to parameterize a hazard-based risk prediction model. The hazard was assumed to follow an inverse function of the effective distance (i.e., the minimum effective length of a path from origin to destination), which was calculated from the airline transportation data, from Saudi Arabia to each country. Both country-specific religion and the incidence data of MERS in Saudi Arabia were used to improve our model prediction.

Results

Our estimates of the risk of MERS importation appeared to be right skewed, which facilitated the visual identification of countries at highest risk of MERS importations in the right tail of the distribution. The simplest model that relied solely on the effective distance yielded the best predictive performance (Area under the curve (AUC) = 0.943) with 100 % sensitivity and 79.6 % specificity. Out of the 30 countries estimated to be at highest risk of MERS case importation, 17 countries (56.7 %) have already reported at least one importation of MERS. Although model fit measured by Akaike Information Criterion (AIC) was improved by including country-specific religion (i.e. Muslim majority country), the predictive performance as measured by AUC was not improved after accounting for this covariate.

Conclusions

Our relatively simple statistical model based on the effective distance derived from the airline transportation network data was found to help predicting the risk of importing MERS at the country level. The successful application of the effective distance model to predict MERS importations, particularly when computationally intensive large-scale transmission models may not be immediately applicable could have been benefited from the particularly low transmissibility of the MERS coronavirus.

Kinetics of Serologic Responses to MERS Coronavirus Infection in Humans, South Korea

We investigated the kinetics of serologic responses to Middle East respiratory syndrome coronavirus (MERS-CoV) infection by using virus neutralization and MERS-CoV S1 IgG ELISA tests. In most patients, robust antibody responses developed by the third week of illness. Delayed antibody responses with the neutralization test were associated with more severe disease.

Clinical Presentation and Outcomes of Middle East Respiratory Syndrome in the Republic of Korea

Background

From May to July 2015, the Republic of Korea experienced the largest outbreak of Middle East respiratory syndrome (MERS) outside the Arabian Peninsula. A total of 186 patients, including 36 deaths, had been diagnosed with MERS-coronavirus (MERS-CoV) infection as of September 30th, 2015.

Materials and Methods

We obtained information of patients who were confirmed to have MERS-CoV infection. MERS-CoV infection was diagnosed using real-time reverse-transcriptase polymerase chain reaction assay.

Results

The median age of the patients was 55 years (range, 16 to 86). A total of 55.4% of the patients had one or more coexisting medical conditions. The most common symptom was fever (95.2%). At admission, leukopenia (42.6%), thrombocytopenia (46.6%), and elevation of aspartate aminotransferase (42.7%) were observed. Pneumonia was detected in 68.3% of patients at admission and developed in 80.8% during the disease course. Antiviral agents were used for 74.7% of patients. Mechanical ventilation, extracorporeal membrane oxygenation, and convalescent serum were employed for 24.5%, 7.1%, and 3.8% of patients, respectively. Older age, presence of coexisting medical conditions including diabetes or chronic lung disease, presence of dyspnea, hypotension, and leukocytosis at admission, and the use of mechanical ventilation were revealed to be independent predictors of death.

Conclusion

The clinical features of MERS-CoV infection in the Republic of Korea were similar to those of previous outbreaks in the Middle East. However, the overall mortality rate (20.4%) was lower than that in previous reports. Enhanced surveillance and active management of patients during the outbreak may have resulted in improved outcomes.

Mortality Risk Factors for Middle East Respiratory Syndrome Outbreak, South Korea, 2015

As of July 15, 2015, the South Korean Ministry of Health and Welfare had reported 186 case-patients with Middle East respiratory syndrome in South Korea. For 159 case-patients with known outcomes and complete case histories, we found that older age and preexisting concurrent health conditions were risk factors for death.

Middle East Respiratory Syndrome in 3 Persons, South Korea, 2015

In May 2015, Middle East respiratory syndrome coronavirus infection was laboratory confirmed in South Korea. Patients were a man who had visited the Middle East, his wife, and a man who shared a hospital room with the index patient. Rapid laboratory confirmation will facilitate subsequent prevention and control for imported cases.

MERS-CoV Antibodies in Humans, Africa, 2013-2014

Dromedaries in Africa and elsewhere carry the Middle East respiratory syndrome coronavirus (MERS-CoV). To search for evidence of autochthonous MERS-CoV infection in humans, we tested archived serum from livestock handlers in Kenya for MERS-CoV antibodies. Serologic evidence of infection was confirmed for 2 persons sampled in 2013 and 2014.

Experimental Infection and Response to Rechallenge of Alpacas with Middle East Respiratory Syndrome Coronavirus

We conducted a challenge/rechallenge trial in which 3 alpacas were infected with Middle East respiratory syndrome coronavirus. The alpacas shed virus at challenge but were refractory to further shedding at rechallenge on day 21. The trial indicates that alpacas may be suitable models for infection and shedding dynamics of this virus.

Epidemiology of a Novel Recombinant Middle East Respiratory Syndrome Coronavirus in Humans in Saudi Arabia

Background. Middle East respiratory syndrome coronavirus (MERS-CoV) causes severe respiratory illness in humans. Fundamental questions about circulating viruses and transmission routes remain.

Methods. We assessed routinely collected epidemiologic data for MERS-CoV cases reported in Saudi Arabia during 1 January–30 June 2015 and conducted a more detailed investigation of cases reported during February 2015. Available respiratory specimens were obtained for sequencing.

Results. During the study period, 216 MERS-CoV cases were reported. Full genome (n = 17) or spike gene sequences (n = 82) were obtained from 99 individuals. Most sequences (72 of 99 [73%]) formed a discrete, novel recombinant subclade (NRC-2015), which was detected in 6 regions and became predominant by June 2015. No clinical differences were noted between clades. Among 87 cases reported during February 2015, 13 had no recognized risks for secondary acquisition; 12 of these 13 also denied camel contact. Most viruses (8 of 9) from these 13 individuals belonged to NRC-2015.

Discussions. Our findings document the spread and eventual predominance of NRC-2015 in humans in Saudi Arabia during the first half of 2015. Our identification of cases without recognized risk factors but with similar virus sequences indicates the need for better understanding of risk factors for MERS-CoV transmission.

Middle East respiratory syndrome-related knowledge, preventive behaviours and risk perception among nursing students during outbreak

Aims and objectives

The aim of this study was to survey nursing students’ Middle East respiratory syndrome–related knowledge, preventive behaviours and risk perception to examine the correlations among the variables during a Middle East respiratory syndrome outbreak.

Background

Middle East respiratory syndrome is a new viral respiratory illness. Nursing students who engage in clinical practice at hospitals may have been exposed to Middle East respiratory syndrome infection during the Middle East respiratory syndrome outbreak.

Design

This study was a descriptive cross‐sectional survey.

Methods

Participants (n = 249) were nursing students in their third or fourth year of the programme who were engaged in clinical practice for eight hours per day at the tertiary hospitals with Middle East respiratory syndrome patients. Knowledge, preventive behaviours and risk perception related to Middle East respiratory syndrome were measured using scales developed through a preliminary survey and validity testing.

Results

The subjects’ knowledge level of Middle East respiratory syndrome was 84·4%; their practice of preventive behaviours was rated at 44·5%; and their risk perception rating was 2·4 out of 5. Middle East respiratory syndrome–related risk perception was significantly different according to gender and Middle East respiratory syndrome education. Middle East respiratory syndrome–related knowledge was significantly correlated with preventive behaviours and risk perception.

Conclusion

Considering the low scores for items regarding knowledge and preventive behaviours, it is necessary to develop effective and systematic publicity and education programmes for nursing students. Enhancing Middle East respiratory syndrome–related knowledge by considering cooperation between hospitals and universities will sharpen nursing students’ risk perception of the disease and effectively increase their preventive behaviours.

Relevance to clinical practice

Similar to other emerging infectious diseases, Middle East respiratory syndrome outbreaks may occur in other countries. The results of this study can be used to develop and apply efficient and feasible Middle East respiratory syndrome education programmes for nursing students during Middle East respiratory syndrome outbreaks.

Avoiding student infection during a Middle East respiratory syndrome (MERS) outbreak: a single medical school experience

PURPOSE

In outbreaks of infectious disease, medical students are easily overlooked in the management of healthcare personnel protection although they serve in clinical clerkships in hospitals. In the early summer of 2015, Middle East respiratory syndrome (MERS) struck South Korea, and students of Sungkyunkwan University School of Medicine (SKKUSOM) were at risk of contracting the disease. The purpose of this report is to share SKKUSOM's experience against the MERS outbreak and provide suggestions for medical schools to consider in the face of similar challenges.

METHODS

Through a process of reflection-on-action, we examined SKKUSOM's efforts to avoid student infection during the MERS outbreak and derived a few practical guidelines that medical schools can adopt to ensure student safety in outbreaks of infectious disease.

RESULTS

The school leadership conducted ongoing risk assessment and developed contingency plans to balance student safety and continuity in medical education. They rearranged the clerkships to another hospital and offered distant lectures and tutorials. Five suggestions are extracted for medical schools to consider in infection outbreaks: instant cessation of clinical clerkships; rational decision making on a school closure; use of information technology; constant communication with hospitals; and open communication with faculty, staff, and students.

CONCLUSION

Medical schools need to take the initiative and actively seek countermeasures against student infection. It is essential that medical schools keep constant communication with their index hospitals and the involved personnel. In order to assure student learning, medical schools may consider offering distant education with online technology.

Lack of transmission among healthcare workers in contact with a case of Middle East respiratory syndrome coronavirus infection in Thailand

Introduction

A hospital-associated outbreak of Middle East Respiratory Syndrome Coronavirus (MERS-CoV) was reported. We aimed to assess the effectiveness of infection control measures among healthcare workers (HCWs) who were exposed to a MERS patient and/or his body fluids in our institute.

Methods

A descriptive study was conducted among HCWs who worked with a MERS patient in Bamrasnaradura Infectious Diseases Institute, Thailand, between 18 June and 3 July 2015. Contacts were defined as HCWs who worked in the patient’s room or with the patient’s body fluids. Serum samples from all contacts were collected within 14 days of last contact and one month later. Paired sera were tested for detection of MERS‐CoV antibodies by using an indirect ELISA.

Results

Thirty-eight (88.4 %) of 43 identified contacts consented to enroll. The mean (SD) age was 38.1 (11.1) years, and 79 % were females. The median (IQR) cumulative duration of work of HCWs in the patient’s room was 35 (20–165) minutes. The median (IQR) cumulative duration of work of HCWs with the patient’s blood or body fluids in laboratory was 67.5 (43.7–117.5) minutes. All contacts reported 100 % compliance with hand hygiene, using N95 respirator, performing respirator fit test, wearing gown, gloves, eye protection, and cap during their entire working period. All serum specimens of contacts tested for MERS-CoV antibodies were negative.

Conclusions

We provide evidence of effective infection control practices against MERS-CoV transmission in a healthcare facility. Strict infection control precautions can protect HCWs. The optimal infection control measures for MERS-CoV should be further evaluated.

Detection of Severe Acute Respiratory Syndrome-Like, Middle East Respiratory Syndrome-Like Bat Coronaviruses and Group H Rotavirus in Faeces of Korean Bats

Bat species around the world have recently been recognized as major reservoirs of several zoonotic viruses, such as severe acute respiratory syndrome coronavirus (SARS‐CoV), Middle East respiratory syndrome coronavirus (MERS‐CoV), Nipah virus and Hendra virus. In this study, consensus primer‐based reverse transcriptase polymerase chain reactions (RT‐PCRs) and high‐throughput sequencing were performed to investigate viruses in bat faecal samples collected at 11 natural bat habitat sites from July to December 2015 in Korea. Diverse coronaviruses were first detected in Korean bat faeces, including alphacoronaviruses, SARS‐CoV‐like and MERS‐CoV‐like betacoronaviruses. In addition, we identified a novel bat rotavirus belonging to group H rotavirus which has only been described in human and pigs until now. Therefore, our results suggest the need for continuing surveillance and additional virological studies in domestic bat.

Molecular Epidemiology of Hospital Outbreak of Middle East Respiratory Syndrome, Riyadh, Saudi Arabia, 2014

A contiguous outbreak was the result of multiple introductions from outside the hospital.

We investigated an outbreak of Middle East respiratory syndrome (MERS) at King Fahad Medical City (KFMC), Riyadh, Saudi Arabia, during March 29–May 21, 2014. This outbreak involved 45 patients: 8 infected outside KFMC, 13 long-term patients at KFMC, 23 health care workers, and 1 who had an indeterminate source of infection. Sequences of full-length MERS coronavirus (MERS-CoV) from 10 patients and a partial sequence of MERS-CoV from another patient, when compared with other MERS-CoV sequences, demonstrated that this outbreak was part of a larger outbreak that affected multiple health care facilities in Riyadh and possibly arose from a single zoonotic transmission event that occurred in December 2013 (95% highest posterior density interval November 8, 2013–February 10, 2014). This finding suggested continued health care–associated transmission for 5 months. Molecular epidemiology documented multiple external introductions in a seemingly contiguous outbreak and helped support or refute transmission pathways suspected through epidemiologic investigation.

Acute Respiratory Infections in Travelers Returning from MERS-CoV-Affected Areas

We examined which respiratory pathogens were identified during screening for Middle East respiratory syndrome coronavirus in 177 symptomatic travelers returning to Ontario, Canada, from regions affected by the virus. Influenza A and B viruses (23.1%) and rhinovirus (19.8%) were the most common pathogens identified among these travelers.

Laboratory Testing for Middle East Respiratory Syndrome Coronavirus, California, USA, 2013-2014

Since Middle East respiratory syndrome coronavirus (MERS-CoV) first emerged, the California Department of Public Health has coordinated efforts to identify possible cases in travelers to California, USA, from affected areas. During 2013–2014, the department investigated 54 travelers for MERS-CoV; none tested positive, but 32 (62%) of 52 travelers with suspected MERS-CoV had other respiratory viruses.

Middle East respiratory syndrome coronavirus: current situation and travel-associated concerns

The emergence of Middle East respiratory syndrome coronavirus (MERS-CoV) in 2012 brought back memories of the occurrence of severe acute respiratory syndrome coronavirus (SARS-CoV) in 2002. More than 1500 MERS-CoV cases were recorded in 42 months with a case fatality rate (CFR) of 40%. Meanwhile, 8000 cases of SARS-CoV were confirmed in six months with a CFR of 10%. The clinical presentation of MERS-CoV ranges from mild and non-specific presentation to progressive and severe pneumonia. No predictive signs or symptoms exist to differentiate MERS-CoV from community-acquired pneumonia in hospitalized patients. An apparent heterogeneity was observed in transmission. Most MERS-CoV cases were secondary to large outbreaks in healthcare settings. These cases were secondary to community-acquired cases, which may also cause family outbreaks. Travel-associated MERS infection remains low. However, the virus exhibited a clear tendency to cause large outbreaks outside the Arabian Peninsula as exemplified by the outbreak in the Republic of Korea. In this review, we summarize the current knowledge about MERS-CoV and highlight travel-related issues.

Emerging infectious diseases: Focus on infection control issues for novel coronaviruses (Severe Acute Respiratory Syndrome-CoV and Middle East Respiratory Syndrome-CoV), hemorrhagic fever viruses (Lassa and Ebola), and highly pathogenic avian influenza viruses, A(H5N1) and A(H7N9)

Over the past several decades, we have witnessed the emergence of many new infectious agents, some of which are major public threats. New and emerging infectious diseases which are both transmissible from patient-to-patient and virulent with a high mortality include novel coronaviruses (SARS-CoV, MERS-CV), hemorrhagic fever viruses (Lassa, Ebola), and highly pathogenic avian influenza A viruses, A(H5N1) and A(H7N9). All healthcare facilities need to have policies and plans in place for early identification of patients with a highly communicable diseases which are highly virulent, ability to immediately isolate such patients, and provide proper management (e.g., training and availability of personal protective equipment) to prevent transmission to healthcare personnel, other patients and visitors to the healthcare facility.