MERS, SARS, and Ebola: The Role of Super-Spreaders in Infectious Disease

Coronavirus Disease 2019 (COVID-19) and pregnancy: what obstetricians need to know

Coronavirus disease 2019 is an emerging disease with a rapid increase in cases and deaths since its first identification in Wuhan, China, in December 2019. Limited data are available about coronavirus disease 2019 during pregnancy; however, information on illnesses associated with other highly pathogenic coronaviruses (ie, severe acute respiratory syndrome and the Middle East respiratory syndrome) might provide insights into coronavirus disease 2019's effects during pregnancy. Coronaviruses cause illness ranging in severity from the common cold to severe respiratory illness and death. Currently the primary epidemiologic risk factors for coronavirus disease 2019 include travel from mainland China (especially Hubei Province) or close contact with infected individuals within 14 days of symptom onset. Data suggest an incubation period of ∼5 days (range, 2-14 days). Average age of hospitalized patients has been 49-56 years, with a third to half with an underlying illness. Children have been rarely reported. Men were more frequent among hospitalized cases (54-73%). Frequent manifestations include fever, cough, myalgia, headache, and diarrhea. Abnormal testing includes abnormalities on chest radiographic imaging, lymphopenia, leukopenia, and thrombocytopenia. Initial reports suggest that acute respiratory distress syndrome develops in 17-29% of hospitalized patients. Overall case fatality rate appears to be ∼1%; however, early data may overestimate this rate. In 2 reports describing 18 pregnancies with coronavirus disease 2019, all were infected in the third trimester, and clinical findings were similar to those in nonpregnant adults. Fetal distress and preterm delivery were seen in some cases. All but 2 pregnancies were cesarean deliveries and no evidence of in utero transmission was seen. Data on severe acute respiratory syndrome and Middle East respiratory syndrome in pregnancy are sparse. For severe acute respiratory syndrome, the largest series of 12 pregnancies had a case-fatality rate of 25%. Complications included acute respiratory distress syndrome in 4, disseminated intravascular coagulopathy in 3, renal failure in 3, secondary bacterial pneumonia in 2, and sepsis in 2 patients. Mechanical ventilation was 3 times more likely among pregnant compared with nonpregnant women. Among 7 first-trimester infections, 4 ended in spontaneous abortion. Four of 5 women with severe acute respiratory syndrome after 24 weeks' gestation delivered preterm. For Middle East respiratory syndrome, there were 13 case reports in pregnant women, of which 2 were asymptomatic, identified as part of a contact investigation; 3 patients (23%) died. Two pregnancies ended in fetal demise and 2 were born preterm. No evidence of in utero transmission was seen in severe acute respiratory syndrome or Middle East respiratory syndrome. Currently no coronavirus-specific treatments have been approved by the US Food and Drug Administration. Because coronavirus disease 2019 might increase the risk for pregnancy complications, management should optimally be in a health care facility with close maternal and fetal monitoring. Principles of management of coronavirus disease 2019 in pregnancy include early isolation, aggressive infection control procedures, oxygen therapy, avoidance of fluid overload, consideration of empiric antibiotics (secondary to bacterial infection risk), laboratory testing for the virus and coinfection, fetal and uterine contraction monitoring, early mechanical ventilation for progressive respiratory failure, individualized delivery planning, and a team-based approach with multispecialty consultations. Information on coronavirus disease 2019 is increasing rapidly. Clinicians should continue to follow the Centers for Disease Control and Prevention website to stay up to date with the latest information (https://www.cdc.gov/coronavirus/2019-nCoV/hcp/index.html).

Novel coronavirus disease 2019 and perinatal outcomes

BACKGROUND AND AIM

Given the prevalence of novel coronavirus disease 2019 (COVID-19) and the lack of information on coronavirus and pregnancy, the purpose of this study was to evaluate the association of COVID-19 and perinatal outcomes in pregnant women.

MATERIALS AND METHODS

In the present review article, the search process was conducted on English and Persian scientific databases of PubMed, Scopus, Google Scholar, Magiran, Irandoc, Iranmedx, and SID as well as the websites of international organizations of World Health Organization and Centers for Disease Control and Prevention using the main keywords of "Pregnancy," "Perinatal outcomes," "Coronavirus," "COVID-19," "MERS-CoV," "MERS," "SARS-CoV-2," and "SARS-CoV-1" and their Persian-equivalent keywords from inception until March 16 2020.

RESULTS

The findings of studies on mothers with COVID-19 were limited, and insufficient information is available on the adverse pregnancy outcomes in pregnant women with COVID-19. In cases of infection with other coronaviruses such as Middle East respiratory syndrome and severe acute respiratory syndrome during pregnancy, there have been reports on adverse pregnancy outcomes such as miscarriage, stillbirth, preterm labor, low birth weight, and congenital malformations following high fever in the first trimester.

CONCLUSION

Pregnant women may be more susceptible to viral respiratory infections, including COVID-19, due to immunological and physiological changes. Therefore, pregnant women should take routine preventive measures, such as washing their hands frequently and avoiding contact with infected people, to prevent infection.

Saliva: potential diagnostic value and transmission of 2019-nCoV

2019-nCoV epidemic was firstly reported at late December of 2019 and has caused a global outbreak of COVID-19 now. Saliva, a biofluid largely generated from salivary glands in oral cavity, has been reported 2019-nCoV nucleic acid positive. Besides lungs, salivary glands and tongue are possibly another hosts of 2019-nCoV due to expression of ACE2. Close contact or short-range transmission of infectious saliva droplets is a primary mode for 2019-nCoV to disseminate as claimed by WHO, while long-distance saliva aerosol transmission is highly environment dependent within indoor space with aerosol-generating procedures such as dental practice. So far, no direct evidence has been found that 2019-nCoV is vital in air flow for long time. Therefore, to prevent formation of infectious saliva droplets, to thoroughly disinfect indoor air and to block acquisition of saliva droplets could slow down 2019-nCoV dissemination. This review summarizes diagnostic value of saliva for 2019-nCoV, possibly direct invasion into oral tissues, and close contact transmission of 2019-nCoV by saliva droplets, expecting to contribute to 2019-nCoV epidemic control.

[COVID-19: Clinical, biological and radiological characteristics in adults, infants and pregnant women. An up-to-date review at the heart of the pandemic]

La propagation du nouveau coronavirus SARS-CoV-2, découvert en Chine en janvier 2020, a mené à une pandémie dès mars 2020, obligeant chaque système de soins des pays touchés à une adaptation rapide. Pour mieux faire face à cette crise sanitaire majeure, qui a donné lieu à de nombreuses publications scientifiques, nous avons synthétisé les principales études cliniques originales afin de faciliter la prise en charge au quotidien des patients atteints de COVID-19. Nous détaillons les premiers signes et l’évolution de la maladie ainsi que les différentes formes cliniques, y compris extra-pulmonaires, telles qu’elles sont connues au début de cette pandémie. Nous insistons sur les marqueurs cliniques, biologiques et scannographiques prédictifs de sévérité ou de mortalité. Enfin, nous discutons de l’impact de l’infection par le SARS-CoV-2 dans les populations suspectes d’être à haut risque de formes sévères.

Comparative Global Epidemiological Investigation of SARS-CoV-2 and SARS-CoV Diseases Using Meta-MUMS Tool Through Incidence, Mortality, and Recovery Rates

COVID-19 is a novel coronavirus that was reported by the world health organization in late December 2019. As an unexplained respiratory disease epidemic, which is similar to respiratory syndrome coronavirus SARS-CoV, it rapidly spread all over the world. The study aims to compare several parameters of COVID-19 and SARS-CoV infectious diseases in terms of incidence, mortality, and recovery rates. The publicly available dataset Worldometer (extracted on April 5, 2020) confirmed by WHO report was available for meta-analysis purposes using the Meta-MUMS tool. And, the reported outcomes of the analysis used a random-effects model to evaluate the event rate, and risk ratios thorough subgroup analysis forest plots. Seventeen countries for COVID-19 and eight countries of SARS infections, including COVID-19 group n = 1124243, and SARS-CoV group n = 8346, were analyzed. In this meta-analysis, a random effect model of relations of incidence, mortality, and recovery rates of COVID-19 and SARS world infections were determined. The meta-analysis and forest plots of two viral world infections showed that the incidence rate of COVID-19 infection is more than SARS infections, while recovery and mortality event rates of SARS-CoV are more than COVID-19 infection. And subgroup analysis showed that the mortality and recovery rates were higher in both SARS-CoV wand COVID-19 in comparison to incidence and mortality rates, respectively. In conclusion, the meta-analysis approach on the abovementioned dataset revealed the epidemiological and statistical analyses for comparing COVID-19 and SARS-CoV outbreaks.

Atypical presentation of SARS-CoV-2 infection: A case report

BACKGROUND

The first case of pneumonia subsequently attributed to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) occurred in Wuhan, Hubei Province on December 8, 2019. The symptoms included fever, coughing, and breathing difficulties. A few patients with this infection may only have atypical symptoms, which could lead to a misdiagnosis and subsequently further facilitate the spread of the virus.

CASE SUMMARY

A 74-year-old female patient complained of severe diarrhea. She did not have fever, coughing, or breathing difficulties. A physical examination revealed no obvious positive signs. The patient had been hypertensive for more than 10 years. Her blood pressure was well controlled. On January 9, 2020, the patient's son visited a colleague who was later confirmed positive for SARS-CoV-2 and his first close contact with our patient was on January 17. The patient was first diagnosed with gastrointestinal dysfunction. However, considering her indirect contact with a SARS-CoV-2-infected individual, we suggested that an atypical pneumonia virus infection should be ruled out. A computed tomography scan was performed on January 26, and showed ground-glass nodules scattered along the two lungs, suggestive of viral pneumonia. Given the clinical characteristics, epidemiological history, and examination, the patient was diagnosed with coronavirus disease-2019 (COVID-19).

CONCLUSION

Our patient had atypical symptoms of COVID-19. Careful acquisition of an epidemiological history is necessary to make a correct diagnosis and strategize a treatment plan.

2019 novel coronavirus pneumonia with onset of dizziness: a case report

The 2019 novel coronavirus (2019-nCoV) epidemic continues, with the number of infections and deaths increasing. The respiratory tract is the main route of transmission of the virus, and the majority of symptoms are respiratory relative. Until now, there has been no reports concerning the nervous system onset. We present a 2019-nCoV patient with the onset of simple dizziness, accompanied by dry throat, no fever, no cough, no headache, no mental abnormality, and no obvious abnormality in the nuclear magnetic resonance imaging (MRI) of the head. Meanwhile, chest computed tomography (CT) scans showed multiple small spot shadows and interstitial changes in the early stage, especially in the extrapulmonary zone. There was a development of multiple ground-glass shadows and infiltrative shadows in both lungs with mild pleural effusion. The nucleic acid gene detection was positive, and thus the diagnosis of 2019-nCoV was confirmed. At last, the prognosis was good after active treatment. After antiviral and anti-infective treatment, the symptoms recovered. We presume that 2019-nCoV can also manifest in the nervous system alone, and lung CT, which has relative specificity, should be used as a routine screening method.

Early Transmission Dynamics in Wuhan, China, of Novel Coronavirus-Infected Pneumonia

BACKGROUND

The initial cases of novel coronavirus (2019-nCoV)-infected pneumonia (NCIP) occurred in Wuhan, Hubei Province, China, in December 2019 and January 2020. We analyzed data on the first 425 confirmed cases in Wuhan to determine the epidemiologic characteristics of NCIP.

METHODS

We collected information on demographic characteristics, exposure history, and illness timelines of laboratory-confirmed cases of NCIP that had been reported by January 22, 2020. We described characteristics of the cases and estimated the key epidemiologic time-delay distributions. In the early period of exponential growth, we estimated the epidemic doubling time and the basic reproductive number.

RESULTS

Among the first 425 patients with confirmed NCIP, the median age was 59 years and 56% were male. The majority of cases (55%) with onset before January 1, 2020, were linked to the Huanan Seafood Wholesale Market, as compared with 8.6% of the subsequent cases. The mean incubation period was 5.2 days (95% confidence interval [CI], 4.1 to 7.0), with the 95th percentile of the distribution at 12.5 days. In its early stages, the epidemic doubled in size every 7.4 days. With a mean serial interval of 7.5 days (95% CI, 5.3 to 19), the basic reproductive number was estimated to be 2.2 (95% CI, 1.4 to 3.9).

CONCLUSIONS

On the basis of this information, there is evidence that human-to-human transmission has occurred among close contacts since the middle of December 2019. Considerable efforts to reduce transmission will be required to control outbreaks if similar dynamics apply elsewhere. Measures to prevent or reduce transmission should be implemented in populations at risk. (Funded by the Ministry of Science and Technology of China and others.).

Evolutionary Trajectory for the Emergence of Novel Coronavirus SARS-CoV-2

Over the last two decades, the world experienced three outbreaks of coronaviruses with elevated morbidity rates. Currently, the global community is facing emerging virus SARS-CoV-2 belonging to Betacoronavirus, which appears to be more transmissible but less deadly than SARS-CoV. The current study aimed to track the evolutionary ancestors and different evolutionary strategies that were genetically adapted by SARS-CoV-2. Our whole-genome analysis revealed that SARS-CoV-2 was the descendant of Bat SARS/SARS-like CoVs and bats served as a natural reservoir. SARS-CoV-2 used mutations and recombination as crucial strategies in different genomic regions including the envelop, membrane, nucleocapsid, and spike glycoproteins to become a novel infectious agent. We confirmed that mutations in different genomic regions of SARS-CoV-2 have specific influence on virus reproductive adaptability, allowing for genotype adjustment and adaptations in rapidly changing environments. Moreover, for the first time we identified nine putative recombination patterns in SARS-CoV-2, which encompass spike glycoprotein, RdRp, helicase and ORF3a. Six recombination regions were spotted in the S gene and are undoubtedly important for evolutionary survival, meanwhile this permitted the virus to modify superficial antigenicity to find a way from immune reconnaissance in animals and adapt to a human host. With these combined natural selected strategies, SARS-CoV-2 emerged as a novel virus in human society.

Topological dynamics of the 2015 South Korea MERS-CoV spread-on-contact networks

Network analysis to examine infectious contact relations provides an important means to uncover the topologies of individual infectious contact networks. This study aims to investigate the spread of diseases among individuals over contact networks by exploring the 2015 Middle East Respiratory Syndrome (MERS) outbreak in Korea. We present several distinct features of MERS transmission by employing a comprehensive approach in network research to examine both the traced relationship matrix of infected individuals and their bipartite transmission routes among healthcare facilities visited for treatment. The results indicate that a few super-spreaders were more likely to hold certain structural advantages by linking to an exceptional number of other individuals, causing several ongoing transmission events in neighbourhoods without the aid of any intermediary. Thus, the infectious contact network exhibited small-world dynamics characterised by locally clustered contacts exposed to transmission paths via short path lengths. In addition, nosocomial infection analysis shows the pattern of a common-source outbreak followed by secondary person-to-person transmission of the disease. Based on the results, we suggest policy implications related to the redesign of prevention and control strategies against the spread of epidemics.

Understanding of COVID-19 based on current evidence

Since December 2019, a series of unexplained pneumonia cases have been reported in Wuhan, China. On 12 January 2020, the World Health Organization (WHO) temporarily named this new virus as the 2019 novel coronavirus (2019‐nCoV). On 11 February 2020, the WHO officially named the disease caused by the 2019‐nCoV as coronavirus disease (COVID‐19). The COVID‐19 epidemic is spreading all over the world, especially in China. Based on the published evidence, we systematically discuss the characteristics of COVID‐19 in the hope of providing a reference for future studies and help for the prevention and control of the COVID‐19 epidemic.

Currently, the world is watching the progress of Corona Virus Disease 2019 (COVID‐19) epidemic. The purpose of our article is to give people a comprehensive understanding of COVID‐19, so that they can better prevent it. We review the latest published papers on COVID‐19. In this paper, the origin of the virus, the mechanism of virus infection, the clinical characteristics of COVID‐19 and the treatment and prevention of COVID‐19 are comprehensively elaborated. We hope this article will help for the prevention and control of the COVID‐19 epidemic.

A Novel Coronavirus from Patients with Pneumonia in China, 2019

In December 2019, a cluster of patients with pneumonia of unknown cause was linked to a seafood wholesale market in Wuhan, China. A previously unknown betacoronavirus was discovered through the use of unbiased sequencing in samples from patients with pneumonia. Human airway epithelial cells were used to isolate a novel coronavirus, named 2019-nCoV, which formed a clade within the subgenus sarbecovirus, Orthocoronavirinae subfamily. Different from both MERS-CoV and SARS-CoV, 2019-nCoV is the seventh member of the family of coronaviruses that infect humans. Enhanced surveillance and further investigation are ongoing. (Funded by the National Key Research and Development Program of China and the National Major Project for Control and Prevention of Infectious Disease in China.).

2019 novel coronavirus of pneumonia in Wuhan, China: emerging attack and management strategies

An ongoing outbreak of 2019-nCoV pneumonia was first identified in Wuhan, Hubei province, China at the end of 2019. With the spread of the new coronavirus accelerating, person-to-person transmission in family homes or hospitals, and intercity spread of 2019-nCoV occurred. At least 40,261 cases confirmed, 23,589 cases suspected, 909 cases death and 3444 cases cured in China and worldwide 24 countries confirmed 383 cases being diagnosed, 1 case death in February 10th, 2020. At present, the mortality of 2019-nCoV in China is 2.3%, compared with 9.6% of SARS and 34.4% of MERS reported by WHO. It seems the new virus is not as fatal as many people thought. Chinese authorities improved surveillance network, made the laboratory be able to recognize the outbreak within a few weeks and announced the virus genome that provide efficient epidemiological control. More comprehensive information is required to understand 2019-nCoV feature, the epidemiology of origin and spreading, and the clinical phenomina. According to the current status, blocking transmission, isolation, protection, and alternative medication are the urgent management strategies against 2019-nCoV.

Real-time tentative assessment of the epidemiological characteristics of novel coronavirus infections in Wuhan, China, as at 22 January 2020

A novel coronavirus (2019-nCoV) causing severe acute respiratory disease emerged recently in Wuhan, China. Information on reported cases strongly indicates human-to-human spread, and the most recent information is increasingly indicative of sustained human-to-human transmission. While the overall severity profile among cases may change as more mild cases are identified, we estimate a risk of fatality among hospitalised cases at 14% (95% confidence interval: 3.9-32%).

Return of the Coronavirus: 2019-nCoV

The emergence of a novel coronavirus (2019-nCoV) has awakened the echoes of SARS-CoV from nearly two decades ago. Yet, with technological advances and important lessons gained from previous outbreaks, perhaps the world is better equipped to deal with the most recent emergent group 2B coronavirus.

The use of nebulized pharmacotherapies during the COVID-19 pandemic

Coronavirus disease 2019 (COVID-19), caused by the highly contagious novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has resulted in a worldwide pandemic and currently represents a major public health issue. COVID-19 has highlighted the need for clear and accurate guidance on the use of aerosol-generating procedures, such as nebulization, for the treatment of patients with respiratory diseases with or without COVID-19. Despite the lack of evidence, there is heightened concern about the potential risk of transmission of SARS-CoV-2 in the form of aerosolized respiratory droplets during the nebulized treatment of patients with COVID-19. Consequently, the use of metered-dose inhalers (MDIs) has risen considerably as an alternative to nebulized therapy, which has led to inadequate supplies of MDIs in some parts of the United States. In this article, we review and discuss the role of nebulization in patients with SARS-CoV-2 and the treatment of noninfected patients with chronic respiratory diseases. The following two important questions are addressed: (1) should nebulized therapy be used in hospital or home settings by patients infected with SARS-CoV-2; and (2) should nebulized therapy be continued in patients already using it for chronic respiratory disease management in hospital or home settings?The reviews of this paper are available via the supplemental material section.

An Epidemiological Framework for Investigating Organized Crime and Terrorist Networks

In the last two decades, organized crime and terrorism has grown more complex, posing evolving challenges to law enforcement nationally, regionally and globally. Within the US ‘…there is a transformation in how criminals are using technology to invent new types of crime, and are creating new methods for committing traditional crimes’ (Wexler C. Critical issues in policing series new national commitment required: The changing nature of crime and criminal investigations police executive research forum, Washington, D.C. 20036 retrieved from https://www.policeforum.org/assets/ChangingNatureofCrime.pdf: 2018). In addition, criminals and terrorists have adopted more agile structural models and internationalized their operations. The UK regards organized crime as a threat to national security which costs the UK at least £32 billion each year, leads to loss of life, and can deprive people of their security and prosperity (https://www.gov.uk/government/publications/official-development-assistance-oda-fco-programme-spend-objectives-2017-to-2018/combatting-serious-and-organised-crime-objectives-2017-to-2018).

Given this threat and risk landscape, it has been argued that the ‘…science of criminal investigations is changing rapidly, and many law enforcement agencies are not prepared for the changes that are taking place’ (Wexler C. Critical issues in policing series new national commitment required: The changing nature of crime and criminal investigations police executive research forum, Washington, D.C. 20036 retrieved from https://www.policeforum.org/assets/ChangingNatureofCrime.pdf: 2018). The inherent complexity associated with serious and organized crime and terrorism calls for intervention and investigative strategies and practices rooted in a science-informed, evidence-based approach. Epidemiology, the science of public health, provides a unique approach that can be leveraged and tailored to support policing operations. The systems lens is key to the application of epidemiological models, and hence the Cynefin framework is introduced to help frame the policing problem space in terms of complexity.

This paper presents a conceptual model that illustrates and operationalizes epidemiological practices to support policing operations.

Clinical outcomes among hospital patients with Middle East respiratory syndrome coronavirus (MERS-CoV) infection

Background

Mortality is high among patients with Middle East Respiratory Syndrome Coronavirus (MERS-CoV) infection. We aimed to determine hospital mortality and the factors associated with it in a cohort of MERS-CoV patients.

Methods

We reviewed hospital records of confirmed cases (detection of virus by polymerase chain reaction from respiratory tract samples) of MERS-CoV patients (n = 63) admitted to Buraidah Central Hospital in Al-Qassim, Saudi Arabia between 2014 and 2017. We abstracted data on demography, vital signs, associated conditions presented on admission, pre-existing chronic diseases, treatment, and vital status. Bi-variate comparisons and multiple logistic regressions were the choice of data analyses.

Results

The mean age was 60 years (SD = 18.2); most patients were male (74.6%) and Saudi citizens (81%). All but two patients were treated with Ribavirin plus Interferon. Hospital mortality was 25.4%. Patients who were admitted with septic shock and/or organ failure were significantly more likely to die than patients who were admitted with pneumonia and/or acute respiratory distress syndrome (OR = 47.9, 95% CI = 3.9, 585.5, p-value 0.002). Age, sex, and presence of chronic conditions were not significantly associated with mortality.

Conclusion

Hospital mortality was 25%; septic shock/organ failure at admittance was a significant predictor of mortality.

Evaluating the potential impact of targeted vaccination strategies against severe acute respiratory syndrome coronavirus (SARS-CoV) and Middle East respiratory syndrome coronavirus (MERS-CoV) outbreaks in the healthcare setting

Background

Severe Acute Respiratory Syndrome (SARS) and Middle East Respiratory Syndrome (MERS) are two coronaviruses with demonstrated potential to generate significant nosocomial outbreaks. In particular, MERS continues to pose a significant threat in the Middle East since 2012. Currently, no licensed vaccine or drug treatment is available to treat patients infected with either coronavirus. However, there are some MERS vaccines in the preclinical stage of development. We sought to evaluate the potential impact of targeted vaccination strategies for mitigating SARS and MERS outbreaks in healthcare settings using simple mathematical models and detailed historic transmission trees describing the progression of past nosocomial outbreaks of SARS and MERS.

Results

Our findings suggest that vaccination strategies targeting patients and healthcare workers, which have been disproportionately affected during past outbreaks, and assuming two vaccination coverage levels at 50 and 75% have the potential to avert nearly 50% or more of MERS or SARS cases.

Conclusion

Our modeling results informed by historic outbreak data for SARS and MERS suggest that vaccination strategies targeting patients could be an effective measure to mitigate and prevent outbreaks in the healthcare setting.

Electronic supplementary material

The online version of this article (10.1186/s12976-019-0112-6) contains supplementary material, which is available to authorized users.

Application of Chinese Medicine in Acute and Critical Medical Conditions

Western medicine is routinely used in developed nations as well as in Eastern countries, where traditional medicine is frequently used by a selection of patients or family member as a complement to mainstream Western medicine. Chinese medicine plays an important role in the treatment of chronic diseases, especially when Western medicine is not very effective. Many published reports have shown that Chinese medicine could also be successfully used in the management of acute and critical illnesses. Chinese medicine has a holistic view of the human body, and emphasizes individualization based on body balance and mind-body interaction and employs herbal medicines and acupuncture. This review paper gives a brief overview of Chinese medicine theory and therapeutic modality and then addresses the application of Chinese medicine in the treatment of acute and critical medical conditions, including epidemics. Using this ancient therapy as a complementary medicine, the management of serious medical conditions, such as SARS, acute heart diseases, and ischemic cerebral stroke, are presented. In order to promote more widespread application of Chinese medicine, well-designed controlled clinical trials are urgently needed to prove its safety and effectiveness.

A point mutation to the long terminal repeat of bovine leukemia virus related to viral productivity and transmissibility

It is important to establish the molecular basis of the high transmissibility of bovine leukemia virus (BLV) to develop new methods of preventing viral transmission. Hence, the aim of this study was to determine whether some strains had transmission advantages. First, we determined the whole BLV genome sequences of all 34 BLV-infected cows from one farm. Phylogenetic analysis divided strains into 26 major and 8 minor strains. The major strains dominantly spread independent of host factor, bovine leucocyte antigen. Further analysis, with molecular clones, associated transmissibility with viral productivity in vitro. In addition, the two groups could be classified by group-specific mutations. The reverse genetic approach demonstrated that a spontaneous mutation at nucleotide 175 of the BLV genome, which is located in the viral promoter region, could alter viral productivity by changing viral transactivation, suggesting that BLV transmissibility is affected by a spontaneous mutation associated with viral productivity.

Onward transmission of viruses: how do viruses emerge to cause epidemics after spillover?

The critical step in the emergence of a new epidemic or pandemic viral pathogen occurs after it infects the initial spillover host and then is successfully transmitted onwards, causing an outbreak chain of transmission within that new host population. Crossing these choke points sets a pathogen on the pathway to epidemic emergence. While many viruses spill over to infect new or alternative hosts, only a few accomplish this transition—and the reasons for the success of those pathogens are still unclear. Here, we consider this issue related to the emergence of animal viruses, where factors involved likely include the ability to efficiently infect the new animal host, the demographic features of the initial population that favour onward transmission, the level of shedding and degree of susceptibility of individuals of that population, along with pathogen evolution favouring increased replication and more efficient transmission among the new host individuals. A related form of emergence involves mutations that increased spread or virulence of an already-known virus within its usual host. In all of these cases, emergence may be due to altered viral properties, changes in the size or structure of the host populations, ease of transport, climate change or, in the case of arboviruses, to the expansion of the arthropod vectors. Here, we focus on three examples of viruses that have gained efficient onward transmission after spillover: influenza A viruses that are respiratory transmitted, HIV, a retrovirus, that is mostly blood or mucosal transmitted, and canine parvovirus that is faecal:oral transmitted. We describe our current understanding of the changes in the viruses that allowed them to overcome the barriers that prevented efficient replication and spread in their new hosts. We also briefly outline how we could gain a better understanding of the mechanisms and variability in order to better anticipate these events in the future.

This article is part of the theme issue ‘Dynamic and integrative approaches to understanding pathogen spillover’.

Networks of face-to-face social contacts in Niakhar, Senegal

We present the first analysis of face-to-face contact network data from Niakhar, Senegal. Participants in a cluster-randomized influenza vaccine trial were interviewed about their contact patterns when they reported symptoms during their weekly household surveillance visit. We employ a negative binomial model to estimate effects of covariates on contact degree. We estimate the mean contact degree for asymptomatic Niakhar residents to be 16.5 (95% C.I. 14.3, 18.7) in the morning and 14.8 in the afternoon (95% C.I. 12.7, 16.9). We estimate that symptomatic people make 10% fewer contacts than asymptomatic people (95% C.I. 5%, 16%; p = 0.006), and those aged 0-5 make 33% fewer contacts than adults (95% C.I. 29%, 37%; p < 0.001). By explicitly modelling the partial rounding pattern observed in our data, we make inference for both the underlying (true) distribution of contacts as well as for the reported distribution. We created an estimator for homophily by compound (household) membership and estimate that 48% of contacts by symptomatic people are made to their own compound members in the morning (95% CI, 45%, 52%) and 60% in the afternoon/evening (95% CI, 56%, 64%). We did not find a significant effect of symptom status on compound homophily. We compare our findings to those from other countries and make design recommendations for future surveys.

Sequential Emergence and Wide Spread of Neutralization Escape Middle East Respiratory Syndrome Coronavirus Mutants, South Korea, 2015

The unexpectedly large outbreak of Middle East respiratory syndrome in South Korea in 2015 was initiated by an infected traveler and amplified by several “superspreading” events. Previously, we reported the emergence and spread of mutant Middle East respiratory syndrome coronavirus bearing spike mutations (I529T or D510G) with reduced affinity to human receptor CD26 during the outbreak. To assess the potential association of spike mutations with superspreading events, we collected virus genetic information reported during the outbreak and systemically analyzed the relationship of spike sequences and epidemiology. We found sequential emergence of the spike mutations in 2 superspreaders. In vivo virulence of the mutant viruses seems to decline in human patients, as assessed by fever duration in affected persons. In addition, neutralizing activity against these 2 mutant viruses in serum samples from mice immunized with wild-type spike antigen were gradually reduced, suggesting emergence and wide spread of neutralization escapers during the outbreak.

Enhancing genetic disease control by selecting for lower host infectivity and susceptibility

Infectious diseases have a huge impact on animal health, production and welfare, and human health. Understanding the role of host genetics in disease spread is important for developing disease control strategies that efficiently reduce infection incidence and risk of epidemics. While heritable variation in disease susceptibility has been targeted in livestock breeding, emerging evidence suggests that there is additional genetic variation in host infectivity, but the potential benefits of including infectivity into selection schemes are currently unknown. A Susceptible-Infected-Recovered epidemiological model incorporating polygenic genetic variation in both susceptibility and infectivity was combined with quantitative genetics selection theory to assess the non-linear impact of genetic selection on field measures of epidemic risk and severity. Response to 20 generations of selection was calculated in large simulated populations, exploring schemes differing in accuracy and intensity. Assuming moderate genetic variation in both traits, 50% selection on susceptibility required seven generations to reduce the basic reproductive number R₀ from 7.64 to the critical threshold of <1, below which epidemics die out. Adding infectivity in the selection objective accelerated the decline towards R₀ < 1, to 3 generations. Our results show that although genetic selection on susceptibility reduces disease risk and prevalence, the additional gain from selection on infectivity accelerates disease eradication and reduces more efficiently the risk of new outbreaks, while it alleviates delays generated by unfavourable correlations. In conclusion, host infectivity was found to be an important trait to target in future genetic studies and breeding schemes, to help reducing the occurrence and impact of epidemics.

Genetic differences in host infectivity affect disease spread and survival in epidemics

Survival during an epidemic is partly determined by host genetics. While quantitative genetic studies typically consider survival as an indicator for disease resistance (an individual's propensity to avoid becoming infected or diseased), mortality rates of populations undergoing an epidemic are also affected by endurance (the propensity of diseased individual to survive the infection) and infectivity (i.e. the propensity of an infected individual to transmit disease). Few studies have demonstrated genetic variation in disease endurance, and no study has demonstrated genetic variation in host infectivity, despite strong evidence for considerable phenotypic variation in this trait. Here we propose an experimental design and statistical models for estimating genetic diversity in all three host traits. Using an infection model in fish we provide, for the first time, direct evidence for genetic variation in host infectivity, in addition to variation in resistance and endurance. We also demonstrate how genetic differences in these three traits contribute to survival. Our results imply that animals can evolve different disease response types affecting epidemic survival rates, with important implications for understanding and controlling epidemics.

Health screening strategies for international air travelers during an epidemic or pandemic

Air travelers can carry an infectious disease's pathogenic microorganism in their bodies and spread the disease from one country to another in a few days. To delay the spread, health screening stations may be set up at airport terminals to screen travelers. This research tested three different health screening strategies, each with a different combination of screening stations at trip origins, destinations and connecting airports. Discrete event simulations were performed, based on the 2014 to 2016 Ebola virus epidemic, with special focus on travelers from the West African countries traveling to the United States, including travelers who transferred flights at airports in European Union member states. The effectiveness of the screening strategies was analyzed in terms of correct detection, missed detection and false alarm rate. The results showed that exit screening at trip origins brought big improvements in the performance measurements compared to no screening. However, additional screening at the destinations and connecting airports contributed marginal benefits.

Aerosol emission and superemission during human speech increase with voice loudness

Mechanistic hypotheses about airborne infectious disease transmission have traditionally emphasized the role of coughing and sneezing, which are dramatic expiratory events that yield both easily visible droplets and large quantities of particles too small to see by eye. Nonetheless, it has long been known that normal speech also yields large quantities of particles that are too small to see by eye, but are large enough to carry a variety of communicable respiratory pathogens. Here we show that the rate of particle emission during normal human speech is positively correlated with the loudness (amplitude) of vocalization, ranging from approximately 1 to 50 particles per second (0.06 to 3 particles per cm3) for low to high amplitudes, regardless of the language spoken (English, Spanish, Mandarin, or Arabic). Furthermore, a small fraction of individuals behaves as "speech superemitters," consistently releasing an order of magnitude more particles than their peers. Our data demonstrate that the phenomenon of speech superemission cannot be fully explained either by the phonic structures or the amplitude of the speech. These results suggest that other unknown physiological factors, varying dramatically among individuals, could affect the probability of respiratory infectious disease transmission, and also help explain the existence of superspreaders who are disproportionately responsible for outbreaks of airborne infectious disease.

An updated roadmap for MERS-CoV research and product development: focus on diagnostics

Diagnostics play a central role in the early detection and control of outbreaks and can enable a more nuanced understanding of the disease kinetics and risk factors for the Middle East respiratory syndrome-coronavirus (MERS-CoV), one of the high-priority pathogens identified by the WHO. In this review we identified sources for molecular and serological diagnostic tests used in MERS-CoV detection, case management and outbreak investigations, as well as surveillance for humans and animals (camels), and summarised the performance of currently available tests, diagnostic needs, and associated challenges for diagnostic test development and implementation. A more detailed understanding of the kinetics of infection of MERS-CoV is needed in order to optimise the use of existing assays. Notably, MERS-CoV point-of-care tests are needed in order to optimise supportive care and to minimise transmission risk. However, for new test development, sourcing clinical material continues to be a major challenge to achieving assay validation. Harmonisation and standardisation of laboratory methods are essential for surveillance and for a rapid and effective international response to emerging diseases. Routine external quality assessment, along with well-characterised and up-to-date proficiency panels, would provide insight into MERS-CoV diagnostic performance worldwide. A defined set of Target Product Profiles for diagnostic technologies will be developed by WHO to address these gaps in MERS-CoV outbreak management.

Assessment of the health status and health service perceptions of international migrants coming to Guangzhou, China, from high-, middle- and low-income countries

BACKGROUND

China, which used to be an export country for migrants, has become a new destination for international migrants due to its rapid economic growth. However, little empirical data is available on the health status of and health service access barriers faced by these international migrants.

METHODS

Foreigners who visited the Guangzhou Municipal Exit-Entry Administration Office to extend their visas were invited to participate in the study. Quantitative data were collected using electronic questionnaire in 13 languages. The participants were characterised by the income level of their country of origin (high-, middle- and low-income countries (HICs, MICs and LICs, respectively)), and the key factors associated with their health status, medical insurance coverage and perceptions of health services in China were examined.

RESULTS

Overall, 1146 participants from 119 countries participated in the study, 57.1, 25.1 and 17.8% of whom were from MICs, HICs and LICs, respectively. Over one fifth of the participants experienced health problems while staying in China, and about half had no health insurance. Although the participants from HICs were more likely than those from MICs and LICs to have medical insurance, they were also more likely to have health problems. Furthermore, 43.0, 45.0 and 12.0% of the participants thought that the health services in China were good, fair and poor, respectively. Among the participants, those from HICs were less likely to have positive feedback.

CONCLUSIONS

Our study is the first to report a quantitative survey of the health status, health insurance coverage, and health service perceptions of a diverse and surging population of international migrants in China. The findings call for more in-depth studies on the challenges presented by the increasing global migration to the health system.

Airflow as a Possible Transmission Route of Middle East Respiratory Syndrome at an Initial Outbreak Hospital in Korea

In this study, the results of an airflow investigation conducted on 7 June 2015 as part of a series of epidemiologic investigations at Pyeongtaek St. Mary's Hospital, South Korea, were investigated. The study involved 38 individuals who were infected directly and indirectly with Middle East Respiratory Syndrome (MERS), by a super-spreader patient. Tracer gas experiments conducted on the eighth floor, where the initial patient was hospitalized, confirmed that the tracer gas spread to adjacent patient rooms and rooms across corridors. In particular, the experiment with an external wind direction and speed similar to those during the hospitalization of the initial patient revealed that the air change rate was 17⁻20 air changes per hour (ACH), with air introduced through the window in the room of the infected patient (room 8104). The tracer gas concentration of room 8110, which was the farthest room, was 7.56% of room 8104, indicating that a high concentration of gas has spread from room 8104 to rooms across the corridor. In contrast, the tracer gas was barely detected in a maternity ward to the south of room 8104, where there was no secondary infected patient. Moreover, MERS is known to spread mainly by droplets through close contact, but long-distance dispersion is probable in certain environments, such as that of a super-spreader patient hospitalized in a room without ventilation, hospitals with a central corridor type, and indoor airflow dispersion due to external wind.

MERS: Progress on the global response, remaining challenges and the way forward

This article summarizes progress in research on Middle East Respiratory Syndrome (MERS) since a FAO-OIE-WHO Global Technical Meeting held at WHO Headquarters in Geneva on 25-27 September 2017. The meeting reviewed the latest scientific findings and identified and prioritized the global activities necessary to prevent, manage and control the disease. Critical needs for research and technical guidance identified during the meeting have been used to update the WHO R&D MERS-CoV Roadmap for diagnostics, therapeutics and vaccines and a broader public health research agenda. Since the 2017 meeting, progress has been made on several key actions in animal populations, at the animal/human interface and in human populations. This report also summarizes the latest scientific studies on MERS since 2017, including data from more than 50 research studies examining the presence of MERS-CoV infection in dromedary camels.

Stochastic two-group models with transmission dependent on host infectivity or susceptibility

Stochastic epidemic models with two groups are formulated and applied to emerging and re-emerging infectious diseases. In recent emerging diseases, disease spread has been attributed to superspreaders, highly infectious individuals that infect a large number of susceptible individuals. In some re-emerging infectious diseases, disease spread is attributed to waning immunity in susceptible hosts. We apply a continuous-time Markov chain (CTMC) model to study disease emergence or re-emergence from different groups, where the transmission rates depend on either the infectious host or the susceptible host. Multitype branching processes approximate the dynamics of the CTMC model near the disease-free equilibrium and are used to estimate the probability of a minor or a major epidemic. It is shown that the probability of a major epidemic is greater if initiated by an individual from the superspreader group or by an individual from the highly susceptible group. The models are applied to Severe Acute Respiratory Syndrome and measles.

Unusual presentation of Middle East respiratory syndrome coronavirus leading to a large outbreak in Riyadh during 2017

Background

The hallmark of Middle East respiratory syndrome coronavirus (MERS-CoV) disease is the ability to cause major health care-associated nosocomial outbreaks with superspreading events leading to massive numbers of cases and excessive morbidity and mortality. In this report, we describe a patient who presented with acute renal failure requiring hemodialysis and became a MERS-CoV superspreader, igniting a recent multihospital outbreak in Riyadh.

Material and Results

Between May 31 and June 15, 2017, 44 cases of MERS-CoV infection were reported from 3 simultaneous clusters from 3 health care facilities in Riyadh, Saudi Arabia, including 11 fatal cases. Out of the total reported cases, 29 cases were reported from King Saud Medical City. The cluster at King Saud Medical City was ignited by a single superspreader patient who presented with acute renal failure. After 14 hours in the open area of the emergency department and 2 hemodialysis sessions he was diagnosed with MERS-CoV. One hundred twenty contacts who had direct unprotected exposure were screened. Among those contacts, 9 out of 107 health care workers (5 nurses, 3 physicians, and 1 paramedic) and 7 out of 13 patients tested positive for MERS-CoV.

Conclusions

This hospital outbreak demonstrated the difficulties in diagnosing pneumonia in patients with renal and cardiac failure, which leads to delayed suspicion of MERS-CoV and hence delay in applying the proper infection control procedures. In MERS-CoV endemic countries there is an urgent need for developing rapid point-of-care testing that would assist emergency department staff in triaging suspected cases of MERS-CoV to ensure timely isolation and management of their primary illness and prevent major MERS-CoV outbreaks.

Preparedness and response against diseases with epidemic potential in the European Union: a qualitative case study of Middle East Respiratory Syndrome (MERS) and poliomyelitis in five member states

Background

EU Decision 1082/2013/EU on serious cross-border health threats provides a legal basis for collaboration between EU Member States, and between international and European level institutions on preparedness, prevention, and mitigation in the event of a public health emergency. The Decision provides a context for the present study, which aims to identify good practices and lessons learned in preparedness and response to Middle East Respiratory Syndrome (MERS) (in UK, Greece, and Spain) and poliomyelitis (in Poland and Cyprus).

Methods

Based on a documentary review, followed by five week-long country visits involving a total of 61 interviews and group discussions with experts from both the health and non-health sectors, this qualitative case study has investigated six issues related to preparedness and response to MERS and poliomyelitis: national plans and overall preparedness capacity; training and exercises; risk communication; linking policy and implementation; interoperability between the health and non-health sectors; and cross-border collaboration.

Results

Preparedness and response plans for MERS and poliomyelitis were in place in the participating countries, with a high level of technical expertise available to implement them. Nevertheless, formal evaluation of the responses to previous public health emergencies have sometimes been limited, so lessons learned may not be reflected in updated plans, thereby risking mistakes being repeated in future. The nature and extent of inter-sectoral collaboration varied according to the sectors involved, with those sectors that have traditionally had good collaboration (e.g. animal health and food safety), as well as those that have a financial incentive for controlling infectious diseases (e.g. agriculture, tourism, and air travel) seen as most likely to have integrated public health preparedness and response plans. Although the formal protocols for inter-sectoral collaboration were not always up to date, good personal relations were reported within the relevant professional networks, which could be brought into play in the event of a public health emergency. Cross-border collaboration was greatly facilitated if the neighbouring country was a fellow EU Member State.

Conclusions

Infectious disease outbreaks remain as an ongoing threat. Efforts are required to ensure that core public health capacities for the full range of preparedness and response activities are sustained.

Electronic supplementary material

The online version of this article (10.1186/s12913-018-3326-0) contains supplementary material, which is available to authorized users.

Network Analysis of MERS Coronavirus within Households, Communities, and Hospitals to Identify Most Centralized and Super-Spreading in the Arabian Peninsula, 2012 to 2016

Contact history is crucial during an infectious disease outbreak and vital when seeking to understand and predict the spread of infectious diseases in human populations. The transmission connectivity networks of people infected with highly contagious Middle East respiratory syndrome coronavirus (MERS-CoV) in Saudi Arabia were assessed to identify super-spreading events among the infected patients between 2012 and 2016. Of the 1379 MERS cases recorded during the study period, 321 (23.3%) cases were linked to hospital infection, out of which 203 (14.7%) cases occurred among healthcare workers. There were 1113 isolated cases while the number of recorded contacts per MERS patient is between 1 (n=210) and 17 (n=1), with a mean of 0.27 (SD = 0.76). Five super-important nodes were identified based on their high number of connected contacts worthy of prioritization (at least degree of 5). The number of secondary cases in each SSE varies (range, 5–17). The eigenvector centrality was significantly (p < 0.05) associated with place of exposure, with hospitals having on average significantly higher eigenvector centrality than other places of exposure. Results suggested that being a healthcare worker has a higher eigenvector centrality score on average than being nonhealthcare workers. Pathogenic droplets are easily transmitted within a confined area of hospitals; therefore, control measures should be put in place to curtail the number of hospital visitors and movements of nonessential staff within the healthcare facility with MERS cases.

MERS transmission and risk factors: a systematic review

Background

Since Middle East respiratory syndrome (MERS) infection was first reported in 2012, many studies have analysed its transmissibility and severity. However, the methodology and results of these studies have varied, and there has been no systematic review of MERS. This study reviews the characteristics and associated risk factors of MERS.

Method

We searched international (PubMed, ScienceDirect, Cochrane) and Korean databases (DBpia, KISS) for English- or Korean-language articles using the terms “MERS” and “Middle East respiratory syndrome”. Only human studies with > 20 participants were analysed to exclude studies with low representation. Epidemiologic studies with information on transmissibility and severity of MERS as well as studies containing MERS risk factors were included.

Result

A total of 59 studies were included. Most studies from Saudi Arabia reported higher mortality (22–69.2%) than those from South Korea (20.4%). While the R₀ value in Saudi Arabia was < 1 in all but one study, in South Korea, the R₀ value was 2.5–8.09 in the early stage and decreased to < 1 in the later stage. The incubation period was 4.5–5.2 days in Saudi Arabia and 6–7.8 days in South Korea. Duration from onset was 4–10 days to confirmation, 2.9–5.3 days to hospitalization, 11–17 days to death, and 14–20 days to discharge. Older age and concomitant disease were the most common factors related to MERS infection, severity, and mortality.

Conclusion

The transmissibility and severity of MERS differed by outbreak region and patient characteristics. Further studies assessing the risk of MERS should consider these factors.

MERS transmission and risk factors: a systematic review

BACKGROUND

Since Middle East respiratory syndrome (MERS) infection was first reported in 2012, many studies have analysed its transmissibility and severity. However, the methodology and results of these studies have varied, and there has been no systematic review of MERS. This study reviews the characteristics and associated risk factors of MERS.

METHOD

We searched international (PubMed, ScienceDirect, Cochrane) and Korean databases (DBpia, KISS) for English- or Korean-language articles using the terms "MERS" and "Middle East respiratory syndrome". Only human studies with > 20 participants were analysed to exclude studies with low representation. Epidemiologic studies with information on transmissibility and severity of MERS as well as studies containing MERS risk factors were included.

RESULT

A total of 59 studies were included. Most studies from Saudi Arabia reported higher mortality (22-69.2%) than those from South Korea (20.4%). While the R₀ value in Saudi Arabia was < 1 in all but one study, in South Korea, the R₀ value was 2.5-8.09 in the early stage and decreased to < 1 in the later stage. The incubation period was 4.5-5.2 days in Saudi Arabia and 6-7.8 days in South Korea. Duration from onset was 4-10 days to confirmation, 2.9-5.3 days to hospitalization, 11-17 days to death, and 14-20 days to discharge. Older age and concomitant disease were the most common factors related to MERS infection, severity, and mortality.

CONCLUSION

The transmissibility and severity of MERS differed by outbreak region and patient characteristics. Further studies assessing the risk of MERS should consider these factors.

Transmission routes of respiratory viruses among humans

Respiratory tract infections can be caused by a wide variety of viruses. Airborne transmission via droplets and aerosols enables some of these viruses to spread efficiently among humans, causing outbreaks that are difficult to control. Many outbreaks have been investigated retrospectively to study the possible routes of inter-human virus transmission. The results of these studies are often inconclusive and at the same time data from controlled experiments is sparse. Therefore, fundamental knowledge on transmission routes that could be used to improve intervention strategies is still missing. We here present an overview of the available data from experimental and observational studies on the transmission routes of respiratory viruses between humans, identify knowledge gaps, and discuss how the available knowledge is currently implemented in isolation guidelines in health care settings.

A study of the probable transmission routes of MERS-CoV during the first hospital outbreak in the Republic of Korea

Infections caused by the Middle East respiratory syndrome coronavirus (MERS-CoV) are a serious health issue due to their prevalence and associated mortality. However, the transmission routes of the virus remain unclear, and thus, the current recommended control strategies are not evidence based. In this study, we investigated the transmission routes of MERS-CoV during the first nosocomial outbreak in the Republic of Korea in May 2015 using a multi-agent modeling framework. We identified seven hypothesized transmission modes based on the three main transmission routes (long-range airborne, close contact, and fomite). The infection risks for each hypothesis were estimated using the multi-agent modeling framework. Least-squares fitting was conducted to compare the distribution of the predicted infection risk in the various scenarios with that of the reported attack rates and to identify the hypotheses with the best fit. In the scenarios in which the index patient was a super-spreader, our model simulations suggested that MERS-CoV probably spread via the long-range airborne route. However, it is possible that the index patient shed an average viral load comparable to the loads reported in the literature, and that transmission occurred via a combined long-range airborne and close contact route.

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.

Human T-cell immunity against the emerging and re-emerging viruses

Over the past decade, we have seen an alarming number of high-profile outbreaks of newly emerging and re-emerging viruses. Recent outbreaks of avian influenza viruses, Middle East respiratory syndrome coronaviruses, Zika virus and Ebola virus present great threats to global health. Considering the pivotal role of host T-cell immunity in the alleviation of symptoms and the clearance of viruses in patients, there are three issues to be primarily concerned about T-cell immunity when a new virus emerges: first, does the population possess pre-existing T-cells against the new virus through previous infections of genetically relevant viruses; second, does a proper immune response arise in the patients to provide protection through an immunopathogenic effect; lastly, how long can the virus-specific immune memory persist. Herein, we summarize the current updates on the characteristics of human T-cell immunological responses against recently emerged or re-emerged viruses, and emphasize the necessity for timely investigation on the T-cell features of these viral diseases, which may provide beneficial recommendations for clinical diagnosis and vaccine development.

Pathogen genomic surveillance elucidates the origins, transmission and evolution of emerging viral agents in China

In the past twenty years, numerous novel zoonotic viral agents with pandemic potential have emerged in China, such as the severe acute respiratory syndrome (SARS) coronavirus and, more recently, the avian-origin influenza A/H7N9 virus, which have caused outbreaks among humans with high morbidity and mortality. In addition, several emerging and re-emerging viral pathogens have also been imported into China from travelers, e.g. the Middle East respiratory syndrome (MERS) coronavirus and Zika virus (ZIKV). Herein, we review these emerging viral pathogens in China and focus on how surveillance by pathogen genomics has been employed to discover and annotate novel pathogenic agents, identify natural reservoirs, monitor the transmission events and delineate their evolution and adaption to the human host. We also highlight the application of genomic sequencing in the recent Ebola epidemics in Western Africa. In summary, genomic sequencing has become a standard research tool in the field of emerging infectious diseases which has been proven invaluable in containing these viral infections and reducing burden of disease in humans and animals. Genomic surveillance of pathogenic agents will serve as a key epidemiological and research tool in the modern era of precision infectious diseases and in the future studies of virosphere.

Newcastle disease virus-based MERS-CoV candidate vaccine elicits high-level and lasting neutralizing antibodies in Bactrian camels

Middle East respiratory syndrome coronavirus (MERS-CoV), a member of the Coronaviridae family, is the causative pathogen for MERS that is characterized by high fever, pneumonia, acute respiratory distress syndrome (ARDS), as well as extrapulmonary manifestations. Currently, there are no approved treatment regimens or vaccines for MERS. Here, we generated recombinant nonvirulent Newcastle disease virus (NDV) LaSota strain expressing MERS-CoV S protein (designated as rLa-MERS-S), and evaluated its immunogenicity in mice and Bactrian camels. The results revealed that rLa-MERS-S showed similar growth properties to those of LaSota in embryonated chicken eggs, while animal immunization studies showed that rLa-MERS-S induced MERS-CoV neutralizing antibodies in mice and camels. Our findings suggest that recombinant rLa-MERS-S may be a potential MERS-CoV veterinary vaccine candidate for camels and other animals affected by MERS.

Emerging Infections and Pertinent Infections Related to Travel for Patients with Primary Immunodeficiencies

In today's global economy and affordable vacation travel, it is increasingly important that visitors to another country and their physician be familiar with emerging infections, infections unique to a specific geographic region, and risks related to the process of travel. This is never more important than for patients with primary immunodeficiency disorders (PIDD). A recent review addressing common causes of fever in travelers provides important information for the general population Thwaites and Day (N Engl J Med 376:548-560, 2017). This review covers critical infectious and management concerns specifically related to travel for patients with PIDD. This review will discuss the context of the changing landscape of infections, highlight specific infections of concern, and profile distinct infection phenotypes in patients who are immune compromised. The organization of this review will address the environment driving emerging infections and several concerns unique to patients with PIDD. The first section addresses general considerations, the second section profiles specific infections organized according to mechanism of transmission, and the third section focuses on unique phenotypes and unique susceptibilities in patients with PIDDs. This review does not address most parasitic diseases. Reference tables provide easily accessible information on a broader range of infections than is described in the text.