Combining clinical and epidemiologic features for early recognition of SARS

Graph data science and machine learning for the detection of COVID-19 infection from symptoms

Background

COVID-19 is an infectious disease caused by SARS-CoV-2. The symptoms of COVID-19 vary from mild-to-moderate respiratory illnesses, and it sometimes requires urgent medication. Therefore, it is crucial to detect COVID-19 at an early stage through specific clinical tests, testing kits, and medical devices. However, these tests are not always available during the time of the pandemic. Therefore, this study developed an automatic, intelligent, rapid, and real-time diagnostic model for the early detection of COVID-19 based on its symptoms.

Methods

The COVID-19 knowledge graph (KG) constructed based on literature from heterogeneous data is imported to understand the COVID-19 different relations. We added human disease ontology to the COVID-19 KG and applied a node-embedding graph algorithm called fast random projection to extract an extra feature from the COVID-19 dataset. Subsequently, experiments were conducted using two machine learning (ML) pipelines to predict COVID-19 infection from its symptoms. Additionally, automatic tuning of the model hyperparameters was adopted.

Results

We compared two graph-based ML models, logistic regression (LR) and random forest (RF) models. The proposed graph-based RF model achieved a small error rate = 0.0064 and the best scores on all performance metrics, including specificity = 98.71%, accuracy = 99.36%, precision = 99.65%, recall = 99.53%, and F1-score = 99.59%. Furthermore, the Matthews correlation coefficient achieved by the RF model was higher than that of the LR model. Comparative analysis with other ML algorithms and with studies from the literature showed that the proposed RF model exhibited the best detection accuracy.

Conclusion

The graph-based RF model registered high performance in classifying the symptoms of COVID-19 infection, thereby indicating that the graph data science, in conjunction with ML techniques, helps improve performance and accelerate innovations.

Association Between Lung Ultrasound Patterns and Pneumonia

ABSTRACT

Pneumonia is a common respiratory infection that affects the lungs. Lung ultrasound (LUS) is a portable, cost-effective imaging method, which is free of ionizing radiation and has been shown to be useful for evaluating pneumonia. The aim of this retrospective analytical study was to determine the association between lung ultrasound patterns and pneumonia. For the purpose of performing the required analysis, LUS patterns including consolidations, pleural line irregularities, A lines and B lines from 90 subjects (44 patients with confirmed pneumonia and 46 controls) were retrieved from a published open-access data set, which was reviewed and approved by medical experts. A χ 2 test was used for the comparison of categorical variables to determine the association between each LUS pattern and the presence of pneumonia. There is a significant association between LUS consolidation and the presence of pneumonia ( P < 0.0001). Lung ultrasound A lines are significantly associated with the absence of pneumonia ( P < 0.0001), whereas there are no associations between B lines or pleural line irregularities with pneumonia. Lung ultrasound consolidation is found to be associated with the presence of pneumonia. A lines are associated with healthy lungs, and there is no association of B lines and pleural irregularities with the presence of pneumonia. Further studies investigating LUS patterns with clinical information and symptoms of patients with pneumonia are required.

Thromboprophylaxis and clinical outcomes in moderate COVID-19 patients: A comparative study

Background

Many thrombotic complications are linked to coronavirus disease 2019 (COVID-19). Antithrombotic treatments are important for prophylaxis against these thrombotic events.

Objectives

This study was designed to compare enoxaparin and rivaroxaban as prophylactic anticoagulants in moderate cases of COVID-19 in terms of efficacy, safety, and clinical outcomes.

Methods

The study involved 124 patients with moderate COVID-19 (pneumonia without hypoxia) divided into two groups. The first group (G1) comprised 66 patients who received enoxaparin subcutaneously at a dose of 0.5 mg/kg every 12 h until discharge from the hospital. The second group (G2) comprised 58 patients who received oral rivaroxaban at a dose of 10 mg once daily until discharge from the hospital. The outcomes evaluated in this study were as follows: intermediate care unit (IMCU) duration, the number of patients transferred from the IMCU to the intensive care unit (ICU), ICU duration, the total length of hospital stay, in-hospital mortality, and thrombotic and bleeding complications.

Results

No significant differences in IMCU duration (p = 0.39), ICU duration (p = 0.96), and total length of hospital stay (p = 0.73) were observed between the two groups. The percentage of patients requiring ICU admission after hospitalization was 21.2% in G1 and 22.4% in G2 (p = 0.87). The mortality rate was 12.1% in G1 and 10.3% in G2 (p = 0.76). The proportion of patients who had thrombotic complications was 9.1% in G1 and 12.1% in G2 (p = 0.59). The incidence of mild bleeding was 3% in G1 and 1.7% in G2 (p = 0.64).

Conclusion

Either enoxaparin or rivaroxaban may be used as thromboprophylaxis agents in managing patients with moderate COVID-19. Either medication has no clear advantage over the other.

Symptom-Based Predictive Model of COVID-19 Disease in Children

BACKGROUND

Testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is neither always accessible nor easy to perform in children. We aimed to propose a machine learning model to assess the need for a SARS-CoV-2 test in children (<16 years old), depending on their clinical symptoms.

METHODS

Epidemiological and clinical data were obtained from the REDCap® registry. Overall, 4434 SARS-CoV-2 tests were performed in symptomatic children between 1 November 2020 and 31 March 2021, 784 were positive (17.68%). We pre-processed the data to be suitable for a machine learning (ML) algorithm, balancing the positive-negative rate and preparing subsets of data by age. We trained several models and chose those with the best performance for each subset.

RESULTS

The use of ML demonstrated an AUROC of 0.65 to predict a COVID-19 diagnosis in children. The absence of high-grade fever was the major predictor of COVID-19 in younger children, whereas loss of taste or smell was the most determinant symptom in older children.

CONCLUSIONS

Although the accuracy of the models was lower than expected, they can be used to provide a diagnosis when epidemiological data on the risk of exposure to COVID-19 is unknown.

Comparison of Anxiety Levels in Patients with Coronavirus Disease (COVID-19) and their Families

Very little research has been done on the anxiety of the families of patients with covid-19. Considering the vital role of the family in the continuation of supportive-psychological therapies and the direct impact on the patient's anxiety level, in this study, we examined the anxiety level of the family of patients with Covid-19 and compared their with their patient's anxiety level. In this comparative study, the samples were 60 people who were given a definitive diagnosis of covid-19 in selected hospitals (Masih Daneshvari Hospital and Besat Hospital). From the family members, the person who, according to the patient, is most affected and has an emotional relationship with him (spouse-father-mother-child) was selected. The standard Spielberger Anxiety Questionnaire has been used to measure apparent (state) and hidden (trait) anxiety. The questionnaire was completed by both groups (patient-family) and compared with each other. The mean of evident anxiety in patients and caregivers was 70.82 and 74.2, respectively, which this difference was statistically significant (P = 0.023). It is also observed that the mean of hidden anxiety in patients and caregivers was 68.83 and 74.71, respectively, which the mean of hidden anxiety in patients was significantly less than caregivers (P = 0.006). After identifying anxiety, nurses can better and more effectively deal with these unwanted conditions in the patient and her family by providing appropriate and correct education.

Origin, Pathogenesis, Diagnosis and Treatment Options for SARS-CoV-2: A Review

Emerging viral infections are among the greatest challenges in the public health sector in the twenty-first century. Among these, most of the viruses jump from other species of animals to humans called zoonotic viruses. The Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2), by crossing species-barrier, has infected the human population for the third time in the current century and has caused the coronavirus disease-2019 (COVID-19) . Mutation and adaptation for years have greatly influenced the co-evolution and existence of coronaviruses and their possible hosts including humans. The appearance of SARS-CoV-2 in China thrust coronaviruses into the limelight and shocked the world. Presently, no coronavirus vaccines are clinically available to combat the virus's devastating effects. To counter the emergence of the COVID-19 pandemic, it is therefore important to understand the complex nature of coronaviruses and their clinical attributes. SARS and MERS outbreaks had ultimately led to socio-economic deprivation in the previous decades. In addressing the recent disastrous situation, the COVID-19 pandemic still needs some lessons from prior experience. In this review, we have highlighted the chronological order of coronavirus strains, their genomic features, the mechanism of action of SARS-CoV-2, and its disastrous repercussions on the world. We have also suggested some therapeutic options that could be effective against the COVID-19.

Diagnostic accuracy of symptoms as a diagnostic tool for SARS-CoV 2 infection: a cross-sectional study in a cohort of 2,173 patients

BACKGROUND

The SARS-CoV-2 pandemic continues to be a priority health problem; According to the World Health Organization data from October 13, 2020, 37,704,153 confirmed COVID-19 cases have been reported, including 1,079,029 deaths, since the outbreak. The identification of potential symptoms has been reported to be a useful tool for clinical decision-making in emergency departments to avoid overload and improve the quality of care. The aim of this study was to evaluate the performances of symptoms as a diagnostic tool for SARS -CoV-2 infection.

METHODS

An observational, cross-sectional, prospective and analytical study was carried out, during the period of time from April 14 to July 21, 2020. Data (demographic variables, medical history, respiratory and non-respiratory symptoms) were collected by emergency physicians. The diagnosis of COVID-19 was made using SARS-CoV-2 RT-PCR. The diagnostic accuracy of these characteristics for COVID-19 was evaluated by calculating the positive and negative likelihood ratios. A Mantel-Haenszel and multivariate logistic regression analysis was performed to assess the association of symptoms with COVID-19.

RESULTS

A prevalence of 53.72% of SARS-CoV-2 infection was observed. The symptom with the highest sensitivity was cough 71%, and a specificity of 52.68%. The symptomatological scale, constructed from 6 symptoms, obtained a sensitivity of 83.45% and a specificity of 32.86%, taking ≥2 symptoms as a cut-off point. The symptoms with the greatest association with SARS-CoV-2 were: anosmia odds ratio (OR) 3.2 (95% CI; 2.52-4.17), fever OR 2.98 (95% CI; 2.47-3.58), dyspnea OR 2.9 (95% CI; 2.39-3.51]) and cough OR 2.73 (95% CI: 2.27-3.28).

CONCLUSION

The combination of ≥2 symptoms / signs (fever, cough, anosmia, dyspnea and oxygen saturation < 93%, and headache) results in a highly sensitivity model for a quick and accurate diagnosis of COVID-19, and should be used in the absence of ancillary diagnostic studies. Symptomatology, alone and in combination, may be an appropriate strategy to use in the emergency department to guide the behaviors to respond to the disease.

TRIAL REGISTRATION

Institutional registration R-2020-3601-145, Federal Commission for the Protection against Sanitary Risks 17 CI-09-015-034, National Bioethics Commission: 09 CEI-023-2017082 .

Clinical progression and outcomes of 260 patients with severe COVID-19: an observational study

This paper presents the results of an observational, prospective study of the clinical progression and outcomes of patients with severe COVID-19. Overall, 260 patients with severe COVID-19 were included. The median age of the patients was 61 years (IQR 42.0–73.0), and 119 (45.8%) patients had one or more medical comorbidities. The median time from initial onset of symptoms to hospital admission was 8 days (IQR 6.0–11.0). Varying degrees of abnormalities in blood biochemical results were detected in most patients. All patients received supportive therapy and antiviral treatment. All patients were administered empirical antibiotic treatment with a median time of 5 days (IQR 3–7). Mechanical ventilation was required in accordance with respiratory conditions. At the data cutoff, 183 (70.4%) patients had been discharged, and 17 (6.5%) patients had been transferred to the intensive care unit (ICU). Twenty-five (9.6%) patients had died, and 35 (13.5%) patients were still in the hospital. During follow-up, 7 patients with fever were negative for SARS-Cov-2 antigens upon retest. The implications of the results are discussed for clinical features and the management of patients with severe COVID-19.

Current status and future prospect of management of biosafety laboratories for emerging infectious diseases

In recent years, there have been several outbreaks of infectious diseases around the world, including severe acute respiratory syndrome, Ebola virus disease, Middle East respiratory syndrome, and corona virus disease 2019. Experience suggests that the detection and research of emergent infectious diseases play a crucial role in the process of responding to the epidemic, which also brings great challenges to biosafety laboratories. In the face of unknown biological risk factors, the non-standard biosafety protection measures have a serious impact on the life safety of laboratory staff and the research of infectious diseases, which stresses the necessity of safety protection in biosafety laboratories. This article will briefly review the current status and future prospect of management of biosafety laboratories both in China and other countries in terms of safety protection measures during new sudden infectious disease incidents.

Evaluating the effect of nurse-led telephone follow-ups (tele-nursing) on the anxiety levels in people with coronavirus

BACKGROUND

Nowadays, the prevalence of coronary heart disease has challenged the lives of families around the world. Anxiety is one of the most important consequences of coronavirus. The nurse-led telephone follow-ups (tele-nursing) are a way to train nurses to further improve nursing services and increase the patients' well-being. The aim of this study was to determine the effect of nurse-led telephone follow-ups (tele-nursing) on the level of anxiety of people with coronavirus who spend their quarantine and treatment at home.

METHODS

In this semi-experimental study, the number of sample was 100 newly diagnosed patients with Corona, who were tested positive using the CT scan of the lungs and were selected by continuous sampling. In this study, Spielberger's state-trait anxiety inventory was used to collect data before and after the intervention. Samples were randomly divided into control and intervention groups (50 subjects in each group) after receiving initial training in the form of lectures on the corona disease, and the tele-nursing program was implemented on the intervention group every other day for 21 consecutive days. Finally, after the end of the 21st day and the completion of the tele-nursing intervention, the questionnaire was again completed by the control and intervention groups and the results of both groups were compared.

RESULTS

The results indicated that the level of anxiety in the two groups after the training program and tele-nursing were significantly different (p < 0.001) and the mean score of the anxiety level after the training program and tele-nursing was significantly reduced (p < 0.001).

CONCLUSION

This study showed that tele-nursing has had a significant effect on reducing the anxiety level of people with Cavid-19 virus. As the telephone technology is available in most clients' homes and its use is easy and accessible, it is recommend including this technology in the field of nursing care and training especially in relation to people with coronavirus.

COVID-19 in a designated infectious diseases hospital outside Hubei Province, China

BACKGROUND

The clinical characteristics of novel coronavirus disease (COVID-2019) patients outside the epicenter of Hubei Province are less understood.

METHODS

We analyzed the epidemiological and clinical features of all COVID-2019 cases in the only referral hospital in Shenzhen City, China, from January 11, 2020, to February 6, 2020, and followed until March 6, 2020.

RESULTS

Among the 298 confirmed cases, 233 (81.5%) had been to Hubei, while 42 (14%) did not have a clear travel history. Only 218 (73.15%) cases had a fever as the initial symptom. Compared with the nonsevere cases, severe cases were associated with older age, those with underlying diseases, and higher levels of C-reactive protein, interleukin-6, and erythrocyte sedimentation rate. Slower clearance of the virus was associated with a higher risk of progression to critical condition. As of March 6, 2020, 268 (89.9%) patients were discharged and the overall case fatality ratio was 1.0%.

CONCLUSIONS

In a designated hospital outside Hubei Province, COVID-2019 patients could be effectively managed by properly using the existing hospital system. Mortality may be lowered when cases are relatively mild, and there are sufficient medical resources to care and treat the disease.

Redesigning emergency department operations amidst a viral pandemic

As shown by the current COVID-19 pandemic, emergency departments (ED) are the front line for hospital-and-community-based care during viral respiratory disease outbreaks. As such, EDs must be able to reorganize and reformat operations to meet the changing needs and staggering patient volume. This paper addresses ways to adapt departmental operations to better manage in times of elevated disease burden, specifically identifying areas of intervention to help limit crowding and spread. Using experience from past outbreaks and the current COVID-19 pandemic, we advise strategies to increase surge capacity and limit patient inflow. Triage should identify and geographically cohort symptomatic patients within a designated unit to limit exposure early in an outbreak. Screening and PPE guidelines for both patient and staff should be followed closely, as determined by hospital administration and the CDC. Equipment needs are also greatly affected in an outbreak; we emphasis portable radiographic equipment to limit transport, and an upstocking of certain medications, respiratory supplies, and PPE.

Effectiveness of the Middle East respiratory syndrome-coronavirus protocol in enhancing the function of an Emergency Department in Qatar

OBJECTIVE

This study aimed to investigate the effectiveness of a Middle East respiratory syndrome coronavirus (MERS-CoV) surveillance protocol in the Emergency Department (ED) at Hamad General Hospital. Effectiveness was measured by: (a) reduction in the number of patients admitted into the MERS-CoV tracking system; (b) identification of positive MERS-CoV cases; (c) containment of cross infectivity; and (d) increased efficiency in ED functioning.

METHODS

A retrospective chart review was carried out of all ED patients suspected of MERS-CoV during the height of the epidemic (August to October 2013). An algorithm was created on the basis of international guidelines to screen and triage suspected MERS-CoV patients. Once identified, patients were isolated, had a chest roentgenogram [chest radiography (CXR)] taken, and a nasopharyngeal swab for polymerase chain reaction (PCR) was sent with sputum samples for testing. Patients with normal CXR and mild respiratory symptoms were discharged with home isolation instructions until nasopharyngeal and sputum PCR results were available. Patients with fever and acute respiratory distress, with or without abnormal CXR, were treated in the hospital until tests proved negative for MERS-CoV.

RESULTS

The protocol successfully reduced the number of patients who needed to be tested for MERS-CoV from 12,563 to 514, identified seven positive cases, and did not lead to apparent cross infectivity that resulted in serious illness or death. The protocol also increased the efficiency of ED and cut the turnaround time for nasopharyngeal swab and sputum results from 3 days to 1 day.

CONCLUSION

A highly protocolized surveillance system limited the impact of MERS-CoV on ED functioning by identifying and prioritizing high-risk patients. The emergence of new infectious diseases requires constant monitoring of interventions to reduce the impact of epidemics on population health and health services.

Population-based triage management in response to surge-capacity requirements during a large-scale bioevent disaster

Both the naturally occurring and deliberate release of a biological agent in a population can bring catastrophic consequences. Although these bioevents have similarities with other disasters, there also are major differences, especially in the approach to triage management of surge capacity resources. Conventional mass-casualty events use uniform methods for triage on the basis of severity of presentation and do not consider exposure, duration, or infectiousness, thereby impeding control of transmission and delaying recognition of victims requiring immediate care. Bioevent triage management must be population based, with the goal of preventing secondary transmission, beginning at the point of contact, to control the epidemic outbreak. Whatever triage system is used, it must first recognize the requirements of those Susceptible but not exposed, those Exposed but not yet infectious, those Infectious, those Removed by death or recovery, and those protected by Vaccination or prophylactic medication (SEIRV methodology). Everyone in the population falls into one of these five categories. This article addresses a population approach to SEIRV-based triage in which decision making falls under a two-phase system with specific measures of effectiveness to increase likelihood of medical success, epidemic control, and conservation of scarce resources.

Modelling the Utility of Body Temperature Readings From Primary Care Consults for SARS Surveillance in an Army Medical Centre

Introduction: There is interest in surveillance systems for outbreak detection at stages where clinical presentation would still be undifferentiated. Such systems focus on detecting clusters of syndromes in excess of baseline levels, which may indicate an outbreak. We model the detection limits of a potential system based on primary care consults for the detection of an outbreak of severe acute respiratory syndrome (SARS). Materials and Methods: Data from an averaged-sized medical centre were extracted from the Patient Care Enhancement System (PACES) [the electronic medical records system serving the Singapore Armed Forces (SAF)]. Thresholds were set to 3 or more cases presenting with particular syndromes and a temperature reading of ≥38o C (T ≥38). Monte Carlo simulation was used to insert simulated SARS outbreaks of various sizes onto the background incidence of febrile cases, accounting for distribution of SARS incubation period, delay from onset to first consult, and likelihood of presenting with T ≥38 to the SAF medical centre. Results: Valid temperature data was available for 2012 out of 2305 eligible syndromic consults (87.2%). T ≥38 was observed in 166 consults (8.3%). Simulated outbreaks would peak 7 days after exposure, but, on average, signals at their peak would consist of 10.9% of entire outbreak size. Under baseline assumptions, the system has a higher than 90% chance of detecting an outbreak only with 20 or more cases. Conclusions: Surveillance based on clusters of cases with T ≥38 helps reduce background noise in primary care data, but the major limitation of such systems is that they are still only able to confidently detect large outbreaks. Key words: Communicable diseases, Emerging, Epidemiology, Military medicine, Syndrome

Emergency department response to SARS, Taiwan

How emergency departments of different levels and types cope with a large-scale contagious infectious disease is unclear. We retrospectively analyzed the response of 100 emergency departments regarding use of personal protective equipment (PPE) and implementation of infection control measures (ICMs) during the severe acute respiratory syndrome outbreak in Taiwan. Emergency department workers in large hospitals were more severely affected by the epidemic. Large hospitals or public hospitals were more likely to use respirators. Small hospitals implemented more restrictive ICMs. Most emergency departments provided PPE (80%) and implemented ICMs (66%) at late stages of the outbreak. Instructions to use PPE or ICMs more frequently originated by emergency department administrators. The difficulty of implementing ICMs was significantly negatively correlated with their effectiveness. Because ability to prepare for and respond to emerging infectious diseases varies among hospitals, grouping infectious patients in a centralized location in an early stage of infection may reduce the extent of epidemics.

Late recognition of SARS in nosocomial outbreak, Toronto

Late recognition of severe acute respiratory syndrome (SARS) was associated with no known SARS contact, hospitalization before the nosocomial outbreak was recognized, symptom onset while hospitalized, wards with SARS clusters, and postoperative status. SARS is difficult to recognize in hospitalized patients with a variety of underlying conditions in the absence of epidemiologic links.

SARS clinical features, United States, 2003

We compared the clinical features of 8 U.S. case-patients with laboratory-confirmed severe acute respiratory syndrome (SARS) to 65 controls who tested negative for SARS coronavirus (SARS-CoV) infection. Shortness of breath, vomiting, diarrhea, progressive bilateral infiltrates on chest radiograph, and need for supplemental oxygen were significantly associated with confirmed SARS-CoV infection.

Can routine laboratory tests discriminate between severe acute respiratory syndrome and other causes of community-acquired pneumonia?

BACKGROUND

The clinical presentation of severe acute respiratory syndrome (SARS) resembles that of other etiologies of community-acquired pneumonia, making diagnosis difficult. Hematological and biochemical abnormalities, particularly lymphopenia, are common in patients with SARS.

METHODS

With the use of 2 databases, we compared the ability of the absolute lymphocyte count, absolute neutrophil count, lactate dehydrogenase level, creatine kinase level, alanine aminotransferase level, and serum calcium level at hospital admission to discriminate between cases of SARS and cases of community-acquired pneumonia. The SARS database contained data for 144 patients with SARS from the 2003 Toronto SARS outbreak. The community-acquired pneumonia database contained data for 8044 patients with community-acquired pneumonia from Edmonton, Canada. Patients from the SARS database were matched to patients from the community-acquired pneumonia database according to age, and receiver operating characteristic curves were constructed for each laboratory variable.

RESULTS

The areas under the receiver operating characteristic curves (AUCs) demonstrated fair to poor discriminatory ability for all laboratory variables tested except absolute neutrophil count, which had an AUC of 0.80, indicating good discriminatory ability (although there was no cutoff value of the absolute neutrophil count at which reasonable sensitivity or specificity could be obtained). Combinations of any 2 tests did not perform significantly better than did the absolute neutrophil count alone.

CONCLUSIONS

Routine laboratory tests, including determination of absolute lymphocyte count, should not be used in the diagnosis of SARS or incorporated into current case definitions of SARS. The role of the absolute neutrophil count in SARS diagnosis is likely limited, but it should be assessed further.

Clinical Issues and Research in Respiratory Failure from Severe Acute Respiratory Syndrome

The National Heart, Lung, and Blood Institute, along with the Centers for Disease Control and Prevention and the National Institute of Allergy and Infectious Diseases, convened a panel to develop recommendations for treatment, prevention, and research for respiratory failure from severe acute respiratory syndrome (SARS) and other newly emerging infections. The clinical and pathological features of acute lung injury (ALI) from SARS appear indistinguishable from ALI from other causes. The mainstay of treatments for ALI remains supportive. Patients with ALI from SARS who require mechanical ventilation should receive a lung protective, low tidal volume strategy. Adjuvant treatments recommended include prevention of venous thromboembolism, stress ulcer prophylaxis, and semirecumbent positioning during ventilation. Based on previous experience in Canada, infection control resources and protocols were recommended. Leadership structure, communication, training, and morale are an essential aspect of SARS management. A multicenter, placebo-controlled trial of corticosteroids for late SARS is justified because of widespread clinical use and uncertainties about relative risks and benefits. Studies of combined pathophysiologic endpoints were recommended, with mortality as a secondary endpoint. The group recommended preparation for studies, including protocols, ethical considerations, Web-based registries, and data entry systems.

Clinical picture, diagnosis, treatment and outcome of severe acute respiratory syndrome (SARS) in children

Children are susceptible to infection by SARS-associated coronavirus (SARS-CoV) but the clinical picture of SARS is milder than in adults. Teenagers resemble adults in presentation and disease progression and may develop severe illness requiring intensive care and assisted ventilation. Fever, malaise, cough, coryza, chills or rigor, sputum production, headache, myalgia, leucopaenia, lymphopaenia, thrombocytopaenia, mildly prolonged activated partial thromboplastin times and elevated lactate dehydrogenase levels are common presenting features. Radiographic findings are non-specific but high-resolution computed tomography of the thorax in clinically suspected cases may be an early diagnostic aid when initial chest radiographs appear normal. The improved reverse transcription-polymerase chain reaction (RT-PCR) assays are critical in the early diagnosis of SARS, with sensitivity approaching 80% in the first 3 days of illness when performed on nasopharyngeal aspirates, the preferred specimens. Absence of seroconversion to SARS-CoV beyond 28 days from disease onset generally excludes the diagnosis. The best treatment strategy for SARS among children remains to be determined. No case fatality has been reported in children and the short- to medium-term outcome appears to be good. The importance of continued monitoring for any long-term complications due to the disease or its empiric treatment, cannot be overemphasised.

Use of simple laboratory features to distinguish the early stage of severe acute respiratory syndrome from dengue fever

BACKGROUND

The diagnosis of severe acute respiratory syndrome (SARS) is difficult early in the illness, because its presentation resembles that of other nonspecific viral fevers, such as dengue. Dengue fever is endemic in many of the countries in which the large SARS outbreaks occurred in early 2003. Misdiagnosis may have serious public health consequences. We aimed to determine simple laboratory features to differentiate SARS from dengue.

METHODS

We compared the laboratory features of 55 adult patients with SARS at presentation (who were all admitted before radiological changes had occurred) and 147 patients with dengue. Features independently predictive of dengue were modeled by multivariate logistic regression to create a diagnostic tool with 100% specificity for dengue.

RESULTS

Multivariate analysis identified 3 laboratory features that together are highly predictive of a diagnosis of dengue and able to rule out the possibility of SARS: platelet count of <140 x 10(9) platelets/L, white blood cell count of <5x10(9) cells/L, and aspartate aminotransferase level of >34 IU/L. A combination of these parameters has a sensitivity of 75% and a specificity of 100%.

CONCLUSIONS

Simple laboratory data may be helpful for the diagnosis of disease in adults admitted because of fever in areas in which dengue is endemic when the diagnosis of SARS needs to be excluded. Application of this information may help to optimize the use of isolation rooms for patients presenting with nonspecific fever.

Laboratory diagnosis of SARS

The emergence of new viral infections of man requires the development of robust diagnostic tests that can be applied in the differential diagnosis of acute illness, or to determine past exposure, so as to establish the true burden of disease. Since the recognition in April 2003 of the severe acute respiratory syndrome coronavirus (SARS-CoV) as the causative agent of severe acute respiratory syndrome (SARS), enormous efforts have been applied to develop molecular and serological tests for SARS which can assist rapid detection of cases, accurate diagnosis of illness and the application of control measures. International progress in the laboratory diagnosis of SARS-CoV infection during acute illness has led to internationally agreed World Health Organization criteria for the confirmation of SARS. Developments in the dissection of the human immune response to SARS indicate that serological tests on convalescent sera are essential to confirm SARS infection, given the sub-optimal predictive value of molecular detection tests performed during acute SARS illness.

Confronting SARS: a view from Hong Kong

Severe acute respiratory syndrome (SARS) emerged as a new disease in Guangdong Province, People's Republic of China in late 2002. Within weeks it had spread to Hong Kong and thence globally to affect over 25 countries across five continents. The disease had the propensity to cause clusters of pneumonia, particularly in healthcare workers or close family contacts. A global effort coordinated by the World Health Organization successfully defined the aetiology, epidemiology and clinical characteristics of the disease, and the implementation of case identification, isolation and infection control measures led to the interruption of the global outbreak by July 2003. The pattern of disease emergence and strategies for control of SARS provides lessons for coping with future emerging infectious disease threats.

Severe acute respiratory syndrome (SARS) in intensive care units (ICUs): limiting the risk to healthcare workers

The global epidemic of severe acute respiratory syndrome (SARS) during the first half of 2003 resulted in over 8000 cases with more than 800 deaths. Many of those who eventually died, did so in the critical (intensive) care units of various hospitals around the world, and many secondary cases of SARS arose in healthcare workers looking after such patients in these units. Research on SARS coronavirus (SARS CoV) demonstrated that this virus belongs to the same family of viruses, the Coronaviridae that causes the common cold, with some important differences. Properties of this virus have been discovered which can be used to develop important infection control policies within hospitals to limit the number of secondary cases. These properties include environmental survival, transmissibility, viral load in various organs and fluids and periods of symptomatic illness during which infectivity is greatest. Various barrier methods were used throughout the epidemic to protect healthcare workers from SARS, with varying degrees of success. Treatment of SARS patients has mainly involved steroid therapy, with or without ribavirin, but there is no consensus on the best treatment protocol, as yet. This review focuses on the implications of SARS for healthcare workers and patients on critical care units.

Transmission and Control of SARS

Severe acute respiratory syndrome (SARS) was first recognized in China in November 2002 and was subsequently associated with a worldwide outbreak involving 8098 people, 774 of whom died. The outbreak was declared contained on July 5, 2003, after the last human chain of transmission of SARS had been broken. Whether outbreaks of SARS will return is debatable, but no one disagrees that it is important to be prepared for this possibility. This article presents an overview of the transmission and control of SARS based on the current state of knowledge derived from published studies of the outbreak and on our own personal experience.