Clinical description of a completed outbreak of SARS in Vietnam, February-May 2003

Dynamic Characteristics of Blood Platelet Count in COVID-19 Patients

Background and purpose: Coronavirus disease 2019 (COVID-19) was spreading all over the world. Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) primarily invades and infects the lungs of humans leading to COVID-19. Mild to severe clinical symptoms such as fever, cough, and shortness of breath were existed in those patients. One of the most common changes in these patients was abnormal blood routine. However, uncertainty remains regarding the dynamic characteristics of platelet in COVID-19 patients due to limited data. Therefore, we aimed to analyze the association between dynamic characteristics of blood platelet and disease severity, and to identify new monitoring indicators to treat the COVID-19 patients. Methods: In this cohort study, 398 COVID-19 patients treated in the Shenzhen Third People’s hospital from December 16, 2019 to March 26, 2020 were collected and participated. All data of participants including the clinical characteristics, imaging and laboratory information were collected. All patients included in our study were classified as four groups (mild, common, severe, and critical types) regarding clinical symptoms and relevant severe failures based on the Diagnosis Criteria. Platelet count was examined at the baseline and every 3–5 days during hospitalization. Results: The platelet count varied with clinical classifications. The platelet count in mild type was normal without significant fluctuation. While the blood platelet count of most common and severe patients had obvious fluctuations, showing as a dynamic change that first rose and then fell to the level at admission, which was consistent with the trend of lung inflammation. Bone marrow smears further showed that bone marrow hyperplasia was normal in mild, common and severe type patients, and megakaryocytes and their platelet-producing functions were not abnormal. Conclusions: Our results suggested that the dynamic changes of platelet count might be a predictor of lung inflammation alteration for COVID-19 patients. The changes in platelet count might be a responsive pattern secondary to lung inflammation. The function of bone marrow may be slightly affected by SARS-CoV-2 infection.

SARS, MERS and CoVID-19: An overview and comparison of clinical, laboratory and radiological features

In the 21st century, we have seen a total of three outbreaks by members of the coronavirus family. Although the first two outbreaks did not result in a pandemic, the third and the latest outbreak of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) culminated in a pandemic. This pandemic has been extremely significant on a social and international level. As these viruses belong to the same family, they are closely related. Despite their numerous similarities, they have slight distinctions that render them distinct from one another. The Severe Acute Respiratory Distress Syndrome and Middle East Respiratory Syndrome (MERS) cases were reported to have a very high case fatality rate of 9.5 and 34.4% respectively. In contrast, the CoVID-19 has a case fatality rate of 2.13%. Also, there are no clear medical countermeasures for these coronaviruses yet. We can cross information gaps, including cultural weapons for fighting and controlling the spread of MERS-CoV and SARS-CoV-2, and plan efficient and comprehensive defensive lines against coronaviruses that might arise or reemerge in the future by gaining a deeper understanding of these coronaviruses and the illnesses caused by them. The review thoroughly summarises the state-of-the-art information and compares the biochemical properties of these deadly coronaviruses with the clinical characteristics, laboratory features and radiological manifestations of illnesses induced by them, with an emphasis on comparing and contrasting their similarities and differences.

Epidemiology, prognosis and management of potassium disorders in Covid-19

Coronavirus disease (Covid-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is currently the largest health crisis facing most countries. Several factors have been linked with a poor prognosis for this disease, including demographic factors, pre-existing comorbidities and laboratory parameters such as white blood cell count, D-dimer, C-reactive protein, albumin, lactate dehydrogenase, creatinine and electrolytes. Electrolyte abnormalities particularly potassium disorders are common among Covid-19 patients. Based on our pooled analysis, hypokalemia and hyperkalemia occur in 24.3% and 4.15% of Covid-19 patients, respectively. Potassium level deviation from the normal range may increase the chances of unfavorable outcomes and even death. Therefore, this article reviewed the epidemiology of potassium disorders and explained how hypokalemia and hyperkalemia are capable of deteriorating cardiac outcomes and the prognosis of Covid-19 for infected patients. The article finishes by highlighting some important considerations in the management of hypokalemia and hyperkalemia in these patients.

The First 100 Days of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Control in Vietnam

Background

One hundred days after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was first reported in Vietnam on 23 January, 270 cases were confirmed, with no deaths. We describe the control measures used by the government and their relationship with imported and domestically acquired case numbers, with the aim of identifying the measures associated with successful SARS-CoV-2 control.

Methods

Clinical and demographic data on the first 270 SARS-CoV-2 infected cases and the timing and nature of government control measures, including numbers of tests and quarantined individuals, were analyzed. Apple and Google mobility data provided proxies for population movement. Serial intervals were calculated from 33 infector-infectee pairs and used to estimate the proportion of presymptomatic transmission events and time-varying reproduction numbers.

Results

A national lockdown was implemented between 1 and 22 April. Around 200 000 people were quarantined and 266 122 reverse transcription polymerase chain reaction (RT-PCR) tests conducted. Population mobility decreased progressively before lockdown. In total, 60% (163/270) of cases were imported; 43% (89/208) of resolved infections remained asymptomatic for the duration of infection. The serial interval was 3.24 days, and 27.5% (95% confidence interval [CI], 15.7%-40.0%) of transmissions occurred presymptomatically. Limited transmission amounted to a maximum reproduction number of 1.15 (95% CI, .·37–2.·36). No community transmission has been detected since 15 April.

Conclusions

Vietnam has controlled SARS-CoV-2 spread through the early introduction of mass communication, meticulous contact tracing with strict quarantine, and international travel restrictions. The value of these interventions is supported by the high proportion of asymptomatic and imported cases, and evidence for substantial presymptomatic transmission.

The First 100 Days of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Control in Vietnam

BACKGROUND

One hundred days after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was first reported in Vietnam on 23 January, 270 cases were confirmed, with no deaths. We describe the control measures used by the government and their relationship with imported and domestically acquired case numbers, with the aim of identifying the measures associated with successful SARS-CoV-2 control.

METHODS

Clinical and demographic data on the first 270 SARS-CoV-2 infected cases and the timing and nature of government control measures, including numbers of tests and quarantined individuals, were analyzed. Apple and Google mobility data provided proxies for population movement. Serial intervals were calculated from 33 infector-infectee pairs and used to estimate the proportion of presymptomatic transmission events and time-varying reproduction numbers.

RESULTS

A national lockdown was implemented between 1 and 22 April. Around 200 000 people were quarantined and 266 122 reverse transcription polymerase chain reaction (RT-PCR) tests conducted. Population mobility decreased progressively before lockdown. In total, 60% (163/270) of cases were imported; 43% (89/208) of resolved infections remained asymptomatic for the duration of infection. The serial interval was 3.24 days, and 27.5% (95% confidence interval [CI], 15.7%-40.0%) of transmissions occurred presymptomatically. Limited transmission amounted to a maximum reproduction number of 1.15 (95% CI, .·37-2.·36). No community transmission has been detected since 15 April.

CONCLUSIONS

Vietnam has controlled SARS-CoV-2 spread through the early introduction of mass communication, meticulous contact tracing with strict quarantine, and international travel restrictions. The value of these interventions is supported by the high proportion of asymptomatic and imported cases, and evidence for substantial presymptomatic transmission.

Timeliness of contact tracing among flight passengers during the COVID-19 epidemic in Vietnam

Background

International air travel plays an important role in the global spread of SARS-CoV-2, and tracing of close contacts is an integral part of the public health response to COVID-19. We aimed to assess the timeliness of contact tracing among airline passengers arriving in Vietnam on flights containing COVID-19 cases and investigated factors associated with timeliness of contact tracing.

Methods

We included data from 2228 passengers on 22 incoming flights between 2 and 19 March 2020. Contact tracing duration was assessed separately for the time between the date of index case confirmation and date of contact tracing initiation (interval I), and the date of contact tracing initiation and completion (interval II). We used log-rank tests and multivariable Poisson regression models to identify factors associated with timeliness.

Results

The median duration of interval I and interval II was one (IQR: 1–2) and 3 days (IQR: 2–5), respectively. The contact tracing duration was shorter for passengers from flights where the index case was identified through mandatory testing directly upon arrival (median = 4; IQR: 3–5) compared to flights with index case detection through self-presentation at health facilities after arrival (median = 7; IQR: 5–8) (p-value = 0.018). Cumulative hazards for successful tracing were higher for Vietnamese nationals compared to non-Vietnamese nationals (p < 0.001).

Conclusions

Contact tracing among flight passengers in the early stage of the COVID-19 epidemic in Vietnam was timely though delays occurred on high workload days. Mandatory SARS-CoV-2 testing at arrival may reduce contact tracing duration and should be considered as an integrated screening tool for flight passengers from high-risk areas when entering low-transmission settings with limited contact tracing capacity. We recommend a standardized risk-based contact tracing approach for flight passengers during the ongoing COVID-19 epidemic.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-06067-x.

An extensive study on the COVID-19 pandemic, an emerging global crisis: Risks, transmission, impacts and mitigation

A number of unexplained cases of pneumonia have been recorded since November 2019 in China. It is officially named the new corona virus (2019-nCov) by the World Health Organization on 12 January 2020. WHO officially named it COVID-19 on 11 February. COVID-19 is a highly transmitted and pathogenic viral infection that has been developed and spread across the world in Wuhan, China, caused by extreme acute respiratory syndrome corona-virus 2 (SARS-CoV-2). Genomic analysis showed that bats may also be a primary reservoir of SARS-CoV-2 phylogenetically associated with severe acute respiratory syndrome-like viruses (SARS). However, the rapid human to human transition has been generally reported. Intermediate source of origin and human transition is unknown. Clinically approved COVID-19 antiviral medication or vaccine is not available. In clinical trials, however, few broad-based COVID-19 antiviral medicinal drugs were tested, resulting in clinical recovery. This analysis summarizes the pathogenicity of COVID-19 and aims to raise awareness of COVID-19 among the population and to continually boost the detection, monitoring, diagnosis and care level. Over 50 COVID-19 scientific publications were included in this systematic analysis. We found that fever (87.0%), cough (65.9%) and malaise/tiredness (35%) were the most common symptoms of COvida-19. However, COVID-19 clinical signs and symptoms were not necessarily obvious. The transmission of COVID-19 in comparison to SARS was more specific. The rate of death of COVID-19 was 2,7% and the pathological characteristics of COVID-19 are very similar to ARDS. There are also discussions on the latest epidemiological changes, clinical manifestations, auxiliary examination and COVID-19 pathological characteristics.

Treatment of severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS), and coronavirus disease 2019 (COVID-19): a systematic review of in vitro, in vivo, and clinical trials

Rationale: Coronavirus disease 2019 (COVID-19) has spread worldwide and poses a threat to humanity. However, no specific therapy has been established for this disease yet. We conducted a systematic review to highlight therapeutic agents that might be effective in treating COVID-19. Methods: We searched Medline, Medrxiv.org, and reference lists of relevant publications to identify articles of in vitro, in vivo, and clinical studies on treatments for severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS), and COVID-19 published in English until the last update on October 11, 2020. Results: We included 36 studies on SARS, 30 studies on MERS, and 10 meta-analyses on SARS and MERS in this study. Through 12,200 title and 830 full-text screenings for COVID-19, eight in vitro studies, 46 randomized controlled trials (RCTs) on 6,886 patients, and 29 meta-analyses were obtained and investigated. There was no therapeutic agent that consistently resulted in positive outcomes across SARS, MERS, and COVID-19. Remdesivir showed a therapeutic effect for COVID-19 in two RCTs involving the largest number of total participants (n = 1,461). Other therapies that showed an effect in at least two RCTs for COVID-19 were sofosbuvir/daclatasvir (n = 114), colchicine (n = 140), IFN-β1b (n = 193), and convalescent plasma therapy (n = 126). Conclusions: This review provides information to help establish treatment and research directions for COVID-19 based on currently available evidence. Further RCTs are required.

Correlations of Clinical and Laboratory Characteristics of COVID-19: A Systematic Review and Meta-Analysis

(1) Background: The global threat of Coronavirus disease 2019 (COVID-19) continues. The diversity of clinical characteristics and progress are reported in many countries as the duration of the pandemic is prolonged. We aimed to perform a novel systematic review and meta-analysis focusing on findings about correlations between clinical characteristics and laboratory features of patients with COVID-19. (2) Methods: We analyzed cases of COVID-19 in different countries by searching PubMed, Embase, Web of Science databases and Google Scholar, from the early stage of the outbreak to late March. Clinical characteristics, laboratory findings, and treatment strategies were retrospectively reviewed for the analysis. (3) Results: Thirty-seven (n = 5196 participants) COVID-19-related studies were eligible for this systematic review and meta-analysis. Fever, cough and fatigue/myalgia were the most common symptoms of COVID-19, followed by some gastrointestinal symptoms which are also reported frequently. Laboratory markers of inflammation and infection including C-reactive protein (CRP) (65% (95% confidence interval (CI) 56–81%)) were elevated, while lymphocyte counts were decreased (63% (95% CI 47–78%)). Meta-analysis of treatment approaches indicated that three modalities of treatment were predominantly used in the majority of patients with a similar prevalence, including antiviral agents (79%), antibiotics (78%), and oxygen therapy (77%). Age was negatively correlated with number of lymphocytes, but positively correlated with dyspnea, number of white blood cells, neutrophils, and D-dimer. Chills had been proved to be positively correlated with chest tightness, lung abnormalities on computed tomography (CT) scans, neutrophil/lymphocyte/platelets count, D-dimer and CRP, cough was positively correlated with sputum production, and pulmonary abnormalities were positively correlated with CRP. White blood cell (WBC) count was also positively correlated with platelet counts, dyspnea, and neutrophil counts with the respective correlations of 0.668, 0.728, and 0.696. (4) Conclusions: This paper is the first systematic review and meta-analysis to reveal the relationship between various variables of clinical characteristics, symptoms and laboratory results with the largest number of papers and patients until now. In elderly patients, laboratory and clinical characteristics indicate a more severe disease course. Moreover, treatments such as antiviral agents, antibiotics, and oxygen therapy which are used in over three quarters of patients are also analyzed. The results will provide “evidence-based hope” on how to manage this unanticipated and overwhelming pandemic.

Comparison of confirmed COVID-19 with SARS and MERS cases - Clinical characteristics, laboratory findings, radiographic signs and outcomes: A systematic review and meta-analysis

INTRODUCTION

Within this large-scale study, we compared clinical symptoms, laboratory findings, radiographic signs, and outcomes of COVID-19, SARS, and MERS to find unique features.

METHOD

We searched all relevant literature published up to February 28, 2020. Depending on the heterogeneity test, we used either random or fixed-effect models to analyze the appropriateness of the pooled results. Study has been registered in the PROSPERO database (ID 176106).

RESULT

Overall 114 articles included in this study; 52 251 COVID-19 confirmed patients (20 studies), 10 037 SARS (51 studies), and 8139 MERS patients (43 studies) were included. The most common symptom was fever; COVID-19 (85.6%, P < .001), SARS (96%, P < .001), and MERS (74%, P < .001), respectively. Analysis showed that 84% of Covid-19 patients, 86% of SARS patients, and 74.7% of MERS patients had an abnormal chest X-ray. The mortality rate in COVID-19 (5.6%, P < .001) was lower than SARS (13%, P < .001) and MERS (35%, P < .001) between all confirmed patients.

CONCLUSIONS

At the time of submission, the mortality rate in COVID-19 confirmed cases is lower than in SARS- and MERS-infected patients. Clinical outcomes and findings would be biased by reporting only confirmed cases, and this should be considered when interpreting the data.

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.

Epidemiological and Clinical Characteristics of Cases During the Early Phase of COVID-19 Pandemic: A Systematic Review and Meta-Analysis

Background: On 29th December 2019, a cluster of cases displaying the symptoms of a "pneumonia of unknown cause" was identified in Wuhan, Hubei province of China. This systematic review and meta-analysis aims to review the epidemiological and clinical characteristics of COVID-19 cases in the early phase of the COVID-19 pandemic. Methods: The search strategy involved peer-reviewed studies published between 1st January and 11th February 2020 in Pubmed, Google scholar and China Knowledge Resource Integrated database. Publications identified were screened for their title and abstracts according to the eligibility criteria, and further shortlisted by full-text screening. Three independent reviewers extracted data from these studies, and studies were assessed for potential risk of bias. Studies comprising non-overlapping patient populations, were included for qualitative and quantitative synthesis of results. Pooled prevalence with 95% confidence intervals were calculated for patient characteristics. Results: A total of 29 publications were selected after full-text review. This comprised of 18 case reports, three case series and eight cross-sectional studies on patients admitted from mid-December of 2019 to early February of 2020. A total of 533 adult patients with pooled median age of 56 (95% CI: 49-57) and a pooled prevalence of male of 60% (95% CI: 52-68%) were admitted to hospital at a pooled median of 7 days (95% CI: 7-7) post-onset of symptoms. The most common symptoms at admission were fever, cough and fatigue, with a pooled prevalence of 90% (95% CI: 81-97%), 58% (95% CI: 47-68%), and 50% (95% CI: 29-71%), respectively. Myalgia, shortness of breath, headache, diarrhea and sore throat were less common with pooled prevalence of 27% (95% CI: 20-36%), 25% (95% CI: 15-35%), 10% (95% CI: 7-13%), 8% (95% CI: 5-13%), and 7% (95% CI: 1-15%), respectively. ICU patients had a higher proportion of shortness of breath at presentation, as well as pre-existing hypertension, cardiovascular disease and COPD, compared to non-ICU patients in 2 studies (n = 179). Conclusion: This study highlights the key epidemiological and clinical features of COVID-19 cases during the early phase of the COVID-19 pandemic.

COVID-19 virus may have neuroinvasive potential and cause neurological complications: a perspective review

Coronavirus disease 2019 (COVID-19) was reported at the end of 2019 in China for the first time and has rapidly spread throughout the world as a pandemic. Since COVID-19 causes mild to severe acute respiratory syndrome, most studies in this field have only focused on different aspects of pathogenesis in the respiratory system. However, evidence suggests that COVID-19 may affect the central nervous system (CNS). Given the outbreak of COVID-19, it seems necessary to perform investigations on the possible neurological complications in patients who suffered from COVID-19. Here, we reviewed the evidence of the neuroinvasive potential of coronaviruses and discussed the possible pathogenic processes in CNS infection by COVID-19 to provide a precise insight for future studies.

No. 225-Management Guidelines for Obstetric Patients and Neonates Born to Mothers With Suspected or Probable Severe Acute Respiratory Syndrome (SARS)

Objective

This document summarizes the limited experience of SARS in pregnancy and suggests guidelines for management.

Outcomes

Cases reported from Asia suggest that maternal and fetal outcomes are worsened by SARS during pregnancy.

Evidence

Medline was searched for relevant articles published in English from 2000 to 2007. Case reports were reviewed and expert opinion sought.

Values

Recommendations were made according to the guidelines developed by the Canadian Task Force on Preventive Health Care.

Sponsors

The Society of Obstetricians and Gynaecologists of Canada.

Recommendations

1.

All hospitals should have infection control systems in place to ensure that alerts regarding changes in exposure risk factors for SARS or other potentially serious communicable diseases are conveyed promptly to clinical units, including the labour and delivery unit (III-C).

2.

At times of SARS outbreaks, all pregnant patients being assessed or admitted to the hospital should be screened for symptoms of and risk factors for SARS (III-C).

3.

Upon arrival in the labour triage unit, pregnant patients with suspected and probable SARS should be placed in a negative pressure isolation room with at least 6 air exchanges per hour. All labour and delivery units caring for suspected and probable SARS should have available at least one room in which patients can safely labour and deliver while in need of airborne isolation (III-C).

4.

If possible, labour and delivery (including operative delivery or Caesarean section) should be managed in a designated negative pressure isolation room, by designated personnel with specialized infection control preparation and protective gear (III-C).

5.

Either regional or general anaesthesia may be appropriate for delivery of patients with SARS (III-C).

6.

Neonates of mothers with SARS should be isolated in a designated unit until the infant has been well for 10 days, or until the mother’s period of isolation is complete. The mother should not breastfeed during this period (III-C).

7.

A multidisciplinary team, consisting of obstetricians, nurses, pediatricians, infection control specialists, respiratory therapists, and anaesthesiologists, should be identified in each unit and be responsible for the unit organization and implementation of SARS management protocols (III-C).

8.

Staff caring for pregnant SARS patients should not care for other pregnant patients. Staff caring for pregnant SARS patients should be actively monitored for fever and other symptoms of SARS. Such individuals should not work in the presence of any SARS symptoms within 10 days of exposure to a SARS patient (III-C).

9.

All health care personnel, trainees, and support staff should be trained in infection control management and containment to prevent spread of the SARS virus (III-A).

10.

Regional health authorities in conjunction with hospital staff should consider designating specific facilities or health care units, including primary, secondary, or tertiary health care centres, to care for patients with SARS or similar illnesses (III-A).

Political will and international collaborative frameworks in infectious diseases

The last few decades have been marked by a rapid expansion in the world?s population, along with an increasingly dynamic mobility of individuals. This accelerated global inter-connectedness enabled microorganisms to reach virtually any location worldwide more rapidly and efficiently than ever before, reshaping the global dynamics of pathogens. As a result, a local infectious disease outbreak anywhere in the world may almost instantaneously assume global dimensions, and should therefore be considered a global priority. The history of several infectious diseases illustrates that in addition to prophylactic and therapeutic medical interventions, the interplay of social, economic, and political factors makes a fundamental contribution to the outcome of infectious disease outbreaks. Furthermore, this multi- and cross-disciplinary interconnectedness is a key determinant of the outcome of efforts to eradicate vaccine-preventable infectious diseases. A combined framework that incorporates teachings provided by previous outbreaks, and integrates medical and biomedical interventions with contributions made by social, economic, and political factors, emerges as vital requirement of successful global public health initiatives.

Clinical management and infection control of SARS: lessons learned

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

Epidemic Intelligence Service investigations of respiratory illness, 1946-2005

Infectious respiratory pathogens were the suspected cause of 480 outbreaks investigated by the Centers for Disease Control and Prevention's Epidemic Intelligence Service officers during 1946-2005. All epidemic-assistance investigation reports and associated articles from scientific journals were reviewed. Investigations identified 25 different infectious respiratory pathogens including, most frequently, tuberculosis, influenza, and legionellosis. Other bacterial-, viral-, and fungal-related pathogens also were identified. Epidemic-assistance investigations were notable for first identifying Legionnaires disease and Pontiac fever, hantavirus pulmonary syndrome, and new strains of human and avian influenza, as well as emerging challenges (e.g., multidrug-resistant tuberculosis and pneumococcus). The investigations provided clinical insights into such diseases as pulmonary anthrax and identified high risks of serious respiratory illnesses for persons infected with human immunodeficiency virus, other immunocompromised persons, and persons with diabetes. They identified settings placing persons at high risk of acquiring disease, including nursing homes, prisons, homeless shelters, and hospitals. Travel also placed persons at risk. Key environmental factors related to spread of diseases and occupational risks for brucellosis and psittacosis were identified. The outbreak investigations constitute a wealth of prevention experience and provide the basis for recommendations to mitigate outbreaks and reduce future risks.

The SARS epidemic in mainland China: bringing together all epidemiological data

OBJECTIVE

To document and verify the number of cases of severe acute respiratory syndrome (SARS) during the 2002-2003 epidemic in mainland China.

METHOD

All existing Chinese SARS data sources were integrated in one final database. This involved removing non-probable and duplicate cases, adding cases at the final stage of the outbreak, and collecting missing information.

RESULTS

The resulting database contains a total of 5327 probable SARS cases, of whom 343 died, giving a case fatality ratio (CFR) of 6.4%. While the total number of cases happens to be equal to the original official reports, there are 5 cases overall which did not result in death. When compared with Hong Kong Special Administrative Region of China, China Taiwan, and Singapore, the SARS epidemic in mainland China resulted in a considerably lower CFR, involved relatively younger cases and included fewer health care workers.

CONCLUSIONS

To optimise future data collection during large-scale outbreaks of emerging or re-emerging infectious disease, China must further improve the infectious diseases reporting system, enhance collaboration between all levels of disease control, health departments, hospitals and institutes nationally and globally, and train specialized staff working at county centres of disease control.

Management guidelines for obstetric patients and neonates born to mothers with suspected or probable severe acute respiratory syndrome (SARS)

Objective

This document summarizes the limited experience of SARS in pregnancy and suggests guidelines for management.

Outcomes

Cases reported from Asia suggest that maternal and fetal outcomes are worsened by SARS during pregnancy.

Evidence

Medline was searched for relevant articles published in English from 2000 to 2007. Case reports were reviewed and expert opinion sought.

Values

Recommendations were made according to the guidelines developed by the Canadian Task Force on Preventive Health Care.

Sponsors

The Society of Obstetricians and Gynaecologists of Canada.

Recommendations

1.

All hospitals should have infection control systems in place to ensure that alerts regarding changes in exposure risk factors for SARS or other potentially serious communicable diseases are conveyed promptly to clinical units, including the labour and delivery unit. (III-C)

2.

At times of SARS outbreaks, all pregnant patients being assessed or admitted to the hospital should be screened for symptoms of and risk factors for SARS. (III-C)

3.

Upon arrival in the labour triage unit, pregnant patients with suspected and probable SARS should be placed in a negative pressure isolation room with at least 6 air exchanges per hour. All labour and delivery units caring for suspected and probable SARS should have available at least one room in which patients can safely labour and deliver while in need of airborne isolation. (III-C)

4.

If possible, labour and delivery (including operative delivery or Caesarean section) should be managed in a designated negative pressure isolation room, by designated personnel with specialized infection control preparation and protective gear. (III-C)

5.

Either regional or general anaesthesia may be appropriate for delivery of patients with SARS. (III-C)

6.

Neonates of mothers with SARS should be isolated in a designated unit until the infant has been well for 10 days, or until the mother’s period of isolation is complete. The mother should not breastfeed during this period. (III-C)

7.

A multidisciplinary team, consisting of obstetricians, nurses, pediatricians, infection control specialists, respiratory therapists, and anaesthesiologists, should be identified in each unit and be responsible for the unit organization and implementation of SARS management protocols. (III-C)

8.

Staff caring for pregnant SARS patients should not care for other pregnant patients. Staff caring for pregnant SARS patients should be actively monitored for fever and other symptoms of SARS. Such individuals should not work in the presence of any SARS symptoms within 10 days of exposure to a SARS patient. (III-C)

9.

All health care personnel, trainees, and support staff should be trained in infection control management and containment to prevent spread of the SARS virus. (III-A)

10.

Regional health authorities in conjunction with hospital staff should consider designating specific facilities or health care units, including primary, secondary, or tertiary health care centres, to care for patients with SARS or similar illnesses. (III-A)

Prognostication in severe acute respiratory syndrome: a retrospective time-course analysis of 1312 laboratory-confirmed patients in Hong Kong

Background and objective:  The temporal importance of prognostic indicators for severe acute respiratory syndrome (SARS) has not been studied. This study identified the various clinical prognostic factors for SARS and described the temporal evolution of these factors in the course of the SARS illness in Hong Kong in 2003.

Methods:  A retrospective analysis of the entire Hong Kong cohort of 1312 laboratory‐confirmed SARS patients aged 15–74 years was undertaken. Demographic, clinical and laboratory data at presentation and investigative data during the first 10 days of illness from the time of symptom onset were compiled. Two adverse outcomes were examined: hospital mortality and the development of oxygenation failure based on the estimated PaO₂/FiO₂ ratio of <200 mm Hg. Logistic regression was used to identify the association between these prognostic factors and outcomes.

Results:  Based on adjusted odds ratios with a P‐value of <0.05, older age, male gender, elevated pulse rate and elevated neutrophil count were all predictive of oxygenation failure and death during the 10‐day illness. Raised serum albumin and creatinine phosphokinase (CPK) levels were predictive of hospital mortality during this period. The presenting ALT and CPK level and the day 7 and day 10 platelet counts were predictive of oxygenation failure while the day 7 LDH was predictive of death. Contact exposure outside health‐care institutions also appeared to carry higher risk of death.

Conclusion:  This large‐scale analysis identified important discriminatory parameters related to the patients’ demographic profile (age and gender), severity of illness (pulse rate and neutrophil count), and multisystem derangement (platelet count, CPK, ALT and LDH), all of which prognosticated adverse outcomes during the SARS episode. While age, pulse rate and neutrophil count consistently remained significant prognosticators during the first 10 days of illness, the prognostic impact of other derangements was more time‐course dependent. Clinicians should be aware of the time‐course evolution of these prognosticators.

Effectiveness of handwashing in preventing SARS: a review

This review examines the literature, including literature in Chinese, on the effectiveness of handwashing as an intervention against severe acute respiratory syndrome (SARS) transmission. Nine of 10 epidemiological studies reviewed showed that handwashing was protective against SARS when comparing infected cases and non‐infected controls in univariate analysis, but only in three studies was this result statistically significant in multivariate analysis. There is reason to believe that this is because most of the studies were too small. The evidence for the effectiveness of handwashing as a measure against SARS transmission in health care and community settings is suggestive, but not conclusive.

Factors associated with nosocomial SARS-CoV transmission among healthcare workers in Hanoi, Vietnam, 2003

Background

In March of 2003, an outbreak of Severe Acute Respiratory Syndrome (SARS) occurred in Northern Vietnam. This outbreak began when a traveler arriving from Hong Kong sought medical care at a small hospital (Hospital A) in Hanoi, initiating a serious and substantial transmission event within the hospital, and subsequent limited spread within the community.

Methods

We surveyed Hospital A personnel for exposure to the index patient and for symptoms of disease during the outbreak. Additionally, serum specimens were collected and assayed for antibody to SARS-associated coronavirus (SARS-CoV) antibody and job-specific attack rates were calculated. A nested case-control analysis was performed to assess risk factors for acquiring SARS-CoV infection.

Results

One hundred and fifty-three of 193 (79.3%) clinical and non-clinical staff consented to participate. Excluding job categories with <3 workers, the highest SARS attack rates occurred among nurses who worked in the outpatient and inpatient general wards (57.1, 47.4%, respectively). Nurses assigned to the operating room/intensive care unit, experienced the lowest attack rates (7.1%) among all clinical staff. Serologic evidence of SARS-CoV infection was detected in 4 individuals, including 2 non-clinical workers, who had not previously been identified as SARS cases; none reported having had fever or cough. Entering the index patient's room and having seen (viewed) the patient were the behaviors associated with highest risk for infection by univariate analysis (odds ratios 20.0, 14.0; 95% confidence intervals 4.1–97.1, 3.6–55.3, respectively).

Conclusion

This study highlights job categories and activities associated with increased risk for SARS-CoV infection and demonstrates that a broad diversity of hospital workers may be vulnerable during an outbreak. These findings may help guide recommendations for the protection of vulnerable occupational groups and may have implications for other respiratory infections such as influenza.

SARS transmission in Vietnam outside of the health-care setting

To evaluate the risk of transmission of SARS coronavirus outside of the health-care setting, close household and community contacts of laboratory-confirmed SARS cases were identified and followed up for clinical and laboratory evidence of SARS infection. Individual- and household-level risk factors for transmission were investigated. Nine persons with serological evidence of SARS infection were identified amongst 212 close contacts of 45 laboratory-confirmed SARS cases (secondary attack rate 4.2%, 95% CI 1.5-7). In this cohort, the average number of secondary infections caused by a single infectious case was 0.2. Two community contacts with laboratory evidence of SARS coronavirus infection had mild or sub-clinical infection, representing 3% (2/65) of Vietnamese SARS cases. There was no evidence of transmission of infection before symptom onset. Physically caring for a symptomatic laboratory-confirmed SARS case was the only independent risk factor for SARS transmission (OR 5.78, 95% CI 1.23-24.24).

Early diagnosis of SARS: lessons from the Toronto SARS outbreak

The clinical presentation of SARS is nonspecific and diagnostic tests do not provide accurate results early in the disease course. Initial diagnosis remains reliant on clinical assessment. To identify features of the clinical assessment that are useful in SARS diagnosis, the exposure status and the prevalence and timing of symptoms, signs, laboratory and radiographic findings were determined for all adult patients admitted with suspected SARS during the Toronto SARS outbreak. Findings were compared between patients with laboratory-confirmed SARS and those in whom SARS was excluded by laboratory or public health investigation. Of 364 cases, 273 (75%) had confirmed SARS, 30 (8%) were excluded, and 61 (17%) remained indeterminate. Among confirmed cases, exposure occurred in the healthcare environment (80%) or in the households of affected patients (17%); community or travel-related cases were rare (<3%). Fever occurred in 97% of patients by the time of admission. Respiratory findings including cough, dyspnea and pulmonary infiltrates evolved later and were present in only 59, 37 and 68% of patients, respectively, at admission. Direct exposure, fever on the first day of illness, and elevated temperature, pulmonary infiltrates, lymphopenia and thrombocytopenia at admission were associated with confirmed cases. Rhinorrhea, sore throat, and an elevated neutrophil count at admission were associated with excluded cases. In the absence of fever or significant exposure, SARS is unlikely. Other clinical, laboratory and radiographic findings further raise or lower the likelihood of SARS and provide a rational basis for estimating the likelihood of SARS and directing initial management.

Clinical and Laboratory Findings of SARS in Singapore

Introduction: Singapore was one of 29 countries worldwide affected by severe acute respiratory syndrome (SARS) in 2003. Materials and Methods: There were 238 cases identified during the outbreak. We performed a retrospective analysis of the clinical and laboratory data of 234 patients admitted to Tan Tock Seng Hospital and Singapore General Hospital. Results: The mean age of patients was 21 years, 31.6% of patients were males and 41.8% were healthcare workers. At presentation, the common symptoms were fever, myalgia, cough and headache; rhinorrhoea was uncommon. On admission, 21% had leukopenia, 18% had thrombocytopaenia, 29% had hyponatraemia, 31% had hypokalaemia, 21% had transaminitis. Polymerase chain reaction (PCR) testing of respiratory and stool samples provided the best yield at the end of the first week of illness. Thirty-two patients were initially not recognised as probable SARS and were reclassified when the serology test results were available. The chief reasons for not identifying these patients early were persistently normal chest X-rays (68.8%), very mild presentation (43.8%) and the presence of a concomitant illness (12.5%). Overall, 12% of the patients were probable SARS with atypical presentations. Overall mortality was 11.8%. Conclusion: Patients infected with the SARS coronavirus had a wide clinical presentation with non-specific symptoms.

Radiographic-clinical correlation in severe acute respiratory syndrome: study of 1373 patients in Hong Kong

PURPOSE

To retrospectively analyze serial chest radiographs in all patients with severe acute respiratory syndrome (SARS) in Hong Kong for temporal changes and differences between patients who died and those who were discharged from the hospital and to compare radiographic and clinical parameters.

MATERIALS AND METHODS

This retrospective study had ethics review board endorsement, and the need for informed consent was waived. Selected serial chest radiographs obtained from the time of presentation until discharge or death in 1373 patients with laboratory-confirmed SARS were scored. Scoring was based on the area and location of lung opacification on radiographs obtained at each of five milestones (presentation, beginning of ribavirin therapy, beginning of corticosteroid therapy, time of most severe radiographic appearance of disease, and before discharge or death). Extents of lung opacification at these five milestones were compared between patients who died and those who survived (by using a repeated-measures analysis of variance model), and the temporal trend of the radiographic-clinical parameters was analyzed (by using Cochran-Armitage trend testing, Kendall tau correlation coefficients, and descriptive graphic analysis).

RESULTS

The final cohort consisted of 1373 patients (1212 of whom [485 male and 727 female patients; mean age, 38.4 years] survived and 161 of whom [84 male and 77 female patients; mean age, 63.0 years] died). Among survivors, older patients had more extensive radiographic changes than younger ones. However, among patients who died, older patients had less extensive radiographic opacification at the worst stage of disease and just before death than did younger patients. Despite a higher mortality risk for male patients, both sexes in the same outcome group had similar radiographic findings. For both outcome groups, the rate of radiographic progression was similar for the first 11 days but diverged afterwards. The extent of opacification increased by approximately one zone every 4-5 days for the initial 11 days. Radiographic scores correlated with the ratio of PaO2 to the fraction of inspired oxygen, lymphocyte count, lactate dehydrogenase level, and neutrophil count at each milestone and in terms of changes between milestones (P < .01 for all correlation coefficients, except for radiographic score and neutrophil count between the first two milestones).

CONCLUSION

The initial extent of radiographic opacification may be useful for prognostic prediction. Radiographic progression correlates well with that of important clinical and laboratory parameters and may be used as an objective prognostic indicator early in SARS.

Thrombocytopenia in patients with severe acute respiratory syndrome (review)

Severe Acute Respiratory Syndrome (SARS) has been recognized as a new human infectious disease caused by a novel coronavirus (SARS-CoV). Hematological changes in patients with SARS were common, including notably lymphopenia and thrombocytopenia. While the former is the result of decreases in CD4+ or CD8+ T-lymphocytes related to the onset of disease or use of glucocorticoids, the latter may involve a number of potential mechanisms. Although the development of autoimmune antibodies or immune complexes triggered by viral infection may play a significant role in inducing thrombocytopenia, SARS-CoV may also directly infect hematopoietic stem/progenitor cells, megakaryocytes and platelets inducing their growth inhibition and apoptosis. Moreover, the increased consumption of platelets and/or the decreased production of platelets in the damaged lungs are a potential alternative mechanism that can contribute to thrombocytopenia in severe critical pulmonary conditions, which has been rarely revealed and will be discussed.

Recombinant nucleocapsid protein-based IgG enzyme-linked immunosorbent assay for the serological diagnosis of SARS

The recombinant nucleocapsid protein (rNP) of severe acute respiratory syndrome (SARS) coronavirus (SARS-CoV) was expressed in a baculovirus system. The purified SARS-CoV rNP was used as an antigen for detection of SARS-CoV antibodies in IgG enzyme-linked immunosorbent assay (ELISA). The ELISA was evaluated in comparison with neutralizing antibody assay and the authentic SARS-CoV antigen-based IgG ELISA. Two-hundred and seventy-six serum samples were collected from health care workers in a hospital in which a nosocomial SARS outbreak took place and used for evaluation. The SARS-CoV rNP-based IgG ELISA has 92% of sensitivity and specificity compared with the neutralizing antibody assay and 94% sensitivity and specificity compared with the authentic SARS-CoV antigen-based IgG ELISA. The results suggest that the newly developed SARS-CoV rNP-based IgG ELISA is a valuable tool for the diagnosis and seroepidemiological study of SARS. The SARS-CoV rNP-based IgG ELISA has an advantage over the conventional IgG ELISA in that the antigen can be prepared by laboratory workers without the risk of 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.

Severe acute respiratory syndrome: pertinent clinical characteristics and therapy

Severe acute respiratory syndrome (SARS) is a newly emerged infection that is caused by a previously unrecognized virus - a novel coronavirus designated as SARS-associated coronavirus (SARS-CoV). From November 2002 to July 2003 the cumulative number of worldwide cases was >8000, with a mortality rate of close to 10%. The mortality has been higher in older patients and those with co-morbidities. SARS has been defined using clinical and epidemiological criteria and cases are considered laboratory-confirmed if SARS coronavirus is isolated, if antibody to SARS coronavirus is detected, or a polymerase chain reaction test by appropriate criteria is positive. At the time of writing (24 May 2004), no specific therapy has been recommended. A variety of treatments have been attempted, but there are no controlled data. Most patients have been treated throughout the illness with broad-spectrum antimicrobials, supplemental oxygen, intravenous fluids, and other supportive measures. Transmission of SARS is facilitated by close contact with patients with symptomatic infection. The majority of cases have been reported among healthcare providers and family members of SARS patients. Since SARS-CoV is contagious, measures for prevention center on avoidance of exposure, and infection control strategies for suspected cases and contacts. This includes standard precautions (hand hygiene), contact precautions (gowns, goggles, gloves) and airborne precautions (negative pressure rooms and high efficiency masks). In light of reports of new cases identified during the winter of 2003-4 in China, it seems possible that SARS will be an important cause of pneumonia in the future, and the screening of outpatients at risk for SARS may become part of the pneumonia evaluation.

ACE1 polymorphism and progression of SARS

We have hypothesized that genetic predisposition influences the progression of SARS. Angiotensin converting enzyme (ACE1) insertion/deletion (I/D) polymorphism was previously reported to show association with the adult respiratory distress syndrome, which is also thought to play a key role in damaging the lung tissues in SARS cases. This time, the polymorphism was genotyped in 44 Vietnamese SARS cases, with 103 healthy controls who had had a contact with the SARS patients and 50 controls without any contact history. SARS cases were divided into either non-hypoxemic or hypoxemic groups. Despite the small sample size, the frequency of the D allele was significantly higher in the hypoxemic group than in the non-hypoxemic group (p = 0.013), whereas there was no significant difference between the SARS cases and controls, irrespective of a contact history. ACE1 might be one of the candidate genes that influence the progression of pneumonia in SARS.

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.

Severe acute respiratory syndrome from the trenches, at a Singapore university hospital

The epidemiology and virology of severe acute respiratory syndrome (SARS) have been written about many times and several guidelines on the infection control and public health measures believed necessary to control the spread of the virus have been published. However, there have been few reports of the problems that infectious disease clinicians encounter when dealing with the protean manifestations of this pathogen. This is a qualitative account of some of the issues faced by an infectious disease physician when identifying and treating patients with SARS as well as protecting other healthcare workers and patients, including: identification of the chain of contagion, early recognition of the disease in the absence of a reliable and rapid diagnostic test, appropriate use of personal protective equipment, and the use of isolation to prevent super-spreading events. Many issues need to be addressed if clinicians are to be able to manage the virus should it reappear.

Epidemiological and genetic analysis of severe acute respiratory syndrome

The severe acute respiratory syndrome (SARS) epidemics in 2002–2003 showed how quickly a novel infectious disease can spread both within communities and internationally. We have reviewed the epidemiological and genetic analyses that have been published both during and since these epidemics, and show how quickly data were collected and analyses undertaken. Key factors that determine the speed and scale of transmission of an infectious disease were estimated using statistical and mathematical modelling approaches, and phylogenetic analyses provided insights into the origin and evolution of the SARS-associated coronavirus. The SARS literature continues to grow, and it is hoped that international collaboration in the analysis of epidemiological and contact-network databases will provide further insights into the spread of this newly emergent infectious disease.

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.

Lack of SARS transmission among public hospital workers, Vietnam

The severe acute respiratory syndrome (SARS) outbreak in Vietnam was amplified by nosocomial spread within hospital A, but no transmission was reported in hospital B, the second of two designated SARS hospitals. Our study documents lack of SARS-associated coronavirus transmission to hospital B workers, despite variable infection control measures and the use of personal protective equipment.