Early diagnosis of SARS: lessons from the Toronto SARS outbreak

Neurocognitive Outcome Following Recovery from Severe Acute Respiratory Syndrome - Coronavirus-1 (SARS-CoV-1)

OBJECTIVE

Severe acute respiratory syndrome (SARS) is a highly contagious viral respiratory illness associated with hypoxia and dyspnea. Many of those who contracted and recovered from SARS during the 2002-2003 outbreak reported persistent physical, psychological, and cognitive difficulties. Here, we investigated the residual influences of SARS on cognition for a subset of healthcare professionals who recovered and were referred for neuropsychological evaluation through their workplace insurance.

METHOD

Twenty-eight healthcare professionals were evaluated on neuropsychological and mood functioning approximately 1.5 years post-recovery from a severe respiratory illness. Test scores were compared with age-matched normative data, and correlations were examined between mood, self-report memory scales, subjective complaints (e.g., poor concentration, pain, fatigue), illness severity (i.e., length of hospitalization, oxygen use during hospital stay), and cognitive performance.

RESULTS

Participants performed within age expectations on the majority of cognitive measures including overall memory ability. Although processing speed was generally within normal limits, 43% showed significant speed-accuracy trade-offs favoring accuracy over maintaining speed. Deficits were observed on measures of complex attention, such as working memory and the ability to sustain attention under conditions of distraction. Participants endorsed poorer memory ability than same-age peers on a meta-memory measure and mild to moderate depression and anxiety symptoms. Objective test performance was largely uncorrelated with self-reports, mood, or illness severity, except for moderate correlations between complex attention and participants' subjective ratings of Everyday Task-Oriented Memory.

CONCLUSIONS

These findings demonstrate specific long-term cognitive deficits associated with SARS and provide further evidence of the cognitive effects of hypoxic illnesses.

The presence of psychological distress in healthcare workers across different care settings in Windsor, Ontario, during the COVID-19 pandemic: A cross-sectional study

Introduction

Few studies have examined psychological distress in healthcare workers (HCWs) across the care continuum. This study describes distress levels reported by HCWs across care settings and factors associated with distress.

Methods

A cross-sectional survey of HCWs from Windsor, Ontario, was conducted between May 30th, 2020, and June 30th, 2020. The survey included the Kessler Psychological Distress Scale (K10), sociodemographic, frontline status, perceptions of training, protection, support, respect among teams, and professional and personal stressors. Univariate analyses were used to compare across settings and multivariate logistic regression assessed factors associated with distress.

Results

Four hundred and three HCWs from the hospital (49.4%), community health and social service (18.4%), first responder (14.7%), primary care (7.9%), home (6.0%), and long-term care (LTC; 4.0%) participated in the survey. Common concerns included fear of transmitting COVID-19 to family, safety on the job, and balancing personal care with work demands. LTC and home-care HCWs reported greater concern about workload and staffing levels, whereas community health workers were more anxious about their financial security. Overall, 228 (74.2%) HCWs who completed the K10 reported high distress, with greater rates among hospital and LTC HCWs. Distress was more likely in HCWs who identified as female, younger than 55, perceived lower respect among team, and experienced greater worry about physical and mental health and managing high workloads.

Conclusion

Results showed a high degree of distress experienced by HCWs across care settings and the impact of the COVID-19 pandemic on personal and work-related stress. Promoting self-care and supportive and collaborative healthcare teams are promising avenues for mitigating symptoms of distress.

Surviving SARS and living through COVID-19: Healthcare worker mental health outcomes and insights for coping

Objective

Explore how previous work during the 2003 Severe Acute Respiratory Syndrome (SARS) outbreak affects the psychological response of clinical and non-clinical healthcare workers (HCWs) to the current COVID-19 pandemic.

Methods

A cross-sectional, multi-centered hospital online survey of HCWs in the Greater Toronto Area, Canada. Mental health outcomes of HCWs who worked during the COVID-19 pandemic and the SARS outbreak were assessed using Impact of Events—Revised scale (IES-R), Generalized Anxiety Disorder scale (GAD-7), and Patient Health Questionnaire (PHQ-9).

Results

Among 3852 participants, moderate/severe scores for symptoms of post- traumatic stress disorder (PTSD) (50.2%), anxiety (24.6%), and depression (31.5%) were observed among HCWs. Work during the 2003 SARS outbreak was reported by 1116 respondents (29.1%), who had lower scores for symptoms of PTSD (P = .002), anxiety (P < .001), and depression (P < .001) compared to those who had not worked during the SARS outbreak. Multivariable logistic regression analysis showed non-clinical HCWs during this pandemic were at higher risk of anxiety (OR, 1.68; 95% CI, 1.19–2.15, P = .01) and depressive symptoms (OR, 2.03; 95% CI, 1.34–3.07, P < .001). HCWs using sedatives (OR, 2.55; 95% CI, 1.61–4.03, P < .001), those who cared for only 2–5 patients with COVID-19 (OR, 1.59; 95% CI, 1.06–2.38, P = .01), and those who had been in isolation for COVID-19 (OR, 1.36; 95% CI, 0.96–1.93, P = .05), were at higher risk of moderate/severe symptoms of PTSD. In addition, deterioration in sleep was associated with symptoms of PTSD (OR, 4.68, 95% CI, 3.74–6.30, P < .001), anxiety (OR, 3.09, 95% CI, 2.11–4.53, P < .001), and depression (OR 5.07, 95% CI, 3.48–7.39, P < .001).

Conclusion

Psychological distress was observed in both clinical and non-clinical HCWs, with no impact from previous SARS work experience. As the pandemic continues, increasing psychological and team support may decrease the mental health impacts.

Clinical Symptoms and Types of Samples Are Critical Factors for the Molecular Diagnosis of Symptomatic COVID-19 Patients: A Systematic Literature Review

BACKGROUND

Currently, a novel coronavirus found in 2019 known as SARS-CoV-2 is the etiological agent of the COVID-19 pandemic. Various parameters including clinical manifestations and molecular evaluation can affect the accuracy of diagnosis. This review aims to discuss the various clinical symptoms and molecular evaluation results in COVID-19 patients, to point out the importance of onset symptoms, type, and timing of the sampling, besides the methods that are used for detection of SARS-CoV-2.

METHODS

A systematic literature review of current articles in the Web of Science, PubMed, Scopus, and EMBASE was conducted according to the PRISMA guideline.

RESULTS

Of the 12946 patients evaluated in this investigation, 7643 were confirmed to be COVID-19 positive by molecular techniques, particularly the RT-PCR/qPCR combined technique (qRT-PCR). In most of the studies, all of the enrolled cases had 100% positive results for molecular evaluation. Among the COVID-19 patients who were identified as such by positive PCR results, most of them showed fever or cough as the primary clinical signs. Less common symptoms observed in clinically confirmed cases were hemoptysis, bloody sputum, mental disorders, and nasal congestion. The most common clinical samples for PCR-confirmed COVID-19 patients were obtained from throat, oropharyngeal, and nasopharyngeal swabs, while tears and conjunctival secretions seem to be the least common clinical samples for COVID-19 diagnosis among studies. Also, different conserved SARS-CoV-2 gene sequences could be targeted for qRT-PCR detection. The suggested molecular assay being used by most laboratories for the detection of SARS-CoV-2 is qRT-PCR.

CONCLUSION

There is a worldwide concern on the COVID-19 pandemic and a lack of well-managed global control. Hence, it is crucial to update the molecular diagnostics protocols for handling the situation. This is possible by understanding the available advances in assays for the detection of the SARS-CoV-2 infection. Good sampling procedure and using samples with enough viral loads, also considering the onset symptoms, may reduce the qRT-PCR false-negative results in symptomatic COVID-19 patients. Selection of the most efficient primer-probe for target genes and samples containing enough viral loads to search for the existence of SARS-CoV-2 helps detecting the virus on time using qRT-PCR.

The linkage "Body Mass Index-Insomnia Levels-Eating Disorder Flexibility" in Italian nurses during the Covid-19 outbreak: a psychoendocrinological employment disease

AIM

To evaluate differences between insomnia condition and flexibility attitude to eating in Italian nurses directly involved in the care of patients affected by Covid-19 according to sex, Body Mass Index, shift working condition and incidence of new Covid-19 cases in the region of participants. Moreover, any correlations between the insomnia condition and the flexible attitude to eat have been investigated.

METHODS

An online questionnaire was administered in October 2020, including the socio-demographic section, the insomnia condition assessment, and the behavioral flexibility evaluation to develop an eating disorder.

RESULTS

341 Italian nurses answered the questionnaire. Regarding the insomnia condition levels, nurses belonging to regions with a higher incidence rate of the Covid-19 pandemic recorded higher levels of insomnia than others (p=.004). Females and nurses belonging to areas with lower Covid-19 incidence rate recorded a significantly higher total eating flexibility attitude (p=.003; p<.001), also, in the Food and Exercise flexibility (p=.007; p<.001). As regards the flexible attitude for weight and shape, significant differences were recorded among nurses according to their BMI values (p<.001) and to their incidence rate of the belonging region (p<.001). The insomnia condition levels significantly correlated with the eat flexibility attitude both in its total score (p=.010), in the general score (p=.010), and the weight and shape score (p<.001). All correlations between the insomnia conditions and the flexibility to eat were significantly inverse except for the food and exercise dimension. All the eat flexibility sub-dimensions significantly correlated among them (p<.001).

CONCLUSION

There was a direct correlation among socio-demographic factors, BMI values, insomnia, and behavioral flexibility scores in Italian nurses. So, it could be assumed that the nursing profession is at risk of developing a metabolic syndrome condition. Therefore, it could be considered a psychoendocrinological employment disease during the Covid-19 outbreak.

Clinical diagnosis of severe COVID-19: A derivation and validation of a prediction rule

BACKGROUND

The widespread coronavirus disease 2019 (COVID-19) has led to high morbidity and mortality. Therefore, early risk identification of critically ill patients remains crucial.

AIM

To develop predictive rules at the time of admission to identify COVID-19 patients who might require intensive care unit (ICU) care.

METHODS

This retrospective study included a total of 361 patients with confirmed COVID-19 by reverse transcription-polymerase chain reaction between January 19, 2020, and March 14, 2020 in Shenzhen Third People’s Hospital. Multivariate logistic regression was applied to develop the predictive model. The performance of the predictive model was externally validated and evaluated based on a dataset involving 126 patients from the Wuhan Asia General Hospital between December 2019 and March 2020, by area under the receiver operating curve (AUROC), goodness-of-fit and the performance matrix including the sensitivity, specificity, and precision. A nomogram was also used to visualize the model.

RESULTS

Among the patients in the derivation and validation datasets, 38 and 9 participants (10.5% and 2.54%, respectively) developed severe COVID-19, respectively. In univariate analysis, 21 parameters such as age, sex (male), smoker, body mass index (BMI), time from onset to admission (> 5 d), asthenia, dry cough, expectoration, shortness of breath, asthenia, and Rox index < 18 (pulse oxygen saturation, SpO₂)/(FiO₂ × respiratory rate, RR) showed positive correlations with severe COVID-19. In multivariate logistic regression analysis, only six parameters including BMI [odds ratio (OR) 3.939; 95% confidence interval (CI): 1.409-11.015; P = 0.009], time from onset to admission (≥ 5 d) (OR 7.107; 95%CI: 1.449-34.849; P = 0.016), fever (OR 6.794; 95%CI: 1.401-32.951; P = 0.017), Charlson index (OR 2.917; 95%CI: 1.279-6.654; P = 0.011), PaO₂/FiO₂ ratio (OR 17.570; 95%CI: 1.117-276.383; P = 0.041), and neutrophil/lymphocyte ratio (OR 3.574; 95%CI: 1.048-12.191; P = 0.042) were found to be independent predictors of COVID-19. These factors were found to be significant risk factors for severe patients confirmed with COVID-19. The AUROC was 0.941 (95%CI: 0.901-0.981) and 0.936 (95%CI: 0.886-0.987) in both datasets. The calibration properties were good.

CONCLUSION

The proposed predictive model had great potential in severity prediction of COVID-19 in the ICU. It assisted the ICU clinicians in making timely decisions for the target population.

Post-exposure prophylaxis against SARS-CoV-2 in close contacts of confirmed COVID-19 cases (CORIPREV): study protocol for a cluster-randomized trial

BACKGROUND

Post-exposure prophylaxis (PEP) is a well-established strategy for the prevention of infectious diseases, in which recently exposed people take a short course of medication to prevent infection. The primary objective of the COVID-19 Ring-based Prevention Trial with lopinavir/ritonavir (CORIPREV-LR) is to evaluate the efficacy of a 14-day course of oral lopinavir/ritonavir as PEP against COVID-19 among individuals with a high-risk exposure to a confirmed case.

METHODS

This is an open-label, multicenter, 1:1 cluster-randomized trial of LPV/r 800/200 mg twice daily for 14 days (intervention arm) versus no intervention (control arm), using an adaptive approach to sample size calculation. Participants will be individuals aged > 6 months with a high-risk exposure to a confirmed COVID-19 case within the past 7 days. A combination of remote and in-person study visits at days 1, 7, 14, 35, and 90 includes comprehensive epidemiological, clinical, microbiologic, and serologic sampling. The primary outcome is microbiologically confirmed COVID-19 infection within 14 days after exposure, defined as a positive respiratory tract specimen for SARS-CoV-2 by polymerase chain reaction. Secondary outcomes include safety, symptomatic COVID-19, seropositivity, hospitalization, respiratory failure requiring ventilator support, mortality, psychological impact, and health-related quality of life. Additional analyses will examine the impact of LPV/r on these outcomes in the subset of participants who test positive for SARS-CoV-2 at baseline. To detect a relative risk reduction of 40% with 80% power at α = 0.05, assuming the secondary attack rate in ring members (p0) = 15%, 5 contacts per case and intra-class correlation coefficient (ICC) = 0.05, we require 110 clusters per arm, or 220 clusters overall and approximately 1220 enrollees after accounting for 10% loss-to-follow-up. We will modify the sample size target after 60 clusters, based on preliminary estimates of p0, ICC, and cluster size and consider switching to an alternative drug after interim analyses and as new data emerges. The primary analysis will be a generalized linear mixed model with logit link to estimate the effect of LPV/r on the probability of infection. Participants who test positive at baseline will be excluded from the primary analysis but will be maintained for additional analyses to examine the impact of LPV/r on early treatment.

DISCUSSION

Harnessing safe, existing drugs such as LPV/r as PEP could provide an important tool for control of the COVID-19 pandemic. Novel aspects of our design include the ring-based prevention approach, and the incorporation of remote strategies for conducting study visits and biospecimen collection.

TRIAL REGISTRATION

This trial was registered at www.ClinicalTrials.gov ( NCT04321174 ) on March 25, 2020.

Perspective on the Role of Antibodies and Potential Therapeutic Drugs to Combat COVID-19

The sudden emergence of the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causing the coronavirus disease of 2019 (COVID-19) has brought the world to a standstill. Thousands of people across the globe are biting the dust with every passing day and yet more are being tested positive for the SARS-CoV-2 infection. In order to dispense this current crisis, numerous treatment options have been tried and tested and many more are still under scrutiny. The development of vaccines may help in the prevention of the global pandemic, however, there is still a need for the development of alternate approaches to combat the disease. In this review we highlight the new discoveries and furtherance in the antibody based therapeutic options and the potent drugs, with special emphasis on the development of the monoclonal and polyclonal antibodies and the repurposed drugs, which may prove to be of significant importance for the treatment of COVID-19, in the days to come. It is an attempt to evaluate the currently presented challenges so as to provide a scope for the ongoing research and assistance in the development of the effective therapeutic options against SARS-CoV-2.

Community Health Workers and Pandemic Preparedness: Current and Prospective Roles

Despite the importance of community health workers (CHWs) to health systems in resource-constrained environments, relatively little has been written about their contributions to pandemic preparedness. In this perspective piece, we draw from the response to the 2014 Ebola and 2015 Zika epidemics to review examples whereby CHWs contributed to health security and pandemic preparedness. CHWs promoted pandemic preparedness prior to the epidemics by increasing the access to health services and products within communities, communicating health concepts in a culturally appropriate fashion, and reducing the burdens felt by formal healthcare systems. During the epidemics, CHWs promoted pandemic preparedness by acting as community-level educators and mobilizers, contributing to surveillance systems, and filling health service gaps. Acknowledging the success CHWs have had in these roles and in previous interventions, we propose that the cadre may be better engaged in pandemic preparedness in the future. Some practical strategies for achieving this include training and using CHWs to communicate One Health information to at-risk communities prior to outbreaks, pooling them into a reserve health corps to be used during public health emergencies, and formalizing agreements and strategies to promote the early engagement of CHWs in response actions. Recognizing that CHWs already play a role in pandemic preparedness, we feel that expanding the roles and responsibilities of CHWs represents a practical means of improving pandemic and community-level resilience.

Emerging and Rare Viral Infections in Transplantation

Immunocompromised patients such as those undergoing solid organ or hematopoietic stem cell transplantation are at substantial risk for infection with numerous pathogens. Infections with cytomegalovirus (CMV), herpes simplex virus (HSV), Epstein–Barr virus (EBV), and human herpesvirus-6 (HHV-6) are well-described complications of transplantation. As viruses previously believed to be quiescent through widespread vaccination (e.g., measles and mumps) reemerge and molecular diagnostic techniques are refined, rare and emerging viral infections are increasingly diagnosed in transplant recipients. This chapter will review the clinical manifestations, diagnosis, and potential antiviral therapies for these viruses in the transplant population.

A North/South collaboration between two national public health institutes--a model for global health protection

Rapid international spread of emerging infections has increased interest in strategic collaborations, as they may be the best way to protect populations. Strategic collaborations can build capacity in less-resourced settings. As specialised institutions that provide a stable locus of expertise, continuity of experience, scientific knowledge, and appropriate human, technical, and financial resources, national public health institutes (NPHIs) are well-prepared to tackle public health challenges. We describe how a collaboration between the NPHIs of England and South Africa built a mutually beneficial professional relationship to help implement the WHO International Health Regulations, build capacity for health protection, and promote the exchange of information, advice, and expertise. We illustrate how this can be achieved in a mutually beneficial way.

Factors Associated With Critical-Care Healthcare Workers' Adherence to Recommended Barrier Precautions During the Toronto Severe Acute Respiratory Syndrome Outbreak

Objective.

To assess factors associated with adherence to recommended barrier precautions among healthcare workers (HCWs) providing care to critically ill patients with severe acute respiratory syndrome (SARS).

Setting.

Fifteen acute care hospitals in Ontario, Canada

Design.

Retrospective cohort study.

Patients.

All patients with SARS who required intubation during the Toronto SARS outbreak in 2003.

Participants.

HCWS who provided care to or entered the room of a SARS patient during the period from 24 hours before intubation until 4 hours after intubation.

Methods.

Standardized interviews were conducted with eligible HCWs to assess their interactions with the SARS patient, their use of barrier precautions, their practices for removing personal protective equipment, and the infection control training they received.

Results.

Of 879 eligible HCWs, 795 (90%) participated. In multivariate analysis, the following predictors of consistent adherence to recommended barrier precautions were identified: recognition of the patient as a SARS case (odds ratio [OR], 2.5 [95% confidence interval {CI}, 1.5-4.5); recent infection control training (OR for interactive training, 2.7 [95% CI, 1.7-4.4]; OR for passive training, 1.7 [95% CI, 1.0-3.0]), and working in a SARS unit (OR, 4.0 [95% CI, 1.8-8.9]) or intensive care unit (OR, 4.3 [95% CI, 2.0-9.0]). Two factors were associated with significantly lower rates of consistent adherence: the provision of care for patients with higher Acute Physiology and Chronic Health Evaluation (APACHE) II scores (OR for score APACHE II of 20 or greater, 0.4 [95% CI, 0.28-0.68]) and work on shifts that required more frequent room entry (OR for 6 or more entries per shift, 0.5 [95% CI, 0.32-0.86]).

Conclusions.

There were significant deficits in knowledge about self-protection that were partially corrected by education programs during the SARS outbreak. HCWs' adherence to self-protection guidelines was most closely associated with whether they provided care to patients who had received a definite diagnosis of SARS.

Genetic associations of fatigue and other symptom domains of the acute sickness response to infection

The acute sickness response to infection is a conserved set of changes in physiology and behaviour, featuring fever, fatigue, musculo-skeletal pain, disturbed mood, and cognitive difficulties. The manifestations differ somewhat between individuals, including those infected with pathogens which do not have genetic variability--suggesting host determinants. Principal components analysis (PCA) was applied to acute phase, self-report symptom data from subjects in the Dubbo Infection Outcomes Study (n=296) to empirically derive indices of fatigue, pain, neurocognitive difficulties, and mood disturbance, as well as overall illness severity. Associations were sought with functional single nucleotide polymorphisms (SNPs) in the cytokine genes, interleukin (IL)-6, tumour necrosis factor (TNF)-α, interferon (IFN)-γ, and IL-10. The summed individual symptom indices correlated with overall severity and also with functional status. The relative contribution of individual symptom domains to the overall illness was stable over time within subjects, but varied between subjects with the same infection. The T allele of the IFN-γ +874 T/A SNP was associated with increased fatigue (p=0.0003; OR: 3.3). The C allele of the IL-10 -592 C/A SNP exerted a protective effect on neurocognitive difficulties (p=0.017; OR: 0.52); while the A allele for the IL-10 -592 SNP was associated with increased mood disturbance (p=0.044; OR: 1.83), as was the G allele of the IL-6 -174 G/C SNP (p=0.051; OR: 1.83). The acute sickness response has discrete symptom domains including fatigue, which have unique genetic associations. These data provide novel insights into the pathophysiology of fatigue states.

Chronic widespread musculoskeletal pain, fatigue, depression and disordered sleep in chronic post-SARS syndrome; a case-controlled study

BACKGROUND

The long term adverse effects of Severe Acute Respiratory Syndrome (SARS), a viral disease, are poorly understood.

METHODS

Sleep physiology, somatic and mood symptoms of 22 Toronto subjects, 21 of whom were healthcare workers, (19 females, 3 males, mean age 46.29 yrs.+/- 11.02) who remained unable to return to their former occupation (mean 19.8 months, range: 13 to 36 months following SARS) were compared to 7 healthy female subjects. Because of their clinical similarities to patients with fibromyalgia syndrome (FMS) these post-SARS subjects were similarly compared to 21 drug free female patients, (mean age 42.4 +/- 11.8 yrs.) who fulfilled criteria for fibromyalgia.

RESULTS

Chronic post-SARS is characterized by persistent fatigue, diffuse myalgia, weakness, depression, and nonrestorative sleep with associated REM-related apneas/hypopneas, an elevated sleep EEG cyclical alternating pattern, and alpha EEG sleep anomaly. Post- SARS patients had symptoms of pre and post-sleep fatigue and post sleep sleepiness that were similar to the symptoms of patients with FMS, and similar to symptoms of patients with chronic fatigue syndrome. Both post-SARS and FMS groups had sleep instability as indicated by the high sleep EEG cyclical alternating pattern rate. The post-SARS group had a lower rating of the alpha EEG sleep anomaly as compared to the FMS patients. The post-SARS group also reported less pre-sleep and post-sleep musculoskeletal pain symptoms.

CONCLUSIONS

The clinical and sleep features of chronic post-SARS form a syndrome of chronic fatigue, pain, weakness, depression and sleep disturbance, which overlaps with the clinical and sleep features of FMS and chronic fatigue syndrome.

Effectiveness of ribavirin and corticosteroids for severe acute respiratory syndrome

OBJECTIVE

Ribavirin and corticosteroids were used widely as front-line treatments for severe acute respiratory syndrome; however, previous evaluations were inconclusive. We assessed the effectiveness of ribavirin and corticosteroids as the initial treatment for severe acute respiratory syndrome using propensity score analysis.

METHODS

We analyzed data on 1755 patients in Hong Kong and 191 patients in Toronto with severe acute respiratory syndrome using a generalized propensity score approach.

RESULTS

The adjusted excess case fatality ratios of patients with severe acute respiratory syndrome receiving the combined therapy of ribavirin and corticosteroids within 2 days of admission, compared with those receiving neither treatment within 2 days of admission, were 3.8% (95% confidence interval, -1.5 to 9.2) in Hong Kong and 2.1% (95% confidence interval, -44.3 to 48.5) in Toronto.

CONCLUSIONS

Our results add strength to the hypothesis that the combination of ribavirin and corticosteroids has no therapeutic benefit when given early during severe acute respiratory syndrome infection. Further studies may investigate the effects of these treatments later in disease course.

Establishing a surveillance network for severe lower respiratory tract infections in Korean infants and young children

To reduce morbidity and mortality through integrated case management, a pilot study to detect respiratory viruses in patients with acute lower respiratory infections (ALRIs) was designed as part of a nationwide surveillance for this disease in Korea. The study population consisted of hospitalized patients under the age of 5 years with bronchiolitis, pneumonia, croup, or acute respiratory distress syndrome. A prospective 6-month study was performed. Two hundred and ninety-seven nasopharyngeal secretions were collected and multiplex reverse transcriptase polymerase chain reactions (RT-PCR)/polymerase chain reactions (PCR) were performed to detect respiratory viruses. If there were any positive RT-PCR/PCR results, viral cultures were proceeded for confirmation. Respiratory viruses were identified in 49.6% of 296 patients. The detection rates were as follows: respiratory syncytial virus (RSV) was the most commonly detected in 52.7% (87/165), human metapneumovirus (hMPV) in 15.8%, human corona virus (hCoV) in 5.5%, adenovirus in 9.7%, human bocavirus (hBoV) in 5.5%, parainfluenza virus (PIV) in 3.6%, rhinovirus (RV) in 4.2%, and the influenza virus in 3% of the patients with ALRIs. The consistent rate of positive results between RT-PCR and viral culture was 92% (105/114). Using our methods to detect viral causes seemed to be acceptable for the national surveillance of severe acute respiratory infections in infants and children.

Impact on health care workers employed in high-risk areas during the Toronto SARS outbreak

BACKGROUND

A number of publications focusing on health care workers (HCWs) during a severe acute respiratory syndrome (SARS) outbreak have suggested that HCWs experienced psychological distress, particularly increased levels of posttraumatic stress symptomatology (PTSS). Factors contributing to increased distress in HCWs working in high-risk areas treating patients with SARS have not been fully elucidated. The goal of this study was to quantify the psychological effects of working in a high-risk unit during the SARS outbreak.

METHODS

HCWs in a Toronto hospital who worked in high-risk areas completed a questionnaire regarding their attitude toward the SARS crisis along with the Impact of Event Scale-Revised, which screens for PTSS. The comparison group consisted of clinical units that had no contact with patients infected with SARS.

RESULTS

Factors that were identified to cause distress in the 248 respondent HCWs were the following: (a) perception of risk to themselves, (b) impact of the SARS crisis on their work life, (c) depressive affect, and (d) working in a high-risk unit. In addition, HCWs who cared for only one SARS patient in comparison to those caring for multiple SARS patients experienced more PTSS.

CONCLUSIONS

As expected, HCWs who were working in high-risk units experienced greater distress. Contrary to expectations, HCWs who experienced greater contact with SARS patients while working in the high-risk units were less distressed. This suggests that HCW experience in treating patients infected with SARS may be a mediating factor that could be amenable to intervention in future outbreaks.

Adverse events associated with high-dose ribavirin: evidence from the Toronto outbreak of severe acute respiratory syndrome

Study Objectives. To distinguish adverse events related to ribavirin therapy from those attributable to severe acute respiratory syndrome (SARS), and to determine the rate of potential ribavirin‐related adverse events.

Design. Retrospective cohort study.

Setting. Hospitals in Toronto, Ontario, Canada.

Patients. A cohort of 306 patients with confirmed or probable SARS, 183 of whom received ribavirin and 123 of whom did not, between February 23, 2003, and July 1, 2003. Of the 183 treated patients, 155 (85%) received very high‐dose ribavirin; the other 28 treated patients received lower‐dose regimens.

Measurements and Main Results. Data on all patients with SARS admitted to hospitals in Toronto were abstracted from charts and electronic databases onto a standardized form by trained research nurses. Logistic regression was used to evaluate the association between ribavirin use and each adverse event (progressive anemia, hypomagnesemia, hypocalcemia, bradycardia, transaminitis, and hyperamylasemia) after adjusting for SARS‐related prognostic factors and corticosteroid use. In the primary logistic regression analysis, ribavirin use was strongly associated with anemia (odds ratio [OR] 3.0, 99% confidence interval [CI] 1.5–6.1, p<0.0001), hypomagnesemia (OR 21, 99% CI 5.8–73, p<0.0001), and bradycardia (OR 2.3, 99% CI 1.0–5.1, p=0.007). Hypocalcemia, transaminitis, and hyperamylasemia were not associated with ribavirin use. The risk of anemia, hypomagnesemia, and bradycardia attributable to ribavirin use was 27%, 45%, and 17%, respectively.

Conclusions. High‐dose ribavirin is associated with a high rate of adverse events. The use of high‐dose ribavirin is appropriate only for the treatment of infectious diseases for which ribavirin has proven clinical efficacy, or in the context of a clinical trial. Ribavirin should not be used empirically for the treatment of viral syndromes of unknown origin.

Community acquired pneumonia in the tropics

PURPOSE OF REVIEW

Due to the exponential growth of international exchange, millions of travelers are exposed to respiratory pathogens in the tropics and may return ill. Community-acquired pneumonia is one of the more prevalent infections.

RECENT FINDINGS

The acquisition of infections in the tropics, including community-acquired pneumonias, has been described for several centuries. During recent decades some microorganisms have been disclosed as causative of the disease (Legionella pneumophila in 1976 and hantavirus in 1990); other microorganisms are real new pathogens that were not previously demonstrated to have a pathogenic role in humans (e.g. severe acute respiratory syndrome coronavirus producing an outbreak in 2003 and H5N1 avian influenza virus producing an increasing number of human cases over the last few years).

SUMMARY

A number of microorganisms may produce pneumonia in people who live or have traveled to tropical zones. History, including geography and epidemiology, physical exam and complementary workout are precious tools for the diagnosis, therapy and prevention. Exposure to microorganisms in tropical areas may show different patterns. A high index of suspicion, detailed investigation of travel, exposure history of the patient, and a basic understanding of the incubation periods and distribution of the various potential pathogens are imperative for the diagnosis.

Alternative methods of estimating an incubation distribution: examples from severe acute respiratory syndrome

BACKGROUND

Accurate and precise estimates of the incubation distribution of novel, emerging infectious diseases are vital to inform public health policy and to parameterize mathematical models.

METHODS

We discuss and compare different methods of estimating the incubation distribution allowing for interval censoring of exposures, using data from the severe acute respiratory syndrome (SARS) epidemic in 2003 as an example.

RESULTS

Combining data on unselected samples of 149 and 168 patients with defined exposure intervals from Toronto and Hong Kong, respectively, we estimated the mean and variance of the incubation period to be 5.1 day and 18.3 days and the 95th percentile to be 12.9 days. We conducted multiple linear regression on the log incubation times and found that incubation was significantly longer in Toronto than in Hong Kong and in older compared with younger patients, while it was significantly shorter in healthcare workers than in other patients.

CONCLUSIONS

Our findings suggest subtle but important heterogeneities in the incubation period of SARS among different strata of patients. Robust estimation of the incubation period should be independently carried out in different settings and subgroups for novel human pathogens using valid statistical methods.

Human immunopathogenesis of severe acute respiratory syndrome (SARS)

Progressive immune-associated injury is a hallmark of severe acute respiratory syndrome (SARS). Viral evasion of innate immunity, hypercytokinemia and systemic immunopathology in the SARS coronavirus (SARS CoV) infected host have been suggested as possible mechanisms for the cause of severe pathology and morbidity in SARS patients. The molecular and cellular basis for how SARS CoV impacts the host immune system resulting in severe SARS, however, has not been elucidated. The variable clinical course of SARS may be the result of complex programs of host responses against the infectious agent. Therefore, the systematic analysis of innate and adaptive immune responses to SARS CoV is imperative in building as complete an immunological model as possible of host immunity and inflammatory responses during illness. Here we review recent advances in SARS immunopathogenesis research and present a summary of our findings regarding host responses in SARS patients. We contend that dysregulated type I and II interferon (IFN) responses during SARS may culminate in a failure of the switch from hyper-innate immunity to protective adaptive immune responses in the human host.

Role of laboratory variables in differentiating SARS-coronavirus from other causes of community-acquired pneumonia within the first 72 h of hospitalization

The Centers for Disease Control and Prevention (CDC) recommend that SARS-coronavirus (SARS-CoV) testing be considered in epidemiologically high-risk patients hospitalized with community-acquired pneumonia (CAP) if no alternative diagnosis is identified after 72 h. The aim of this study was to identify routine laboratory variables that might indicate the need for SARS-CoV testing. Routine hematological/biochemical variables in patients with laboratory-confirmed SARS (2003) were compared with those in consecutive patients hospitalized June–December 2004 with radiologically confirmed CAP. Stepwise logistic regression analyses were performed to identify discriminating variables at baseline and by day 3 of hospitalization. Nasopharyngeal aspiration and antigen detection for influenza virus and respiratory syncytial virus using an immunofluorescence assay (IFA) were routinely performed in patients with CAP. Altogether, 181 patients with CAP (who remained undiagnosed by IFA) and 303 patients with SARS were studied. The mean intervals from symptom onset to admission were 3.1 and 2.8 days, respectively (p > 0.05). The etiological agent of CAP was identified retrospectively in only 39% of cases, the majority being bacterial pathogens. At baseline, age and absolute neutrophil count (ANC) were the only independent discriminating variables (p < 0.0001). Using a value of <4.4 × 10⁹/l as the cutoff for ANC, the sensitivity and specificity of ANC for discriminating SARS were 64 and 95%, respectively (AUC 0.90). By day 3 of hospitalization, age (p < 0.0001), change in ANC (p = 0.0003), and change in bilirubin (p = 0.0065) were discriminating variables. A model combining age <65 years, a change in ANC of >−3 × 10⁹/l, and a change in bilirubin of ≥0 mmol/l had a sensitivity of 43% and a specificity of 95% for SARS (AUC 0.90). There are only a few laboratory features (including lymphopenia) that clearly discriminate SARS from other causes of CAP. Nevertheless, when evaluating epidemiologically high-risk patients with CAP and no immediate alternative diagnosis, a low ANC on presentation along with poor clinical and laboratory responses after 72 h of antibiotic treatment may raise the index of suspicion for SARS and indicate a need to perform SARS-CoV testing.

Research translation: a new frontier for clinical laboratories

Translational research and translational medicine (referred to hereafter as translational research) are interchangeable terms that underline the pressing need to translate into practical benefits for those affected by disease the extensive investments divested by the private and public sectors in biomedical research. For people more directly involved in clinical practice (physicians, clinical laboratory professionals and patients), translational research responds to the need to accelerate the capture of benefits of research, closing the gap between what we know and what we practice. This basically means the transfer of diagnostic and therapeutic advances proven effective in large, well-conducted trials (and, therefore, evidence-based) to daily medical practice. Translational research should be regarded as a two-way road: bench to bedside, and bedside to bench. In particular, to make possible a more effective translation process, a new road map should be implemented through interaction and cooperation between basic researchers, clinicians, laboratory professionals and manufacturers. Some examples of recent developments in clinical laboratory testing, including markers of cardiovascular diseases, clinical proteomics and recombinant allergens, may explain the importance of careful evaluation of all variables that allow the introduction of such new insights into clinical practice to assure better clinical outcomes. The vital role of laboratory medicine in the delivery of safer and more effective healthcare requires more careful evaluation not only of the analytical characteristics, but also of any other variable that may affect the clinical usefulness and diagnostic performances of laboratory tests, thus allowing more accurate interpretation and utilization of laboratory information.

Clin Chem Lab Med 2006;44:1303–12.