When should a diagnosis of influenza be considered in adults requiring intensive care unit admission? Results of population-based active surveillance in Toronto

Introduction

There is a paucity of data about the clinical characteristics that help identify patients at high risk of influenza infection upon ICU admission. We aimed to identify predictors of influenza infection in patients admitted to ICUs during the 2007/2008 and 2008/2009 influenza seasons and the second wave of the 2009 H1N1 influenza pandemic as well as to identify populations with increased likelihood of seasonal and pandemic 2009 influenza (pH1N1) infection.

Methods

Six Toronto acute care hospitals participated in active surveillance for laboratory-confirmed influenza requiring ICU admission during periods of influenza activity from 2007 to 2009. Nasopharyngeal swabs were obtained from patients who presented to our hospitals with acute respiratory or cardiac illness or febrile illness without a clear nonrespiratory aetiology. Predictors of influenza were assessed by multivariable logistic regression analysis and the likelihood of influenza in different populations was calculated.

Results

In 5,482 patients, 126 (2.3%) were found to have influenza. Admission temperature ≥38°C (odds ratio (OR) 4.7 for pH1N1, 2.3 for seasonal influenza) and admission diagnosis of pneumonia or respiratory infection (OR 7.3 for pH1N1, 4.2 for seasonal influenza) were independent predictors for influenza. During the peak weeks of influenza seasons, 17% of afebrile patients and 27% of febrile patients with pneumonia or respiratory infection had influenza. During the second wave of the 2009 pandemic, 26% of afebrile patients and 70% of febrile patients with pneumonia or respiratory infection had influenza.

Conclusions

The findings of our study may assist clinicians in decision making regarding optimal management of adult patients admitted to ICUs during future influenza seasons. Influenza testing, empiric antiviral therapy and empiric infection control precautions should be considered in those patients who are admitted during influenza season with a diagnosis of pneumonia or respiratory infection and are either febrile or admitted during weeks of peak influenza activity.     

Should lower respiratory tract secretions from intensive care patients be systematically screened for influenza virus during the influenza season?

ABSTRACT: INTRODUCTION: Influenza is easily overlooked in intensive care units (ICUs), particularly in patients with alternative causes of respiratory failure or in those who acquire influenza during their ICU stay. METHODS: We performed a prospective study of patients admitted to three adult ICUs of our hospital from December 2010 to February 2011. All tracheal aspirate (TA) samples sent to the microbiology department were systematically screened for influenza. We defined influenza as unsuspected if testing was not requested and the patient was not receiving empirical antiviral therapy after sample collection. RESULTS: We received TA samples from 105 patients. Influenza was detected in 31 patients and was classified as unsuspected in 15 (48.4%) patients, and as hospital acquired in 13 (42%) patients. Suspected and unsuspected cases were compared, and significant differences were found for age (53 versus 69 median years), severe respiratory failure (68.8% versus 20%), surgery (6.3% versus 60%), median days of ICU stay before diagnosis (1 versus 4), nosocomial infection (18.8% versus 66.7%), cough (93.8% versus 53.3%), localized infiltrate on chest radiograph (6.3% versus 40%), median days to antiviral treatment (2 versus 9), pneumonia (93.8% versus 53.3%), and acute respiratory distress syndrome (75% versus 26.7%). Multivariate analysis showed admission to the surgical ICU (odds ratio (OR), 37.1; 95% confidence interval (CI), 2.1 to 666.6; P = 0.01) and localized infiltrate on chest radiograph (OR, 27.8; 95% CI, 1.3 to 584.1; P = 0.03) to be independent risk factors for unsuspected influenza. Overall mortality at 30 days was 29%. ICU admission for severe respiratory failure was an independent risk factor for poor outcome. CONCLUSION: During the influenza season, almost one third of critical patients with suspected lower respiratory tract infection had influenza, and in 48.4%, the influenza was unsuspected. Lower respiratory samples from adult ICUs should be systematically screened for influenza during seasonal epidemics.     

Surveillance of viral respiratory tract infections over a one year period in mainly hospitalized Austrian infants and children by a rapid enzyme-linked immunosorbent assay diagnosis

In order to obtain more information on viral respiratory tract infections in Austrian infants and children, nasopharyngeal secretions from 1432 infants and children, collected from October 1984 to October 1985, were screened for the presence of respiratory syncytial virus (RSV), adenoviruses, parainfluenza virus type 1, 2, and 3, and influenza viruses type A and B, by enzyme-linked immunosorbent assay (ELISA). The results obtained were analyzed with respect to incidence, seasonal distribution and clinical syndromes associated with the different viral pathogens investigated and also with the practicability of ELISA diagnostics over long distances. A viral etiology of acute respiratory tract infection was confirmed in 372 (26%) infants. RSV was detected in 286 (20%) of the nasal secretions and was thus the most frequently encountered agent. RSV infections occurred mainly in the winter months and were often associated with bronchitis, bronchiolitis, and pneumonia. Only sporadic infections were found with one of the other viruses investigated.     

1197例患者呼吸道感染病原体IgM检测结果分析

目的探讨9项呼吸道感染病原体IgM抗体检测在成人急性呼吸道感染中的作用,为临床提供早期诊断依据。方法选取成都军区昆明总医院呼吸道感染患者1 197例,通过9项呼吸道感染病原体IgM抗体试剂检测住院成人患者血清病原体抗体,分析9项呼吸道感染病原体在不同年龄段及性别患者血清中的检出情况。结果1 197例患者血清IgM抗体阳性共371例,总阳性率为30.99%(371/1 197);肺炎支原体(MP)阳性率最高,为16.96%(203/1 197);其次为乙型流感病毒(IFB),阳性率为16.21%(194/1 197);副流感病毒(PIV)、甲型流感病毒(IFA)阳性率分别为10.03%、7.44%。病原体合并感染170例,阳性率为14.20%(170/1 197),占阳性病例的45.82%(170/371)。结论昆明地区呼吸道感染的病原体主要为MP、IFB、PIV及IFA等,且病原体的检出率和年龄具有相关性。     

胶体金免疫层析法检测住院患者流感病毒感染临床分析

目的 使用胶体金免疫层析(GICA)法检测流感病毒,了解因急性呼吸道感染住院患者的常见流感病毒感染状况.方法 对2所三级甲等医院呼吸科收治的1145例各类呼吸道疾病患者应用GICA法检测流感病毒A、B(FIuA、B)抗原的结果进行分析,并对在不同季节、不同性别、年龄、病种及是否合并基础病的呼吸道疾病患者的流感病毒抗原检出率进行分析,找出规律和特点.结果 第一季度FluA、B检出率与第二、第三季度比较差异均有统计学意义(F1u A:x2=17.735,P=0.000;x2=14.855,P=0.000.Flu B:x2=5.326,P=0.021;x2=4.349,P=0.037);第四季度FluA、B检出率与第二、第三季度比较差异均有统计学意义(Flu A:x2=19.480,P=0.000;x2=16.771,P=0.000.Flu B:x2=6.885,P=0.009;x2=5.959,P=0.015).老年患者(≥65岁)Flu A、B检出率高于65岁以下患者(Flu A:x2=55.362,P=0.000;Flu B:x2=8.984,P=0.003).没有基础疾病的患者与合并1种、2种及3种以上基础疾病患者FluA、B检出率比较,差异均有统计学意义,随着合并基础病种类增多,FluA、B阳性检出率增高.各种疾病中COPD急性发作组(18.2%)及肺炎组(17.1%)FluA抗原检出率较其他病种高.结论 呼吸科病房住院患者中全年均有流感散发病例,第一、四季度多见.老年患者及有基础疾病患者并发流感病毒感染风险较大.     

Influenza complicating pregnancy

Influenza is a highly contagious acute respiratory infection that is of major clinical importance both in Japan and worldwide. This infection usually is not life-threatening in otherwise healthy adults, but pregnant women do not tolerate serious pulmonary involvement. In previous reports of influenza pandemics, pregnant women have experienced increased risk of morbidity and mortality compared to non-pregnant women. In addition, mothers with severe respiratory infections may have an increased risk of preterm labor. Vaccination against influenza is recommended for all women who will be pregnant during the influenza season to prevent the occurrence of influenza and the development of pneumonia. There is no firm evidence that maternal infection is associated with an increased risk of spontaneous abortion, stillbirth, or congenital anomalies. However, an infant delivered to an acutely infected patient may develop neonatal influenza as a result of close personal contact with its mother.     

Evaluation of FilmArray respiratory panel multiplex polymerase chain reaction assay for detection of pathogens in adult outpatients with acute respiratory tract infection

Although viruses are the major pathogen that causes upper respiratory tract infection (URTI) and acute bronchitis, antibiotics have been prescribed. This was a prospective observational study in influenza epidemics that enrolled adult outpatients who visited a hospital with respiratory tract infection symptoms. In this study, we evaluated the usefulness of FilmArray respiratory panel (RP). Fifty patients were enrolled. FilmArray RP detected the pathogens in 28 patients. The common pathogens were influenza virus (n = 14), respiratory syncytial virus (n = 6), and human rhinovirus (n = 6). Of the 14 patients with influenza virus, 6 were negative for the antigen test. The physicians diagnosed and treated the patients without the result of FilmArray in this study. Of the patients with positive FilmArray RP, 9 were treated with antibiotics; however, bacteria were detected in only 3 patients. By implementing FilmArray RP, URTI and acute bronchitis would be precisely diagnosed, and inappropriate use of antibiotics can be reduced.     

快速检测方法在呼吸道感染病原体检测的临床价值

目的探讨快速检测方法对呼吸道流感病毒、肺炎支原体检测的临床应用价值。方法选取该院2011年1月至2015年12月收集的386例上呼吸道感染患者标本进行检测,采用胶体金免疫沉积法检测患者鼻咽部分泌物中的A、B型流感病毒,采用快速培养法检测肺炎支原体,以间接免疫荧光法检测患者的血清病原体抗体IgM结果作为金标准,判断2种快速方法检测的临床价值。结果间接免疫荧光法共检出A型流感病毒感染患者54例,检出率13.59%;检出B型流感病毒感染患者37例,检出率9.59%;检出肺炎支原体感染患者61例,检出率15.80%。胶体金免疫沉积法检出A型流感病毒感染的敏感度为20.37%,特异性为92.77%;胶体金免疫沉积法检出B型流感病毒感染的敏感度为18.92%,特异性为93.41%;快速培养法检出肺炎支原体感染的敏感度为37.70%,特异性为89.85%。结论快速检测方法对呼吸道流感病毒、肺炎支原体检出的敏感度较低,临床上只能作为间接免疫荧光法检测的1种辅助手段。     

Viral pneumonias. Epidemic respiratory viruses

Influenza, respiratory syncytial, and parainfluenza viruses usually cause mild, self-limited illness in adults. However, elderly and immunocompromised persons are at increased risk for development of severe pneumonia. Clinical and radiographic features of epidemic viral pneumonias are often nonspecific. Newer and faster methods of viral culture and viral antigen detection have improved the capability for definitive diagnosis in recent years. Preventive measures for influenza virus pneumonia center on limiting exposure of high-risk patients to active cases of influenza, administering annual vaccinations, and providing chemoprophylaxis. Prophylaxis against RSV is effective in preventing complications. No effective vaccines have been developed against RSV or parainfluenza. Therapy for viral pneumonia is primarily supportive. Amantadine may be beneficial for influenza virus pneumonia, and ribavirin may be useful for RSV and parainfluenza virus disease. However, further definitive studies are necessary to determine their roles in these viral pneumonias.     

An outbreak of penicillin-resistantStreptococcus pneumoniae infections on an internal medicine ward

An outbreak of penicillin-resistantStreptococcus pneumoniae (PRSP) infections occurred in our hospital between January and May of 1993. Nine patients with infections/colonizations were located in 3 multiplebed rooms on an internal medicine ward. Two of the 9 patients developed pneumonia, 3 developed acute bronchitis, and 4 patients demonstrated colonization in the respiratory tract. Only 1 case of acute bronchitis was confirmed as a community-acquired infection, while the others were considered nosocomial infections, subsequently shown to be caused by at least 2 different bacterial strains. The cases of pneumonia were thought to be cross-infections transmitted by droplets. All patients with either pneumonia or bronchitis were cured by the administration of various antibiotics, including imipenem and ofloxacin. Of the 4 colonization cases, 3 patients were treated with antibiotics and the organisms successfully eradicated. Although all 5 patients with infections were cured, it is important to be attentive to the emergence of PRSP infections, as there are potential difficulties in the treatment of this organism.     

Impact of Influenza Infection Among Adult and Pediatric Populations With Hematologic Malignancy and Hematopoietic Stem Cell Transplant: A Systematic Review and Meta-Analysis

PurposeInfluenza is increasingly recognized as a leading cause of morbidity and mortality in patients with hematologic malignancies and recipients of hematopoietic stem cell transplantation (HSCT). However, the impact of influenza on this population has not been previously evaluated in a systematic review. This study systematically reviewed and summarized the outcomes of influenza infection as to in-hospital influenza-related mortality, development of lower respiratory tract infection and acute respiratory distress syndrome, need for hospitalization, intensive care unit admission, and mechanical ventilation.MethodsWe conducted a systematic search of literature using the PubMed and EMBASE databases for articles published from January 1989 through January 19, 2020, reporting laboratory-confirmed influenza in patients of any age with hematologic malignancies and HSCT. Time from transplantation was not included in the search criteria. The impact of antiviral therapy on influenza outcomes was not assessed due to heterogeneity in antiviral treatment provision across the studies. Patients with influenza-like illness, solid-tumor cancers, or nonmalignant hematologic diseases were excluded from the study. A random-effects meta-analysis was performed to estimate the prevalences and 95% CIs of each outcome of interest. A subgroup analysis was carried out to assess possible sources of heterogeneity and to evaluate the potential impact of age on the influenza infection outcomes. Heterogeneity was assessed using the I² statistic.FindingsData from 52 studies providing data on 1787 patients were included in this analysis. During seasonal epidemics, influenza-related in-hospital mortality was 16.60% (95% CI, 7.49%–27.7%), with a significantly higher death rate in adults compared to pediatric patients (19.55% [95% CI, 10.59%–29.97%] vs 0.96% [95% CI, 0%–6.77%]; P < 0.001). Complications from influenza, such as lower respiratory tract infection, developed in 35.44% of patients with hematologic malignancies and HSCT recipients, with a statistically significant difference between adults and children (46.14% vs 19.92%; P < 0.001). However, infection resulted in a higher hospital admission rate in pediatric patients compared to adults (61.62% vs 22.48%; P < 0.001). For the 2009 H1N1 pandemic, no statistically significant differences were found between adult and pediatric patients when comparing the rates of influenza-related in-hospital mortality, lower respiratory tract infection, and hospital admission. Similarly, no significant differences were noted in any of the outcomes of interest when comparing H1N1 pandemic with seasonal epidemics.ImplicationsRegardless of influenza season, patients, and especially adults, with underlying hematologic malignancies and HSCT recipients with influenza are at risk for severe outcomes including lower respiratory tract infection and in-hospital mortality.     

Cefdinir: an oral cephalosporin for the treatment of respiratory tract infections and skin and skin structure infections

Cefdinir is an oral third-generation cephalosporin (also known as an advanced-spectrum or generation cephem) with good in vitro activity against the pathogens responsible for community-acquired respiratory tract infections and uncomplicated skin and skin structure infections. The drug distributes very well in respiratory tract tissues and fluids, as well as skin blisters and ear fluids; its pharmacokinetic profile allows once- or twice-daily administration. Oral cefdinir 300 mg twice daily or 600 mg once daily in adults and adolescents, or 14 mg/kg/day in one or two daily doses in pediatric patients, administered for 5 or 10 days, has shown good clinical and bacteriological efficacy, at least equivalent to that of other oral agents in randomized controlled trials conducted in patients with community-acquired pneumonia, acute bacterial exacerbation of chronic bronchitis, sinusitis, acute otitis media, pharyngitis and uncomplicated skin and skin structure infections. Cefdinir is well tolerated and the oral suspension has shown superior taste or palatability over other comparator oral antimicrobial agents. Thus, cefdinir continues to represent an important cephalosporin option for the treatment of adult, adolescent and pediatric patients with mild or moderate respiratory tract or cutaneous infections, especially in areas with elevated rates of beta-lactamase production in Haemophilus influenzae and where resistance to other commonly used agents has emerged (e.g., macrolides, penicillins, tetracyclines, fluoroquinolones and trimethoprim-sulfamethoxazole).     

重庆南岸地区急性呼吸道感染儿童肺炎支原体临床感染特点分析

目的了解2010～2011年重庆南岸地区急性呼吸道感染儿童肺炎支原体(MP)的感染特点及流行规律,为MP感染的防治提供依据。方法收集重庆市第五人民医院儿科2010年12月至2011年11月急性呼吸道感染患儿的血清标本256例,采用肺炎支原体血清学抗体(MP-IgM)检测试剂进行血清MP-IgM检测,对不同季节、年龄及性别MP感染患儿的发病情况进行统计。结果检测MP-IgM阳性78例,阳性率为30.5%。MP阳性患儿中,39.7%(31/78)为4～7岁的学龄前儿童,不同年龄组比较,差异有统计学意义(P<0.05)。MP感染一年四季均可发生,但具有季节性差异,秋冬季感染率最高。MP感染的临床诊断主要为大叶性肺炎和节段性肺炎28例(35.9%)、间质性肺炎23例(29.5%)。临床表现主要为发热(56.4%)、咳嗽(98.5%)、喘息(35.9%)、气促(67.7%)等,但肺部体征不明显。结论 MP感染是重庆南岸地区儿童呼吸道感染的主要病因之一,其感染率有增高趋势,临床需加强对MP感染的防治。     

A virologic survey of patients admitted to a critical care unit for acute cardiorespiratory failure

Objective To document the prevalence of respiratory virus infections in patients with chronic cardiac or pulmonary disorders admitted to a critical care unit for acute cardiorespiratory failure.Design, setting, patients The study took place in a critical care unit during two consecutive winters. All patients admitted to the unit for acute respiratory or cardiac failure were enrolled. A nasal swab was taken for polymerase chain reaction (PCR) detection of influenza virus, respiratory syncytial virus (RSV), metapneumovirus, rhinovirus, and coronavirus.Results One hundred twenty-two patients were enrolled. Their mean age was 69 years; 42% of the patients were female; the new simplified acute physiology score (SAPS II) score on admission was 35.6; 94% of patients had acute respiratory failure, 14% reported influenza-like illness before admission, and 11% of patients died in the unit. Twenty-one patients (17%) tested positive for a respiratory virus. The per-1,000 positivity rates were influenza virus 66, RSV 49, rhinovirus 33, metapneumovirus 16, and coronavirus 8. No link was found between virologic results and clinical outcome. A strong link was found between the rate of influenza virus positivity and the incidence of flu-like illness in the community (p=0.017).Conclusion These results show that respiratory virus infection—particularly influenza virus infection during epidemic periods—is common among patients hospitalized for acute cardiorespiratory failure.The authors have no conflicts of interest. The study was supported by a grant from Roche (France).     

Diagnostic accuracy of acute maxillary sinusitis in adults in primary care

Objective - To evaluate the diagnostic value of symptoms and signs used in diagnosing acute community-acquired maxillary sinusitis (ACAMS), and to find useful clinical predictors for diagnosing it in adults in primary care. Design - Prospective study in the study group and retrospective study in the reference group. Setting - One primary care centre in the study group and another in the reference group. Subjects - 50 adults with prolonged upper respiratory tract infection ( &#83 7 days) or self-suspected maxillary sinusitis. As a reference group, an analysis of records and diagnoses made by GP of 45 adult patients with the same inclusion criteria from another primary care clinic. Main outcome measures - The signs and symptoms associated with the diagnosis of ACAMS by GP and otorhinolaryngologist. The value of CRP, ultrasound and peak nasal expiratory flow in the diagnosis. Results - Neither ultrasound nor any of the clinical signs increased the accuracy of diagnosis. Peak nasal expiratory flow below the normal range was associated with the diagnosis of ACAMS (p = 0.03). The presence of an otorhinolaryngologist had an influence on GP practice when compared with the reference group. Conclusion - The diagnosis of ACAMS is difficult with the available clinical methods. Peak nasal expiratory flow needs further study. New diagnostic means are needed.     

Influenza C virus surveillance during the first influenza A (H1N1) 2009 pandemic wave in Catalonia, Spain

Although particular attention is paid to influenza A and B virus isolates during influenza surveillance, influenza C virus (FLUCV) coexisted during the first influenza A (H1N1) 2009 pandemic wave during the 2009-2010 season. From 27 April 2009 to 9 May 2010, 12 strains of FLUCV were detected in specimens collected from 1713 nonhospitalized patients with upper respiratory tract illness using a molecular method. Half of the patients with FLUCV infection were older than 14 years. The most frequent symptoms were cough and fever, similar to other viral respiratory infections. Phylogenetic analysis of the hemagglutinin-esterase gene revealed that the strains belonged to the C/Kanagawa/1/76-related and C/Sao Paulo/378/82-related lineages, demonstrating their co-circulation in Catalonia. In addition to regular virological surveillance that provides information about the incidence and the exact role of FLUCV in acute viral respiratory infections in the general population, the genetic lineage identification offers additional data for epidemiological purposes.     

Healthy neonate born to a SARS-CoV-2 infected woman: A case report and review of literature

BACKGROUNDSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a newly discovered coronavirus that has generated a worldwide outbreak of infections. Many people with coronavirus disease-2019 (COVID-19) have developed severe illness, and a significant number have died. However, little is known regarding infection by the novel virus in pregnant women. We herein present a case of COVID-19 confirmed in a woman delivering a neonate who was negative for SARS-CoV-2 and related it to a review of the literature on pregnant women and human coronavirus infections.CASE SUMMARYThe patient was a 36-year-old pregnant woman in her third trimester who had developed progressive clinical symptoms when she was confirmed as infected with SARS-CoV-2. Given the potential risks for both the pregnant woman and the fetus, an emergency cesarean section was performed, and the baby and his mother were separately quarantined and cared for. As a result, the baby currently shows no signs of SARS-CoV-2 infection (his lower respiratory tract samples were negative for the virus), while the mother completely recovered from COVID-19.CONCLUSIONAlthough we presented a single case, the successful result is of great significance for pregnant women with SARS-CoV-2 infection and with respect to fully understanding novel coronavirus pneumonia.