Isolationsmaßnahmen bei Infektionen der Luftwege

Respiratory tract infections belong to the most important infections in children and adults. One third of all infection-related hospitalizations are due to respiratory tract infections. Upper respiratory tract infections are one of the most important reasons for absence from school or work. The majority of respiratory tract infections are of viral origin. Viral infections are usually highly contagious. They are transmitted mainly by droplets, but also by direct or indirect contact via contaminated objects. Isolation precautions in respiratory tract infections are important to protect health-care workers from infection and prevent nosocomial transmission in the hospital and ambulatory care setting. Unlike for the hospital setting there are no detailed recommendations available for isolation precautions in the ambulatory care setting. Isolation precautions for outpatients are described in this article.     

Respiratory syncytial virus infection in patients with hematological diseases: single-center study and review of the literature.

BACKGROUND: Respiratory syncytial virus (RSV) causes significant mortality in patients with hematological diseases, but diagnosis and treatment are uncertain. METHODS: We retrospectively identified RSV-infected patients with upper or lower respiratory tract infection (RTI) by culture, antigen testing, and polymerase chain reaction from November 2002 through April 2007. Patients with severe immunodeficiency (SID; defined as transplantation in the previous 6 months, T or B cell depletion in the previous 3 months, graft-versus-host disease [grade, >or=2], leukopenia, lymphopenia, or hypogammaglobulinemia) preferentially received oral ribavirin, intravenous immunoglobulin, and palivizumab. The remaining patients with moderate immunodeficiency (MID) preferentially received ribavirin and intravenous immunoglobulin. RESULTS: We identified 34 patients, 22 of whom had upper RTI (10 patients with MID and 12 with SID) and 12 of whom had lower RTI (2 with MID and 10 with SID). Thirty-one patients were tested by polymerase chain reaction (100% of these patients had positive results; median RSV load, 5.46 log(10) copies/mL), 30 were tested by culture (57% had positive results), and 25 were tested by antigen testing (40% had positive results). RSV-attributed mortality was 18% (6 patients died) and was associated with having >or=2 SID factors (P=.04), lower RTI (P=.01), and preengraftment (P=.012). Among 12 patients with MID (7 of whom received treatment), no progression or death occurred. Nine patients with SID and upper RTI received treatment (7 patients received ribavirin, intravenous immunoglobulin, and palivizumab); infection progressed to the lower respiratory tract in 2 patients, and 1 patient died. Ten patients with SID and lower RTI were treated, 5 of whom died, including 4 of 6 patients who received ribavirin, intravenous immunoglobulin, and palivizumab. The duration of RSV shedding correlated with the duration of symptoms in patients with SID but exceeded symptom duration in patients with MID (P<.05). CONCLUSIONS: Lower RTI, >or=2 SID criteria, and preengraftment are risk factors for RSV-attributed mortality. Polymerase chain reaction may optimize diagnosis and monitoring. Oral ribavirin therapy seems safe, but trials are needed to demonstrate its efficacy.     

Parainfluenza virus infections after hematopoietic stem cell transplantation: risk factors, response to antiviral therapy, and effect on transplant outcome

Parainfluenza virus (PIV) infections may be significant causes of morbidity and mortality in patients undergoing stem cell transplantation, but data regarding their impact on transplant-related mortality is limited. This study sought to determine the risk factors of PIV acquisition and progression to lower respiratory tract infection, their impact on transplant-related mortality, and the effectiveness of antiviral therapy. A total of 3577 recipients of hematopoietic stem cell transplantation (HSCT) between 1990 and 1999 were studied. PIV infections occurred in 253 patients (7.1%); 78% of these infections were community acquired. Multivariable analysis identified the receipt of an unrelated transplant as the only risk factor for PIV acquisition; the dose of corticosteroids at the time of PIV infection acquisition was the primary factor associated with the development of PIV-3 pneumonia, both among allogeneic and autologous HSCT recipients. Both PIV-3 upper respiratory infection and pneumonia were associated with overall mortality. Pulmonary copathogens were isolated from 29 patients (53%) with pneumonia. Mortality was highly influenced by the presence of copathogens and the need for mechanical ventilation. Aerosolized ribavirin with or without intravenous immunoglobulin did not appear to alter mortality from PIV-3 pneumonia, nor did such therapy decrease the duration of viral shedding from the nasopharynx among patients with pneumonia. Corticosteroid administration thus drives the development of PIV pneumonia in a dose-dependent fashion, even among autologous HSCT recipients. Both upper and lower tract PIV infections are predictors of mortality after HSCT. Currently available antiviral therapy appears to be inadequate in reducing viral shedding or mortality once pneumonia is established. (Blood. 2001;98:573-578)     

Parainfluenza virus 3 infection after stem cell transplant: relevance to outcome of rapid diagnosis and ribavirin treatment.

All 456 recipients of hemopoietic stem cell transplants (SCT) at the Hammersmith Hospital, London, from January 1990 through September 1996 were reviewed for parainfluenza virus (PIV) infections. Of the 24 (5.3%) PIV type 3 (PIV3)-infected patients, 10 had upper respiratory tract infection and all survived, but 8 of 14 with pneumonia died. A same-day immunofluorescence test diagnosed PIV3 infection in 20 (83%) of the 24 cases, but virus culture diagnosed only 10 (42%) of the 24 cases after a mean delay of 12 days. Eighteen PIV3-infected patients first received ribavirin at a median of 3 days after onset of symptoms, but, nevertheless, 2 patients shed PIV3 for 4 months. Six of 10 patients with pneumonia died despite early ribavirin therapy. The cause of death was not established by autopsy; 3 patients had concurrent infections, but in 3, only PIV3 was detected. The value of immunofluorescence testing for early diagnosis and treatment of PIV3 infection after SCT is demonstrated, but the outcome was not altered.     

SARS: hospital infection control and admission strategies

Nosocomial clustering with transmission to health care workers, patients and visitors is a prominent feature of severe acute respiratory syndrome (SARS). Hospital outbreaks of SARS typically occurred within the first week after admission of the very first SARS cases when the disease was not recognized and before isolation measures were implemented. In the majority of nosocomial infections, there was a history of close contact with a SARS patient, and transmission occurred via large droplets, direct contact with infectious material or by contact with fomites contaminated by infectious material. In a few instances, potential airborne transmission was reported in association with endotracheal intubation, nebulised medications and non-invasive positive pressure ventilation of SARS patients. In all SARS-affected countries, nosocomial transmission of the disease was effectively halted by enforcement of routine standard, contact and droplet precautions in all clinical areas and additional airborne precautions in the high-risk areas. In Hong Kong, where there are few private rooms for patient isolation, some hospitals have obtained good outcome by having designated SARS teams and separate wards for patient triage, confirmed SARS cases and step-down of patients in whom SARS had been ruled out. In conclusion, SARS represents one of the new challenges for those who are involved in hospital infection control. As SARS might re-emerge, all hospitals should take advantage of the current SARS-free interval to review their infection control programmes, alert mechanisms, response capability and to repair any identified inadequacies.     

恶性血液病医院感染分析

对我院2000年12月～2001年11月血液科住院病人中发生医院感染的81例患者进行回顾性统计分析。结果发现：恶性血液病医院感染率明显高于普通疾病，尤其是髓系细胞恶性血液病；感染好发部位为呼吸道、血液、口腔、消化道等，病原菌以G-杆菌为主，原发病性质及化疗是医院感染率明显增高的主要因素。认为对于恶性血液病患者采取预防措施，提高机体免疫力，早期给予积极的干预，可以减少或减轻医院感染。     

An outbreak of the 2009 influenza a (H1N1) virus in a children's hospital

Please cite this paper as: Bearden et al. (2012) An outbreak of the 2009 influenza a (H1N1) virus in a children’s hospital. Influenza and Other Respiratory Viruses 6(5), 374–379. Context Preventing nosocomial transmission of influenza is essential to reduce the morbidity and mortality associated with this infection. In October 2009, an outbreak of the 2009 influenza A (H1N1) virus occurred in a hematology ward of a children’s hospital over a 21‐day period and involved two patients and four healthcare workers. Objective To investigate nosocomial transmission of the 2009 influenza A (H1N1) virus in patients and healthcare workers. Design, setting, and participants An outbreak investigation was initiated in response to suspected nosocomial transmission of the 2009 influenza A (H1N1) virus during the peak of the 2009 pandemic. Cases were confirmed using a polymerase chain reaction (PCR) test specific for the 2009 H1N1 influenza A virus. Viruses isolated from nasopharyngeal swabs were genetically characterized using Sanger sequencing of uncloned “bulk” PCR products. Main outcome measures Virus sequencing to investigate nosocomial transmission. Results Two immunocompromised patients and four healthcare workers were found to be part of a nosocomial outbreak of the 2009 influenza A (H1N1) virus. One immunocompromised patient had a second episode of clinical influenza infection after isolation precautions had been discontinued, resulting in additional exposures. Strain‐specific PCR showed that all cases were caused by infection of the 2009 H1N1 virus. Sequencing of viral genes encoding hemagglutinin and polymerase basic subunit 2 (PB2) revealed that all viruses isolated were genetically identical at these loci, including the two episodes occurring in the same immunocompromised patient. Conclusions Prompt institution of isolation precautions is essential in preventing nosocomial outbreaks of the 2009 novel influenza A (H1N1) virus. Our data suggest that isolation precautions may need to be continued for a prolonged period of time in immunocompromised patients with influenza infection.     

Failure to Institute Appropriate Isolation Precautions for Suspected Respiratory Syncytial Virus (RSV) Infection: Frequency and Identification of Risk Factors

BACKGROUND: RSV, spread by contaminated secretions, is an important cause of respiratory illness among children, particularly in winter months. To prevent nosocomial spread, infants and young children with suspected RSV infection should be placed on contact isolation. However, the frequency with which such precautions are not appropriately implemented and the factors that influence the likelihood of effective isolation are not known.METHODS: To determine the frequency with which children with suspected RSV infection are not appropriately isolated, daily prospective surveillance was done of all children younger than 5 years old admitted to a pediatric hospital with respiratory symptoms and/or who had a specimen sent for RSV testing. Results were expressed as a percentage of all admissions eligible for isolation. A case-control study was used to identify risk factors for the failure to appropriately isolate.RESULTS: Of the 598 patients meeting isolation criteria, 211(35%) were not isolated appropriately. After multivariable analysis, significant risk factors for the failure to appropriately isolate were: admission to a Stepdown unit (OR = 1.77, CI = 1.03–3.04), age between 3 and 4 years (OR = 4.21, CI = 1.94–9.16), age between 4 and 5 years (OR = 7.35, CI = 3.08–17.51), admission in October (OR = 13.29, CI = 4.13–42.73), November (OR = 4.86, CI = 2.12–11.16), and December (OR = 3.84, CI = 1.93–7.65).CONCLUSIONS: Patients with suspected RSV infection are frequently not appropriately isolated. Risk factors for the failure to isolate offer targets for future interventions, including earlier awareness campaigns and targeted education to high-risk units.     

Methicillin-resistant Staphylococcus aureus and Acinetobacter baumannii: An unexpected difference in epidemiologic behavior

Background: The Dutch guideline on hospital policy for the prevention of nosocomial spread of methicillin-resistant Staphylococcus aureus (MRSA) states that patients transferred from hospitals abroad must be placed in strict isolation immediately on admission to a hospital in the Netherlands. Three patients colonized with both MRSA and a multiresistant Acinetobacter were transferred from hospitals in Mediterranean countries to 3 different hospitals in the Netherlands. Despite isolation precautions, Acinetobacter spread in 2 of the 3 hospitals, whereas nosocomial spread of MRSA did not occur. Methods: For outbreak analysis, the Acinetobacter isolates, identified as Acinetobacter baumannii by the use of amplified ribosomal DNA restriction analysis, were comparatively typed by 4 methods. Comparison of isolation measures in the hospitals was performed retrospectively. Results: In the 2 hospitals in which nosocomial spread of Acinetobacter occurred, most of the epidemiologically related isolates were indistinguishable from the index strains. In these 2 hospitals, isolation measures were in concordance with those recommended for the prevention of contact transmission. The precautions of the hospital in which no outbreak occurred included the prevention of airborne transmission. Conclusions: Precautions recommended for multiresistant gram-negative organisms are insufficient for the prevention of nosocomial spread of multiresistant Acinetobacter . The airborne mode of spread of acinetobacters should be taken into account, and guidelines should be revised accordingly. (AJIC Am J Infect Control 1998;26:544-51)     

The natural history of respiratory syncytial virus infection in cancer and transplant patients: implications for management

Respiratory syncytial virus (RSV) has been reported to cause severe morbidity and mortality among cancer patients receiving chemotherapy with or without autologous peripheral blood stem cell transplantation (APBSCT). However, little is known about the natural history of this infection in these patients, and current standard practice, aerosolized ribavirin plus intravenous immunoglobulin (IVIG), is extremely expensive, difficult to use, and not supported by controlled clinical trials. The purpose of this observational study was to determine the frequency, seasonality, morbidity, and mortality of RSV infection in a group of cancer patients receiving cytotoxic chemotherapy with neither ribavirin nor IVIG treatment. During the period of October 3, 1997, through October 14, 1998, 190 cancer patients (median age, 58 years; 71 women) underwent viral nasopharyngeal washing prior to chemotherapy. Multiple myeloma (MM) accounted for most patients (147, 77%). RSV was recovered from cultures taken from 71 patients (37%) throughout the year, although more frequently during fall and winter seasons (P <.001) than spring and summer. Serious respiratory complications developed in 19 (27%) of 71 RSV-positive patients versus 24 (20%) of 119 patients whose RSV cultures were negative (P =.384). The presence of renal failure or increased lactate dehydrogenase (LDH) prior to chemotherapy and the development of mucositis were the only predictive factors for severe respiratory complications. Recovery of RSV from nasopharyngeal washings among cancer patients is common, occurs throughout the year, and does not appear to increase serious morbidity or mortality. RSV infection may not necessarily be a contraindication for APBSCT or an indication for therapy with aerosolized ribavirin and IVIG.     

SARS in the intensive care unit

Approximately 20% of patients with severe acute respiratory syndrome (SARS) develop respiratory failure that requires admission to an intensive care unit (ICU). Old age, comorbidity, and elevated lactate dehydrogenase on hospital admission are associated with increased risk for ICU admission. ICU admission usually is late and occurs 8 to 10 days after symptom onset. Acute respiratory distress syndrome occurs in almost all admitted patients and most require mechanical ventilation. ICU admission is associated with significant morbidity, particularly an apparent increase in the incidence of barotrauma and nosocomial sepsis. Long-term mortality for patients admitted to the ICU ranges from 30% to 50%. Many procedures in ICUs pose a high risk for transmission of SARS coronavirus to health care workers. Contact and airborne infection isolation precautions, in addition to standard precautions, should be applied when caring for patients with SARS. Ensuring staff safety is important to maintain staff morale and delivery of adequate services.     

Parainfluenza virus type 3 infections in hematopoetic stem cell transplant recipients: response to ribavirin therapy.

Parainfluenza virus (PIV) infection can be a problem among hematopoetic stem cell transplant recipients. 125 patients were prospectively evaluated for respiratory viral infections. We describe 5 patients with PIV 3 infection and their response to early treatment with ribavirin.     

Risk of respiratory infections in health care workers: lessons on infection control emerge from the SARS outbreak

Close proximity of persons together with handling of human secretions (eg respiratory secretions) make health care workers (HCW) particularly vulnerable to transmission of droplet-transmitted respiratory infections. This was tragically highlighted during the international outbreak of severe acute respiratory syndrome (SARS) in 2003 with attack rates of more than 50% in HCW. The purpose of this article is to review common airborne and droplet-transmitted bacterial and viral respiratory tract infections with regard to their impact on health care workers. Lessons need to be learned from the SARS epidemic. The three main strategies to prevent or control occupationally acquired infections are relatively simple and cost-effective-droplet and contact precautions and for some pathogens also vaccination. Enforced implementation of stringent droplet precautions during the SARS crisis should be maintained; and this will most likely have a major additional impact on other nosocomial infections. Employee health services should proactively and creatively devise delivery systems that enhance compliance with vaccination programs for all health care workers. Hospital surveillance should be expanded to all respiratory diseases to facilitate early detection of nosocomial outbreaks, and this should also include surveillance of all HCW. Integrated syndromic and virological surveillance systems set up during the SARS epidemic will also further our understanding of other respiratory infections in the hospital setting. Even if pursuing early diagnosis for unspecific respiratory illnesses is expensive, identification of the causative organism may reduce unnecessary isolation, contact tracing and anxiety, in particular during an outbreak situation. We have a duty to protect our health care workers.     

Pre-emptive oral ribavirin therapy of paramyxovirus infections after haematopoietic stem cell transplantation: a pilot study.

Infections with the paramyxoviruses, respiratory syncytial virus (RSV) and parainfluenza virus (PIV) can result in serious morbidity and mortality after haemopoietic stem cell transplant (HSCT). Once pneumonia develops, the outcome of these infections is often poor despite anti-viral therapy. Aerosolised ribavirin has been evaluated as pre-emptive therapy for post-transplant RSV infections with some success. Due to the financial and logistic burden involved with the use of aerosolised ribavirin, we explored the efficacy and toxicity of oral ribavirin for pre-emptive therapy of post-transplant RSV and PIV infections in a dose escalating schedule (15-60 mg/kg/day). Five episodes each of RSV and PIV were treated in seven patients. Five patients were receiving treatment for GVHD and two acquired the infection in the pre-engraftment period. All the episodes of RSV infection improved with oral ribavirin with dose escalation to 30-45 mg/kg in three of them. On the other hand, only two of the five PIV infections improved with oral ribavirin. Of the three non-responders, two infections were acquired in the pre-engraftment period with one death from PIV pneumonia. Reversible anaemia was the only side-effect noted in patients treated for over 2 weeks. Thus, the use of oral ribavirin was well tolerated in the post-transplant period with no untoward toxicities. There was a trend towards better response in RSV infections, which needs to be further explored in controlled studies.     

Management of RSV infections in adult recipients of hematopoietic stem cell transplantation

Respiratory syncytial virus (RSV) is a common cause of seasonal respiratory viral infection in patients who have undergone hematopoietic stem cell transplantation. RSV usually presents as an upper respiratory tract infection in this patient population but may progress rapidly to lower respiratory tract infection. Available therapies that have been used for the treatment of RSV infections are limited to ribavirin, intravenous immunoglobulin, and palivizumab. The use of aerosolized ribavirin, alone or in combination with either palivizumab or intravenous immunoglobulin, remains controversial. In this comprehensive review, we present and discuss the available literature on management of RSV infections in adult hematopoietic stem cell transplantation recipients with a focus on therapeutic modalities and outcomes.     

Prevention and control of methicillin-resistant Staphylococcus aureus infections

PURPOSE OF REVIEW: This article reviews many recent publications relevant to the prevention and control of nosocomial methicillin-resistant Staphylococcus aureus (MRSA) infection. RECENT FINDINGS: Higher risk-adjusted costs and mortality have been found for MRSA infections than for methicillin-susceptible S. aureus infections confirming their epidemiologic importance. Staphylococcal cassette chromosome mec, the genetic basis for MRSA, does not develop in methicillin-susceptible S. aureus exposed to antimicrobials. Instead virtually all patients acquire MRSA via spread. Nevertheless, antibiotic therapy provides a selective advantage for such spread, especially within healthcare settings where antimicrobial therapy is most frequent. Several studies have suggested better control of MRSA through antibiotic control, but far more studies have reported control using surveillance cultures and contact precautions for preventing spread (rather than just using standard precautions). More rapid detection of MRSA (within 6 h) has been reported using polymerase chain reaction, but studies using this method to reduce spread have not yet been published. A structured survey of research methods used regarding MRSA control noted that many studies had methodologic shortcomings (for example, none was a randomized trial), but nevertheless concluded that active detection and isolation work should be used. A Society for Healthcare Epidemiology of America guideline emphasized the same approach noting that scores of studies on multiple continents had reported success with this approach, with best results in several northern-European countries where all facilities used it routinely. SUMMARY: Improved MRSA control is possible by detecting and isolating colonized patients.     

Renal transplantation in chronic hepatitis C

Abstract   Hepatitis C virus (HCV) infection is present in 2–70% of patients receiving hemodialysis. The major risks for transmission are transfusions and nosocomial spread within dialysis units and the incidence has declined dramatically following the introduction of universal precautions and blood and organ donor screening. Renal transplantation confers an overall survival benefit in HCV+ hemodialysis patients, with similar 5-year patient and graft survival to those without HCV infection. However, long-term studies (more than 10 years) have reported increased liver-related and sepsis-related mortality in HCV-infected recipients. Attempts to eradicate HCV prior to transplant have been disappointing. Interferon is poorly tolerated in patients with end-stage renal disease and ribavirin is contraindicated because of universal severe hemolysis related to reduced renal clearance. Interferon is associated with unacceptable rates of allograft dysfunction and loss (attributed to interferon-induced rejection).     

Reducing the rate of nosocomially transmitted respiratory syncytial virus

BACKGROUND: A large number (17) of nosocomial respiratory syncytial virus cases led to the development of control measures to prevent transmission of respiratory syncytial virus (RSV) within the Johns Hopkins Hospital's Children's Center. METHODS: The control plan is based on a 2-stage process. In stage 1, the staff are notified that RSV is in the community, and information is distributed through a communication tree. Stage 2 requires that nasopharyngeal aspirates be obtained from all children <3 years of age who have respiratory symptoms. The aspirates are tested directly for RSV antigen and cultured for RSV. The children are placed on pediatric droplet precautions pending those results. RESULTS: The proportion of nosocomial RSV cases dropped from 16.5% before the use of RSV control measures to 7.2% after the initiation of the control program. A case of RSV identified in the hospital was 2.6 times more likely to be nosocomially acquired before the intervention compared with after the intervention. Approximately 14 cases of RSV are prevented each year, which results in a savings of 56 hospital-days and more than $84,000 in direct hospital-related charges alone. CONCLUSIONS: The nosocomial spread of RSV can be reduced by a specific and feasible control plan that includes early identification and rapid isolation of potential RSV cases.     

Nosocomial viral respiratory infections: perennial weeds on pediatric wards

The frequency and importance of nosocomial infections of the respiratory tract in pediatrics have generally been underestimated. In part this has resulted from the emphasis on bacterial infections which occur primarily in select at-risk populations. Most respiratory infections in pediatric patients, hospital- and community-acquired, are viral and all patients are potentially susceptible The epidemiologic patterns of these viral respiratory agents on the ward mirror those seen in the community in terms of frequency, season, age affected and severity of illness. Hence, the most frequent nosocomial agents are the viruses that occur in outbreaks or epidemics and cause respiratory illness, epidemic respiratory viruses--respiratory syncytial virus, which causes the greatest morbidity and mortality; influenza, and the parainfluenza viruses. Their import, as exemplified by respiratory syncytial virus, results from (1) the severity of disease produced in young children, which is magnified in those hospitalized with certain underlying conditions; (2) the abundant and prolonged viral shedding, allowing easy spread; (3) the potential susceptibility of all patients and staff, since infections recur throughout life; and (4) the difficulty in controlling nosocomial spread.     

Severe respiratory syncytial virus pneumonia after autologous bone marrow transplantation: a report of three cases and review.

Three patients with acute leukemia who underwent autologous bone marrow transplantation (BMT) in complete remission, developed a severe respiratory syncytial virus (RSV) pneumonia, which was fatal in two. Identification of RSV was made on the products of bronchoalveolar lavage by direct immunofluorescence. As already described by others, the initial course of RSV infection varies, depending on whether it occurs sooner or later after BMT with a better prognosis in the latter situation. Treatment consists of aerosolized ribavirin. Infection by RSV is caused by manual contact with infected persons and contaminated surfaces. The severity of lung RSV infection in the course of BMT suggests the need for prophylactic measures in addition to standard isolation precautions.