Conventional Infection Control Measures Research Articles

EVALUATION ON INDOOR ENVIRONMENT AND ALTERNATIVE VENTILATION METHODS IN A SCHOOL CLASSROOM IN A COLD REGION UNDER COVID-19 PANDEMIC

COVID-19 caused a global pandemic. The possibility of aerosol transmission has been pointed out as a possible route of infection, and there are reports that conventional infection control measures are insufficient to counteract aerosol transmission. Therefore, this report presents the results of an actual survey at a high school, including measurement of CO2 concentration and a questionnaire survey, and the results of an experiment to evaluate the attenuation of particle concentration by an air cleaner based on this survey.

Explosive nosocomial outbreak of SARS-CoV-2 in a rehabilitation clinic: the limits of genomics for outbreak reconstruction

BackgroundNosocomial outbreaks of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) are frequent despite implementation of conventional infection control measures. An outbreak investigation was undertaken using advanced genomic and statistical techniques to reconstruct likely transmission chains and assess the role of healthcare workers (HCWs) in SARS-CoV-2 transmission.MethodsA nosocomial SARS-CoV-2 outbreak in a university-affiliated rehabilitation clinic was investigated, involving patients and HCWs, with high coverage of pathogen whole-genome sequences (WGS). The time-varying reproduction number from epidemiological data (Rt) was estimated, and maximum likelihood phylogeny was used to assess genetic diversity of the pathogen. Genomic and epidemiological data were combined into a Bayesian framework to model the directionality of transmission, and a case–control study was performed to investigate risk factors for nosocomial SARS-CoV-2 acquisition in patients.FindingsThe outbreak lasted from 14th March to 12th April 2020, and involved 37 patients (31 with WGS) and 39 employees (31 with WGS), 37 of whom were HCWs. Peak Rt was estimated to be between 2.2 and 3.6. The phylogenetic tree showed very limited genetic diversity, with 60 of 62 (96.7%) isolates forming one large cluster of identical genomes. Despite the resulting uncertainty in reconstructed transmission events, the analyses suggest that HCWs (one of whom was the index case) played an essential role in cross-transmission, with a significantly greater fraction of infections (P<2.2e-16) attributable to HCWs (70.7%) than expected given the number of HCW cases (46.7%). The excess of transmission from HCWs was higher when considering infection of patients [79.0%; 95% confidence interval (CI) 78.5–79.5%] and frail patients (Clinical Frailty Scale score >5; 82.3%; 95% CI 81.8–83.4%). Furthermore, frail patients were found to be at greater risk for nosocomial COVID-19 than other patients (adjusted odds ratio 6.94, 95% CI 2.13–22.57).InterpretationThis outbreak report highlights the essential role of HCWs in SARS-CoV-2 transmission dynamics in healthcare settings. Limited genetic diversity in pathogen genomes hampered the reconstruction of individual transmission events, resulting in substantial uncertainty in who infected whom. However, this study shows that despite such uncertainty, significant transmission patterns can be observed.

Explosive Nosocomial Outbreak of SARS-CoV-2 in a Rehabilitation Clinic: The Limits of Genomics for Outbreak Reconstruction

Background: Nosocomial outbreaks of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are frequent despite implementation of conventional infection control measures. We performed an outbreak investigation using advanced genomic and statistical techniques to reconstruct likely transmission chains and assess the role of healthcare workers (HCWs) in SARS-CoV-2 transmission.Methods: We investigated a nosocomial SARS-CoV-2 outbreak in a university-affiliated rehabilitation clinic, involving patients and HCWs, with high coverage of pathogen whole genome sequences (WGS). We estimated the time-varying reproduction number from epidemiological data (Rt) and produced a maximum likelihood phylogeny to assess genetic diversity of the pathogen. We combined genomic and epidemiological data into a Bayesian framework to model directionality of transmission. We performed a case-control study to investigate risk factors for nosocomial SARS-CoV-2 acquisition in patients.Findings: The outbreak spanned from March 14 to April 12, 2020 and involved 37 patients (31 with WGS) and 39 employees (31 with WGS) of whom 37 are HCWs. We estimated a peak Rt between 2·2 – 3·6. The phylogenetic tree showed very limited genetic diversity, with 60/62 (96·7%) isolates forming one large cluster of identical genomes. Despite the resulting uncertainty in reconstructed transmission events, our analyses suggest that HCWs (one of whom was the index case) played an essential role in cross-transmission, with a significantly larger fraction of infections (p 5: 82·3%; 95%CI 81·8% - 83·4%). Furthermore, frail patients were found to be at greater risk for nosocomial COVID-19 than other patients (adjusted OR 6·94; 95%CI 2·13 – 22·57).Interpretation: This outbreak report highlights the essential role of HCWs in SARS-CoV-2 transmission dynamics in healthcare settings. Limited genetic diversity in pathogen genomes hampered the reconstruction of individual transmission events, resulting in substantial uncertainty in who infected whom. However, our study shows that despite such uncertainty, significant transmission patterns can be observed.Funding: This work was supported by a grant from the Swiss National Science Foundation under the NRP78 Covid-19 funding scheme (Grant no. 4078P0_198363).Declaration of Interests: All authors have no conflicts of interest to declare.Ethics Approval Statement: Outbreak investigations are within the purview of the IPC programme. For additional investigations, the local Ethic Committee approved this study (no. 2020-01330).

Inactivation of biofilms in endotracheal tube by cold atmospheric plasma treatment for control and prevention of ventilator‐associated pneumonia

AbstractVentilator‐associated pneumonia (VAP) is a type of hospital‐acquired infection with high mortality and morbidity rates that is seen in critically ill patients who are connected to mechanical ventilators in intensive care units. Conventional infection control measures may remain insufficient for control and prevention of VAP. In the present study, biofilms of most common pathogens, which are responsible for VAP, namely Pseudomonas aeruginosa, Acinetobacter baumannii, Staphylococcus aureus, and Candida albicans, were grown in the lumen of endotracheal tubes (ETs) under low shear to mimic the biofilm formation in clinical settings using the drip flow reactor system. Antibiofilm efficacies of two different plasma treatment methods were tested on the biofilms that were grown in ETs. In the first method, deionized water (DIW), phosphate‐buffered saline (PBS) solution, and N‐acetylcysteine (NAC) solution were treated with air dielectric barrier discharge (DBD) plasma and then nebulized on the biofilms. In the second method, air plasma afterglow (APA), which was generated using a DBD jet electrode, was flown through the lumen of ETs. Effects of two different plasma treatment methods on biofilms were evaluated using colony‐counting and XTT assays. The quantity of extracellular polymeric substance (EPS) was evaluated with the safranin assay. Scanning electron microscopy (SEM) was used to visualize the effect of various plasma treatment methods on biofilms. Cytotoxic effects of two different plasma treatment methods were tested on the human tracheal epithelial cell line. Our results suggest that the nebulized plasma‐treated NAC solution had a superior antibiofilm effect as compared with DIW and PBS. Two different plasma treatment methods used effectively inactivated biofilms and significantly reduced the quantity of EPS without a significant damage to the human tracheal epithelial cell line. Furthermore, SEM images showed the inactivation of microbial cells mainly through membrane damage.

Best Practices and Evolving Techniques for Preventing Infection After Fracture Surgery

Orthopedic trauma-related infections remain one of the major complications in modern trauma and orthopedic surgery. Despite current preventive practices, infection rates range from ~1% after operative fixation of closed low-energy fractures to &gt;30% in complex open tibia fractures. Fracture-related infections negatively impact clinical outcome with lifelong functional impairment and significantly increase health care expenditure. In addition, the escalating issue of antimicrobial resistance continues to pose a challenge to clinicians. Unfortunately, in orthopedic trauma, only a few preventive measures are strongly supported by past studies and for most measures, there are insufficient data. Surgical site infection prevention guidelines established by the Centers for Disease Control and Prevention (CDC) and the World Health Organization (WHO) are generalized for all surgical disciplines and do not take into account the specifics of fracture-related infections. The most important difference in orthopedic trauma patients from the other surgical disciplines is the ability of skin colonizers and contaminating organisms to establish infection on implants and form biofilms. The bacteria can then resist conventional infection control measures and prophylactic antibiotic therapy. To effectively decrease fracture-related infections, there needs to be a multidisciplinary clinical approach, which should recognize the unique aspects of such infections and develop strategies on the basis of these specific needs. There is also a dire need for future research for prevention of infections focusing on specifics of musculoskeletal trauma. This review highlights the established practices for infection prevention in fractures and discusses the emerging strategies still under investigation.

Enterovirus D68 Infection.

First described in 1962 in children hospitalized for pneumonia and bronchiolitis, the Enterovirus D68 (EV-D68) is an emergent viral pathogen. Since its discovery, during the long period of surveillance up to 2005, EV-D68 was reported only as a cause of sporadic outbreaks. In recent years, many reports from different countries have described an increasing number of patients with respiratory diseases due to EV-D68 associated with relevant clinical severity. In particular, an unexpectedly high number of children have been hospitalized for severe respiratory disease due to EV-D68, requiring intensive care such as intubation and mechanical ventilation. Moreover, EV-D68 has been associated with acute flaccid paralysis and cranial nerve dysfunction in children, which has caused concerns in the community. As no specific antiviral therapy is available, treatment is mainly supportive. Moreover, because no vaccines are available, conventional infection control measures (i.e., standard, for contacts and droplets) in both community and healthcare settings are recommended. However, further studies are required to fully understand the real importance of this virus. Prompt diagnosis and continued surveillance of EV-D68 infections are essential to managing and preventing new outbreaks. Moreover, if the association between EV-D68 and severe diseases will be confirmed, the development of adequate preventive and therapeutic approaches are a priority.

Conventional Infection-Control Measures Reduce MRSA

Conventional Infection-Control Measures Reduce MRSA

Experience with the use of palivizumab together with infection control measures to prevent respiratory syncytial virus outbreaks in neonatal intensive care units

Respiratory syncytial virus (RSV) frequently causes nosocomial outbreaks in general paediatric wards and occasionally in neonatal intensive care units (NICUs). Conventional infection control measures often fail to prevent the spread of RSV, and it can cause significant morbidity especially in preterm and young infants. We report our experience in preventing an outbreak on a NICU after RSV had been detected in a premature infant. The index case was a 34-day-old premature infant who presented with clinical infection and RSV was detected in a clinical specimen. There were 11 patients in the ward at the time including the index case. The RSV-positive patient was isolated, the ward closed to admissions and infection control measures were implemented. Two patients were transferred to another hospital. Palivizumab 15 mg/kg i.m. was given to all patients and no further cases occurred. All subsequent RSV tests on nasal secretions were negative. Palivizumab combined with conventional infection control measures appeared to prevent the spread of RSV in this NICU. Strategies for the prevention of RSV outbreaks on NICUs all recommend the reinforcement of routine infection control measures. Recommendations concerning the use of palivizumab range from monthly prophylaxis to all infants at risk, to prophylaxis of selected cases only. Currently there are no guidelines for the use of palivizumab in NICUs or for the control of RSV outbreaks.

Post-operative endophthalmitis: the application of hazard analysis critical control points (HACCP) to an infection control problem

Hazard analysis critical control points (HACCP) is a quality assurance system widely used in the food industry to ensure safety. We adopted the HACCP approach when conventional infection control measures had failed to solve an ongoing problem with an increased incidence of postoperative endophthalmitis, and our ophthalmology unit was threatened with permanent cessation of intraocular surgery. Although time-consuming, the result was an entirely new set of protocols for the care of patients undergoing intraocular surgery, the development of an integrated care pathway, and a comprehensive and robust audit programme, which enabled intraocular surgery to continue in a new spirit of confidence. HACCP methodology has so far been little used in healthcare, but it might be usefully applied to a variety of apparently intractable infection control problems.

The use of palivizumab monoclonal antibodyto control an outbreak of respiratory syncytial virus infection in a special care baby unit

An outbreak of respiratory syncytial virus (RSV) infection affected seven premature infants in a special care baby unit during November and December 1999. Conventional infection control measures (cohorting infected babies, strict reinforcement of the use of gloves and aprons, emphasis on hand disinfection) failed to prevent spread. Palivizumab, a respiratory syncytial virus monoclonal antibody, was given to eight high-risk preterm infants. There were no further cases of RSV in the unit and none of the babies given palivizumab developed RSV. One baby who acquired RSV during the outbreak (and who was not given palivizumab) was subsequently admitted to hospital with another episode of RSV bronchiolitis. The role of palivizumab in the control of hospital outbreaks of RSV infection merits further investigation.

Staphylococcal infections in the intensive care unit.

Staphylococcus aureus and coagulase-negative staphylococci are among the most common causes of nosocomial infections in the intensive care unit (ICU). The clinical presentation of staphylococcal device-related infections, pneumonias, or surgical wound infections is not unique. However, treatment of these infections is increasingly problematic because of the resistance of clinical isolates to a widening number of antimicrobial agents. The confluence of critically ill patients and the need for multiple invasive procedures, as well as the use of broad-spectrum antimicrobial agents in the ICU, set the stage for the emergence of these multidrug-resistant staphylococci. In the past 10 years, there has been a progressive increase in the overall resistance of staphylococci to antimicrobial agents. Conventional infection control measures, such as handwashing and isolation precautions, to prevent the spread of staphylococcal infections in the ICU setting remain of critical importance. New approaches, including the prophylactic use of topical antistaphylococcal agents to eliminate nasal colonization in high-risk ICU patients and the development of antistaphylococcal vaccines, are currently being investigated.

Selective decontamination of the digestive tract as an infection-control measure in intensive care unit patients.

Infection is responsible for a large percentage of morbidity and mortality in intensive care unit (ICU) patients. Conventional infection-control measures are directed at decreasing infection by exogenous sources and have had variable success in significantly reducing nosocomial infection rates. Selective gastrointestinal decontamination with topical nonabsorbable antibiotics attempts to reduce infection by eliminating intestinal mucosal colonization by pathogenic microorganisms. These antibiotics are selectively bactericidal against gram-negative organisms and yeasts, thereby leaving the normal flora (mainly anaerobes) unharmed. In the majority of clinical trials, selective decontamination effectively reduced colonization and infection among ICU patients, with the most significant reductions observed in gram-negative respiratory infections. Resistance to the antimicrobials was not documented in the majority of trials; however, follow-up periods were minimal and may not have been adequate to detect selection of resistant strains. Reductions in infection do not alter mortality; however, patients without significant underlying disease appear to be the subgroup that will most likely benefit.

Failure of infection control in intensive care units: Can sucralfate improve the situation?

Conventional infection control measures in intensive care units (ICUs) are aimed primarily at stemming cross-infections. The role of patients' endogenous flora in the pathogenesis of nosocomial infection and occasional lapses in aseptic technique in ICUs help to explain the frequent failure of the conventional approaches. Newer control strategies include avoiding gastric and oropharyngeal overgrowth of gram-negative bacilli by using sucralfate to avoid gastric alkalinization and/or suppressing nosocomial flora by use of topical antimicrobials.

Colonization of the oropharynx with gram-negative bacilli: A major antecedent to nosocomial pneumonia

The initiating event in the development of gram-negative nosocomial pneumonia is usually colonization of the oropharynx with gram-negative bacilli. Normally, the bacterial equilibrium of the oropharynx excludes gram-negative bacilli. This equilibrium is maintained by dynamic interactions involving recognition mechanisms and bacterial interference. Broad-spectrum antimicrobial therapy or serious illness may alter these interactions and lead to adherence of gram-negative bacilli to the oropharyngeal epithelial cells. Antibiotics appear to suppress normal bacterial inhibitors, allowing proliferation of gram-negative bacteria. Serious illness appears to result in availability of epithelial cell receptors for gram-negative bacteria. Conventional infection control measures often fail to prevent colonization. Effective additional measures may include (1) reduction of total antibiotic usage in the hospital, (2) selective administration of antimicrobial prophylaxis, and (3) exploitation of the natural interactions among bacteria and between bacteria and host cells to enhance resistance to colonization.