Managment of adult lower respiratory tract infection in primary care

%0 per cent of antibiotic use in the community is for respiratory infection. this editorial considers wwh 8 out of 10 consultations for cough in general practice result inantibiotic prescribing

Relative Respiratory Syncytial Virus Cytopathogenesis in Upper and Lower Respiratory Tract Epithelium

Respiratory syncytial virus (RSV) is a major pathogen that primarily infects airway epithelium. Most infants suffer mild upper respiratory tract (URT) symptoms, while approximately one third progress to lower respiratory tract (LRT) involvement. Despite the ubiquity of URT infection, little is known about the relative cytopathogenesis of RSV infection in infant URT and LRT.

Sequential antimicrobial therapy: treatment of severe lower respiratory tract infections in children

Although there have been a number of studies in adults, to date there has been little research into sequential antimicrobial therapy (SAT) in paediatric populations. The present study evaluates the impact of a SAT protocol for the treatment of severe lower respiratory tract infection in paediatric patients. The study involved 89 paediatric patients (44 control and 45 SAT). The SAT patients had a shorter length of hospital stay (4.0 versus 8.3 days), shorter duration of inpatient antimicrobial therapy (4.0 versus 7.9 days) with the period of iv therapy being reduced from a mean of 5.6 to 1.7 days. The total healthcare costs were reduced by 52%. The resolution of severe lower respiratory tract infection with a short course of iv antimicrobials, followed by conversion to oral therapy yielded clinical outcomes comparable to those achieved using longer term iv therapy. SAT proved to be an important cost-minimizing tool for realizing substantial healthcare costs savings.

An audit of antimicrobial treatment of lower respiratory and urinary tract infections in a hospital setting

Objectives: To audit the quality of treatment of lower respiratory tract infections (LRTIs) and urinary tract infections (UTIs) and to identify targets for antibiotic stewardship. Methods: The audit involved collecting data on admitted patients, who were diagnosed with LRTIs or UTIs and subsequently received antibiotic treatment (January 2009-April 2009). Key findings: The percentage adherence rate for hospital antibiotic policy was 68.6% (24/35). Documentation of the CURB-65 score was found in 80% (16/20) of the patients' clinical notes, for which 46.2% (6/13) of patients were treated according to their CURB- 65 score. The percentages of delayed and missed doses for all antibiotics were 21.7% (254/1171) and 8.6% (101/1171), respectively. The percentage of patients switched from intravenous to oral antibiotics in accordance with the policy was 58.5% (31/53). The mean length of stay for patients switched in line with the guidelines was 6.9 days (range: 2-18 days) compared with 13.2 days (range: 4-28 days) for patients treated with intravenous antibiotics >24 h after the intravenous to oral switch criteria were fulfilled; this equates to on average an extra 6.3 days of hospitalisation (p=0.01). Conclusions: The study identified a number of targets for quality improvement including adherence to antibiotic policy, documentation of the CURB-65 score in patients' notes and treating patients accordingly, addressing the issue of missed and delayed doses, and maintaining adherence to the hospital intravenous-to-oral antibiotic switch policy. The findings suggest that the quality of antibiotic prescribing could be improved by measuring and addressing such performance indicators.

Cough hypersensitivity syndrome is an important clinical concept:a pro/con debate

The major etiologies of chronic cough are generally accepted to consist of upper airway cough syndrome (formerly postnasal drip syndrome), eosinophilic airway inflammation (asthma, nonasthmatic eosinophilic bronchitis), and gastroesophageal reflux disease (GERD). However, only a small percentage of patients with these very common conditions suffers from chronic cough. Furthermore, acute cough due to viral upper respiratory tract infection (URI) is almost always a transient, self-limited condition, yet in a small subgroup of patients, URI heralds the onset of chronic, refractory cough. The cough hypersensitivity syndrome has been proposed to explain the occurrence of chronic cough in a subgroup of patients exposed to the same putative triggers as the vast majority of the population in whom chronic cough does not result. Although conceptually the cough hypersensitivity syndrome may be intellectually satisfying, differences of opinion remain as to whether this newly recognized entity is of clinical significance, i.e., useful for the treatment of patients suffering from chronic cough. The Third American Cough Conference, held in New York in June 2011, provided an ideal forum for the debate of this issue between two internationally recognized authorities in the field of cough.

Effect of a clinical pathway to reduce hospitalizations in nursing home residents with pneumonia:A randomized controlled trial

Context: Nursing home residents with pneumonia are frequently hospitalized. Such transfers may be associated with multiple hazards of hospitalization as well as economic costs. Objective: To assess whether using a clinical pathway for on-site treatment of pneumonia and other lower respiratory tract infections in nursing homes could reduce hospital admissions, related complications, and costs. Design, Setting, and Participants: A cluster randomized controlled trial of 680 residents aged 65 years or older in 22 nursing homes in Hamilton, Ontario, Canada. Nursing homes began enrollment between January 2, 2001, and April 18, 2002, with the last resident follow-up occurring July 4, 2005. Residents were eligible if they met a standardized definition of lower respiratory tract infection. Interventions: Treatment in nursing homes according to a clinical pathway, which included use of oral antimicrobials, portable chest radiographs, oxygen saturation monitoring, rehydration, and close monitoring by a research nurse, or usual care. Main Outcome Measures: Hospital admissions, length of hospital stay, mortality, health-related quality of life, functional status, and cost. Results: Thirty-four (10%) of 327 residents in the clinical pathway group were hospitalized compared with 76 (22%) of 353 residents in the usual care group. Adjusting for clustering of residents in nursing homes, the weighted mean reduction in hospitalizations was 12% (95% confidence interval [CI], 5%-18%; P=.001). The mean number of hospital days per resident was 0.79 in the clinical pathway group vs 1.74 in the usual care group, with a weighted mean difference of 0.95 days per resident (95% CI, 0.34-1.55 days; P=.004). The mortality rate was 8% (24 deaths) in the clinical pathway group vs 9% (32 deaths) in the usual care group, with a weighted mean difference of 2.9% (95% CI, -2.0% to 7.9%; P=.23). There were no significant differences between the groups in health-related quality of life or functional status. The clinical pathway resulted in an overall cost savings of US $1016 per resident (95% CI, $207-$1824) treated. Conclusion: Treating residents of nursing homes with pneumonia and other lower respiratory tract infections with a clinical pathway can result in comparable clinical outcomes, while reducing hospitalizations and health care costs. ©2006 American Medical Association. All rights reserved.

Early target cells of measles virus after aerosol infection of non-human primates

Measles virus (MV) is highly infectious, and has long been thought to enter the host by infecting epithelial cells of the respiratory tract. However, epithelial cells do not express signaling lymphocyte activation molecule (CD150), which is the high-affinity cellular receptor for wild-type MV strains. We have generated a new recombinant MV strain expressing enhanced green fluorescent protein (EGFP), based on a wild-type genotype B3 virus isolate from Khartoum, Sudan (KS). Cynomolgus macaques were infected with a high dose of rMV(KS)EGFP by aerosol inhalation to ensure that the virus could reach the full range of potential target cells throughout the entire respiratory tract. Animals were euthanized 2, 3, 4 or 5 days post-infection (d.p.i., n?=?3 per time point) and infected (EGFP(+)) cells were identified at all four time points, albeit at low levels 2 and 3 d.p.i. At these earliest time points, MV-infected cells were exclusively detected in the lungs by fluorescence microscopy, histopathology and/or virus isolation from broncho-alveolar lavage cells. On 2 d.p.i., EGFP(+) cells were phenotypically typed as large mononuclear cells present in the alveolar lumen or lining the alveolar epithelium. One to two days later, larger clusters of MV-infected cells were detected in bronchus-associated lymphoid tissue (BALT) and in the tracheo-bronchial lymph nodes. From 4 d.p.i. onward, MV-infected cells were detected in peripheral blood and various lymphoid tissues. In spite of the possibility for the aerosolized virus to infect cells and lymphoid tissues of the upper respiratory tract, MV-infected cells were not detected in either the tonsils or the adenoids until after onset of viremia. These data strongly suggest that in our model MV entered the host at the alveolar level by infecting macrophages or dendritic cells, which traffic the virus to BALT or regional lymph nodes, resulting in local amplification and subsequent systemic dissemination by viremia.

Relative Contribution of P5 and Hap Surface Proteins to Nontypable Haemophilus influenzae Interplay with the Host Upper and Lower Airways

Nontypable Haemophilus influenzae (NTHi) is a major cause of opportunistic respiratory tract disease, and initiates infection by colonizing the nasopharynx. Bacterial surface proteins play determining roles in the NTHi-airways interplay, but their specific and relative contribution to colonization and infection of the respiratory tract has not been addressed comprehensively. In this study, we focused on the ompP5 and hap genes, present in all H. influenzae genome sequenced isolates, and encoding the P5 and Hap surface proteins, respectively. We employed isogenic single and double mutants of the ompP5 and hap genes generated in the pathogenic strain NTHi375 to evaluate P5 and Hap contribution to biofilm growth under continuous flow, to NTHi adhesion, and invasion/phagocytosis on nasal, pharyngeal, bronchial, alveolar cultured epithelial cells and alveolar macrophages, and to NTHi murine pulmonary infection. We show that P5 is not required for bacterial biofilm growth, but it is involved in NTHi interplay with respiratory cells and in mouse lung infection. Mechanistically, P5NTHi375 is not a ligand for CEACAM1 or α5 integrin receptors. Hap involvement in NTHi375-host interaction was shown to be limited, despite promoting bacterial cell adhesion when expressed in H. influenzae RdKW20. We also show that Hap does not contribute to bacterial biofilm growth, and that its absence partially restores the deficiency in lung infection observed for the ΔompP5 mutant. Altogether, this work frames the relative importance of the P5 and Hap surface proteins in NTHi virulence.

Neural dysfunction following respiratory viral infection as a cause of chronic cough hypersensitivity

Respiratory viral infections are a common cause of acute coughing, an irritating symptom for the patient and an important mechanism of transmission for the virus. Although poorly described, the inflammatory consequences of infection likely induce coughing by chemical (inflammatory mediator) or mechanical (mucous) activation of the cough-evoking sensory nerves that innervate the airway wall. For some individuals, acute cough can evolve into a chronic condition, in which cough and aberrant airway sensations long outlast the initial viral infection. This suggests that some viruses have the capacity to induce persistent plasticity in the neural pathways mediating cough. In this brief review we present the clinical evidence of acute and chronic neural dysfunction following viral respiratory tract infections and explore possible mechanisms by which the nervous system may undergo activation, sensitization and plasticity.

Generation and Characterization of ALX-0171, a Potent Novel Therapeutic Nanobody for the Treatment of Respiratory Syncytial Virus Infection

Respiratory Syncytial Virus (RSV) is an important causative agent of lower respiratory tract infections in infants and elderly. Its fusion (F) protein is critical for virus infection. It is targeted by several investigational antivirals and by palivizumab, a humanised monoclonal antibody used prophylactically in infants considered at high risk of severe RSV disease. ALX-0171 is a trimeric Nanobody that binds the antigenic site II of RSV F-protein with subnanomolar affinity. ALX-0171 demonstrated superior in vitro neutralisation compared to palivizumab against prototypic RSV A and B strains. Moreover, ALX-0171 completely blocked replication below limit of detection in 87% of the viruses tested versus 18% for palivizumab at a fixed concentration. Importantly, ALX-0171 was highly effective in reducing both nasal and lung RSV titers when delivered prophylactically or therapeutically directly to the lungs of cotton rats. ALX-0171 represents a potent novel antiviral compound with significant potential to treat RSV-mediated disease.