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The incidence of Chlamydia pneumoniae lower respiratory tract infections among university students in northern California.

Chlamydia pneumoniae has recently been identified as a cause of lower respiratory tract infections. From March 1987 to March 1988, 259 university students-151 students with lower respiratory tract infections and 108 controls-from the University of California, Berkeley, were studied to determine the incidence and pattern of C pneumoniae lower respiratory tract infections. Serologic evidence of a recent C pneumoniae infection was found in less than 2%, and the organism was not isolated from any of the subjects. Despite the paucity of evidence of a recent infection, 47.5% of this university population showed serologic evidence of a previous C pneumoniae infection. The lower incidence of C pneumoniae infection in our population, when compared with previous reports, suggests that there may be geographic and temporal differences or fluctuations among populations.

Adult↗

Single-dose azithromycin for respiratory tract infections.

OBJECTIVE: To describe the pharmacology, efficacy, and safety data of the use of single-dose azithromycin for respiratory tract infections in children and adults. DATA SOURCES: A MEDLINE search (1990-September 2003) was performed to identify all pertinent studies and review articles. When appropriate information was not available in the literature, data were obtained from the product manufacturers or abstracts from international conferences. STUDY SELECTION AND DATA EXTRACTION: All available studies were reviewed to provide pharmacokinetic, pharmacodynamic, efficacy, and safety data on use of single-dose azithromycin for respiratory tract infections. DATA SYNTHESIS: Several studies have demonstrated that shorter regimens of azithromycin (1500 mg over 3 day vs 5 day or single dose vs 3 day) provide higher serum exposures compared with the longer regimens. This makes it possible to give the same dose over a shorter period of time and achieve the same efficacy with the potential for enhanced adherence. Single-dose azithromycin 30 mg/kg was approved in 2003 for treatment of acute otitis media (AOM) in children. Studies have demonstrated that, when administering azithromycin as a single dose, its efficacy and safety are comparable to that of other standard regimens for AOM. Single-dose regimens for treatment of respiratory tract infections in adults have not been studied widely, with only 2 studies being conducted for treatment of community-acquired pneumonia and one study for treatment of tonsillitis; all demonstrated at least equal efficacy with the single-dose regimen compared with comparators given for longer periods of time. CONCLUSIONS: Available data regarding single-dose azithromycin are promising. Although use of this regimen in children is warranted based on studies to date, additional large-scale trials are needed prior to mainstream use of the regimen in adults.

Adult↗

Monoclonal antibodies versus reverse transcription-PCR for detection of respiratory viruses in a patient population with respiratory tract infections admitted to hospital.

UNLABELLED: In the winter season 2001-2002, 239 nasopharyngeal aspirate and 15 bronchoalveolar lavage samples from 208 patients (135 pediatric and 73 adults, including 19 lung transplant recipients) admitted to hospital because of an acute respiratory tract infection were examined for rapid diagnosis of respiratory viruses by two diagnostic approaches: immunological, using specific monoclonal antibodies (MAb); and molecular, using specific reverse transcription (RT)-PCR assays. Both methods detected influenza viruses A (H1N1 and H3N2) and B, human parainfluenza virus types 1 to 3, human respiratory syncytial virus (hRSV) types A and B, and human adenoviruses. In addition, human coronavirus (hCoV) groups I (229E-like) and II (OC43-like), as well as the new human metapneumovirus (hMPV), types A and B, were searched for by RT-PCR alone. When results obtained by both methods were added, the overall percentage of patients positive for at least one respiratory virus peaked at 44.2%, involving 92/208 patients (81 pediatric, and 11 adults), while 116 patients (55.8%) were negative for any respiratory virus tested. The most common circulating virus was hRSV, infecting 54 (25.9%) patients (24 type A, and 30 type B strains), followed by hMPV, infecting 12 (5.8%) patients (7 type A and 5 type B strains). Coinfections by two respiratory viruses interested 11 (5.3%) patients, and 9 (81.8%) of these were infected by hRSV in association with another respiratory virus. In the great majority of infected children, hRSV and hMPV were associated with lower respiratory tract infections. In lung transplant recipients, viruses present in bronchoalveolar lavage appeared to be associated frequently with lower respiratory tract infections. IN CONCLUSION: the combination of immunological and molecular assays is the most sensitive approach to the diagnosis of respiratory viral infections; and infections caused by the less investigated hCoVs and hMPVs represent a fair proportion of respiratory infections.

Adenoviridae↗

Airway interleukin-8 in elderly patients with bacterial lower respiratory tract infections.

We investigated the interleukin-8 (IL-8) levels and neutrophil numbers in the sputum of 9 elderly patients with lower respiratory tract infections, including Pseudomonas aeruginosa infection, before and after treatment with various antimicrobial agents. The IL-8 levels in sputum supernatants and the neutrophil numbers in sputum smears from 9 patients decreased significantly after the elimination of the causative respiratory pathogens. We also demonstrated that human recombinant IL-8 at a range of 6.25-25 ng/ml significantly enhanced opsonophagocytic killing of P. aeruginosa immunotype-1 strain by human neutrophils in the presence of a serotype-specific anti-lipopolysaccharide monoclonal antibody and fresh normal human serum. These data suggest that the level of IL-8 production in the airways of patients with lower respiratory tract infections is dependent on bacterial densities, and indicate the important role of IL-8 not only in neutrophil migration but also in opsonophagocytic killing of bacteria in the lower respiratory tract.

Aged↗

Management of acute asthma attacks associated with respiratory tract infection: a postal survey of general practitioners in the U.K.

Asthma attacks in general practice are frequently associated with respiratory tract infection. The aim of this study was to examine how U.K. general practitioners (GPs) might use oral steroids and antibiotics in such situations. The timing of follow-up and use of self-management plans were also examined. A postal questionnaire was sent to all 205 GP principals in Bath Health District, U.K. in February and March 1993. Respondents were asked questions regarding the management of an adult and a child presenting with acute asthma associated with respiratory tract infection. Replies were received from 185 of 205 (90%) doctors approached. Antibiotics would have been prescribed by 119 of 179 (66%) doctors for the adult and 98 of 169 (58%) doctors for the child. The modal initial dosage of oral prednisolone was 40 mg for the adult and 30 mg for the child, and modal duration of oral steroid dosage was 5 days for both adult and child. Planned follow-up was mainly doctor initiated within 24 h of initial consultation. There was low reported use of self-management plans (49% for adults and 33% in children over 7 years of age). Antibiotic prescription appears to be common practice by GPs when faced with an acute asthma attack associated with respiratory tract infection. There may also be inadequate duration of oral steroid courses in adults. There is a need to examine further the proper role, if any, of antibiotics in such situations, to determine the optimum dose and course length of oral steroid therapy, and to continue validating the use of self-management plans in acute asthma management.

Acute Disease↗

[Clinical evaluation of an ampicillin suppository (KS-R1) in respiratory tract infections in children].

Fundamental and clinical studies of ampicillin (ABPC) suppository (KS-R1) were performed in children with respiratory tract infections. Serum levels of ABPC after rectal administration of KS-R1 at a dose of 250 mg (11.4-17.7 mg/kg) in 3 children (3-5 years old) were 4.0-10.2 micrograms/ml (average 6.4 micrograms/ml) at 1/4 hour, 3.8-9.4 micrograms/ml (average 6.2 micrograms/ml) at 1/2 hour, 1.2-4.5 micrograms/ml (average 2.8 micrograms/ml) at 1 hour, 0.3-1.4 micrograms/ml (average 0.7 micrograms/ml) at 2 hours, and 0.3 microgram/ml in 1 case and unmeasurable amount in 2 cases at 4 hours. Urine concentrations of ABPC were 230-445 micrograms/ml (average 312 micrograms/ml) in 0-2 hours, 5.3-156 micrograms/ml (average 66.7 micrograms/ml) in 2-4 hours, and 1.3-13.4 micrograms/ml (average 6.1 micrograms/ml) in 4-6 hours, and the recovery rate into urine was 6.6-27.7% (average 15.6%) up to 6 hours. Clinical effects of KS-R1 on 16 childish patients with respiratory tract infections (acute purulent tonsillitis in 9 cases, acute bronchitis in 5 cases, acute bronchopneumonia in 1 case and acute purulent otitis media in 1 case) were excellent in 13 cases, good in 2 cases and poor in 1 case, and the effective rate was 93.8%. Bacteriologically, 5 strains of S. pyogenes, 4 strains of S. pneumoniae and 3 strains of H. influenzae were all eradicated with eradication rate of 100%. Side effect was weak diarrhea in 1 case, but this diarrhea immediately disappeared with discontinuation of treatment. There was no abnormality of clinical laboratory findings. It was concluded that KS-R1 is a useful drug for the treatment of respiratory tract infections in children.

Ampicillin↗

[Respiratory tract diseases, their health-political importance and trends].

The diseases of the respiratory organs are defined and classified according to the 8th revision of the international classification of the diseases. The acute forms are above all represented by the infections of the respiratory tract. They are the problem No. 1 in health politics, since the most frequent exemptions from work are given on their account. A transition into chronic diseases of the respiratory tract is not infrequent. Among the causes of death the diseases of the respiratory system occupy the 3rd place, the chronic forms are an essential cause of early invalidity. Among the chronic diseases of the respiratory organs considerable shifts to the unspecific side took place. The tuberculosis is vastly reduced. The methods practised in its combat and the graduated, well functioning system of specialised outpatient institutions and hospitals proved as a very suitable instrumentarium also for the combat against the unspecific diseases of the respiratory organs. Three main groups increasingly demand our attention: bronchial carcinoma, chronic obstructive lung disease and the professionally conditioned diseases of the respiratory organs. Their combat demands a broad partnership with the physicians of the "first line", the factory health service and the internists. For this purpose the description of the own possibilities is necessary.

Carcinoma, Bronchogenic↗

Antibiotics for upper respiratory tract infections. Follow-up utilization and antibiotic use.

OBJECTIVES: To examine the effects of antibiotic prescribing during an initial visit for viral respiratory tract infections on future care seeking and the cost of care. MATERIALS AND METHODS: Retrospective analysis of recorded visits for viral respiratory tract infections (N = 49,862) between January 1, 1995, and December 31, 1997, to practices in a large network of affiliated practices that use the same electronic medical record. RESULTS: Patients receiving antibiotics at the initial visit were less likely to return for a second visit, but this difference was small (15.4% vs 17.4%, P < .001). When returning for the second visit, those who received an antibiotic on the initial visit were prescribed more expensive antibiotics than those who had not received an antibiotic on the initial consultation. Overall, cost from initial antibiotic use outweighed any benefit from reduced utilization in adults and children. CONCLUSIONS: Antibiotic prescribing at an initial contact for a viral respiratory tract illness may reduce the likelihood that an individual will return for a subsequent visit, but adds substantial costs to care for the initial antibiotic and for more expensive antibiotics used on subsequent visits.

Adolescent↗

Passive smoke exposure in infants and children with respiratory tract diseases.

1. The adverse effect of passive smoke exposure on the respiratory tract, particularly in infants and children, is not an issue of dispute. It was the objective of this study to analyse the extent and the intensity of passive smoke exposure in infants and children with respiratory tract diseases, and compare the information obtained with parents' subjective assessment. At the time of admission to the hospital, the parents of 295 infants and children (aged 1 month to 11 years) were questioned by the physician as to the smoking habits in the families' homes. An HPLC method was employed to determine simultaneously nicotine, cotinine and trans-3'-hydroxycotinine in the children's urine. 2. The sum of the nicotine metabolites turned out to be a sensitive marker in determining passive smoke exposure. Measurements revealed passive smoke exposure in 66% of the children, the frequency in younger children being significantly (P < 0.001) higher than in children over 5 years (84% vs 52%). The average concentration of nicotine metabolites in younger passive smokers was significantly (P < 0.001) higher when compared to the older ones (193 nmol/l vs 86 nmol/l). Forty-nine per cent of the parents assessed that their children had experienced passive smoke exposure, and another 10% emphasised that they only smoked in the absence of their child. In children with cystic fibrosis and bronchial asthma, the number of passive smokers as assessed by their parents were lower by 65% and 29% respectively when compared to the findings obtained from measurements. In children without respiratory diseases, the difference was as little as 18%. 3. Parents when questioned in conjunction with an illness of their children, tended to understate, or even withhold the truth about, passive smoke exposure. Therefore, reliable information on passive smoke exposure of patients can only be obtained through objective measurements.

Adult↗

Influences of parameter uncertainties within the ICRP 66 respiratory tract model: particle deposition.

Risk assessment associated with the inhalation of radioactive aerosols requires as an initial step the determination of particle deposition within the various anatomic regions of the respiratory tract. The model outlined in ICRP Publication 66 represents to date one of the most complete overall descriptions of not only particle deposition, but of particle clearance and local radiation dosimetry of lung tissues. In this study, a systematic review of the deposition component within the ICRP 66 respiratory tract model was conducted in which probability density functions were assigned to all input parameters. These distributions were subsequently incorporated within a computer code LUDUC (LUng Dose Uncertainty Code) in which Latin hypercube sampling techniques are used to generate multiple (e.g., 1,000) sets of input vectors (i.e., trials) for all of the model parameters needed to assess particle deposition within the extrathoracic (anterior and posterior), bronchial, bronchiolar, and alveolar-interstitial regions of the ICRP 66 respiratory tract model. Particle deposition values for the various trial simulations were shown to be well described by lognormal probability distributions. Geometric mean deposition fractions from LUDUC were found to be within approximately +/- 10% of the single-value estimates from the LUDEP computer code for each anatomic region and for particle diameters ranging from 0.001 to 50 microm. In all regions of the respiratory tract, LUDUC simulations for an adult male at light exertion show that uncertainties in particle deposition fractions are distributed only over a range of about a factor of approximately 2-4 for particle sizes between 0.005 to 0.2 microm. Below 0.005 microm, uncertainties increase only for deposition within the alveolar region. At particle sizes exceeding 1 microm, uncertainties in the deposition fraction within the extrathoracic regions are relatively small, but approach a factor of 20 for deposition in the bronchial region. Deposition fractions for particles above 1 microm become very uncertain within the deeper regions of the lungs (bronchiolar and alveolar-interstitial).

Body Height↗

Evidence-based guidelines for treatment of bacterial respiratory tract infections in the era of antibiotic resistance.

Antimicrobial resistance in bacterial respiratory tract pathogens is a rapidly evolving and increasingly disconcerting problem. Major factors that have contributed to resistance are inappropriate prescribing of antibiotics for viral infections and the use of antibiotics with poor activity. The treatment of respiratory tract infections is significantly affected by resistance in organisms such as Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis. Resistance to beta-lactams, sulfonamides, and macrolides continues to rise. Evidence-based guidelines, founded on clinical and bacteriological outcomes, are imperative to treat patients effectively, to limit the spread of these pathogens, and to minimize further development of resistance. Pharmacokinetic and pharmacodynamic parameters have recently been shown to correlate with clinical outcome, and offer a more rational approach to predicting antimicrobial efficacy and determining clinically relevant susceptibility breakpoints.

Anti-Bacterial Agents↗

Respiratory viruses and severe lower respiratory tract complications in hospitalized patients.

BACKGROUND: Acute respiratory viral infections are generally self-limited in healthy subjects but can lead to severe complications in immunocompromised hosts. We report the clinical impact of acute lower respiratory tract viral infections in hospitalized patients. MATERIALS AND METHODS: Of 1,001 fiberoptic bronchoscopies performed during a period of 5 years, 33 BAL samples were positive for respiratory viruses by cell culture. The main diagnosis, length of hospitalization, response to initial treatment, and the mortality rate at 30 days were analyzed. Spirometry performed before and after infection was compared in lung transplant recipients. RESULTS: The following respiratory viruses were identified in 33 cases: influenza A or B (n = 13), parainfluenza virus 1-3 (n = 7), rhinovirus (n = 5), respiratory syncytial virus (n = 4), and adenovirus (n = 4). All cases were immunocompromised patients who acquired new respiratory symptoms and/or radiologic abnormalities suggesting a pulmonary infection. Twenty-five patients (74%) did not respond to initial broad-spectrum antibiotics, and 11 patients (33%) required intensive care for respiratory failure. The overall mortality rate at 1 month was 24%. In patients with a sole viral pathogen identified in their BAL, the mortality rate was 39%. In lung transplant recipients (n = 10), the mean FEV(1) decreased from 2.2 to 1.9 L/s before and during the infection episode, respectively (p < 0.01); 3 months later, 60% of the patients had still not completely recovered to baseline values. CONCLUSION: Respiratory viruses recovered in BAL samples of immunocompromised patients are associated with severe lower respiratory complications. In lung transplant recipients, we observed a persisting impairment of pulmonary function.

Acute Disease↗

Sarcoidosis of the upper respiratory tract (SURT).

A series of eight hundred and eighteen patients with histologically-confirmed multisystem sarcoidosis was analysed; within this series were 53 (6 per cent) patients with sarcoidosis of the upper respiratory tract (SURT). Two-thirds presented with predominantly upper respiratory tract symptoms when the systemic disorder was minimal or unrecognized. Women were affected twice as often as men. SURT is commonly associated with lupus pernio and other manifestations of chronic fibrotic sarcoidosis, and it follows the same indolent course. When granulomas are found on biopsy of the upper respiratory tract, there should be a management plan to determine whether they are due to multisystem sarcoidosis or other granulomatous disorders including tuberculosis, Wegener's granulomatosis and leprosy. About one-half of patients with SURT will need oral steroids, either alone or in combination with topical steroids or chloroquine.

Adolescent↗

Detection of rhinovirus and enterovirus in upper respiratory tract samples using a multiplex nested PCR.

Human enteroviruses and rhinoviruses are respiratory pathogens whose role in acute respiratory infection is underestimated due to the use of diagnostic procedures with poor sensitivity. To determine the prevalence of these two pathogens in the upper respiratory tract infections, a multiplex procedure was developed that both detect and differentiate rhinoviruses and enteroviruses. This sensitive procedure allowed the detection of both pathogens from archival material (nasal swabs) collected during the previous winters and differentiated rhinoviruses from enteroviruses. This procedure can be used to determine the role of these pathogens in mild or severe upper respiratory tract infections.

Animals↗

Ribavirin for respiratory syncytial virus lower respiratory tract infection. A systematic overview.

OBJECTIVE: To systematically review the evidence evaluating the efficacy of aerosolized ribavirin for the treatment of infants with respiratory syncytial virus lower respiratory tract infection. DESIGN: A computerized search of MEDLINE from 1975 to the present, a review of the reference lists of each retrieved article, and contact with experts. PATIENTS: infants with documented respiratory syncytial virus lower respiratory tract infection who were the subjects of 8 double-blind randomized placebo-controlled trials. METHODS: Two independent reviewers assessed study quality and extracted data on the study populations, the drug regimens, and clinically relevant outcome measurements. RESULTS: Ribavirin does not significantly reduce mortality rate (relative risk [RR] = 0.42, 95% confidence interval [CI] = 0.13, 1.44) or lower the probability of respiratory deterioration (RR = 0.42, 95% CI = 0.16, 1.34) when meta-analysis is used to pool the outcomes of 3 trials, although strong trends in the direction of benefit are present. No study found ribavirin to shorten length of hospitalization. Results on length of ventilation and oxygen supplementation are conflicting. CONCLUSIONS: Use of ribavirin in infants with respiratory syncytial virus lower respiratory tract infection is not supported by evidence of significant benefit. However, previous studies lack sufficient power to rule out a potential reduction in mortality rate or respiratory deterioration. A large randomized controlled trial of ribavirin for ventilated and other high-risk patients is needed.

Antiviral Agents↗

Perceptions and behaviors of patients with upper respiratory tract infection.

A questionnaire was administered to outpatients with uncomplicated viral upper respiratory tract infection in order to study the perceptions and behaviors of these individuals. Most patients sought advice or prescriptions to treat symptoms, felt that their symptoms had lasted longer than expected, or were worried that their symptoms could represent serious illness. There was considerable misunderstanding of the natural history of untreated upper respiratory tract infection and of the role of penicillin. The reasons for these findings and their implications for providers of primary care are discussed.

Adolescent↗

Clinical efficacy, tolerance and pharmacokinetics of temocillin in patients with respiratory tract infections.

In this study 13 patients with a history of chronic respiratory disease were treated with temocillin for severe infection of the lower respiratory tract. Eleven patients were clinically improved or cured at the end of treatment and 4 remained free of infection at follow up. However, the 2 remaining patients failed to respond clinically and bacteriologically to temocillin. Blood and sputum pharmacokinetics were studied in patients receiving temocillin at 12-hourly intervals in doses of either 1g by intravenous bolus or 2g by intravenous infusion. On the first day of treatment the mean peak serum concentration was 102 mg/L for the 1g dose and 220 mg/L for the 2g dose, falling to 11 mg/L (1g) and 18.8 mg/L (2g) at 12 hours. Similar results were recorded on the last day of treatment. Temocillin concentrations in the sputum ranged from 1.5 to 2.8 mg/L, with no difference being found in the sputum concentrations of the 2 doses. Temocillin was well tolerated and was found to be an effective treatment for Gram-negative bacterial infections of the lower respiratory tract.

Drug Tolerance↗