How deadly is seasonal influenza-associated pneumonia? The German Competence Network for Community-Acquired Pneumonia.

The emergence of new influenza virus subtypes has rekindled the interest in the clinical course and outcome of patients with influenza-associated pneumonia. Based on prospective data from 5,032 patients with community-acquired pneumonia (CAP) included in the German Competence Network for Community-Acquired Pneumonia (CAPNETZ), we studied the incidence, clinical characteristics and outcome of patients with influenza-associated CAP and compared these findings with patients without influenza. Diagnosis relied on a positive PCR for influenza in throat washings. 160 patients with influenza-associated CAP were identified (3.2% of total population, 12% of those with defined aetiology). 34 (21%) patients with seasonal influenza had a concomitant pathogen (mostly Streptococcus pneumoniae). Patients with influenza-associated CAP were significantly older, had been vaccinated less often and had preceding antibacterial treatment less often. 30-day mortality was low (4.4%) and not different to that of patients with pneumonia caused by bacterial (6.2%) or viral (other than influenza) pathogens (4%). Patients with influenza plus a bacterial pathogen (mixed influenza-associated pneumonia) had a higher mortality than those with pure influenza-associated pneumonia (9% versus 3.2%). Mortality was higher in patients with mixed compared with pure influenza-associated pneumonia. However, we could not observe any excess mortality in patients with influenza-associated pneumonia.

[The impact of viruses in lower respiratory tract infections of the adult. Part II: acute bronchitis, acute exacerbated COPD, pneumonia, and influenza]. / Die Rolle von Viren bei tiefen Atemwegsinfektionen des Erwachsenen. Teil 2: Akute Bronchitis, exazerbierte COPD, Pneumonie und Influenza.

In industrialized countries respiratory tract infections are one of the most common reasons for medical consultations. It is assumed that almost one third of these infections affect the lower respiratory tract (LRTI), e. g. acute bronchitis, acute exacerbation of chronic obstructive pulmonary disease (COPD), community- or hospital-acquired pneumonia and influenza. Due to a lack of sufficient and valid investigations on the epidemiology of respiratory viruses, their impact on the pathogenesis of LRTI has probably been underestimated for a long time. Therefore, there might have been many cases of needless antibiotic treatment, particularly in cases of acute bronchitis or acute exacerbations of COPD, because of an assumed bacteriological aetiology. Following the introduction of diagnostic procedures with increased sensitivity, such as polymerase chain reaction, it is possible to reliably detect respiratory viruses and to illuminate their role in the pathogenesis of LRTI of the adult. We have reviewed the current literature to elucidate the role of viruses in the pathogenesis of LRTI. The first part of this series described frequent viral pathogens, pathogenesis of viral LRTI, and diagnostic procedures. In this 2 (nd) part the aetiological role of viruses in the most frequent forms of LRTI will be highlighted, and the third and last part will provide an overview of therapeutic and preventive options.

[The impact of viruses in lower respiratory tract infections of the adult. Part I: Pathogenesis, viruses, and diagnostics]. / Die Rolle von Viren bei tiefen Atemwegsinfektionen des Erwachsenen. Teil 1: Erreger, Pathogenese und Diagnostik.

In industrialised countries respiratory tract infections are one of the most common reasons for medical consultations. It is assumed that almost one third of these infections include the lower respiratory tract (LRTI), e. g. acute bronchitis, acute exacerbation of chronic obstructive pulmonary disease (COPD), community- or hospital-acquired pneumonia and influenza. Due to a lack of sufficient and valid investigations on the epidemiology of respiratory viruses, their impact on the pathogenesis of LRTI has probably been underestimated for a long time. Therefore, there might have been many cases of needless antibiotic treatment, particularly in cases of acute bronchitis or acute exacerbations of COPD, because of an assumed bacteriological aetiology. Following the introduction of diagnostic procedures with increased sensitivity, such as polymerase chain reaction, it is possible to reliably detect respiratory viruses and to illuminate their role in the pathogenesis of LRTI of the adult. We have reviewed the current literature to elucidate the role of viruses in the pathogenesis of LRTI. The first part of this series deals with the relevant pathogens, pathogenesis, and diagnostic procedures. In the subsequent 2 parts of this series a review will be given on the most common variants of viral LRTI (part II), and therapeutic and preventive options (part III).

Influence of azithromycin and clarithromycin on macrolide susceptibility of viridans streptococci from the oral cavity of healthy volunteers.

Oral viridans streptococci are a reservoir of resistance genes for pathogens. Through prolonged exposure, long-acting macrolides (e.g., azithromycin) may induce the resistance of the commensals to macrolides more frequently than macrolides with a shorter half-life (e.g., clarithromycin). In a prospective, randomized, evaluator-blinded trial in healthy volunteers receiving standard courses of either azithromycin (n = 20) or clarithromycin (n = 20), we compared the susceptibility of oral viridans streptococci to macrolides over a period of 12 weeks. There was a significant temporal increase in the numbers of resistant isolates in both groups (p < 0.0005 at week 1). The proportion of macrolide-resistant isolates over time was significantly higher following azithromycin treatment (p = 0.0005), but returned to baseline values until week 12 in both groups. Temporal differential effects of azithromycin and clarithromycin on the induction of resistance were observed and need to be investigated regarding their effect on co-colonizing pathogens.

Fluoroquinolone resistance in invasive Streptococcus pyogenes isolates due to spontaneous mutation and horizontal gene transfer.

Fluoroquinolone resistance in Streptococcus pyogenes has been described only anecdotally. In this study we describe two invasive ciprofloxacin-resistant S. pyogenes isolates (ciprofloxacin MICs, 8 mg/liter), one of which shows evidence of interspecies recombination. The quinolone resistance-determining regions of gyrA and parC were sequenced. In both isolates, there was no evidence for an efflux pump and no mutation in gyrA. Both isolates had an S79F mutation in parC that is known to confer fluoroquinolone resistance. In addition, a D91N mutation in parC, which is not related to fluoroquinolone resistance but is a feature of the parC sequence of Streptococcus dysgalactiae, was found in one isolate. The parC nucleotide sequence of that isolate showed greater diversity than that of S. pyogenes. A GenBank search and phylogenetic analysis suggest that this isolate acquired resistance by horizontal gene transfer from S. dysgalactiae. Statistical testing for recombination confirmed interspecies recombination of a 90-bp sequence containing the S79F mutation from S. dysgalactiae. For the other isolate, we could confirm that it acquired resistance by spontaneous mutation by identifying the susceptible ancestor in an outbreak setting.

Impact of corticosteroids on the immune response to a MF59-adjuvanted influenza vaccine in elderly COPD-patients.

The influence of steroids on the antibody response to a MF59-adjuvanted influenza vaccine in elderly COPD patients has not been studied previously. In the influenza season 2001/02 (October-February) elderly COPD patients were recruited at 14 doctor's offices and our 250-bed hospital. Patients were stratified into three groups according to current treatment regimen: (a) > 10 mg of prednisolone/day (SS); (b) inhaled steroids (IS); (c) no steroid treatment (control group, CG). All patients were vaccinated with the MF59-adjuvanted influenza vaccine. Antibodies against the influenza strains A/H1N1, A/H3N2, and B were measured at baseline, 4 and 24 weeks after vaccination by hemagglutination inhibition (HI) assay. One-hundred and sixty-two patients completed the study (CG n = 42; IS n = 87; SS n = 33). Mean age was 71.3 years (range 60-89). Twenty-one percent of all patients reported local reactions; no serious adverse events were observed. Four weeks after vaccination, mean geometric HI titres (GMT) for A/H1N1, A/H3N and B increased significantly in all groups (p < or = 0.05). After 24 weeks, GMTs to A/H1N1 and A/H3N2 returned to baseline, while GMTs to type B remained significantly higher than baseline in all groups. Significant differences between the groups as regards GMTs, seroconversion (56-89%) or seroprotection rates (64-93%) were not observed. Systemic steroids did not influence the antibody response towards the MF59-adjuvanted influenza vaccine. We found that the strains included in the vaccine showed varying long-term immunogenicity.

Ciprofloxacin treatment failure in a patient with resistant Streptococcus pneumoniae infection following prior ciprofloxacin therapy.

Reported here is the case of a patient with underlying chronic obstructive pulmonary disease (COPD) in whom ciprofloxacin treatment of a lower respiratory tract infection failed subsequent to ciprofloxacin treatment of an exacerbation of COPD several weeks earlier. During the second course of ciprofloxacin therapy, the patient's condition continued to deteriorate, and she was admitted to the intensive care unit. Bilateral pneumonia was diagnosed. Streptococcus pneumoniae, serotype 11A, resistant to ciprofloxacin was isolated from the sputum. Sequencing revealed a S79F mutation in parC and there was evidence of an efflux pump. The patient improved rapidly after administration of azithromycin and ampicillin/sulbactam. This report of treatment failure due to ciprofloxacin-resistant Streptococcus pneumoniae shows that fluoroquinolones should be avoided when treating patients who have recently received this class of antibiotics.

Reduced spontaneous apoptosis in peripheral blood neutrophils during exacerbation of COPD.

A major feature of acute exacerbation of chronic obstructive pulmonary disease (COPD) is the accumulation of activated neutrophils in the bronchial tree. This phenomenon can be explained by an increased migration and/or by a prolonged survival due to an inhibition of spontaneous apoptosis. The aim of this study was to assess the apoptotic behaviour of peripheral blood neutrophils in COPD patients during an acute exacerbation. Thirty-six hospitalised COPD patients with an acute exacerbation and 10 healthy volunteers were included. Blood samples were obtained at admission, after 3-5 days and at discharge. Spontaneous apoptosis of isolated neutrophils was measured based on Annexin V-PE binding and nuclear morphology after culturing for 18 h. At admission, significantly lower rates of spontaneous apoptosis were noted in COPD patients compared with healthy volunteers (mean +/- SD 31 +/- 13% versus 44 +/- 18%). The mean percentages of apoptotic neutrophils were 31 +/- 13% at admission, 39 +/- 15% after 3-5 days and 47 +/- 18% at discharge. There was a statistically significant difference between the rates of spontaneous apoptosis on the first day and at discharge. Neither forced expiratory volume in one second < 35% predicted, smoking habit, corticosteroid therapy nor evidence of bacterial infection showed any influence on the spontaneous apoptosis in this study. In conclusion, during acute exacerbations of chronic obstructive pulmonary disease, neutrophil granulocytes show a reduced spontaneous apoptosis that increases progressively after treatment and clinical remission. This raises the question of the importance of neutrophil apoptosis in the development and resolution of exacerbations of chronic obstructive pulmonary disease.