Metagenomic analysis of a sample from a patient with respiratory tract infection reveals the presence of a γ-papillomavirus

Previously unknown or unexpected pathogens may be responsible for that proportion of respiratory diseases in which a causative agent cannot be identified. The application of broad-spectrum, sequence independent virus discovery techniques may be useful to reduce this proportion and widen our knowledge about respiratory pathogens. Thanks to the availability of high-throughput sequencing (HTS) technology, it became today possible to detect viruses which are present at a very low load, but the clinical relevance of those viruses must be investigated. In this study we used VIDISCA-454, a restriction enzyme based virus discovery method that utilizes Roche 454 HTS system, on a nasal swab collected from a subject with respiratory complaints. A γ-papillomavirus was detected (complete genome: 7142 bp) and its role in disease was investigated. Respiratory samples collected both during the acute phase of the illness and 2 weeks after full recovery contained the virus. The patient presented antibodies directed against the virus but there was no difference between IgG levels in blood samples collected during the acute phase and 2 weeks after full recovery. We therefore concluded that the detected γ-papillomavirus is unlikely to be the causative agent of the respiratory complaints and its presence in the nose of the patient is not related to the disease. Although HTS based virus discovery techniques proved their great potential as a tool to clarify the etiology of some infectious diseases, the obtained information must be subjected to cautious interpretations. This study underlines the crucial importance of performing careful investigations on viruses identified when applying sensitive virus discovery techniques, since the mere identification of a virus and its presence in a clinical sample are not satisfactory proofs to establish a causative link with a disease.

Airway obstruction and bronchodilator responsiveness in adults with acute cough

PURPOSE

We sought to determine the prevalence of airway obstruction and bronchodilator responsiveness in adults consulting for acute cough in primary care.

METHODS

Family physicians recruited 3,105 adult patients with acute cough (28 days or shorter) attending primary care practices in 12 European countries. After exclusion of patients with preexisting physician-diagnosed asthma or chronic obstructive pulmonary disease (COPD), we undertook complete case analysis of spirometry results (n = 1,947) 28 to 35 days after inclusion. Bronchodilator responsiveness was diagnosed if there were recurrent complaints of wheezing, cough, or dyspnea and an increase of the forced expiratory volume in 1 second (FEV(1)) of 12% or more after bronchodilation. Airway obstruction was diagnosed according to 2 thresholds for the (postbronchodilator) ratio of FEV(1) to forced vital capacity (FEV(1):FVC): less than 0.7 and less than the lower limit of normal.

RESULTS

There were 240 participants who showed bronchodilator responsiveness (12%), 193 (10%) had a FEV(1)/FVC ratio of less than 0.7, and 126 (6%) had a ratio of less than the lower limit of normal. Spearman's correlation between the 2 definitions of obstruction was 0.71 (P <.001), with discordance most pronounced among those younger than 30 years and in older participants.

CONCLUSIONS

Both bronchodilator responsiveness and persistent airway obstruction are common in adults without established asthma or COPD who consult for acute cough in primary care, which suggests a high risk of undiagnosed asthma and COPD. Different accepted methods to define airway obstruction detected different numbers of patients, especially at the extremes of age. As both conditions benefit from appropriate and timely interventions, clinicians should be aware and responsive to potential underdiagnosis.

Incidental chest radiographic findings in adult patients with acute cough

PURPOSE

Imaging may produce unexpected or incidental findings with consequences for patients and ordering of future investigations. Chest radiography in patients with acute cough is among the most common reasons for imaging in primary care, but data on associated incidental findings are lacking. We set out to describe the type and prevalence of incidental chest radiography findings in primary care patients with acute cough.

METHODS

We report on data from a cross-sectional study in 16 European primary care networks on 3,105 patients with acute cough, all of whom were undergoing chest radiography as part of a research study workup. Apart from assessment for specified signs of pneumonia and acute bronchitis, local radiologists were asked to evaluate any additional finding on the radiographs. For the 2,823 participants with good-quality chest radiographs, these findings were categorized according to clinical relevance based on previous research evidence and analyzed for type and prevalence by network, sex, age, and smoking status.

RESULTS

Incidental findings were reported in 19% of all participants, and ranged from 0% to 25% by primary care network, with the network being an independent contributor (P <.001). Of all participants 3% had clinically relevant incidental findings. Suspected nodules and shadows were reported in 1.8%. Incidental findings were more common is older participants and smokers (P <. 001).

CONCLUSIONS

Clinically relevant incidental findings on chest radiographs in primary care adult patients with acute cough are uncommon, and prevalence varies by setting.