A novel host-protein assay outperforms routine parameters for distinguishing between bacterial and viral lower respiratory tract infections

Bacterial and viral lower respiratory tract infections (LRTIs) are often clinically indistinguishable, leading to antibiotic overuse. We compared the diagnostic accuracy of a new assay that combines 3 host-biomarkers (TRAIL, IP-10, CRP) with parameters in routine use to distinguish bacterial from viral LRTIs. Study cohort included 184 potentially eligible pediatric and adult patients. Reference standard diagnosis was based on adjudication by an expert panel following comprehensive clinical and laboratory investigation (including respiratory PCRs). Experts were blinded to assay results and assay performers were blinded to reference standard outcomes. Evaluated cohort included 88 bacterial and 36 viral patients (23 did not fulfill inclusion criteria; 37 had indeterminate reference standard outcome). Assay distinguished bacterial from viral LRTI patients with sensitivity of 0.93 ± 0.06 and specificity of 0.91 ± 0.09, outperforming routine parameters, including WBC, CRP and chest x-ray signs. These findings support the assay's potential to help clinicians avoid missing bacterial LRTIs or overusing antibiotics.     

Acute Lower Respiratory Tract Infections in Soldiers,South Korea,April 2011–March 2012

During April 2011–March 2012, we retrospectively reviewed medical records for South Korea soldiers to assess the etiology and epidemiology of acute viral lower respiratory tract infections. Adenovirus was the most commonly identified virus (63.2%) and the most common cause of pneumonia (79.3%) and hospitalization (76.6%); 3 soldiers died of adenovirus-related illness.     

Value of serum procalcitonin, neopterin, and C-reactive protein in differentiating bacterial from viral etiologies in patients presenting with lower respiratory tract infections

The values of procalcitonin (PCT), neopterin, and C-reactive protein (CRP) alone and in combination to differentiate bacterial from viral etiology in patients with lower respiratory tract infections (LRTIs) were evaluated. Sera obtained on the day of hospitalization for LRTI from 139 patients with confirmed bacterial etiology and 128 patients with viral etiology were examined. A further 146 sera from healthy Chinese subjects with no infection were included as controls. The area under the receiver operating characteristic (ROC) curve (area under curve [AUC]) for distinguishing bacterial from viral infections was 0.838 for CRP and 0.770 for PCT (P < 0.05). The AUC for distinguishing viral from bacterial infections was 0.832 for neopterin (P < 0.05). When the markers were used in combination, AUC of ROC (CRP/neopterin) was 0.857, whereas (CRP x PCT)/neopterin was 0.856. Combination of 2 or all 3 of the biomarkers may improve the discriminatory power in delineating bacterial versus viral etiology in LRTI.     

老年下呼吸道感染病原菌的分布及药敏试验

目的 探讨1992年1月至1997年12月住院的老年下呼吸道感染患者的病原菌分布、耐药情况,供临床用药借鉴.方法对痰中分离的细菌进行分类、鉴定,并对其中的不动杆菌进行药敏试验.结果6年的病原菌分布已发生改变,虽然仍以革兰氏阴性杆菌为主,且肠杆菌仍居首位,但不动杆菌和其它非发酵菌呈逐年上升趋势.用12种抗生素,对钙不动杆菌的药敏结果表示,钙不动杆菌耐药率较高,但对氧哌嗪青霉素、复达欣、氧氟沙星及氨基甙类的抗生素,仍保持较好的敏感性,敏感率为55.2～86.8%.结论虽然病原菌发生变迁,耐药情况严重,但仍有敏感的抗生素可选用.     

Bacterial agents of lower respiratory tract infections (LRTIs), beta-lactamase production, and resistance to antibiotics in elderly people. DEDALO Study Group

This study determined the etiology of lower respiratory tract infections in the elderly and assessed whether the growth of β-lactamase producing bacteria is particularly favoured in these patients. Between December 1998 and May 1999, 187 patients with community-acquired pneumonia (CAP), and 887 patients with acute exacerbations of chronic obstructive pulmonary disease (AECOPD) were enrolled. The mean age was 74 years (range of 65–94 year). Sputum and bronchial aspirate for microbiological investigation were obtained. Besides organisms commonly involved in bacterial infections of the lower respiratory tract (i.e. Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis), Enterobacteriaceae and Pseudomonas spp. were also found. A high percentage of these bacteria were β-lactamase producers. These data along with the clinical presentation, severity of infection, and epidemiological knowledge, might represent a guide for the choice of empiric antimicrobial treatment.     

Paediatric pneumonia in high-income countries: Defining and recognising cases at increased risk of severe disease

World Health Organisation definitions of pneumonia severity are routinely used in research. In high income health care settings with high rates of pneumococcal vaccination and low rates of mortality, malnutrition and HIV infection, these definitions are less applicable. National guidelines from leading thoracic and infectious disease societies describe ‘severe pneumonia’ according to criteria derived from expert consensus rather than a robust evidence base. Contemporary cohort studies have used clinical outcomes such as intensive care therapy or invasive procedures for complicated pneumonia, to define severe disease. Describing severe pneumonia in such clinically relevant terms facilitates the identification of risk factors associated with worsened disease and the subsequently increased morbidity, and need for tertiary level care. The early recognition of children at higher risk of severe pneumonia informs site of care decisions, antibiotic treatment decisions as well as guiding appropriate investigations. Younger age, malnutrition, comorbidities, tachypnoea, and hypoxia have been identified as important associations with ‘severe pneumonia’ by WHO definition. Most studies have been performed in low-middle income countries and whilst they provide some insight into those at risk of mortality or treatment failure, their generalisability to the high-income setting is limited. There is a need to determine more precise definitions and criteria for severe disease in well-resourced settings and to validate factors associated with intensive care admission or invasive procedures to enhance the early recognition of those at risk.