In the Clinic: Community-Acquired Pneumonia

Risk factors for drug-resistant pathogens in community-acquired pneumonia: systematic review and meta-analysis

INTRODUCTION

Community-acquired pneumonia (CAP) is a leading cause of death worldwide. Reducing inappropriate and excessive use of extended-spectrum antibiotics is essential for treating CAP effectively. Evaluating the risk of drug-resistant pathogens (DRPs) is crucial for determining initial antibiotic therapy in clinical settings.

METHODS

This systematic review and meta-analysis assessed the risk factors for DRPs in patients with CAP. CAP-DRPs were defined as pathogens resistant to commonly used antibiotics for CAP, including nonpseudomonal β-lactams such as ceftriaxone or sulbactam-ampicillin, macrolides and respiratory fluoroquinolones. The studies included were divided into two cohorts, namely an all-patient cohort, comprising both culture-positive and culture-negative patients, and a culture-positive pneumonia cohort, comprising patients with identified causative pathogens. The primary objective of this study was to evaluate the risk factors for CAP-DRPs in the all-patient cohort.

RESULTS

24 articles were included with 11 categorised into the all-patient cohort. The meta-analysis identified 11 significant risk factors for CAP-DRPs, namely prior DRP infection/colonisation, tracheostomy, severe respiratory failure requiring early induction of mechanical ventilation, prior use of antibiotics, chronic lung disease, COPD, wound care, neurological disorders, prior hospitalisation, nursing home residence and low activities of daily living.

CONCLUSION

To our knowledge, this is the first systematic review focused on CAP-DRP. Unlike previous reviews, the all-patient and culture-positive pneumonia cohorts were analysed separately. Findings from the all-patient cohort are particularly relevant for guiding initial antimicrobial selection in clinical practice. Furthermore, the abovementioned factors should be considered when developing prediction models for CAP-DRPs.

Association between Pneumonia, Fracture, Stroke, Heart Attack and Other Hospitalizations with Changes in Mobility Disability and Gait Speed in Older Adults

Pathophysiological changes after acute hospitalizations may influence physical functioning in older adults, which can lead to disability and loss of independence. This study evaluated the association between pneumonia, fracture, heart attack, stroke, and other hospitalizations with major mobility disability (MMD) and gait speed. This was a secondary analysis of the Lifestyle Interventions and Independence for Elders (LIFE) Study, which was conducted across eight sites during 2010–2013 with longitudinal follow-up for 1635 individuals over an average of 2.6 years. Participants included adults ≥70 years old with pre-existing mobility limitations randomized to a physical activity intervention or a health education control arm. Hospitalizations were recorded via self-report and adjudicated by medical reviewers. MMD was measured by the inability to complete a 400 m walk test, or other proxies, as a binary outcome. Gait speed was recorded during the walk test in meters per second (m/s) and measured on a linear scale. Mixed-effects repeated measures regression adjusted for baseline demographics, comorbid conditions, and frailty. Among the 1635 participants, there were 1458 hospitalizations, which included 80 (5.5% of all hospitalizations) cases of pneumonia, 92 (6.3%) hospitalized fractures, 87 (6.0%) heart attacks, and 61 (4.2%) strokes. In the short-term measurement period immediately following hospitalization (1 day to 6 months), stroke (OR = 3.98 (3.41–4.54)) had the strongest association with MMD followed by fracture (OR = 3.03 (2.54–3.52)), pneumonia (OR = 2.76 (2.23–3.30)), and heart attack (OR = 2.03 (1.52–2.53)). Associations with long-term (6–12 months after) MMD were decreased or not significant for all causes. Pneumonia, fracture, stroke, and other hospitalizations were associated with short-term relative gait speed changes between −4.8% up to −19.5%, and only fracture was associated with long-term changes. Hospitalizations for pneumonia, heart attack, stroke, and fractures were associated with short-term decreases in mobility in older adults. Older adults may be at risk for decreased mobility and disability following acute hospitalizations, with the magnitude determined by the cause of the precipitating event.

Immunochromatography for the diagnosis of Mycoplasma pneumoniae infection: A systematic review and meta-analysis

The aim of this study was to evaluate the diagnostic performance of immunochromatographic tests (ICTs) for the detection of Mycoplasma pneumoniae. Medline/Pubmed, Embase, the Cochrane Library, and ISI Web of Science were searched through June 12, 2019 for relevant studies that used ICTs for the detection of M. pneumoniae infection with polymerase chain reaction (PCR) or microbial culturing as reference standards. Pooled diagnostic accuracy with 95% confidence interval (CI) was calculated using a bivariate random effects model. We also constructed summary receiver operating characteristic curves and calculated the area under the curve (AUC). Statistical heterogeneity was evaluated by χ² test or Cochrane’s Q test. Thirteen studies including 2,235 samples were included in the meta-analysis. The pooled sensitivity and specificity for diagnosing M. pneumoniae infection were 0.70 (95% CI: 0.59–0.79) and 0.92 (95% CI: 0.87–0.95), respectively. The positive likelihood ratio (LR) was 8.94 (95% CI: 4.90–14.80), negative LR 0.33 (95% CI: 0.22–0.46), diagnostic odds ratio 29.20 (95% CI: 10.70–64.20), and AUC 0.904. In subgroup analysis, ICTs demonstrated similar pooled sensitivities and specificities in populations of children only and mixed populations (children + adults). Specimens obtained from oropharyngeal swabs exhibited a higher sensitivity and specificity than those of nasopharyngeal swab. Moreover, pooled estimates of sensitivity and accuracy for studies using PCR as a reference standard were higher than those using culture. The pooled sensitivity and specificity of Ribotest Mycoplasma^®, the commercial kit most commonly used in the included studies, were 0.66 and 0.89, respectively. Overall, ICT is a rapid user-friendly method for diagnosing M. pneumoniae infection with moderate sensitivity, high specificity, and high accuracy. This suggests that ICT may be useful in the diagnostic workup of M. pneumoniae infection; however, additional studies are needed for evaluating the potential impact of ICT in clinical practice.

Impact of the Hospitalist System in Japan on the Quality of Care and Healthcare Economics

Objective The hospitalist system is considered successful with respect to the quality of care and cost effectiveness in the United States. Studies have consistently demonstrated an improved clinical efficiency with this system. In Japan, however, the efficacy of the hospitalist system has not yet been examined. As a "super-aged society", Japan has a high number of elderly patients with multiple comorbidities who may theoretically receive better care by the hospitalist system than by the conventional system. This study investigates the impact of the hospitalist system on the quality of care and healthcare economics in a Japanese population. Methods We analyzed 274 patients ≥65 years of age in whom the most resource-consuming diagnosis at admission was aspiration pneumonia over a 1-year period. We categorized patients as those managed by hospitalists and those managed by various departments (control group) and compared the groups. Propensity score matching was used to minimize selection bias. Results For matched pairs, the length of hospital stay in the hospitalist group was shorter than that in the control group. Care by the hospitalist system was associated with significantly lower hospital costs. The quality of care (rate of switching from intravenous to oral antibiotics, duration of antibiotics therapy, number of chest X-rays and blood tests during hospitalization) was also considered to be favorably impacted by the hospitalist system. There was no statistically significant difference in the mortality rate or readmission rate between the groups. Conclusion This study showed that the hospitalist system had a favorable impact on the quality of care and cost effectiveness, suggesting the potential utility of its implementation in the Japanese medical system.

Missed opportunities for pneumococcal vaccinations in high-risk and older adults in the United States

Pneumococcal vaccination rates remain sub-optimal in high-risk adult populations. This analysis quantified "missed opportunities," defined as number of healthcare encounters in unvaccinated patients who are recommended to be vaccinated. The 2015 National Health Interview Survey was used to assess vaccination status from adults 18-64 with risk factor and adults ≥65 years-old. In older adults, there was a mean of 5.15 (95% CI: 4.90-5.39) healthcare visits that could be opportunities for pneumococcal vaccination. In adults 18-64 years at high risk, there was a mean of 4.83 (95% CI: 4.66-4.99). Healthcare providers should take advantage of patient interactions to increase vaccination rates.

[Place of biomarkers in the management of pulmonary infections]

INTRODUCTION

The management of acute lower respiratory tract infections and, in particular, the decision whether or not to commence antibiotic therapy, still remains difficult in the absence of reliable clinical or radiological criteria allowing confident distinction between bacterial and viral infections. Numerous biomarkers have been developed to help the clinician in his/her diagnostic and therapeutic approach, but the role and significance of each has not been clearly defined.

BACKGROUND

Though procalcitonin (PCT) or C-reactive protein (CRP) seem equal in helping the clinician to decide whether to commence antibiotic therapy or not during the course of an exacerbation of asthma or chronic obstructive pulmonary disease (COPD), PCT is currently the most useful biomarker to distinguish sepsis from other causes of inflammation and to determine the bacterial or viral origin of a pneumonia.

OUTLOOK

The ability of PCT to reduce the global exposure to antibiotics remains uncertain and the results of randomised trials are contradictory.

CONCLUSIONS

Prescription algorithms involving PCT may be used without increased risk for patients even though clinical signs of severity remain important. Changes in PCT also have a prognostic value in identifying those patients with unfavourable outcome.

Pneumonia

By nearly any criteria, pneumonia (infection of the pulmonary parenchyma) must be considered one of the most important categories of disease affecting the respiratory system. This chapter is organized primarily as a general discussion of the clinical problem of pneumonia. As appropriate, the focus on individual etiologic agents highlights some characteristic features of each that are particularly useful to the physician. Also covered is a commonly used categorization of pneumonia based on the clinical setting: community-acquired versus nosocomial (hospital-acquired) pneumonia. In current clinical practice, the approach to evaluation and management of these two types of pneumonia is often quite different. The chapter concludes with a brief discussion of several infections that were uncommon or primarily of historical interest until recently, as the threat of bioterrorism emerged. In addition to reviewing inhalational anthrax, the chapter briefly describes two other organisms considered to be of concern as potential weapons of bioterrorism: Yersinia pestis (the cause of plague) and Francisella tularensis (the cause of tularemia).

The relative burden of community-acquired pneumonia hospitalizations in older adults: a retrospective observational study in the United States

Background

The risk of community-acquired pneumonia (CAP) increases with age and significantly impacts morbidity and mortality in the elderly population. The burden of illness and cost of preventing CAP has not been compared to other serious diseases.

Methods

This retrospective analysis used claims data from 2014 to 2015 and compared hospitalizations for CAP, myocardial infarction (MI), stroke, and osteoporotic fractures (OF) in adults aged ≥65 years enrolled in a Medicare Advantage insurance plan. Individuals who had not already been hospitalized for one of these conditions and did not have evidence of long-term care were included in the study. Hospitalizations for each condition were described by length of stay, readmissions, mortality, and total costs. Preventive measures included vaccinations for CAP and medications for MI, stroke, and OF.

Results

A total of 1,949,352 individuals were included in the cohort. In 2015, the rate of CAP-related hospitalizations was the highest at 846.7 per 100,000 person-years compared to 405 for MI, 278.9 for stroke, and 343.9 for OF. Vaccination costs for CAP were $40.2 million including $14.1 million for pneumococcal and $26.1 million for influenza vaccines. The cost of preventive medications for MI and stroke reached over $661 million and OF totaled $169 million.

Conclusions

Although CAP has a higher burden of hospitalization and total costs than MI, stroke, and OF in the elderly population, prevention efforts were disproportionately smaller for CAP. Prioritization of CAP prevention is needed to substantially reduce the burden of CAP.

Characterization and evaluation of a novel immunochromatographic assay for pharyngeal Mycoplasmapneumoniae ribosomal protein L7/L12 antigens

Point-of-care testing for Mycoplasma pneumoniae infection may be ideal and useful because significant numbers of the cases will be seen as outpatients. Recently, a new immunochromatographic method (ICM) targeting M. pneumoniae ribosomal protein L7/L12 (RP-L7/L12) in pharyngeal swabs became available in Japan, although clinical data and basic information regarding efficacy and characterization of this ICM are limited. The present study examined the fate of M. pneumoniae RP-L7/L12 during in vitro growth and the correlation between M. pneumoniae concentration in clinical specimens and the sensitivity of the ICM test. The usefulness of the ICM was investigated in patients suspected of having M. pneumoniae pneumonia and upper respiratory tract infection (137 children and 39 adults). The limit of detection for the ICM test was 1.1×104 c.f.u. ml-1 of M. pneumoniae. Bacterial production of RP-L7/L12 correlated positively with the viable M. pneumoniae concentration in vitro; antigen was then degraded in culture broth, with an in vitro half-life of approximately 2 days. Five other Mycoplasma spp. and 14 representative respiratory pathogens were ICM assay negative at bacterial concentrations of 106 c.f.u. ml-1. The clinical sensitivity and specificity of the ICM assay were 57.1 % (20/35) and 92.2 % (130/141), respectively, in comparison with bacterial culture. Clinical specimens containing ≥106 c.f.u. ml-1 of M. pneumoniae burden were ICM positive in 13 of 18 cases (72.2 %). The ICM is a poorly sensitive but reasonably specific means for detecting M. pneumoniae infections.

Pulmonary Infections: Imaging with CT

Computed tomography (CT) plays a key role in various kinds of pulmonary infections especially in immunocompromised patients, owing to its much higher sensitivity and specificity than the traditionally performed chest X-ray. CT permits the detection of the main infectious pattern and associated findings with high confidence and allows for the precise assessment of all involved structures, to potentially guide a bronchoalveolar lavage or another diagnostic procedure, and to ensure a reliable follow-up. It may be performed at a carefully chosen dose, which may nearly reach that of a chest X-ray in specific situations. The importance of post-processing tools is undeniable in some conditions, in particular for the evaluation of micronodules in the immunocompromised population. The wide spectrum of features of specific organisms according to the immune status, such as in aspergillosis or tuberculosis, must be known, as well as the potential of atypical presentations in case of Pneumocystis jirovecii (PCP) pneumonia when occurring in non-HIV immunocompromised patients. In all cases, underlying disorders must be considered as well as all the differential diagnoses. Overall, CT definitely helps clinicians to diagnose pulmonary infections and to make treatment decisions, especially in vulnerable patients.