New and emerging etiologies for community-acquired pneumonia with implications for therapy. A prospective multicenter study of 359 cases

Pseudomonas aeruginosa community-acquired pneumonia following soil ingestion: A case report

BACKGROUND

Pseudomonas aeruginosa (P. aeruginosa) is an uncommon etiological agent in community-acquired pneumonia (CAP), typically associated with nosocomial or healthcare-associated infections, particularly in patients with underlying structural lung abnormalities or immunosuppression. P. aeruginosa is a ubiquitous gram-negative rod, widely distributed in the environment. However, CAP due to P. aeruginosa following soil ingestion is exceedingly rare.

CASE PRESENTATION

We present the case of a previously healthy 31-year-old patient, a middle school teacher, who developed CAP due to P. aeruginosa after ingesting garden soil for three consecutive days. The patient was admitted with symptoms including fever, chest pain, vomiting, and diarrhea. Chest computed tomography (CT) revealed two suspicious lesions in the left lower lobe, with one lesion exhibiting cavitation. Microbiological culture of bronchoalveolar lavage fluid (BALF) and stool confirmed the presence of P. aeruginosa infection. Subsequent antimicrobial susceptibility testing revealed that the P. aeruginosa isolate was pan-sensitive. Following 13 days of targeted antimicrobial therapy, the patient's symptoms and laboratory markers of infection improved significantly. A follow-up CT scan one month later demonstrated substantial resolution of the left lower lobe lesions, and the patient remained asymptomatic.

CONCLUSIONS

This case, along with a review of related literature, suggests that geophagy may be a potential risk factor for P. aeruginosa infection. It underscores the importance of avoiding the consumption of unprocessed soil, which may be contaminated with pathogenic organisms.

Aetiological agents of adult community-acquired pneumonia in Japan: systematic review and meta-analysis of published data

OBJECTIVE

Epidemiological information is essential in providing appropriate empiric antimicrobial therapy for pneumonia. This study aimed to clarify the epidemiology of community-acquired pneumonia (CAP) by conducting a systematic review of published studies in Japan.

DESIGN

Systematic review.

DATA SOURCE

PubMed and Ichushi web database (January 1970 to October 2022).

ELIGIBILITY CRITERIA

Clinical studies describing pathogenic micro-organisms in CAP written in English or Japanese, excluding studies on pneumonia other than adult CAP, investigations limited to specific pathogens and case reports.

DATA EXTRACTION AND SYNTHESIS

Patient setting (inpatient vs outpatient), number of patients, concordance with the CAP guidelines, diagnostic criteria and methods for diagnosing pneumonia pathogens as well as the numbers of each isolate. A meta-analysis of various situations was performed to measure the frequency of each aetiological agent.

RESULTS

Fifty-six studies were included and 17 095 cases of CAP were identified. Pathogens were undetectable in 44.1% (95% CI 39.7% to 48.5%). Streptococcus pneumoniae was the most common cause of CAP requiring hospitalisation or outpatient care (20.0% (95% CI 17.2% to 22.8%)), followed by Haemophilus influenzae (10.8% (95% CI 7.3% to 14.3%)) and Mycoplasma pneumoniae (7.5% (95% CI 4.6% to 10.4%)). However, when limited to CAP requiring hospitalisation, Staphylococcus aureus was the third most common at 4.9% (95% CI 3.9% to 5.8%). Pseudomonas aeruginosa was more frequent in hospitalised cases, while atypical pathogens were less common. Methicillin-resistant S. aureus accounted for 40.7% (95% CI 29.0% to 52.4%) of S. aureus cases. In studies that used PCR testing for pan-respiratory viral pathogens, human enterovirus/human rhinovirus (9.4% (95% CI 0% to 20.5%)) and several other respiratory pathogenic viruses were detected. The epidemiology varied depending on the methodology and situation.

CONCLUSION

The epidemiology of CAP varies depending on the situation, such as in the hospital versus outpatient setting. Viruses are more frequently detected by exhaustive genetic searches, resulting in a significant variation in epidemiology.

Herd immunity in older adults from a middle-income country: A time-series trend analysis of community-acquired pneumonia mortality 2003-2017

Background and Aims

Community-acquired pneumonia is responsible for substantial mortality, and pneumococcus is commonly accepted as a major cause of pneumonia, regardless of laboratory confirmation. Child immunization programs have reported success in decreasing pneumonia mortality: directly in young children and indirectly (herd immunity) in unvaccinated adult populations in some countries. We assess changes in mortality trends for all-cause pneumonia in older adults associated with the introduction of pneumococcal vaccination for children in Peru.

Methods

This is a secondary analysis on administrative data collected periodically by the Peruvian Ministry of Health. An observational retrospective time series analysis was conducted using longitudinal population-based data from death certificates in Peru between 2003 and 2017. The time series includes 6 years before and 9 years after the introduction of the pneumococcal-conjugated vaccines in the national child immunization program in 2009. Monthly frequencies and annual rates for all-cause pneumonia deaths in children under 5 years of age and adults over 65 years of age are presented. Linear and quadratic trends are analyzed.

Results

Deaths among older adults accounted for 75.6% of all-cause pneumonia mortality in Peru, with 94.4% of these reporting "pneumonia due to unspecified organism" as the underlying cause of death. Comparing pre- and post-child immunization program periods, annual average mortality rates from unspecified pneumonia decreased by 22.7% in young children but increased by 19.6% in older adults. A linear trend model supports this overall tendency, but a quadratic curve explains the data better.

Conclusion

Pneumococcal-conjugated vaccines are developed using serotypes prevalent in selected countries from less common (invasive) pneumococcal disease and expected to prevent mortality worldwide from widespread (noninvasive) pneumonia. Our results do not support the presence of herd immunity from pneumococcal vaccination of children for community-acquired pneumonia in the increasingly ageing population of Peru. This should direct future research and could influence public health policy.

Adherence to use of blood cultures according to current national guidelines and their impact in patients with community acquired pneumonia: A retrospective cohort

BACKGROUND

Community acquired pneumonia (CAP) is the most frequent cause of mortality secondary to infectious etiologies. Recommendations about the use of blood cultures in the diagnosis and treatment of CAP has been a contentious topic of debate and ever-changing recommendations.

METHODS

A cohort study was conducted in a community teaching hospital. All the patients that were admitted with a diagnosis of CAP, between January and December of 2019 were included. Sociodemographic and clinical characteristics were obtained. Blood cultures results were obtained, and it was evaluated if they were done in compliance with current recommendations by the Infectious Disease Society of America (IDSA).

RESULTS

721 patients were included in the study. Median age was 68 years and 50% of the patients were male (n = 293). Patients presented from home (84%) and the most common comorbidities were hypertension and diabetes (68% and 31%). 96 patients had positive blood culture and 34% (n = 247) of all the blood cultures were adequately ordered. 80 patients died or went to hospice and the median length of hospital stay in our cohort was 7 days. The multivariate model showed that mortality was associated with positive blood cultures (OR = 3.1 95%CI 1.63-5.87) and appropriateness of blood cultures (OR = 2.96 95% CI 1.2-5.7).

CONCLUSION

Adequate use of blood cultures in patients with CAP might have some association with the outcomes of this disease. However, a prospective study evaluating the utility of this test following current IDSA recommendations is needed to understand their impact in mortality and morbidity.

The Microbial Etiology of Community-Acquired Pneumonia in Adults: from Classical Bacteriology to Host Transcriptional Signatures

All modern advances notwithstanding, pneumonia remains a common infection with substantial morbidity and mortality. Understanding of the etiology of pneumonia continues to evolve as new techniques enable identification of already known organisms and as new organisms emerge. We now review the etiology of pneumonia (at present often called "community-acquired pneumonia") beginning with classic bacteriologic techniques, which identified Streptococcus pneumoniae as the overwhelmingly common cause, to more modern bacteriologic studies, which emphasize Haemophilus influenzae, Staphylococcus aureus, Moraxella catarrhalis, Enterobacteriaceae, Pseudomonas, and normal respiratory flora. Urine antigen detection is useful in identifying Legionella and pneumococcus. The low yield of bacteria in recent studies is due to the failure to obtain valid sputum samples before antibiotics are administered. The use of high-quality sputum specimens enables identification of recognized ("typical") bacterial pathogens as well as a role for commensal bacteria ("normal respiratory flora"). Nucleic acid amplification technology for viruses has revolutionized diagnosis, showing the importance of viral pneumonia leading to hospitalization with or without coinfecting bacterial organisms. Quantitative PCR study of sputum is in its early stages of application, but regular detection of high counts of bacterial DNA from organisms that are not seen on Gram stain or grown in quantitative culture presents a therapeutic dilemma. This finding may reflect the host microbiome of the respiratory tract, in which case treatment may not need to be given for them. Finally, host transcriptional signatures might enable clinicians to distinguish between viral and bacterial pneumonia, an important practical consideration.

Role of cholesterol, lipoproteins, and neutrophilic-lymphocytic ratio in patients with pneumonia

Background

Lipids play numerous functions in lung biology and pathophysiology of infection, in addition to their role in lipid transport, lipoproteins share in innate immunity that is the most important way for the host to defend against microbes. The NLR (neutrophil-lymphocytic ratio) is a good indicator of systemic inflammation and infection.

Objective

To evaluate the role of cholesterol, lipoproteins, and neutrophilic-lymphocytic ratio in the assessment of patients with pneumonia.

Patients and methods

This prospective case–control study included 52 subjects; they were categorized into 2 groups. Group A included 42 patients with pneumonia admitted to the Chest Department,Menoufia University, and group B included 10 healthy people during the period from May 2019 to December 2019. History taking, clinical examination, laboratory investigation in the form of CBC and lipid profile, and radiological investigation in the form of CXR and CT chest if needed were done to all subjects of the study.

Results

The mean cholesterol level in group A was 149.76 ± 42.79 which was statistically significantly lower as compared with group B (165.90 ± 45.50) (p = 0.039). The mean HDL level in group A was 43.16 ± 6.32 which was statistically significantly lower as compared with group B (50.51 ± 9.60) (p = 0.026). No statistically significant difference was found in the triglyceride level, LDL level and VLDL between the subjects in the two studied groups (p = 0.479, 0.792, and 0.606), respectively, but all levels were still within normal levels. Mean NLR in group A was 7.04 ± 7.98 which was statistically significantly higher as compared with group B (3.04 ± 1.6) (p = 0.004). Roc curve of neutrophil–lymphocyte ratio shows that the cutoff point is 1.94 and the N/L ratio had area under curve of 78% with 79.6% sensitivity and 67.8% specificity.

Conclusion

Serum cholesterol and high-density lipoprotein levels significantly decreased in patients with pneumonia when compared to the control group but were still within normal range. Lipid profile is affected by different variables like smoking index, body mass index, and sex. The neutrophil–lymphocyte at cutoff point is 1.94, and N/L ratio had area under curve of 78% with 79.6% sensitivity and 67.8% specificity.

Trial registration

TCTR, TCTR20220524001. Registered on 24 May 2022, retrospectively registered.

Q Fever as a Cause of Community-Acquired Pneumonia in French Guiana

In French Guiana, community-acquired pneumonia (CAP) represents over 90% of Coxiella burnetii acute infections. Between 2004 and 2007, we reported that C. burnetii was responsible for 24.4% of the 131 CAP hospitalized in Cayenne. The main objective of the present study was to determine whether the prevalence of Q fever pneumonia remained at such high levels. The secondary objectives were to identify new clinical characteristics and risk factors for C. burnetii pneumonia. A retrospective case-control study was conducted on patients admitted in Cayenne Hospital, between 2009 and 2012. All patients with CAP were included. The diagnosis of acute Q fever relied on titers of phase II IgG ≥ 200 and/or IgM ≥ 50 or seroconversion between two serum samples. Patients with Q fever were compared with patients with non-C. burnetii CAP in bivariate and multivariate analyses. During the 5-year study, 275 patients with CAP were included. The etiology of CAP was identified in 54% of the patients. C. burnetii represented 38.5% (106/275; 95% CI: 31.2-45.9%). In multivariate analysis, living in Cayenne area, being aged 30-60 years, C-reactive protein (CRP) > 185 mg/L, and leukocyte count < 10 G/L were independently associated with Q fever. The prevalence of Q fever among CAP increased to 38.5%. This is the highest prevalence ever reported in the world. This high prevalence justifies the systematic use of doxycycline in addition to antipneumococcal antibiotic regimens.

Validating a clinical prediction score for Legionella-related community acquired pneumonia

BACKGROUND

Legionella-related community acquired pneumonia (CAP) is a disease with an increasing incidence and a high mortality rate, especially if empirical antibiotic therapy is inadequate. Antibiotic treatment highly relies on clinical symptoms, although proven non-specific, because currently available diagnostic techniques provide insufficient accuracy for detecting Legionella CAP on admission. This study validates a diagnostic scoring system for detection of Legionella-related CAP, based on six items on admission (Legionella prediction score).

METHODS

We included patients with Legionella-related CAP admitted to five large Dutch hospitals between 2006 and 2016. Controls were non-Legionella-related CAP patients. The following six conditions were rewarded one point if present: fever > 39.4 °C; dry cough; hyponatremia (sodium) < 133 mmol/L; lactate dehydrogenase (LDH) > 225 mmol/L; C-reactive protein (CRP) > 187 mg/L and platelet count < 171 × 10⁹/L. The accuracy of the prediction score was assessed by calculating the area under the curve (AUC) through logistic regression analysis.

RESULTS

We included 131 cases and 160 controls. A score of 0 occurred in non-Legionella-related CAP patients only, a score of 5 and 6 in Legionella-related CAP patients only. A cut-off ≥ 4 resulted in a sensitivity of 58.8% and a specificity of 93.1%. The AUC was 0.89 (95% CI 0.86-0.93). The strongest predictors were elevated LDH, elevated CRP and hyponatremia.

CONCLUSIONS

This multi-centre study validates the Legionella prediction score, an easily applicable diagnostic scoring system, in a large group of patients and finds high diagnostic accuracy. The score shows promise for future prospective validation and could contribute to targeted antibiotic treatment of suspected Legionella CAP.

Prognostic utility of CURB-65 and E-CURB-65 scoring systems in healthcare associated pneumonia patients: Short- and long-term mortality

Background

The aim of our study is to evaluate whether the CURB-65 or expanded-CURB-65 score can be used in healthcare-associated pneumonia (HCAP) and subgroups of HCAP patients at the same efficiency. Thirty and 90-day mortality rates of the patients and predictive values of CURB-65 and E-CURB-65 scores were compared.

Patients and Methods

This is a retrospective study of patients who presented to the Emergency Department between January 2015 and January 2016. All patient charts above 18 years of age were evaluated according to American Thoracic Society and the Infectious Diseases Society of America (ATS/IDSA) pneumonia diagnostic criteria and pneumonia diagnoses were confirmed.

Results

167 pneumonia patients (27.8%) of all pneumonia cases were grouped as HCAP and 433 (54.4%) were grouped as community-acquired pneumonia (CAP). 43% (n = 72) of HCAP patients were classified as nursing home-associated pneumonia (NHAP) and 57% (n = 95) were classified as HCAP (except NHAP) group. NHAP patients were older than the other groups. HCAP (except NHAP) group had somehow more comorbid diseases when compared with the other groups. However, the NHAP group had more unstable vital signs and confusion rates. Hospital and ICU admissions, 30-90-day mortality rates were all significantly higher in NHAP group E-CURB-65 was found to have better predictive values than CURB-65 for 30-day and 90-day mortalities overall.

Conclusion

According to our results, commonly used scoring systems, CURB 65 and E-CURB 65, are not suitable for HCAP, NHAP, and HCAP (except NHAP) patients. NHAP patients have significant worse prognosis compared with CAP and HCAP (except NHAP) in terms of admission to intensive care and 30 and 90-day mortality rates.

Outcomes of respiratory viral-bacterial co-infection in adult hospitalized patients

BACKGROUND

Viral infections of the respiratory tract represent a major global health concern. Co-infection with bacteria may contribute to severe disease and increased mortality in patients. Nevertheless, viral-bacterial co-infection patterns and their clinical outcomes have not been well characterized to date. This study aimed to evaluate the clinical features and outcomes of patients with viral-bacterial respiratory tract co-infections.

METHODS

We included 19,361 patients with respiratory infection due to respiratory viruses [influenza A and B, respiratory syncytial virus (RSV), parainfluenza] and/or bacteria in four tertiary hospitals in Hong Kong from 2013 to 2017 using a large territory-wide healthcare database. All microbiological tests were conducted within 48 h of hospital admission. Four etiological groups were included: (1) viral infection alone; (2) bacterial infection alone; (3) laboratory-confirmed viral-bacterial co-infection and (4) clinically suspected viral-bacterial co-infection who were tested positive for respiratory virus and negative for bacteria but had received at least four days of antibiotics. Clinical features and outcomes were recorded for laboratory-confirmed viral-bacterial co-infection patients compared to other three groups as control. The primary outcome was 30-day mortality. Secondary outcomes were intensive care unit (ICU) admission and length of hospital stay. Propensity score matching estimated by binary logistic regression was used to adjust for the potential bias that may affect the association between outcomes and covariates.

FINDINGS

Among 15,906 patients with respiratory viral infection, there were 8451 (53.1%) clinically suspected and 1,087 (6.8%) laboratory-confirmed viral-bacterial co-infection. Among all the bacterial species, Haemophilus influenzae (226/1,087, 20.8%), Pseudomonas aeruginosa (180/1087, 16.6%) and Streptococcus pneumoniae (123/1087, 11.3%) were the three most common bacterial pathogens in the laboratory-confirmed co-infection group. Respiratory viruses co-infected with non-pneumococcal streptococci or methicillin-resistant Staphylococcus aureus was associated with the highest death rate [9/30 (30%) and 13/48 (27.1%), respectively] in this cohort. Compared with other infection groups, patients with laboratory-confirmed co-infection had higher ICU admission rate (p < 0.001) and mortality rate at 30 days (p = 0.028), and these results persisted after adjustment for potential confounders using propensity score matching. Furthermore, patients with laboratory-confirmed co-infection had significantly higher mortality compared to patients with bacterial infection alone.

INTERPRETATION

In our cohort, bacterial co-infection is common in hospitalized patients with viral respiratory tract infection and is associated with higher ICU admission rate and mortality. Therefore, active surveillance for bacterial co-infection and early antibiotic treatment may be required to improve outcomes in patients with respiratory viral infection.

Community-acquired versus nosocomial Legionella pneumonia: factors associated with Legionella-related mortality

Over the past decade, changes in the diagnosis and management of Legionella pneumonia occurred and risk factors for severe infection and increased mortality were identified. Previous reports found that nosocomial infection is associated with higher mortality while others showed no differences. We aimed to evaluate the differences in the clinical course and mortality rates between hospital-acquired pneumonia (HAP) and community-acquired pneumonia (CAP) caused by Legionella pneumophila. A retrospective cohort study of patients admitted due to Legionella pneumonia between January 2012 through November 2019 was conducted in a tertiary referral center (Rambam Health Care Campus, Haifa, Israel). The primary outcome was 30-day Legionella pneumonia-related mortality. A multivariable logistic regression was performed to determine whether a nosocomial infection is an independent predictor of mortality. One hundred nine patients were included. Seventy (64.2%) had CAP and 39 (35.8%) had HAP. The groups were comparable regarding age, gender, and comorbidities. Time to diagnosis was longer and the number of patients receiving initial empiric anti-Legionella spp. treatment was smaller in the HAP group (8 days [IQR 5.5-12.5] vs. 5 days [IQR 3-8], p < 0.001 and 65.5% vs. 78.6%, p = 0.003, respectively). Patients with HAP had higher 30-day mortality, 41% vs. 18.6%, p = 0.02. In a multivariable logistic regression model, only pneumonia severity index and nosocomial source were independently associated with increased mortality. HAP caused by Legionella spp. is independently associated with increased mortality when compared to CAP caused by the same pathogen. The possible reasons for this increased mortality include late diagnosis and delayed initiation of appropriate treatment.

Predicting 30-day mortality of patients with pneumonia in an emergency department setting using machine-learning models

OBJECTIVE

This study aimed to confirm the accuracy of a machine-learning-based model in predicting the 30-day mortality of patients with pneumonia and evaluating whether they were required to be admitted to the intensive care unit (ICU).

METHODS

The study conducted a retrospective analysis of pneumonia patients at an emergency department (ED) in Seoul, Korea, from January 1, 2016 to December 31, 2017. Patients aged 18 years or older with a pneumonia registry designation on their electronic medical record were enrolled. We collected their demographic information, mental status, and laboratory findings. Three models were used: the pre-existing CURB-65 model, and the CURB-RF and Extensive CURB-RF models, which were machine-learning models that used a random forest algorithm. The primary outcomes were ICU admission from the ED or 30-day mortality. Receiver operating characteristic curves were constructed for the models, and the areas under these curves were compared.

RESULTS

Out of the 1,974 pneumonia patients, 1,732 patients were eligible to be included in the study; from these, 473 patients died within 30 days or were initially admitted to the ICU from the ED. The area under receiver operating characteristic curves of CURB-65, CURB-RF, and extensive-CURB-RF were 0.615 (0.614-0.616), 0.701 (0.700-0.702), and 0.844 (0.843-0.845), respectively.

CONCLUSION

The proposed machine-learning models could predict the mortality of patients with pneumonia more accurately than the pre-existing CURB-65 model and can help decide whether the patient should be admitted to the ICU.

Effect of prior receipt of antibiotics on the pathogen distribution: a retrospective observational cohort study on 27,792 patients

Background

There have been no systematic studies of microbiological differences before and after antibiotics treatment. The aim of this study was to evaluate the effect of prior receipt of antibiotics on the microorganism distribution.

Methods

A retrospective, observational cohort study was conducted in a 3200-bed tertiary, referral, teaching hospital in eastern China. During a 2-year period, all hospitalized patients treated with antimicrobial agents were enrolled in this study. Among 48,692 patients evaluated, the 27,792 (57.1%) who were sampled within 2 days before or after administration of the first dose of antimicrobial agents were included. Distribution of clinical specimens and the microorganism were compared between before and after antibiotic drug treatment groups.

Results

Compared to specimens taken after antibiotics exposure, specimens taken before antibiotics exposure had a higher proportion of blood and urine specimens and a higher culture positive rate (all P < 0.001). Higher percentages of Staphylococcus aureus (9.9% vs. 8.5%, P = 0.041), non-fermenting bacteria (27.7% vs. 19.9%, P < 0.001), and fungi (8.4% vs. 4.0%, P < 0.001) were isolated from the group after antibiotics exposure, while the percentages of Streptococcus spp. (4.8% vs. 2.7%, P < 0.001), Haemophilus influenzae (2.3% vs. 0.8%, P < 0.001), and Moraxella catarrhalis (0.7% vs. 0.1%, P < 0.001) were higher in the group before antibiotics exposure. Further analysis found significant differences of microbes derived from respiratory secretions, blood or urine samples. We found, after antibiotics exposure, the separation rate of non-fermenting bacteria was significantly increased (all P < 0.05), and the separation rate of Candida spp. was higher, with statistical significance in airway secretion and urine samples (both P < 0.05), but the separation rate of Staphylococcus aureus among the three groups was not affected by antibiotics. In addition, the isolation rate of Streptococcus spp. in blood and urine samples decreased significantly (both P < 0.05) after antibiotics exposure. Interestingly, no statistical difference was found for microbes isolated from body fluid specimens between the two groups.

Conclusions

The outcome revealed that antibiotic-insensitive organisms such as non-fermentative bacteria and fungi were more frequently isolated after antibiotics exposure. However, this trend might be specimen dependent and was not obvious in body fluid specimens.

Systematic review on respiratory syncytial virus epidemiology in adults and the elderly in Latin America

OBJECTIVES

The present study provides a comprehensive review of the recently published data on RSV epidemiology in adults and the elderly in Latin America.

METHODS

A systematic literature search was carried out in Medline, Scielo, Lilacs, and Cochrane Library. The search strategy aimed at retrieving studies focusing on RSV prevalence, burden, risk factors, and the routine clinical practice in the prevention and management of RSV infections in Latin American countries. Only articles published between January 2011 and December 2017 were considered.

RESULTS

Eighteen studies were included. Percentages of RSV detection varied highly across included studies for adult subjects with respiratory infections (0% to 77.9%), influenza-like illness (1.0% to 16.4%) and community-acquired pneumonia (1.3% to 13.5%). Considerable percentages of hospitalization were reported for RSV-infected adults with influenza-like illness (40.9% and 69.9%) and community-acquired pneumonia (91.7%).

CONCLUSIONS

Recent RSV data regarding adult populations in Latin America are scarce. RSV was documented as a cause of illness in adults and the elderly, being identified in patients with acute respiratory infections, influenza-like illness and community-acquired pneumonia. The studies suggest that RSV infections may be a significant cause of hospitalization in adult populations in Latin America, including younger adults.

Cytokine levels predict 30-day mortality in octogenarians and nonagenarians with community-acquired pneumonia: a retrospective observational study

To analyze the value of cytokines (tumor necrosis factor [TNF]-α, interleukin [IL]-1β, IL-6, IL-8, IL-10) as predictors of mortality at 30 days in octogenarians and nonagenarians hospitalized in an internal medicine unit for community-acquired pneumonia (CAP). An observational, analytical, retrospective cohort study was conducted in the Department of Internal Medicine at Alicante General University Hospital between January 2014 and December 2015. Blood samples were frozen at - 80 °C, and cytokines were measured by ELISA. We included 115 patients, of whom 54% were men, with a mean age of 86.4 (standard deviation 4.5) years. There is a moderate correlation between IL-10 levels and CURB-65 score (p < 0.001) and a weak correlation with creatinine levels (p = 0.012) and urea levels (p = 0.032). Forty-five (39.1%) patients died within 30 days. In a multivariate analysis, the variables associated with mortality at 30 days were the following: age (adjusted odds ratio [ORa] 1.134, 95% confidence interval [CI] 1.02, 1.26), male sex (ORa 2.85, 95% CI 1.14, 7.14), IL-8 of 19 pg/mL or more (ORa 4.09, 95% CI 1.67, 10.01), and IL-10 of 11.29 pg/mL or more (ORa 4.00, 95% CI 1.58, 10.12). High IL-8 and IL-10 levels were shown to predict 30-day mortality in elderly patients with CAP. The inflammatory response in these patients seems to condition their prognosis. Further research in this line would provide more understanding about the physiopathological mechanisms and potential therapeutic targets for improving survival.

Costunolide alleviates HKSA-induced acute lung injury via inhibition of macrophage activation

Staphylococcus aureus (S. aureus) infection leads to a severe inflammatory response and causes acute lung injury (ALI), eventually threatening human life. Therefore, it is of importance to find an agent to inhibit inflammation and reduce ALI. Here, we found that costunolide, a sesquiterpene lactone, displays anti-inflammatory effects and ameliorates heat-killed S. aureus (HKSA)-induced pneumonia. Costunolide treatment attenuated HKSA-induced murine ALI in which pulmonary neutrophil infiltration was inhibited, lung edema was decreased, and the production of pro-inflammatory cytokines was significantly reduced. In addition, costunolide dose-dependently inhibited the generation of IL-6, TNF-α, IL-1β, and keratinocyte-derived cytokine (KC), as well as the expression of iNOS, in HKSA-induced macrophages. Furthermore, costunolide attenuated the phosphorylation of p38 MAPK and cAMP response element-binding protein (CREB). Collectively, our findings suggested that costunolide is a promising agent for alleviating bacterial-induced ALI via the inhibition of the MAPK signaling pathways.

Why is the rate of pneumococcal pneumonia declining?

PURPOSE OF REVIEW

As Streptococcus pneumoniae was considered the etiological agent of nearly all the cases of pneumonia at the beginning of the 20th century, and today is identified in fewer than 10-15% of cases, we analyze the possible causes of such a decline.

RECENT FINDINGS

Extensive use of early empiric antimicrobial therapy, discovery of previously unrecognized pathogens, availability to newer diagnostic methods for the recognition of the pneumonia pathogens (PCR, urinary antigens, monoclonal antibodies etc.) and of improved preventive measures, including vaccines, are some of possible explanations of the declining role of S. pneumoniae in the cause of pneumonia.

SUMMARY

The 14-valent and the 23-valent capsular polysaccharide pneumococcal vaccines were licensed in 1977 and 1983, respectively. The seven-valent protein-conjugated capsular polysaccharide vaccine, approved for routine use in children starting at 2 months of age, was highly effective in preventing invasive pneumococcal disease in children but also in adults because of the herd effect. In 2010, the 13-valent protein-conjugated capsular polysaccharide vaccine replaced seven-valent protein-conjugated capsular polysaccharide vaccine. With the use of conjugated vaccines, a decrease of the vaccine-type invasive pneumococcal disease for all age groups was observed. Both the direct effect of the vaccine and the so-called herd immunity are considered responsible for much of the decline.

Decreased relative risk of pneumococcal pneumonia during the last decade, a nested case-control study

Background

Streptococcus pneumoniae (SP) is one of the most common pathogens of Community-Acquired Pneumonia (CAP), but recent reports suggest that its incidence may be declining in relation to the use of the conjugate 13-valent pneumococcal vaccine in children. We compared the result of the immunochromatographic SP urinary antigen test (SPUAT) and clinical outcomes in patients with CAP admitted in two periods of time: 2001–2002(CAP1) and 2015–2016(CAP2).

Methods

This was a matched nested case-control study of two prospectively recorded cohorts of patients admitted with CAP, with SPUAT and blood culture performed in all patients. CAP2 cases and CAP1 controls were matched for age ± 4 years, sex, and Pneumonia Severity Index (PSI) score ± 10 points. Odds ratios (OR) for having SPUAT positive was estimated by conditional logistic regression. A multivariate model assessed the contribution of individual variables.

Results

Four hundred ninety-eight patients were recruited; 307 during the CAP1 and 191 during the CAP2 periods. Comparing both periods we observed differences, in age, PSI score, and the percentage of smokers, outpatients, previously immunized with pneumococcal vaccine, and positive SPUAT. On the other hand, mortality, admission from nursing homes, pneumococcal bacteremia and hospital admission were not different. After matching, pneumonia due to SP per the SPUAT was observed in 34(23.4%) of CAP1 and in 12(8.3%) of CAP2 patients (p < 0.001), and 6/145 CAP1 vs 33/145 CAP2 patients had received pneumococcal immunization before their admission (p < 0.001). A multivariate analysis confirmed that, independent of falling into PSI class 5, having not received the pneumococcal vaccine and having not survived the episode of pneumonia, there were two factors that increased the probability of having SPUAT positive: developing pneumonia during the CAP1 period (OR = 1.23) and having pneumococcal bacteremia (OR = 2.66).

Conclusion

We observed a reduction of the role of SP as pathogen, along with an increase in the number of patients who received pneumococcal immunization before admission, in 2015-2016 compared to 2001-2002. In addition, the use of conjugate 13-valent vaccine, starting in 2012 for childhood immunization, could be an additional factor contributing to these changes, as a result of early herd immunity in adults pneumonia.

Phytosome complexed with chitosan for gingerol delivery in the treatment of respiratory infection: In vitro and in vivo evaluation

Respiratory infection is a viral spreading disease and a common issue, particularly in kids. The treatments are available but have so many limitations because the drawback of this disease is more morbidity and mortality in the severely immune compromised. Even, the phyto-constituent antibacterial drug Gingerol was selected to treat respiratory infection but it exhibits low bioavailability profile, less aqueous-solubility issue and most important is rapidly eliminated from the body. To overcome these problems, novel drug delivery (nanoparticle) based phytosome complexed with chitosan approach was implemented. In this research work, the phytosome (GP) was prepared by blending of gingerol with soya lecithin in organic solvent using anti-solvent precipitation technique and it was further loaded in the aqueous solution of chitosan to formulate the phytosome complexed with chitosan (GLPC). To optimize the formulations of gingerol, it was characterized for percentage yield, percentage entrapment efficiency, drug loading and particle size, physical compatibility studies etc. which demonstrated the confirmation of complex of GLPC with soya lecithin and chitosan. The % entrapment efficiency and % drug loading of GLPC was found (86.02 ± 0.18%, 08.26 ± 0.72%) and of GP (84.36 ± 0.42%, 08.05 ± 0.03%), respectively. The average particle size and zeta potential of GLPC and GP were 254.01 ± 0.05 nm (-13.11 mV), and 431.21 ± 0.90 nm (-17.53 mV), respectively which confirm the inhibition of particle aggregation by using chitosan in complex. The in vitro release rate of GP (86.03 ± 0.06%) was slower than GLPC (88.93 ± 0.33%) in pH 7.4 phosphate buffer up to 24 h by diffusion process (Korsmeyer Peppas model). The optimized GLPC and GP were shown irregular particle shapes & spherical and oval structures with smooth surface by SEM analysis. Furthermore, GLPC has shown the potent in vitro antioxidant activity, susceptible antibacterial activity and effective anti-inflammatory activity as compared to GP against stress, microbial infection and inflammation which were causable reason for the respiratory infections. GLPC has improved the significant bioavailability and also correlated the hematological values on rabbit blood against the incubation of microorganisms. Thus, the prepared nanoparticle based approach to deliver the gingerol, has the combined effect of chitosan and phytosome which shown better sustained-release profile and also prolonging the oral absorption rate of gingerol with effective antibacterial activity to treat respiratory infection.

Evolving Understanding of the Causes of Pneumonia in Adults, With Special Attention to the Role of Pneumococcus

Before 1945, Streptococcus pneumoniae caused more than 90% of cases of pneumonia in adults. After 1950, the proportion of pneumonia caused by pneumococcus began to decline. Pneumococcus has continued to decline; at present, this organism is identified in fewer than fewer10%-15% of cases. This proportion is higher in Europe, a finding likely related to differences in vaccination practices and smoking. Gram-negative bacilli, Staphylococcus aureus, Chlamydia, Mycoplasma, and Legionella are each identified in 2%-5% of patients with pneumonia who require hospitalization. Viruses are found in 25% of patients, up to one-third of these have bacterial coinfection. Recent studies fail to identify a causative organism in more than 50% of cases, which remains the most important challenge to understanding lower respiratory infection. Our findings have important implications for antibiotic stewardship and should be considered as new policies for empiric pneumonia management are developed.

Impact of Procalcitonin Guidance with an Educational Program on Management of Adults Hospitalized with Pneumonia

BACKGROUND

Community-acquired pneumonia and healthcare-associated pneumonia are often treated with prolonged antibiotic therapy. Procalcitonin (PCT) has effectively and safely reduced antibiotic use for pneumonia in controlled studies. However, limited data exist regarding PCT guidance in real-world settings for management of pneumonia.

METHODS

A retrospective, preintervention/postintervention study was conducted to compare management for patients admitted with pneumonia before and after implementation of PCT guidance at 2 teaching hospitals in Pittsburgh, Pennsylvania. The preintervention period was March 1, 2014 through October 31, 2014, and the postintervention period was March, 1 2015 through October 31, 2015.

RESULTS

A total of 152 and 232 patients were included in the preintervention and postintervention cohorts, respectively. When compared with the preintervention group, mean duration of therapy decreased (9.9 vs 6.0 days; P < .001). More patients received an appropriate duration of 7 days or less (26.9% vs 66.4%; P < .001). Additionally, mean hospital length of stay decreased in the postintervention group (4.9 vs 3.5 days; P = .006). Pneumonia-related 30-day readmission rates (7.2% vs 4.3%; P = .26) were unaffected. In the postintervention group, patients with PCT levels <0.25 µg/L received shorter mean duration of therapy compared with patients with levels >0.25 µg/L (4.6 vs 8.0 days; P < .001), as well as reduced hospital length of stay (3.2 vs 3.9 days; P = .02).

CONCLUSIONS

In this real-world study, PCT guidance led to shorter durations of total antibiotic therapy and abridged inpatient length of stay without affecting hospital readmissions.

Lung Infections

A review of pulmonary infections of all types with diagnostic and morphological features.

Can we truly rely on the urinary antigen test for the diagnosis? Legionella case report

It is critical to diagnose and treat Legionella pneumonia (LP) immediately after infection because of the associated high mortality. The urine antigen test (UAT) is often used for the diagnosis of LP; however, it cannot detect the serogroups of all Legionella species. A detained medical history and several clinical findings such as liver enzyme elevation and hyponatremia are useful in diagnosis. Some specific types of Legionella are found in compost. Herein, we report a case of LP in which the patient's medical history and several clinical findings were useful for diagnosis.

Management of community-acquired pneumonia in immunocompetent adults: updated Swedish guidelines 2017

Based on expert group work, Swedish recommendations for the management of community-acquired pneumonia in adults are here updated. The management of sepsis-induced hypotension is addressed in detail, including monitoring and parenteral therapy. The importance of respiratory support in cases of acute respiratory failure is emphasized. Treatment with high-flow oxygen and non-invasive ventilation is recommended. The use of statins or steroids in general therapy is not found to be fully supported by evidence. In the management of pleural infection, new data show favourable effects of tissue plasminogen activator and deoxyribonuclease installation. Detailed recommendations for the vaccination of risk groups are afforded.

Rare presentation of an old bug

We highlight a rare presentation of Legionella infection in a 77-year-old woman with a clinical diagnosis of giant cell arteritis 2 months prior to presentation. She was started on 60 mg prednisone that was tapered to 10 mg after 4 weeks following her diagnosis. She presented with a 1-month progressive dyspnoea in the absence of any other symptoms. Her exposure history was significant only for a recent trip to Florida where she stayed at a hotel. Initial laboratory workup was significant for hyponatraemia (127 mmol/L). Workup including bronchoalveolar lavage (BAL) and induced sputum for gram stain, acid fast stain and bacterial culture were negative for Pneumocystis jirovecii pneumonia and other opportunistic infectious agents. However, BAL was positive for Legionella pneumophila via PCR that was confirmed by a positive urinary Legionella antigen. The patient received treatment with levofloxacin that led to full resolution of her symptoms.

Bacterial Pneumonia in Older Adults

The incidence of pneumonia increases with age, and is particularly high in patients who reside in long-term care facilities (LTCFs). Mortality rates for pneumonia in older adults are high and have not decreased in the last decade. Atypical symptoms and exacerbation of underlying illnesses should trigger clinical suspicion of pneumonia. Risk factors for multidrug-resistant organisms are more common in older adults, particularly among LTCF residents, and should be considered when making empiric treatment decisions. Monitoring of clinical stability and underlying comorbid conditions, potential drug-drug interactions, and drug-related adverse events are important factors in managing elderly patients with pneumonia.

Legionnaire's Disease and Influenza

Legionella pneumophila and influenza types A and B viruses can cause either community-acquired pneumonia with respiratory failure, or Legionella infection could attribute to influenza infection with potentially fatal prognosis. Copathogenesis between pandemic influenza and bacteria is characterized by complex interactions between coinfecting pathogens and the host. Understanding the underlying reason of the emersion of the secondary bacterial infection during an influenza infection is challenging. The dual infection has an impact on viral control and may delay viral clearance. Effective vaccines and antiviral therapy are crucial to increase resistance toward influenza, decrease the prevalence of influenza, and possibly interrupt the potential secondary bacterial infections.

Bacterial Etiology of Lower Respiratory Tract Infections and Their Antimicrobial Susceptibility

BACKGROUND

Lower respiratory tract infection (LRTI) is one of the common major health problems in Nigeria causing morbidity and mortality. The study was conducted to determine the current trends of bacterial etiology of LRTIs among patients who attended the University of Nigeria Teaching Hospital (UNTH) and their antimicrobial susceptibility profile with special interest on pandrug resistance.

MATERIALS AND METHODS

The study was conducted between February 2014 and June 2016 in the bacteriology laboratory of UNTH. Sputum samples of 954 patients with suspected LRTIs were received, after obtaining patients' informed consent and ethical clearance from the UNTH. The samples were collected and processed according to standard laboratory procedures.

RESULTS

The mean age of the patients was 42.6 ± 16.8 years. Of the total 954 sputum samples, 431 (45.2%) were positive for micro-organisms. A single, unique pathogen was recovered in 415 patients (96.3%), and 16 (3.7%) were polymicrobial. The most predominant single pathogen was Klebsiella pneumoniae, 215 (49.9%), and the most prevalent bacterial combination was Klebsiella spp and Pseudomonas aeruginosa, 6 (1.4%). Antimicrobial susceptibility testing shows that most isolates of K pneumoniae were susceptible to imipenem (94.8%). Among the bacteria, Escherichia coli (13.3%) ranked highest, followed by P aeruginosa (12.5%), and the least was Staphylococcus aureus (2.1%).

CONCLUSIONS

Knowledge of the diversity of pathogens responsible for LRTIs and their susceptibility patterns to antibiotics, as well as antibiotic resistance surveillance, are important in the effective management of LRTI with prompt clinical and laboratory diagnosis along with appropriate treatment strategies.

Severe Pneumonia Caused by Legionella pneumophila: Differential Diagnosis and Therapeutic Considerations

Severe legionella pneumonia poses a diagnostic challenge and requires early intervention. Legionnaire's disease can have several presenting signs, symptoms, and laboratory abnormalities that suggest that Legionella pneumophila is the pathogen, but none of these are sufficient to distinguish L pneumophila pneumonia from other respiratory pathogens. L pneumophila is primarily an intracellular pathogen and needs treatment with antibiotics that efficiently enter the intracellular space.

SIRT1‑mediated regulation of oxidative stress induced by Pseudomonas aeruginosa lipopolysaccharides in human alveolar epithelial cells

Sirtuin1 (SIRT1) is an NAD+‑dependent deacetylase that exhibits multiple biological functions, including cell differentiation inhibition, transcription regulation, cell cycle regulation and anti‑apoptosis. Lipopolysaccharides (LPS) are crucial virulence factors produced by Pseudomonas aeruginosa and serve an important role in adjusting the interactions between the host and the pathogen. However, the effect of SIRT1 in the regulation of LPS‑induced A459 human alveolar epithelial cells (AECs) oxidative stress remains unclear. The cellular reactive oxygen species (ROS) production was examined in A549 cells that were supplemented with LPS. Relative cell signaling pathway proteins were further investigated by western blot analysis. It was identified that LPS downregulated SIRT1 expression, however, upregulated ROS generation, which was associated with the increase of nuclear factor (NF)‑κB and acetyl‑NF‑κB. Activation of SIRT1 by resveratrol significantly reversed the effects of LPS on A549 cells. By contrast, inhibition of SIRT1 by nicotinamide had the opposite effects that enhance cell ROS production. Thus, the results indicated that SIRT1 serves an important role in the regulation of oxidative stress induced by LPS in human AECs.

Clinical presentations and outcome of severe community-acquired pneumonia

Background

Severe community-acquired pneumonia (SCAP) represents a frequent and potentially life-threatening condition. About 10% of all hospitalized patients with CAP require admission to the intensive care unit (ICU), and the mortality of these patients reaches 20–50%.

Objective

To evaluate the clinical presentation, bacteriological profile and outcome of severe community-acquired pneumonia (SCAP).

Patients and methods

54 patients presented by symptoms and sign of severe community acquired pneumonia who were admitted to respiratory care unit of Alhussein, Al-Azhar University Hospital from August 2015 to March 2016 were subjected to full clinical examination, chest X ray, complete blood picture, sputum and blood culture, PCR for suspected cases of Influenza H1N1 and MERS-COV, treatment, follow up, data collections and statistical analysis.

Results

The present study included 54 patients 26 males and 28 females with SCAP who were admitted to respiratory care unit of Alhussein, Al-Azhar University Hospital. The most common comorbidities were diabetes mellitus and hypertension. The most common presentations were fever, cough, dyspnea and hypoxemia. Two patients developed renal failure and 4 patients developed septic shock. The most common isolated organism was Streptococcus pneumoniae, Influenza H1N1, and Staphylococcus aureus. Mortality was 24% and it was common in patients with comorbidity than in patients without comorbidities.

Conclusion

SCAP occurs more frequently in those with comorbidities. The most frequent isolated causative organism of SCAP is S. pneumoniae, Influenza H1N1 and S. aureus. SCAP is associated with significant mortality, early recognition and prompt treatment may improve outcome.

Sensitivity, Specificity, and Positivity Predictors of the Pneumococcal Urinary Antigen Test in Community-Acquired Pneumonia

RATIONALE

Detection of the C-polysaccharide of Streptococcus pneumoniae in urine by an immune-chromatographic test is increasingly used to evaluate patients with community-acquired pneumonia.

OBJECTIVES

We assessed the sensitivity and specificity of this test in the largest series of cases to date and used logistic regression models to determine predictors of positivity in patients hospitalized with community-acquired pneumonia.

METHODS

We performed a multicenter, prospective, observational study of 4,374 patients hospitalized with community-acquired pneumonia.

MEASUREMENTS AND MAIN RESULTS

The urinary antigen test was done in 3,874 cases. Pneumococcal infection was diagnosed in 916 cases (21%); 653 (71%) of these cases were diagnosed exclusively by the urinary antigen test. Sensitivity and specificity were 60 and 99.7%, respectively. Predictors of urinary antigen positivity were female sex; heart rate≥125 bpm, systolic blood pressure<90 mm Hg, and SaO2<90%; absence of antibiotic treatment; pleuritic chest pain; chills; pleural effusion; and blood urea nitrogen≥30 mg/dl. With at least six of all these predictors present, the probability of positivity was 52%. With only one factor present, the probability was only 12%.

CONCLUSIONS

The urinary antigen test is a method with good sensitivity and excellent specificity in diagnosing pneumococcal pneumonia, and its use greatly increased the recognition of community-acquired pneumonia due to S. pneumoniae. With a specificity of 99.7%, this test could be used to direct simplified antibiotic therapy, thereby avoiding excess costs and risk for bacterial resistance that result from broad-spectrum antibiotics. We also identified predictors of positivity that could increase suspicion for pneumococcal infection or avoid the unnecessary use of this test.

Community Acquired Pneumonia in Internal Medicine: A One-Year Retrospective Study Based on Pneumonia Severity Index

Community acquired pneumonia (CAP) represents the sixth cause of death and the first cause of death for an infectious disease in the USA. The aim of the present study is to evaluate how CAP is managed in a hospital setting, with particular attention to the wards of internal medicine, compared to the recommendations based and validated PSI (Pneumonia Severity Index). 42 subjects were included in the study, 25 males and 17 females. According to the PSI, nine (21%) patients were classified in class I, two (5%) in class II, ten (24%) in class III, fifteen (36%) in class IV and six (14%) in class V. Three patients died during the stay in the hospital (2 males and 1 female), all in the highest PSI class (V). According to the criteria used to evaluate the adequacy of the admission to the hospital, twentyeight patients were classified in the HRG, with an appropriate admission, whilst fourteen (33%) were in the LRG, with an inappropriate admission to the hospital. The data of the study confirm the validity of a PSI based strategy for the management of CAP since admittance to the hospital. This approach is not yet widely implemented in Italy, and a better dialogue between hospital and health system representatives would be convenient, to reduce costs and ensure the safety of patients affected by CAP.

The significance of oral streptococci in patients with pneumonia with risk factors for aspiration: the bacterial floral analysis of 16S ribosomal RNA gene using bronchoalveolar lavage fluid

Background

Aspiration pneumonia has been a growing interest in an aging population. Anaerobes are important pathogens, however, the etiology of aspiration pneumonia is not fully understood. In addition, the relationship between the patient clinical characteristics and the causative pathogens in pneumonia patients with aspiration risk factors are unclear. To evaluate the relationship between the patient clinical characteristics with risk factors for aspiration and bacterial flora in bronchoalveolar lavage fluid (BALF) in pneumonia patients, the bacterial floral analysis of 16S ribosomal RNA gene was applied in addition to cultivation methods in BALF samples.

Methods

From April 2010 to February 2014, BALF samples were obtained from the affected lesions of pneumonia via bronchoscopy, and were evaluated by the bacterial floral analysis of 16S rRNA gene in addition to cultivation methods in patients with community-acquired pneumonia (CAP) and healthcare-associated pneumonia (HCAP). Factors associated with aspiration risks in these patients were analyzed.

Results

A total of 177 (CAP 83, HCAP 94) patients were enrolled. According to the results of the bacterial floral analysis, detection rate of oral streptococci as the most detected bacterial phylotypes in BALF was significantly higher in patients with aspiration risks (31.0 %) than in patients without aspiration risks (14.7 %) (P = 0.009). In addition, the percentages of oral streptococci in each BALF sample were significantly higher in patients with aspiration risks (26.6 ± 32.0 %) than in patients without aspiration risks (13.8 ± 25.3 %) (P = 0.002). A multiple linear regression analysis showed that an Eastern Cooperative Oncology Group (ECOG) performance status (PS) of ≥3, the presence of comorbidities, and a history of pneumonia within a previous year were significantly associated with a detection of oral streptococci in BALF.

Conclusions

The bacterial floral analysis of 16S rRNA gene revealed that oral streptococci were mostly detected as the most detected bacterial phylotypes in BALF samples in CAP and HCAP patients with aspiration risks, especially in those with a poor ECOG-PS or a history of pneumonia.

Legionnaires' disease

Since first identified in early 1977, bacteria of the genus Legionella are recognised as a common cause of community-acquired pneumonia and a rare cause of hospital-acquired pneumonia. Legionella bacteria multisystem manifestations mainly affect susceptible patients as a result of age, underlying debilitating conditions, or immunosuppression. Water is the major natural reservoir for Legionella, and the pathogen is found in many different natural and artificial aquatic environments such as cooling towers or water systems in buildings, including hospitals. The term given to the severe pneumonia and systemic infection caused by Legionella bacteria is Legionnaires' disease. Over time, the prevalence of legionellosis or Legionnaires' disease has risen, which might indicate a greater awareness and reporting of the disease. Advances in microbiology have led to a better understanding of the ecological niches and pathogenesis of the condition. Legionnaires' disease is not always suspected because of its non-specific symptoms, and the diagnostic tests routinely available do not offer the desired sensitivity. However, effective antibiotics are available. Disease notification systems provide the basis for initiating investigations and limiting the scale and recurrence of outbreaks. This report reviews our current understanding of this disease.

Prognostic factors of Streptococcus pneumoniae infection in adults

OBJECTIVES

The mortality of severe sepsis has markedly decreased since the implementation of the Surviving Sepsis Campaign guidelines. The next logical step is to examine the necessity of individualized management guidelines for targeted therapy against specific bacteria. Streptococcus pneumoniae is the leading cause of community-acquired severe sepsis; however, little is known regarding the prognostic factors in adult patients with S pneumoniae sepsis. We aimed to identify prognostic factors in patients with S pneumoniae sepsis and to explore a subgroup of patients at high risk for death with detailed Sequential Organ Failure Assessment (SOFA) score analysis.

METHODS

We retrospectively reviewed the records of patients with S pneumoniae infection treated between 1st January 2006 and 31st July 2012. We identified prognostic factors for 28-day mortality using univariate and multivariate logistic regression models.

RESULTS

Of 171 patients (median age, 72 years) with S pneumoniae infection who were included in this study, the 28-day mortality was 17% (29/171). The SOFA score (odds ratio, 2.25; 95% confidence interval, 1.60-3.18; P < .001) and bacteremia (odds ratio, 19.0; 95% confidence interval, 4.06-90.20; P < .001) were identified as prognostic factors for the 28-day mortality. In a subgroup analysis with a cutoff value of the SOFA score determined by receiver operating characteristic analysis, patients with bacteremia and a SOFA score of at least 7 had a significantly higher mortality than did patients without bacteremia and a SOFA score lower than 7 (84% vs 0%, respectively).

CONCLUSIONS

Bacteremia and a SOFA score at least 7 were independent prognostic factors of poor outcome in S pneumoniae sepsis.

Serum inorganic phosphorus levels predict 30-day mortality in patients with community acquired pneumonia

Background

Community acquired pneumonia is a major cause of morbidity and mortality. The association between serum phosphorus levels on admission and the outcome of patients with community acquired pneumonia has not been widely examined. We aimed to investigate the prognostic value of serum phosphorus levels on admission on the 30- day mortality.

Methods

The cohort included patients of 18 years old or older who were diagnosed with community acquired pneumonia between 2006 and 2012. Patients were retrospectively analyzed to identify risk factors for a primary endpoint of 30-day mortality. Binary logistic regression analysis was used for the calculation of the odds ratios (OR) and p values in bivariate and multivariate analysis to identify association between patients’ characteristic and 30-day mortality.

Results

The cohort included 3894 patients. In multivariate regression analysis, variables associated with increased risk of 30-day mortality included: age >80 years, increased CURB-65 score, RDW >15, hypernatremia >150 mmol/l, hypoalbuminemia <2 gr/dl and abnormal levels of phosphorus. Levels of <1.5 mg/dl and >4.5 mg/dl were significantly associated with excess 30-day mortality, 38 % (OR 2.9, CI 1.8-4.9, P = 0.001) and 39 % (OR 3.4, CI 2.7-4.2, P = 0.001), respectively. Phosphorus levels within the upper normal limits (4-4.5 mg/dl) were associated with higher mortality rates compared to levels between 1.5-3.5 mg/dl, the reference group, 24 % (OR 1.9, CI 1.5-2.4, P = 0.001).

Conclusions

Abnormal phosphorus levels on admission are associated with increased mortality rates among patients hospitalized with Community acquired pneumonia.

Impact of bacterial coinfection on clinical outcomes in pneumococcal pneumonia

The aim of this study was to investigate the influence of bacterial coinfection on patients with pneumococcal pneumonia. We retrospectively analyzed the incidence, clinical features, microbial distributions, and outcomes of patients with bacterial coinfection in a cohort of 433 hospitalized patients with pneumococcal pneumonia. Eighty-five patients (19.6 %) were diagnosed with bacterial coinfection; the most frequent pathogens were Haemophilus influenzae (25 patients, 33.3 %), methicillin-susceptible Staphylococcus aureus (MSSA) (15 patients, 20.0 %), and Moraxella catarrhalis (13 patients, 17.3 %). The CURB-65 score and pneumonia severity index (PSI) were significantly higher in patients with bacterial coinfection (both P < 0.001). In addition, the proportion of patients with bacterial coinfection who met the Infectious Disease Society of America (IDSA)/American Thoracic Society (ATS) severe pneumonia criteria was significantly higher (P < 0.001). Multivariate logistic regression analysis identified three risk factors for bacterial coinfection in patients with pneumococcal pneumonia: alcoholism (odds ratio [OR], 5.12; 95 % confidence interval (95 % CI), 1.60-16.4; P = 0.006), hospitalization for 2 days or more within 90 days preceding admission (OR, 2.02; 95 % CI, 1.03-3.98; P = 0.041), and residence in a nursing home or extended care facility (OR, 3.22; 95 % CI, 1.48-6.97; P = 0.003). Multivariate analysis for 30-day mortality showed that bacterial coinfection was a significant adverse prognostic factor (OR, 2.50; 95 % CI, 1.13-5.53; P = 0.023), independent of IDSA/ATS severe pneumonia, PSI, or healthcare-associated pneumonia. In conclusion, bacterial coinfection may have an adverse impact on severity and outcomes of pneumococcal pneumonia.

When practice and policy conflict: blood cultures in community-acquired pneumonia

Optimal evidence-based management of patients with uncomplicated community-acquired pneumonia in the emergency department (ED) setting remains a topic of discussion. This discussion was recently revitalized by a 2014 study published in JAMA Internal Medicine by Makam et al showing an increase in the use of blood cultures for patients with community-acquired pneumonia during ED visits from 29.4% of patients in 2002 to 51.1% in 2010. As the authors acknowledge, one of the most likely explanations could be the former pneumonia core measures required by the Centers for Medicaid & Medicare Services and the Joint Commission, potentially encouraging both ED and inpatient providers to reflexively order cultures. As these measures were the subject of fierce debate in the emergency medicine literature almost a decade ago, with recent policy changes affecting practicing clinicians, we aimed to briefly revisit the developments and concerning guidelines and discuss some important potentials for research in this setting.

Hantavirus pulmonary syndrome, Southern Chile, 1995-2012

Hantavirus is endemic to the Region de Los Lagos in southern Chile; its incidence is 8.5 times higher in the communes of the Andean area than in the rest of the region. We analyzed the epidemiologic aspects of the 103 cases diagnosed by serology and the clinical aspects of 80 hospitalized patients during 1995-2012. Cases in this region clearly predominated during winter, whereas in the rest of the country, they occur mostly during summer. Mild, moderate, and severe disease was observed, and the case-fatality rate was 32%. Shock caused death in 75% of those cases; high respiratory frequency and elevated creatinine plasma level were independent factors associated with death. Early clinical suspicion, especially in rural areas, should prompt urgent transfer to a hospital with an intensive care unit and might help decrease the high case-fatality rate.

Risk factors and antibiotic therapy in P. aeruginosa community-acquired pneumonia

BACKGROUND AND OBJECTIVE

Current guidelines recommend empirical treatment against Pseudomonas aeruginosa in community-acquired pneumonia (CAP) patients with specific risk factors. However, evidence to support these recommendations is limited. We evaluate the risk factors and the impact of antimicrobial therapy in patients hospitalized with CAP due to P. aeruginosa.

METHODS

We performed a retrospective population-based study of >150 hospitals. Patients were included if they had a diagnosis of CAP and P. aeruginosa was identified as the causative pathogen. Univariate and multivariate analyses were performed using the presence of risk factors and 30-day mortality as the dependent measures.

RESULTS

Seven hundred eighty-one patients with P. aeruginosa pneumonia were identified in a cohort of 62 689 patients with pneumonia (1.1%). Of these, 402 patients (0.6%) were included in the study and 379 (0.5%) were excluded due to health care-associated pneumonia or immunosuppression. In patients with CAP due to P. aeruginosa, 272 (67.8%) had no documented risk factors. These patients had higher rates of dementia and cerebrovascular disease. Empirical antibiotic therapy against P. aeruginosa within the first 48 h of presentation was independently associated with lower 30-day mortality in patients with CAP due to P. aeruginosa (hazard ratio (HR) 0.42, 95% confidence interval (CI): 0.23-0.76) and in patients without risk factors for P. aeruginosa CAP (HR 0.40, 95% CI: 0.21-0.76).

CONCLUSIONS

Risk factor recommended by current guidelines only detect one third of the patients admitted with CAP due to P. aeruginosa. Risk factors did not define the whole benefit observed due to empirical therapy covering P. aeruginosa.

Azithromycin for acute lower respiratory tract infections

BACKGROUND

Acute lower respiratory tract infections (LRTI) range from acute bronchitis and acute exacerbations of chronic bronchitis to pneumonia. Approximately five million people die from acute respiratory tract infections annually. Among these, pneumonia represents the most frequent cause of mortality, hospitalisation and medical consultation. Azithromycin is a macrolide antibiotic, structurally modified from erythromycin and noted for its activity against some gram-negative organisms associated with respiratory tract infections, particularly Haemophilus influenzae (H. influenzae).

OBJECTIVES

To compare the effectiveness of azithromycin to amoxycillin or amoxycillin/clavulanic acid (amoxyclav) in the treatment of LRTI, in terms of clinical failure, incidence of adverse events and microbial eradication.

SEARCH METHODS

We searched CENTRAL (2014, Issue 10), MEDLINE (January 1966 to October week 4, 2014) and EMBASE (January 1974 to November 2014).

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs, comparing azithromycin to amoxycillin or amoxycillin/clavulanic acid in participants with clinical evidence of an acute LRTI, such as acute bronchitis, pneumonia and acute exacerbation of chronic bronchitis.

DATA COLLECTION AND ANALYSIS

The review authors independently assessed all potential studies identified from the searches for methodological quality. We extracted and analysed relevant data separately. We resolved discrepancies through discussion. We initially pooled all types of acute LRTI in the meta-analyses. We investigated the heterogeneity of results using the forest plot and Chi(2) test. We also used the index of the I(2) statistic to measure inconsistent results among trials. We conducted subgroup and sensitivity analyses.

MAIN RESULTS

We included 16 trials involving 2648 participants. We were able to analyse 15 of the trials with 2496 participants. The pooled analysis of all the trials showed that there was no significant difference in the incidence of clinical failure on about days 10 to 14 between the two groups (risk ratio (RR), random-effects 1.09; 95% confidence interval (CI) 0.64 to 1.85). A subgroup analysis in trials with acute bronchitis participants showed significantly lower clinical failure in the azithromycin group compared to amoxycillin or amoxyclav (RR random-effects 0.63; 95% CI 0.45 to 0.88). A sensitivity analysis showed a non-significant reduction in clinical failure in azithromycin-treated participants (RR 0.55; 95% CI 0.25 to 1.21) in three adequately concealed studies, compared to RR 1.32; 95% CI 0.70 to 2.49 in 12 studies with inadequate concealment. Twelve trials reported the incidence of microbial eradication and there was no significant difference between the two groups (RR 0.95; 95% CI 0.87 to 1.03). The reduction of adverse events in the azithromycin group was RR 0.76 (95% CI 0.57 to 1.00).

AUTHORS' CONCLUSIONS

There is unclear evidence that azithromycin is superior to amoxycillin or amoxyclav in treating acute LRTI. In patients with acute bronchitis of a suspected bacterial cause, azithromycin tends to be more effective in terms of lower incidence of treatment failure and adverse events than amoxycillin or amoxyclav. However, most studies were of unclear methodological quality and had small sample sizes; future trials of high methodological quality and adequate sizes are needed.

Epidemiology of severe acute respiratory illness (SARI) among adults and children aged ≥5 years in a high HIV-prevalence setting, 2009-2012

OBJECTIVE

There are few published studies describing severe acute respiratory illness (SARI) epidemiology amongst older children and adults from high HIV-prevalence settings. We aimed to describe SARI epidemiology amongst individuals aged ≥5 years in South Africa.

METHODS

We conducted prospective surveillance for individuals with SARI from 2009-2012. Using polymerase chain reaction, respiratory samples were tested for ten viruses, and blood for pneumococcal DNA. Cumulative annual SARI incidence was estimated at one site with population denominators.

FINDINGS

We enrolled 7193 individuals, 9% (621/7067) tested positive for influenza and 9% (600/6519) for pneumococcus. HIV-prevalence was 74% (4663/6334). Among HIV-infected individuals with available data, 41% of 2629 were receiving antiretroviral therapy (ART). The annual SARI hospitalisation incidence ranged from 325-617/100,000 population. HIV-infected individuals experienced a 13-19 times greater SARI incidence than HIV-uninfected individuals (p<0.001). On multivariable analysis, compared to HIV-uninfected individuals, HIV-infected individuals were more likely to be receiving tuberculosis treatment (odds ratio (OR):1.7; 95%CI:1.1-2.7), have pneumococcal infection (OR 2.4; 95%CI:1.7-3.3) be hospitalised for >7 days rather than <2 days (OR1.7; 95%CI:1.2-2.2) and had a higher case-fatality ratio (8% vs 5%;OR1.7; 95%CI:1.2-2.3), but were less likely to be infected with influenza (OR 0.6; 95%CI:0.5-0.8). On multivariable analysis, independent risk indicators associated with death included HIV infection (OR 1.8;95%CI:1.3-2.4), increasing age-group, receiving mechanical ventilation (OR 6.5; 95%CI:1.3-32.0) and supplemental-oxygen therapy (OR 2.6; 95%CI:2.1-3.2).

CONCLUSION

The burden of hospitalized SARI amongst individuals aged ≥5 years is high in South Africa. HIV-infected individuals are the most important risk group for SARI hospitalization and mortality in this setting.