Community-acquired pneumonia in patients requiring hospitalization

Diagnostic performance of an in-house multiplex PCR assay and the retrospective surveillance of bacterial respiratory pathogens at a teaching hospital, Kelantan, Malaysia

Respiratory tract infections (RTIs), including pneumonia and pulmonary tuberculosis, are among the leading causes of death worldwide. The use of accurate diagnostic tests is crucial to initiate proper treatment and therapy to reduce the mortality rates for RTIs. A PCR assay for simultaneous detection of six respiratory bacteria: Haemophilus influenzae, Klebsiella pneumoniae, Mycobacterium tuberculosis, Pseudomonas aeruginosa, Staphylococcus aureus and Streptococcus pneumoniae, was developed in our lab. The current study aimed to evaluate the performance of this assay along with the retrospective surveillance of respiratory pathogens at a teaching hospital in Kelantan, Malaysia. Leftover sputa (n = 200) from clinical laboratories were collected and undergone DNA template preparation for PCR analysis. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of the PCR assay were determined in comparison with the gold standard sputum culture. Overall, the accuracy performance of this assay was 94.67% (95% CI: 90.87% to 97.21%) with sensitivity, specificity, PPV and NPV of 100%, 91.67%, 87.1% and 100%, respectively. Based on the organisms detected from sputa, K. pneumoniae ranked as the top isolate (n = 48), followed by P. aeruginosa (n = 13) and H. influenzae (n = 10). Surveillance among the patients showed that the associations of bacterial positive with gender and means of acquisition were found significant (p values = 0.049 and 0.001, respectively). Besides the promising performance of this ready-to-use molecular-based assay for the rapid detection of selected bacteria pathogens, this study also highlighted significant spread of K. pneumoniae RTIs in the community.

Carriage of upper respiratory tract pathogens in rural communities of Sarawak, Malaysian Borneo

Introduction

Pneumonia is a leading cause of death in Malaysia. Whilst many studies have reported the aetiology of pneumonia in Western countries, the epidemiology of pneumonia in Malaysia remains poorly understood. As carriage is a prerequisite for disease, we sought to improve our understanding of the carriage and antimicrobial resistance (AMR) of respiratory tract pathogens in Malaysia. The rural communities of Sarawak are an understudied part of the Malaysian population and were the focus of this study, allowing us to gain a better understanding of bacterial epidemiology in this population.

Methods

A population-based survey of bacterial carriage was undertaken in participants of all ages from rural communities in Sarawak, Malaysia. Nasopharyngeal, nasal, mouth and oropharyngeal swabs were taken. Bacteria were isolated from each swab and identified by culture-based methods and antimicrobial susceptibility testing conducted by disk diffusion or E test.

Results

140 participants were recruited from five rural communities. Klebsiella pneumoniae was most commonly isolated from participants (30.0%), followed by Staphylococcus aureus (20.7%), Streptococcus pneumoniae (10.7%), Haemophilus influenzae (9.3%), Moraxella catarrhalis (6.4%), Pseudomonas aeruginosa (6.4%) and Neisseria meningitidis (5.0%). Of the 21 S. pneumoniae isolated, 33.3 and 14.3% were serotypes included in the 13 valent PCV (PCV13) and 10 valent PCV (PCV10) respectively. 33.8% of all species were resistant to at least one antibiotic, however all bacterial species except S. pneumoniae were susceptible to at least one type of antibiotic.

Conclusion

To our knowledge, this is the first bacterial carriage study undertaken in East Malaysia. We provide valuable and timely data regarding the epidemiology and AMR of respiratory pathogens commonly associated with pneumonia. Further surveillance in Malaysia is necessary to monitor changes in the carriage prevalence of upper respiratory tract pathogens and the emergence of AMR, particularly as PCV is added to the National Immunisation Programme (NIP).

Supplementary Information

The online version contains supplementary material available at 10.1186/s41479-021-00084-9.

A Hospital-based Study on the Local Epidemiology of Pneumonia Including the Contribution of Legionella Pneumonia

Background

In real-life practice, only 20% of hospitalised pneumonia cases have an identified etiology. The usage of Legionella urine antigen test (LUAT) in developed nations revolutionised case detection rates. Accordingly, our objectives were to study the microbiological etiology for hospitalised pneumonia patients and the diagnosis of Legionella pneumonia.

Methods

A prospective, observational single-centre study was conducted where all 504 cases that were consecutively admitted for pneumonia were enrolled. Blood and sputum samples obtained were used to identify pathogens using standard microbiological culture methods. The urine samples collected were tested using the Immunocatch^TMLegionella immunochromatographic (ICT) urine antigen test.

Results

A microbiological diagnosis was only achieved in 104 cases (20.6%) and a Gram-negative infection predominance was observed. Culture-positive cases required longer hospitalisation (8.46 days versus 5.53 days; P < 0.001) and the higher usage of antipseudomonal antibiotics (23.1% versus 8.3%; P < 0.001). Only 3 cases (0.6%) were diagnosed with Legionella pneumonia.

Conclusion

The local pathogen distribution is diverse compared to other regions. Culture-negative pneumonia is common and significantly differs from culture-positive pneumonia. Legionella pneumophila serotype 1 is not a common cause of pneumonia and LUAT did not help demystify the cause of culture-negative pneumonia.

Community-Acquired Pneumonia in the Asia-Pacific Region

Community-acquired pneumonia (CAP) is an important cause of mortality and morbidity worldwide. Aging population, dense urbanization, and poor access to health care make the Asia-Pacific region vulnerable to CAP. The high incidence of CAP poses a significant health and economic burden in this region. Common etiologic agents in other global regions including Streptococcus pneumoniae, Mycoplasma pneumoniae, Haemophilus influenzae, Chlamydophila pneumoniae, Staphylococcus aureus, and respiratory viruses are also the most prevalent pathogens in the Asia-Pacific region. But the higher incidence of Klebsiella pneumoniae and the presence of Burkholderia pseudomallei are unique to the region. The high prevalence of antimicrobial resistance in S. pneumoniae and M. pneumoniae has been raising the need for more prudent use of antibiotics. Emergence and spread of community-acquired methicillin-resistant S. aureus deserve attention, while the risk has not reached significant level yet in cases of CAP. Given a clinical and socioeconomic importance of CAP, further effort to better understand the epidemiology and impact of CAP is warranted in the Asia-Pacific region.

Whole-Genome Comparative Analysis of Two Carbapenem-Resistant ST-258 Klebsiella pneumoniae Strains Isolated during a North-Eastern Ohio Outbreak: Differences within the High Heterogeneity Zones

Klebsiella pneumoniae has become one of the most dangerous causative agents of hospital infections due to the acquisition of resistance to carbapenems, one of the last resort families of antibiotics. Resistance is usually mediated by carbapenemases coded for by different classes of genes. A prolonged outbreak of carbapenem-resistant K. pneumoniae infections has been recently described in northeastern Ohio. Most strains isolated from patients during this outbreak belong to MLST sequence type 258 (ST258). To understand more about this outbreak two isolates (strains 140 and 677), one of them responsible for a fatal infection, were selected for genome comparison analyses. Whole genome map and sequence comparisons demonstrated that both strains are highly related showing 99% average nucleotide identity. However, the genomes differ at the so-called high heterogeneity zone (HHZ) and other minor regions. This study identifies the potential value of the HHZ as a potential marker for K. pneumoniae clinical and epidemiological studies.

Sputum bacteriology and antibiotic sensitivity patterns of community-acquired pneumonia in hospitalized adult patients in Nigeria: a 5-year multicentre retrospective study

BACKGROUND

A clear knowledge of the pathogens responsible for community-acquired pneumonia (CAP) in a given region and their antibiotic sensitivity patterns is necessary for optimal treatment. We determined the common bacterial pathogens causing CAP in Nigeria and further reviewed their antibiotic senstivity patterns with a view to providing recommendations to improve antibiotic management of CAP.

METHODS

Case notes of all adult patients who were 18 years or more admitted to four major tertiary hospitals in South East Nigeria with a diagnosis of CAP between 2008 and 2012 were retrospectively studied. To be eligible, patients were required to have sputum culture and sensitivity results available. Socio-demographic, clinical, pre-admission and in-hospital treatment data were also obtained.

RESULTS

Of 400 patients with a radiologically confirmed diagnosis of CAP, 232 fulfilled the study criteria; 122 (52.6%) were women and the mean age was 50.6 ± 18.8 years. Aetiological agents were identified from sputum in 189 (81.5%) patients. Streptococcus pneumoniae (n = 90, 47.6%) was the most frequent isolate followed by Klebsiella pneumoniae (n = 62, 32.8%), Staphylococcus aureus (n = 24, 12.7%) and Streptococcus pyogenes (n = 13, 6.9%). The pathogens were most sensitive to levofloxacin (77%), ceftazidime (75.5%) and ofloxacin (55.8%). The susceptibility of the isolates to antibiotics most frequently presecribed for empirical therapy was low (co-amoxiclav, 47.6%; ciprofloxacin, 45.9% and ceftriaxone, 47.6%) and this was associated with higher mortality and/or longer duration of hospital stay in survivors.

CONCLUSION

Strep. pneumoniae and K. pneumoniae were the most common causes of CAP. The pathogens were most sensitive to levofloxacin and ceftazidime. We suggest that these antibiotics should increasingly be considered as superior options for empirical treatment of CAP in Nigeria.

Plasmid-Mediated Antibiotic Resistance and Virulence in Gram-negatives: the Klebsiella pneumoniae Paradigm

Plasmids harbor genes coding for specific functions including virulence factors and antibiotic resistance that permit bacteria to survive the hostile environment found in the host and resist treatment. Together with other genetic elements such as integrons and transposons, and using a variety of mechanisms, plasmids participate in the dissemination of these traits resulting in the virtual elimination of barriers among different kinds of bacteria. In this article we review the current information about physiology and role in virulence and antibiotic resistance of plasmids from the gram-negative opportunistic pathogen Klebsiella pneumoniae. This bacterium has acquired multidrug resistance and is the causative agent of serious communityand hospital-acquired infections. It is also included in the recently defined ESKAPE group of bacteria that cause most of US hospital infections.

The bacterial aetiology of adult community-acquired pneumonia in Asia: a systematic review

BACKGROUND

Community-acquired pneumonia (CAP) is a major cause of adult mortality in Asia. Appropriate empirical treatment depends on knowledge of the pathogens commonly responsible. However, assessing the aetiological significance of identified organisms is often difficult, particularly with sputum isolates that might represent contamination with oropharyngeal flora.

METHODS

A systematic review of all adult CAP aetiology studies from Asia, excluding the Middle East, published in English between 1 January 1990 and 1 March 2012 was conducted. Forty-eight studies reporting on 10 423 patients were included, representing data from China, India, Indonesia, Japan, Malaysia, The Philippines, Singapore, South Korea, Taiwan, Thailand and Vietnam. Data from large parts of Asia were unavailable and there was substantial heterogeneity in methodology.

RESULTS

As in western studies, Streptococcus pneumoniae, Mycoplasma pneumoniae, Chlamydophila pneumoniae, Legionella spp. and Haemophilus influenzae were all significant pathogens. However, compared with western studies, S. pneumoniae was of less relative importance. Gram-negative bacilli and Mycobacterium tuberculosis were more important, and in northeast Thailand Burkholderia pseudomallei was a major pathogen.

CONCLUSION

These data have major implications for diagnostic strategies and empirical treatment. Narrow-spectrum antibiotics targeting S. pneumoniae may be inappropriate in many Asian settings, and agents active against TB may lead to partial response and delayed TB diagnosis.

Antibodies to both terminal and internal B-cell epitopes of Francisella tularensis O-polysaccharide produced by patients with tularemia

Francisella tularensis, the Gram-negative bacterium that causes tularemia, is considered a potential bioterrorism threat due to its low infectivity dose and the high morbidity and mortality from respiratory disease. We previously characterized two mouse monoclonal antibodies (MAbs) specific for the O-polysaccharide (O antigen [OAg]) of F. tularensis lipopolysaccharide (LPS): Ab63, which targets a terminal epitope at the nonreducing end of OAg, and Ab52, which targets a repeating internal OAg epitope. These two MAbs were protective in a mouse model of respiratory tularemia. To determine whether these epitope types are also targeted by humans, we tested the ability of each of 18 blood serum samples from 11 tularemia patients to inhibit the binding of Ab63 or Ab52 to F. tularensis LPS in a competition enzyme-linked immunosorbent assay (ELISA). Although all serum samples had Ab63- and Ab52-inhibitory activities, the ratios of Ab63 to Ab52 inhibitory potencies varied 75-fold. However, the variation was only 2.3-fold for sequential serum samples from the same patient, indicating different distributions of terminal- versus internal-binding antibodies in different individuals. Western blot analysis using class-specific anti-human Ig secondary antibodies showed that both terminal- and internal-binding OAg antibodies were of the IgG, IgM, and IgA isotypes. These results support the use of a mouse model to discover protective B-cell epitopes for tularemia vaccines or prophylactic/therapeutic antibodies, and they present a general strategy for interrogating the antibody responses of patients and vaccinees to microbial carbohydrate epitopes that have been characterized in experimental animals.

Regional epidemiology of invasive pneumococcal disease in Asian adults: epidemiology, disease burden, serotype distribution, and antimicrobial resistance patterns and prevention

OBJECTIVES

To summarize published data on the clinical and economic burden, epidemiology, antimicrobial resistance levels, serotype prevalence, and prevention strategies for pneumococcal disease among adults in Asia.

METHODS

We performed a systematic search of the PubMed database for relevant, peer-reviewed articles published between January 1995 and December 2011, covering China, Hong Kong, India, Indonesia, Japan, Malaysia, Pakistan, the Philippines, Singapore, South Korea, Taiwan, Thailand, and Vietnam.

RESULTS

Taiwan and Thailand had the most comprehensive epidemiological data on adult pneumococcal disease. Very little relevant data were found for Indonesia, Pakistan, the Philippines, and Vietnam; surveillance is urgently needed in these countries. The emergence and spread of resistance emphasize the importance of vaccination to prevent infection in adults at increased risk for serious pneumococcal disease. Vaccination policies and opinions on the efficacy of vaccination vary widely in Asian countries, although a new option in the form of a pneumococcal conjugate vaccine is now available.

CONCLUSIONS

Increased awareness of the public health and economic benefits of pneumococcal vaccination is critically needed to help both the public and policymakers in making changes to vaccination policies in the region. Maximizing access to pneumococcal vaccines will decrease the number of hospitalizations, complications, and deaths associated with pneumococcal disease.

Clinical symptoms and signs for the diagnosis of Mycoplasma pneumoniae in children and adolescents with community-acquired pneumonia

BACKGROUND

Mycoplasma pneumoniae (M. pneumoniae) is a significant cause of community-acquired pneumonia in children and adolescents. Treatment with macrolide antibiotics is recommended. However, M. pneumoniae is difficult to diagnose based on clinical symptoms and signs. Diagnostic uncertainty can lead to inappropriate antibiotic prescribing, which may worsen clinical prognosis and increase antibiotic resistance.

OBJECTIVES

The objectives of this review are (i) to assess the diagnostic accuracy of symptoms and signs in the clinical recognition of M. pneumoniae in children and adolescents with community-acquired pneumonia; and (ii) to assess the influence of potential sources of heterogeneity on the diagnostic accuracy of symptoms and signs in the clinical recognition of M. pneumoniae.

SEARCH METHODS

We searched MEDLINE (January 1950 to 26 June 2012) and EMBASE (January 1980 to 26 June 2012). We identified additional references by handsearching the reference lists of included articles and snowballing. We searched the reference lists of relevant systematic reviews identified by searching the Medion database, Database of Reviews of Effects 2012, Issue 6 (25 June 2012) and the Cochrane Register of Diagnostic Test Accuracy studies (2 July 2012). Experts in the field reviewed our list of included studies for any obvious omissions.

SELECTION CRITERIA

We included peer-reviewed published studies which prospectively and consecutively recruited children with community-acquired pneumonia from any healthcare setting, confirmed the presence of M. pneumoniae using serology with or without other laboratory methods and reported data on clinical symptoms and signs in sufficient detail to construct 2 x 2 tables.

DATA COLLECTION AND ANALYSIS

One review author scanned titles to exclude obviously irrelevant articles. Two review authors independently scanned the remaining titles and abstracts, reviewed full-text versions of potentially relevant articles, assessed the quality of included articles and extracted data on study characteristics and the following clinical features: cough, wheeze, coryza, crepitations, fever, rhonchi, shortness of breath, chest pain, diarrhea, myalgia and headache.We calculated study-specific values for sensitivity, specificity and positive and negative likelihood ratios with 95% confidence intervals (CIs). We estimated the post-test probability of M. pneumoniae based on the absence or presence of symptoms and signs.We calculated pooled sensitivities, specificities, positive and negative likelihood ratios with 95% CIs for symptoms and signs where data were reported by at least four included studies by fitting a bivariate normal model for the logit transforms of sensitivity and specificity. We explored potential sources of heterogeneity by fitting bivariate models with covariates using multi-level mixed-effects logistic regression. We performed sensitivity analyses excluding data from studies for which we were concerned about the representativeness of the study population and/or the acceptability of the reference standard.

MAIN RESULTS

Our search identified 8299 articles (excluding duplicates). We examined the titles and abstracts of 1125 articles and the full-text versions of 97 articles. We included seven studies in our review, which reported data from 1491 children; all were conducted in hospital settings. Overall, study quality was moderate. In two studies the presence of chest pain more than doubled the probability of M. pneumoniae. Wheeze was 12% more likely to be absent in children with M. pneumoniae (pooled positive likelihood ratio (LR+) 0.76, 95% CI 0.60 to 0.97; pooled negative likelihood ratio (LR-) 1.12, 95% CI 1.02 to 1.23). Our sensitivity analysis showed that the presence of crepitations was associated with M. pneumoniae, but this finding was of borderline statistical significance (pooled LR+ 1.10, 95% CI 0.99 to 1.23; pooled LR- 0.66, 95% CI 0.46 to 0.96).

AUTHORS' CONCLUSIONS

M. pneumoniae cannot be reliably diagnosed in children and adolescents with community-acquired pneumonia based on clinical symptoms and signs. Although the absence of wheeze is a statistically significant diagnostic indicator, it does not have sufficient diagnostic value to guide empirical macrolide treatment. Data from two studies suggest that the presence of chest pain more than doubles the probability of M. pneumoniae. However, further research is needed to substantiate this finding. More high quality large-scale studies in primary care settings are needed to help develop prediction rules based on epidemiological data as well as clinical and baseline patient characteristics.

Clinical and economic burden of community-acquired pneumonia amongst adults in the Asia-Pacific region

Community-acquired pneumonia (CAP) is an important cause of mortality and morbidity amongst adults in the Asia-Pacific region. Literature published between 1990 and May 2010 on the clinical and economic burden of CAP amongst adults in this region was reviewed. CAP is a significant health burden with significant economic impact in this region. Chronic obstructive pulmonary disease, cardiovascular disease, diabetes mellitus and advanced age were risk factors for CAP. Aetiological agents included Streptococcus pneumoniae, Klebsiella pneumoniae, Gram-negative bacteria, Mycobacterium tuberculosis, Burkholderia pseudomallei, Staphylococcus aureus and atypical pathogens (Mycoplasma pneumoniae, Chlamydophila pneumoniae and Legionella spp.), with important differences in the prevalence of these pathogens within the region. Antibiotic resistance was significant but was not linked to excess mortality. Aetiological pathogens remained susceptible to newer antimicrobial agents. Rational antibiotic use is essential for preventing resistance, and increased surveillance is required to identify future trends in incidence and aetiology and to drive treatment and prevention strategies.

Risk factors and severity scores in hospitalized patients with community-acquired pneumonia: prediction of severity and mortality

Morbidity and mortality in patients with moderate to severe community-acquired pneumonia (CAP) is a global problem, and CAP is a leading cause of death due to infectious diseases. Prompt initiation of expanded-spectrum antimicrobials is essential for the prevention of unnecessary mortality and complications in patients, particularly in the elderly and other at-risk populations, and the treatment decisions made by practitioners have important implications for healthcare systems when hospitalization is required. Empirical antimicrobial treatment and the appropriate management of CAP patients will initially require the proper assessment of severity and patient risk for increased mortality, as well as risk factors for difficult-to-treat bacteria. This review will examine risk factors and scoring systems that may be predictive of moderate to severe CAP, which is often linked to increased risk of mortality. Understanding and recognizing potential risk factors will allow practitioners to proactively identify patients at the highest risk for severe illness or complications, thereby, guiding site-of-care decisions, as well as the choices for empiric antibiotic regimens. The decision to hospitalize a patient with CAP should include not only a clinical perspective and laboratory and radiographic findings, but also at least one objective tool of risk assessment, all in combination with sound clinical judgment.

Pseudomonas aeruginosa: host defence in lung diseases

Lung infections caused by the opportunistic pathogen Pseudomonas aeruginosa can present as a spectrum of clinical entities from a rapidly fatal pneumonia in a neutropenic patient to a multi-decade bronchitis in patients with cystic fibrosis. P. aeruginosa is ubiquitous in our environment, and one of the most versatile pathogens studied, capable of infecting a number of diverse life forms and surviving harsh environmental factors. It is also able to quickly adapt to new environments, including the lung, where it orchestrates virulence factors to acquire necessary nutrients, and if necessary, turn them off to prevent immune recognition. Despite these capabilities, P. aeruginosa rarely infects healthy human lungs. This is secondary to a highly evolved host defence mechanism that efficiently removes inhaled or aspirated pseudomonads. Many arms of the respiratory host defence have been elucidated using P. aeruginosa as a model pathogen. Human infections with P. aeruginosa have demonstrated the importance of the mechanical barrier functions including mucus clearance, and the innate immune system, including the critical role of the neutrophilic response. As more models of persistent or biofilm P. aeruginosa infections are developed, the role of the adaptive immune response will likely become more evident. Understanding the pathogenesis of P. aeruginosa, and the respiratory host defence response to it has, and will continue to, lead to novel therapeutic strategies to help patients.

Respiratory infections unique to Asia

Asia is a highly heterogeneous region with vastly different cultures, social constitutions and populations affected by a wide spectrum of respiratory diseases caused by tropical pathogens. Asian patients with community‐acquired pneumonia differ from their Western counterparts in microbiological aetiology, in particular the prominence of Gram‐negative organisms, Mycobacterium tuberculosis, Burkholderia pseudomallei and Staphylococcus aureus. In addition, the differences in socioeconomic and health‐care infrastructures limit the usefulness of Western management guidelines for pneumonia in Asia. The importance of emerging infectious diseases such as severe acute respiratory syndrome and avian influenza infection remain as close concerns for practising respirologists in Asia. Specific infections such as melioidosis, dengue haemorrhagic fever, scrub typhus, leptospirosis, salmonellosis, penicilliosis marneffei, malaria, amoebiasis, paragonimiasis, strongyloidiasis, gnathostomiasis, trinchinellosis, schistosomiasis and echinococcosis occur commonly in Asia and manifest with a prominent respiratory component. Pulmonary eosinophilia, endemic in parts of Asia, could occur with a wide range of tropical infections. Tropical eosinophilia is believed to be a hyper‐sensitivity reaction to degenerating microfilariae trapped in the lungs.

This article attempts to address the key respiratory issues in these respiratory infections unique to Asia and highlight the important diagnostic and management issues faced by practising respirologists.

A one-year prospective study of infectious etiology in patients hospitalized with acute exacerbations of COPD and concomitant pneumonia

Aim

This study assessed the infectious etiology of patients hospitalized for acute exacerbations of chronic obstructive pulmonary disease (AECOPD) with concomitant pneumonia.

Methods

Patients admitted to medical wards in an acute hospital were recruited prospectively from May 1, 2004 to April 30, 2005. Sputum culture, blood culture, paired serology, and nasopharyngeal aspirates (NPA) viral culture and polymerase chain reaction (PCR) studies were performed. Spirometry was assessed in stable phase at 2–3 months post-hospital discharge.

Results

Seventy eight subjects were admitted for AECOPD with concomitant pneumonia. The mean (SD) age was 77.1 (7.5) years, with FEV₁ of 41.5 (20.8)% predicted normal. Overall, an infectious etiology could be established in 48.7% of the subjects. Among the 71 subjects with sputum collected, 40.8% had positive bacterial culture. The commonest bacteria identified were Streptococcus pneumoniae (8[11.3%]), Pseudomonas aeruginosa (7[9.9%]) and Haemophilus influenzae (7[9.9%]). Among the 66 subjects with NPA collected, 9.0 and 12.2% had positive viral culture and PCR results, respectively. The commonest viruses identified by NPA PCR were influenza A (4[6.1%] subjects) and rhinovirus (2[3.0%]). Paired serology was positive in 4.4%. Patients on high dose inhaled corticosteroid (ICS) (>1000 mcg beclomethasone-equivalent/day) had a higher rate of positive sputum bacterial culture than those on low-medium dose of ICS (50.0% vs 18.2%, p = 0.02).

Conclusion

An infectious etiology could be established in about half of patients hospitalized with AECOPD and concomitant pneumonia. The majority of identifiable causes were bacterial. Patients on high dose ICS might have impaired airway defense as reflected by the higher rate of positive sputum culture.

Adverse Hospital Outcomes Associated With the Choice of Empiric Antibiotics in Klebsiella pneumoniae Pneumonia: A Retrospective Observational Study

Introduction: In Malaysia, Klebsiella pneumoniae ranks high as a cause of adult pneumonia requiring hospitalisation. Patients and Methods: With concern over its rising microbial resistance, we explored the association of empiric antibiotics choices with the hospital outcomes of patients treated for microbial proven K. pneumoniae pneumonia in an urban-based teaching hospital. Results: In 313 eligible cases reviewed retrospectively, hospital mortality and requirement for ventilation were 14.3% and 10.8% respectively. Empiric regimes that had in vitro resistance to at least one empiric antibiotic (n = 90) were associated with higher hospital mortality (23.3% vs. 10.8%, P = 0.004) with risk increased by about two-fold [Odds ratio (OR), 2.5; 95% confidence interval (CI), 1.3 to 4.8]. Regimes (n = 84) other than the commonly recommended “standard” regimes (a β-lactam stable antibiotic with or without a macrolide) were associated with higher ventilation rates (16.7% vs. 8.8%, P = 0.047) with similar increased risk [OR, 2.0; 95% CI, 1.0 to 4.3]. Conclusions: Our findings reiterate the clinical relevance of in vitro microbial resistance in adult K. pneumoniae pneumonia and support empiric regimes that contain β-lactam stable antibiotics. Key words: In vitro resistance, Malaysia

Sputum bacteriology in patients hospitalized with acute exacerbations of chronic obstructive pulmonary disease and concomitant pneumonia in Hong Kong

AIM

To study the sputum microbiology of patients admitted to a teaching hospital with acute exacerbations of chronic obstructive pulmonary disease (AECOPD) with concomitant pneumonia.

METHODS

This was a retrospective study in a tertiary university hospital in Hong Kong. All episodes of AECOPD with pneumonia, patient demographics, length of stay, sputum culture and radiological results admitted in the first half of the year 2000 were retrieved from hospital records.

RESULTS

There were 118 patients (91 male) with 150 episodes of AECOPD with concomitant pneumonia. The age of the patients was 74.8 +/- 10.0 years. Positive routine sputum culture was detected in 45.6% of the patients. Among these hospital admissions, 8.7, 4.0 and 12.0%, respectively, required intensive care unit admissions, mechanical ventilation and non-invasive positive pressure ventilation. Haemophilus influenzae was the commonest organism found in sputum (26.0%), followed by Pseudomonas aeruginosa (5.5%), Streptococcus pneumoniae (3.4%), and Moraxella catarrhalis (3.4%). Mycobacterium tuberculosis was found in 1.5% of the admissions. The presence of P. aeruginosa in sputum was associated with a longer hospital length of stay (9.1 +/- 3.1 vs. 7.1 +/- 4.2 days, P = 0.03).

CONCLUSION

In contrast to most other studies reporting S. pneumoniae as the most likely bacterial pathogen, H. influenzae was the commonest bacterium isolated in sputum in our patients with AECOPD and concomitant pneumonia.

Addition of macrolide in treating adult hospitalized community-acquired pneumonia

OBJECTIVES

Current clinical practice guidelines, including those in south Asia, recommend the addition of a macrolide to a broad-spectrum antibiotic for the treatment of severe hospitalized community-acquired pneumonia (CAP). The aim of this study was to observe the influence of macrolide addition on clinical outcomes of hospitalized adult patients with CAP.

METHODOLOGY

Over a 16-month period between 2002 and 2004, 141 eligible patients were prospectively recruited from an urban-based teaching hospital in Malaysia.

RESULTS

Of the 141 patients, 63 (44.7%) patients (age (standard deviation (SD)) 56 (20.0) years; 50.8% male) received a macrolide-containing antibiotic regimen, while 78 (55.3%; age (SD) 57 (20.2) years; 52.6% male) were on a single broad-spectrum antibiotic only. In total, 39 (27.7%) and 102 (72.3%) patients had severe and 'non-severe' pneumonia, respectively. Irrespective of whether they had severe or non-severe pneumonia, there were no significant differences in mortality (non-severe pneumonia, 6.5% vs. 5.4%, P = 0.804; severe pneumonia, 17.6% vs. 18.2%, P = 0.966), need of ventilation (non-severe pneumonia, 8.7% vs. 3.6%, P = 0.274; severe pneumonia, 23.5% vs. 13.6%, P = 0.425) or median length of hospital stay (non-severe pneumonia, 5.5 vs. 5 days, P = 0.954; severe pneumonia, 7 vs. 6 days, P = 0.401) between the two treatment regimens.

CONCLUSION

This observational, non-randomized study suggests that addition of a macrolide may not convey any extra clinical benefits in adult hospitalized patients with CAP.

[Guidelines for the management of community pneumonia in adult who needs hospitalization]

Community acquired pneumonia is still an important health problem. In Spain the year incidence is 162 cases per 100,000 inhabitants with 53,000 hospital admission costing 115 millions of euros per year. In the last years there have been significant advances in the knowledge of: aetiology, diagnostic tools, treatment alternatives and antibiotic resistance. The Spanish Societies of Intensive and Critical Care (SEMICYUC), Infectious Diseases and Clinical Microbiology (SEIMC) and Pulmonology and Thoracic Surgery (SEPAR) have produced these evidence-based Guidelines for the management of community acquired pneumonia in Adults. The main objective is to help physicians to make decisions about this disease. The different points that have been developed are: aetiology, diagnosis, treatment and prevention.

Adult community-acquired pneumonia in Malaysia: prediction of mortality from severity assessment on admission

OBJECTIVES

Prediction of mortality in patients with community-acquired pneumonia (CAP) can be assessed using clinical severity scores on admission to hospital. The clinical benefit of such tools is untested in Asian countries. The aim of this study was to determine the early adverse prognostic factors in patients hospitalized with CAP in Malaysia and to assess the usefulness of the British Thoracic Society (BTS) severity criteria.

METHODOLOGY

A prospective study was undertaken of all adult patients admitted between August 2002 and March 2003 in an urban-based university teaching hospital.

RESULTS

One hundred and eight patients (mean +/- SD age 55 +/- 20 years; 58% men) were eligible for the study. Thirteen patients (12%) died in hospital and 95 (88%) survived to hospital discharge. Older age, the presence of chronic illness, severity of comorbidity, reduced oxygen saturation and higher blood urea were associated with mortality during admission. Multivariate logistic regression of these variables identified reduced oxygen saturation as the only independently associated variable. BTS criteria fared poorly in predicting mortality compared with clinical assessment by attending clinicians (36-fold increased risk of death by 'clinical assessment' vs two-threefold by 'BTS criteria').

CONCLUSIONS

In hospitalized patients with CAP, certain factors are adversely associated with mortality during admission. Severity criteria validated in specific countries might not be universally applicable.

Complete nucleotide sequence of Klebsiella pneumoniae multiresistance plasmid pJHCMW1

The multiresistance plasmid pJHCMW1, harbored by a clinical Klebsiella pneumoniae strain isolated from a neonate with meningitis, was sequenced. A circular sequence of 11,354 bp was generated, of which 7,993 bp make up Tn1331, a transposon including the antibiotic resistance genes aac(6')-Ib, aadA1, bla(OXA-9), and bla(TEM-1). The gene aac(6')-Ib is included in a gene cassette, and both aadA1 and bla(OXA-9) are included in a single-gene cassette that may have arisen as a consequence of a recombination event involving two integrons. The pJHCMW1 plasmid replicates through a ColE1-like RNA-regulated mechanism, includes a functional oriT, and two loci with similarity to XerCD site-specific recombination target sites involved in plasmid stabilization by the resolution of multimers. One of these two loci, mwr, is active and has been the subject of previous studies, and the other, dxs, is not functional but binds the recombinase XerD with low affinity. Two additional open reading frames were identified, one with low similarity to two hypothetical membrane proteins from Mycobacterium tuberculosis and Mycobacterium leprae and the other with low similarity to psiB, a gene encoding a function that facilitates the establishment of the transferring plasmid in the recipient bacterial cell during the process of conjugation.

[Prognostic factors associated with community-acquired aspiration pneumonia]

BACKGROUND

Aspiration pneumonia (AP) represents about 5-24% of community-acquired pneumonias. This condition mainly affects elderly patients and causes a high mortality. Our objective was to quantify the AP mortality rate and to identify prognostic factors upon patients admission.

PATIENTS AND METHOD

We underwent a retrospective observational study of a cohort of AP patients admitted to a tertiary care hospital during a 29 months period. The in-hospital mortality rate was calculated. To identify prognostic factors, basal characteristics of patients as well as their clinical presentation and complementary tests performed on admission were studied and analyzed by univariate and multivariate techniques. Odds ratios and 95% confidence intervals were estimated.

RESULTS

Thirty six out of 105 admitted patients with AP died (cumulative mortality incidence rate 34%, 95% CI 25-44%). In the univariate analysis, demographic, clinical and complementary test variables were associated with mortality. Final logistic model revealed the following independent variables: living in a nursing home (OR = 3.4; 95% CI 1.1-10.9), high degree of dependence (OR = 0.3; 95% CI, 0.1-0.9), body temperature (OR = 0.5 per Celsius degree; 95% CI, 0.3-1.0), serum creatinine levels (OR = 2.2 per mg/100 ml; 95% CI, 1.2-4.1) and LDH serum concentrations (OR = 1.5 per 100 IU/L; 95% CI, 1.1-2.0).

CONCLUSIONS

The mortality of community-acquired AP is very high. In addition to clinical and biological parameters on admission such as body temperature and LDH and creatinine serum concentrations, living in a nursing home and having a high degree of dependence for the basic daily activities were identified as independent prognostic factors. An in-depth knowledge of prognostic factors related to pre-admission care and assistance is needed to decrease the mortality in these patients.

Etiology and management of community-acquired pneumonia in Asia

The causative organisms of community-acquired pneumonia, especially in Japan and Korea, are essentially similar to those in Western countries. If there are any differences, these are due to the laboratory tests and criteria used to define pathogenicity. Overall, Streptococcus pneumoniae is the most frequently occurring pathogen and Haemophilus influenzae, Mycoplasma pneumoniae, Chlamydia pneumoniae and viruses follow. Legionella spp. look likely to be low frequency pathogens in Asian countries, but a reason for this might be limitations of the laboratory tests used. A high frequency of Gram-negative bacilli as pathogens of community-acquired pneumonia in some Asian countries may be due to different criteria used to identify disease-causing organisms. A small number of papers about antibiotic resistance have shown no large differences between Asian countries, but considerable differences to Western countries, such as frequency of macrolide-resistant S. pneumoniae. Some Asian countries have their own guidelines for community-acquired pneumonia, but these are written in their own languages.