Community acquired pneumonia--a prospective UK study

The Relationship between Gut Microbiota and Respiratory Tract Infections in Childhood: A Narrative Review

Respiratory tract infections (RTIs) are common in childhood and represent one of the main causes of hospitalization in this population. In recent years, many studies have described the association between gut microbiota (GM) composition and RTIs in animal models. In particular, the “inter-talk” between GM and the immune system has recently been unveiled. However, the role of GM in human, and especially infantile, RTIs has not yet been fully established. In this narrative review we provide an up-to-date overview of the physiological pathways that explain how the GM shapes the immune system, potentially influencing the response to common childhood respiratory viral infections and compare studies analysing the relationship between GM composition and RTIs in children. Most studies provide evidence of GM dysbiosis, but it is not yet possible to identify a distinct bacterial signature associated with RTI predisposition. A better understanding of GM involvement in RTIs could lead to innovative integrated GM-based strategies for the prevention and treatment of RTIs in the paediatric population.

Hide and seek in a pandemic: review of SARS-CoV-2 infection and sequelae in children

New Findings

What is the topic of this review?

A description of the current literature relating to COVID‐19 infection in children and the associated inflammatory condition, paediatric multi‐inflammatory syndrome temporally associated with SARS‐CoV‐2 (PIMS‐TS).

What advances does it highlight?

Children with SARS‐CoV‐2 infection have a distinct clinical phenotype when compared to adults. This may relate to relative differences in their adaptive immunity and in the degree and distribution of expression of the SARS‐CoV‐2 receptor (angiotensin‐converting enzyme 2). There are several similarities between PIMS‐TS, Kawasaki disease shock syndrome and other known inflammatory disorders such as macrophage activation syndrome. Few data are available to date regarding vaccination responses of children against COVID‐19.

Abstract

Children infected with SARS‐CoV‐2 have a clinical phenotype that is distinct from that observed in adult cases. They can present with a range of respiratory, gastrointestinal and neurological symptoms, or with a delayed hyperinflammatory syndrome (paediatric multisystem inflammatory system temporally associated with SARS‐CoV‐2; PIMS‐TS) that frequently requires treatment in an intensive care unit. These manifestations may be related to unique expression of transmembrane receptors and immune physiology in children. The clinical features and inflammatory profile of PIMS‐TS are similar to other inflammatory disorders that occur in children such as Kawasaki disease, macrophage activation syndrome and sepsis. Given children are infected less frequently and have less severe disease due to COVID‐19 compared to adults, their physiological profile is of great interest. An understanding of the unique mechanisms of infection and disease in children could aid the identification of potential therapeutic targets. Like adults, children can have long‐term complications of SARS‐CoV‐2 infection, including neurological and cardiac morbidity. Vaccination against SARS‐CoV‐2 is not yet authorised in children aged <12 years, and hence we anticipate ongoing paediatric presentations of COVID‐19 in the coming months.

Human coronavirus OC43 and other respiratory viruses from acute respiratory infections of Egyptian children

Respiratory infections have a significant impact on health worldwide. Viruses are major causes of acute respiratory infections among children. Limited information regarding its prevalence in Egypt is available. This study investigated prevalence of 10 respiratory viruses; Adenovirus, influenza A, B, respiratory syncytial virus (RSV), Parainfluenza virus (PIV)type 1-4, enterovirus, and human coronavirus OC43 (HCoV-OC43) among children in Alexandria, Egypt presenting with acute lower respiratory tract infections.The study was conducted on children <14 years of age selected from ElShatby Pediatric Hospital, Alexandria University, Egypt. One hundred children presenting during winter season with influenza-like illness were eligible for the study. Oropharyngeal swabs were collected and subjected to viral RNA and DNA extraction followed by polymerase chain reaction.Viral infections were detected in 44% of cases. Adenovirus was the most common, it was found in 19% of the patients. Prevalence of PIV (3 and 4) and enterovirus was 7% each. Prevalence of RSV and HCoV-OC43 was 5% and 3% respectively. Two percentage were Influenza A positive and 1% positive for influenza B. Mixed viral infection was observed in 7%.To the best of our knowledge, this is the first report of the isolation of HCoV-OC43 from respiratory infections in Alexandria, Egypt.

Urinary antigen testing for pneumococcal pneumonia: is there evidence to make its use uncommon in clinical practice?

Microbiological confirmation of pneumonia caused by Streptococcus pneumoniae remains challenging as culture from blood or pleural fluid is positive in only 15–30% cases. It was hoped that a commercially available urine antigen test would improve diagnosis and consequently patient care, with improved antimicrobial stewardship. Urine antigen testing for pneumococcal pneumonia is recommended in current British Thoracic Society guidelines, whilst the National Institute for Health and Care Excellence and The American Thoracic Society and the Infectious Diseases Society of America guidelines consider its usage. Urine antigen testing is therefore widely used in hospital medicine. The assay is noninvasive, simple and culture-independent, producing a result within 15 min. Whilst initial evidence suggested urine antigen testing had a high sensitivity, recently data have suggested the actual sensitivity is lower than expected, at approximately 60–65%. Evidence has also emerged indicating that clinicians infrequently rationalise antibiotics following positive urine antigen testing, with multiple publications evaluating the role of urine antigen testing in clinical care. Furthermore, urine antigen testing does not appear to lead to any cost saving or reduction in length of hospital stay. We therefore conclude that the pneumococcal urinary antigen test does not alter patient management and leads to no cost saving, and has a lower than expected accuracy. Therefore, it may be time to make its use uncommon in clinical practice.

This article reviews the pneumococcal urine antigen test (Pn UAT), recommended in BTS, NICE and ATS/IDSA guidelines. Pn UAT is less accurate than expected, and has not been shown to improve patient care or antimicrobial stewardship or lead to cost saving.http://bit.ly/2MJpjWL

Microbiological Diagnosis of Respiratory Illness

A wide variety of microorganisms are potential respiratory pathogens, and the spectrum of known pathogens for each respiratory infection syndrome has not changed markers over recent years. Detection of likely etiologic agents of respiratory infections can help direct management and can also play an important role in disease surveillance. For this purpose, we are still reliant on many traditional diagnostic tools that have been used for decades in order to determine the microbial etiology of respiratory infections. However, these tools have been increasingly supplemented by newer methods, particular molecular diagnostic techniques, which have enabled the more rapid detection of many pathogens that were previously difficult to detect. These advances have particularly lead to improvements in the ability to detect respiratory viruses and also other microorganisms that do not normally colonize the respiratory tract. Recognition of the existence of the lung microbiome has challenged the traditional views of pneumonia pathogenesis and may provide the opportunity for new diagnostic tools that are focused on more than just detection of specific known pathogens. Continued liaison between clinicians and laboratory staff is vital in order to facilitate the most cost-effective use of laboratory diagnostics.

Indications for chest X-rays in children and how to obtain and interpret them

Chest X-ray (CXR) is one of the most common radiological investigations undertaken in practice with children. CXRs are requested for a number of suspected diagnoses, including pneumonia, pneumothorax and foreign body aspiration or ingestion. They may also be requested as part of a skeletal survey or to confirm the position of central and umbilical lines, as well as nasogastric tubes. Nurses play a vital role in ensuring that X-rays are performed in a safe and timely manner, and to ensure children are supported and positioned appropriately to obtain the best quality images. It is useful for nurses working with children to understand the underlying mechanism and rationale for requesting X-rays because this helps them to communicate the relevance of the procedure to other team members. This article provides an overview of the fundamental principles of obtaining a CXR and interpreting the images.

Treatment of Community-Acquired Pneumonia: Are All Countries Treating Children in the Same Way? A Literature Review

Background

Pneumonia represents an important threat to children's health in both developed and developing countries. In the last 10 years, many national and international guidelines on the treatment of pediatric CAP have been published, in order to optimize the prescription of antibiotics and limit their cost and side effects. However, the practical implementation of these guidelines is still limited.

Main Text

We analyzed the current recommendations for the therapy of pediatric community-acquired pneumonia (CAP) that all converge on the identification of aminopenicillins and beta-lactams as the optimal treatment for CAP. We also conducted a review of the current literature on antibiotic regimens used for pediatric CAP to identify the current state of guidelines implementation in different settings. We selected 37 studies published from 2010 to 2016, including both retrospective and prospective studies, mainly cross-sectional and hospital based. The results show a global heterogeneity in the antibiotics prescription for pediatric CAP, with application of guidelines varying from 0% to more than 91% and with important differences even within the same country.

Conclusions

Our review has demonstrated that the implementation of the guidelines is still limited but also that achieving the optimal prescription is possible and can be done in both developed and developing countries.

Etiology of Pneumonia in a Pediatric Population with High Pneumococcal Vaccine Coverage: A Prospective Study

BACKGROUND

Improved Childhood Immunizations Programs, especially the introduction of pneumococcal vaccination, better diagnostic methods and the importance of reduced antibiotic misuse, make this a critical time to increase knowledge on the etiology of pediatric pneumonia. Our main objective was to identify the contribution of various microbiological species that causes pneumonia in previously healthy children and adolescents in a population with high pneumococcal conjugate vaccine coverage.

METHODS

This prospective, observational study enrolled patients with clinical and radiological signs of pneumonia over a 2-year period. Both inpatients and outpatients were included. Paired sera, nasopharyngeal polymerase chain reaction and bacterial cultures from blood and pleura were analyzed to detect potential viral and bacterial causative pathogens.

RESULTS

TWO HUNDRED AND SIXTY-FIVE: cases of clinical and radiological verified pneumonia were identified. The pneumococcal vaccine coverage was 85%. We identified a causative pathogen in 84.2% of all cases; 63.4% with single viral etiology, 11.3% with pneumococcus and 7.5% with mycoplasma infection. Respiratory syncytial virus was the most common pathogen in children younger than 5 years, whereas mycoplasma was the most common in older children.

CONCLUSIONS

We identified the majority of 265 cases with radiology proven pneumonia as single viral infections, predominantly respiratory syncytial virus and a much lower proportion of bacterial causes. These findings may impact pneumonia management guidelines in areas where widespread pneumococcal vaccination is provided and contribute to reduced antibiotic overuse in pediatric pneumonia.

Indirect effects of a 7 year PCV7/PCV13 mass vaccination program in children on the incidence of pneumonia among adults: a comparative study based on two Polish cities

BACKGROUND AND OBJECTIVES

In 2006 the city of Kielce, Poland, introduced a mandatory PCV7 (replaced by PCV13 in 2011) vaccination program against S. pneumoanie for all children under 2 years old. At that time, the neighboring city of Ostrowiec Świętokrzyski had no such large-scale vaccination program in place. This created an opportunity to observe the results of the vaccination by comparing the incidence of pneumonia in these two cities. The aim of this study was to analyze how the incidence of pneumonia among adults was indirectly affected by the PCV7/PCV13 vaccination program in children during the 7 year follow-up period.

METHODS

We performed a retrospective study. PCV7/PCV13 vaccinations were delivered according to a 2 + 1 schedule. The vaccination rate in the analyzed period amounted to almost 99%. The following age groups were analyzed: 30-49, 50-64 and 65+. The Cochran-Armitage test was used to investigate the significance of the observed trend in pneumonia morbidity. The significance of deviations from a linear trend was also tested. In addition, the importance of the trend (in the case of deviations from linearity) was confirmed with the use of the Mantel test.

RESULTS

In the 65+ age group there was a decrease of 66.5% in the incidence of diagnosed pneumonia (p < 0.0001). This was followed by smaller, but statistically significant, declines in the other age groups: 30.75% in the 30-49 age group (p = 0.001) and 56.8% in the 50-64 age group (p < 0.0001). This decreasing trend continued for seven consecutive years of observation. In addition, we demonstrated a statistically significant higher rate of pneumonia in all age groups in the City of Ostrowiec Świętokrzyski.

CONCLUSIONS

The results clearly indicate that the indirect effectiveness of the PCV7/PCV13 vaccine program, performed according to the 2 + 1 schedule and applied in Kielce, Poland, is statistically significant.

Children hospitalised with influenza-associated pneumonia during the 2009 pandemic displayed increased disease severity

AIM

The precise role of the influenza virus in the morbidity of hospitalised paediatric pneumonia cases is unknown. We identified how many cases hospitalised during the 2009 pandemic had influenza-associated pneumonia and assessed their severity.

METHODS

Children admitted to three Israeli medical centres during the 2009 influenza pandemic with radiologically confirmed pneumonia were prospectively screened for influenza. We compared the clinical, laboratory and radiologic findings for positive and negative cases.

RESULTS

The pandemic H1N1 virus was detected in 89 (30%) of the 297 patients hospitalised for pneumonia and 55% of the Paediatric Intensive Care Unit admissions for pneumonia. There were no significant differences in the rates of underlying disease between the two groups. Logistic regression analysis revealed that children with pandemic H1N1 virus-associated pneumonia had significantly increased disease severity than those without, with a higher incidence of hypoxemia (41.6% versus 24%) with a relative risk (RR) of 2.2, higher rate of paediatric intensive care unit admission (16.9% versus 5.8%, RR of 2.7) and higher rate of mechanical ventilation (10.1% versus 2.4%, RR:4.4).

CONCLUSION

During the 2009 influenza pandemic, 30% of children hospitalised for pneumonia had the influenza infection and these children displayed increased disease severity.

Identification of viral and bacterial pathogens from hospitalized children with severe acute respiratory illness in Lusaka, Zambia, 2011-2012: a cross-sectional study

BACKGROUND

Morbidity and mortality from respiratory infections are higher in resource-limited countries than developed countries, but limited studies have been conducted in resource-limited settings to examine pathogens from patients with acute respiratory infections. Influenza surveillance has been conducted in Zambia since 2008; however, only 4.3% of patients enrolled in 2011-2012 were positive for influenza. Therefore, we examined non-influenza respiratory pathogens in children with severe acute respiratory illness (SARI) in Zambia, to estimate the scope of disease burden and determine commonly-identified respiratory pathogens.

METHODS

Two reverse transcriptase polymerase chain reaction (rRT-PCR) methods (single and multiplex) were used to analyze nasopharyngeal and throat swabs collected from SARI cases under five years of age from January 2011 through December 2012. All specimens were negative for influenza by rRT-PCR. The panel of singleplex reactions targeted seven viruses, while the multiplex assay targeted thirty-three bacteria, fungi, and viruses.

RESULTS

A set of 297 specimens were tested by singleplex rRT-PCR, and a different set of 199 were tested by multiplex rRT-PCR. Using the singleplex assay, 184/297 (61.9%) specimens were positive for one or more viruses. The most prevalent viruses were human rhinovirus (57/297; 19.2%), human adenovirus (50/297; 16.8%), and respiratory syncytial virus (RSV) (45/297; 15.2%). Using multiplex PCR, at least one virus was detected from 167/199 (83.9%) specimens, and at least one bacteria was detected from 197/199 (99.0%) specimens. Cytomegalovirus (415/199; 208.5%) and RSV (67/199; 33.7%) were the most commonly detected viruses, while Streptococcus pneumonie (109/199; 54.8%) and Moraxella catarrhalis (92/199; 46.2%) were the most commonly detected bacteria.

CONCLUSIONS

Single infections and co-infections of many viruses and bacteria were identified in children with SARI. These results provide an estimate of the prevalence of infection and show which respiratory pathogens are commonly identified in patients. Further studies should investigate causal associations between individual pathogens and SARI.

Population-based incidence of community-acquired pneumonia hospitalization in Hong Kong children younger than 5 years before universal conjugate pneumococcal immunization

OBJECTIVES

We sought to document the incidence of pediatric hospitalization for bacterial pneumonia before universal childhood conjugate pneumococcal vaccination using two different methods of diagnosis.

METHODS

By following the World Health Organization (WHO) chest radiography (CXR) protocol, two radiologists independently read the CXRs of a cohort of systematically recruited children younger than 5 years. The children had acute respiratory infections and were admitted to one of two hospitals that care for 72.5% of all pediatric admissions on Hong Kong Island. Medical records were reviewed for clinical manifestation and to identify bacterial pneumonia diagnosed by pediatricians.

RESULTS

In children younger than 5 years, the incidences of bacterial pneumonia, as diagnosed by pediatricians and by the WHO CXR standard, were 775.7 per 100,000 population [95% confidence interval (CI, 591.8-998.3)] and 439.5 per 100,000 population (95% CI, 304.6-614.5), respectively. The study period was from 2002 to 2004.

CONCLUSION

This study provided a reliable baseline estimate of the hospitalization burden of pneumococcal pneumonia in Hong Kong children before the advent of universal conjugate pneumococcal vaccination.

Immunohistochemistry analysis of pulmonary infiltrates in necropsy samples of children with non-pandemic lethal respiratory infections (RSV; ADV; PIV1; PIV2; PIV3; FLU A; FLU B)

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Respiratory infections represent a globally cause of mortality in childhood.

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Individuals with impaired cellular immunity have more severe diseases.

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The inflammatory response appears to play role in recovery from these diseases.

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TCD8+ count (immunohistochemistry) was higher in the viral pneumonias (p  = 0.04).

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Tissue TCD8+ lymphocytes play role in the viral pneumonia inflammatory response.

Background

Acute viral respiratory infections represent a globally important cause of morbidity and mortality in childhood. An individual's cellular response appears to play a critical role in recovery from infections, given that individuals with impaired cellular immunity, congenital or acquired, have more severe diseases and secrete the virus for longer periods.

Objectives

The aim of this study was to immunohistochemically evaluate the expression of the cell surface antigens CD4, CD8, CD25, CD14 and CD74, in pneumonic infiltrates in the alveolar septa using paraffin-embedded lung samples from autopsies of immunocompetent children who died of lethal, non-pandemic, severe acute respiratory infections.

Study design

From 794 cases of pediatric autopsies of patients with severe respiratory disease (between 1960 and 2004), 193 cases were selected for this study. To identify subpopulations of inflammatory cells in the alveolar septa, cell surface antigen expression was assessed by immunohistochemistry using the following primary antibodies: anti-CD4, anti-CD8, anti-CD14, anti-CD25 and anti-CD74.

Results

The TCD8+ lymphocyte count was higher in the virus-positive group (p = 0.04) and was also much higher among cases that were positive for more than three viral types (p = 0.016). There were fewer CD14+ cells in cases of AdV (adenovirus) infection (p = 0.002), and there was a predominance of CD74+ cells in the histopathological pattern defined as interstitial pneumonitis (p = 0.037).

Conclusions

The results of this study demonstrate that TCD8+ lymphocytes present in the alveolar septa participate to a greater extent in the response toward viral pneumonia, while CD14+ cell numbers are often reduced in cases of AdV.

Epidemiology and microbiological investigations of community-acquired pneumonia in children admitted at the emergency department of a university hospital

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Systematic antimicrobials are recommended in community-acquired pneumonia of child.

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A large panel of bacteria and viruses was detected in 85 children exhibiting CAP.

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More than 60% of children with CAP exhibited an exclusive viral infection.

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A co-infection with at least 2 viruses was observed in >40% of the children.

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Data suggest that the use of antimicrobials in child's CAP should be revisited.

Background

The management of children with community-acquired pneumonia (CAP) is largely influenced by the development of new molecular diagnostic tests that allow the simultaneous detection of a wide range of pathogens.

Objectives

Evaluation of a diagnostic approach including multiplex PCR assays for revisiting the epidemiology and etiology of CAP in children at hospital.

Study design

Children of all ages consulting at the Emergency Department of the University hospital of Saint-Etienne, France, during the 2012–2013 winter period were included. In addition to bacterial cultures, the following pathogens were detected using biplex commercially-available rt-PCR tests: adenovirus, respiratory syncytial virus, human metapneumovirus, bocavirus, rhinovirus/enterovirus, coronavirus, influenza viruses A and B, parainfluenza viruses, Mycoplasma pneumoniae and Chlamydophila pneumonia.

Results

From 85 patients with CAP, at least one pathogen was identified in 81 cases (95.3%), including 4 bacterial exclusive infections (4.7%), 53 viral exclusive infections (62.4%) and 24 mixed infections (28.2%). Coinfection by at least two viruses was observed in 37 cases (43.5%). Mean age was higher in the case of documented bacterial infection (P < 0.05). In the subgroup of viral exclusive infection, the mean age of severe cases was 2.0 years vs 3.8 years in mild and moderate cases (P < 0.05).

Conclusions

These findings highlight the huge proportion of CAP of viral origin, the high number of co-infection by multiple viruses and the low number of bacterial CAP, notably in children under 5 years, and address the need to re-evaluate the indications of empiric antimicrobial treatment in this age group.

International guidelines on tackling community-acquired pneumonia show major discrepancies between developed and developing countries

AIM

The goal of this study was to compare the current guidelines on diagnosis and treatment of paediatric community-acquired pneumonia (CAP) in developing and developed countries.

METHODS

A literature search was performed consulting the Medline, Embase, Current Contents, National Guideline Clearinghouse and Cochrane database, from January 2000 to March 2013.

RESULTS

Twelve guidelines were selected: six from developed countries and six from developing countries. Major discrepancies between the diagnosis and treatment approaches recommended by guidelines covering developing and developed countries were revealed. The search also highlighted differences between recommendations issued in similar settings.

CONCLUSION

The guidelines show wide variations and weak recommendations and further research is needed to improve clinical outcomes and make better use of resources.

A population-based analysis of children with pneumonia among intensive care units in Taiwan

BACKGROUND

Pneumonia is a major diagnosis in children that requires intensive care and is a major cause of mortality in critically ill children. A survey on current epidemiology and case fatality-associated conditions is crucial for the care of critically ill children with pneumonia in an intensive care unit (ICU).

METHODS

The sex, age, seasonality of admission, area of distribution, and case fatality rate of children younger than 18 years who had pneumonia and were admitted to an ICU during the period 2006-2010 were obtained from the National Health Insurance Research Database (NHIRD) of Taiwan. The enrolled children were grouped by age (0-2 years, 3-5 years, 6-11 years, and 12-17 years). The need for invasive procedures such as endotracheal tube (ET) insertion, mechanical ventilation (MV), tracheostomy, central venous catheter (CVC) insertion, chest tube insertion/drainage, chest surgery, and extracorporeal membranous oxygenation (ECMO) were analyzed to clarify their association with case fatality in critically ill children with pneumonia.

RESULTS

Of the 12,577 children enrolled, 7131 (56.7%) were boys and 5446 (43.3%) were girls. The younger age groups had more cases of pneumonia, but less often required invasive procedures. Children 0-2 years old (n = 6083) accounted for approximately one-half (48.4%) of all enrolled children. This group had the lowest case fatality rate (3.1%; 187/6083 children) and lowest need for invasive procedures (31.1%; 1892/6083 children), whereas children in the 12-17 year-old group had the highest case fatality rate (9.9%; 140/1417 children) and the highest need for invasive procedures (59.8%; 847/1417 children) (p < 0.001). The percentage of pneumonia cases was highest in the spring (30.1%) and lowest in the summer (21.7%). The invasive procedures associated with case fatality were ET/MV (OR, 14.31; p < 0.001), CVC insertion (OR, 7.46; p < 0.001), ECMO intervention (OR, 4.59; p < 0.001), and chest tube insertion/drainage (OR, 1.87; p < 0.001).

CONCLUSION

The number of cases of pneumonia that required ICU admission was greater among younger children than among older children. Factors associated with the higher case fatality rate included older age at presentation, the need for invasive procedures (e.g., ET/MV, CVC insertion, chest tube insertion/drainage, and ECMO), underlying comorbidities and complications.

Aetiology of paediatric pneumonia after the introduction of pneumococcal conjugate vaccine

We describe the aetiology of community-acquired pneumonia in children before and after the introduction of the pneumococcal conjugate vaccination (PCV) programme in 2006.

Prospective studies were conducted in 2001–2002 (pre-vaccine) and 2009–2011 (post-vaccine) of children aged 0–16 years with radiologically confirmed pneumonia seen in hospital. Investigations included culture, serology, immunofluorescence antibody and urine antigen testing, with an increased use of PCR assays and expanded panels of pathogens in the post-vaccine study.

241 and 160 children were enrolled in the pre- and post-vaccine studies, respectively (73% aged <5 years). Identification of a causative pathogen was higher post-vaccination (61%) than pre-vaccination (48.5%) (p=0.019). Rates of bacterial infections were not different between post- and pre-vaccine studies (17.5% versus 24%, p=0.258). Viral (31%) and mixed (12.5%) infections were found more often post-vaccination (19.5%, p=0.021) than pre-vaccination (5%, p=0.015). Rates of identified pneumococcal infections were comparable between pre- and post-vaccine studies (14.7% versus 17.4%, p=0.557). Diagnosis of pneumococcal infection post-vaccination improved when PCR was used compared to culture (21.6% versus 6%, p=0.0004). Serotypes included in PCV13 but not PCV7 were identified in 75% (18 out of 24) post-vaccination.

Infection with nonvaccine pneumococcal serotypes continues to be a significant cause of pneumonia in children in the UK.

Aetiology of community-acquired pneumonia in children following a pneumococcal conjugate vaccination programmehttp://ow.ly/p9Wub

Pneumococcal diagnosis and serotypes in childhood community-acquired pneumonia

The 7-valent pneumococcal conjugate vaccine (PCV7) was introduced routinely in the UK from September 2006 and replaced by PCV13 in 2010. In a prospective study from 2009 to 2011 of 160 children aged ≤16 years with radiologically confirmed pneumonia, likely pneumococcal infections were identified in 26%. Detection of pneumococci was improved with polymerase chain reaction compared to culture (21.6% versus 6% of children tested, P = 0.0004). Where serotyping was possible, all (n = 23) were non-PCV7 but PCV13 serotypes; 1 (43.5%), 3 (21.7%), 7A/F, and 19A (17.4% each).

Microbiological diagnosis of community-acquired respiratory tract infections by nucleic acid detection

BACKGROUND

Microbiological diagnostic procedures have changed significantly over the last decade. Initially the implementation of the polymerase chain reaction (PCR) resulted in improved detection tests for microbes that were difficult or even impossible to detect by conventional methods such as culture and serology, especially in community-acquired respiratory tract infections (CA-RTI). A further improvement was the development of real-time PCR, which allows end point detection and quantification, and many diagnostic laboratories have now implemented this powerful method.

OBJECTIVE

At present, new performant and convenient molecular tests have emerged targeting in parallel many viruses and bacteria responsible for lower and/or upper respiratory tract infections. The range of test formats and microbial agents detected is evolving very quickly and the added value of these new tests needs to be studied in terms of better use of antibiotics, better patient management, duration of hospitalization and overall costs.

CONCLUSIONS

Molecular tools for a better microbial documentation of CA-RTI are now available. Controlled studies are now required to address the relevance issue of these new methods, such as, for example, the role of some newly detected respiratory viruses or of the microbial DNA load in a particular patient at a particular time. The future challenge for molecular diagnosis will be to become easy to handle, highly efficient and cost-effective, delivering rapid results with a direct impact on clinical management.

Viral etiologies of lower respiratory tract infections among Egyptian children under five years of age

Background

Lower respiratory tract infections (LRTI) are responsible for a considerable number of deaths among children, particularly in developing countries. In Egypt and the Middle East region, there is a lack of data regarding the viral causes of LRTI. In this study, we aimed to identify the relative prevalence of various respiratory viruses that contribute to LRTIs in young children. Although, nucleic acid-based methods have gained importance as a sensitive tool to determine the viral infections, their use is limited because of their prohibitive cost in low-income countries. Therefore, we applied three different laboratory methods, and presented the different virus prevalence patterns detected by each method.

Methods

We collected nasopharyngeal aspirate samples, demographic data and, clinical data from 450 children under five years of age who presented with LRTI at Abou El Reesh hospital in Cairo during a one-year period. To identify the viral causes of the LRTI we used direct fluorescence assay, real-time reverse-transcriptase polymerase chain reaction (rt-RT-PCR), and shell vial culture. We tested for eight major respiratory viruses.

Results

Two hundred sixty-nine patients (59.9%) had a viral infection, among which 10.8% had a co-infection with two or more viruses. By all three methods, respiratory syncytial virus (RSV) was the most predominant, and parainfluenza virus type 2 (HPIV-2), influenza B virus (FLUBV) were the least predominant. Other viral prevalence patterns differed according to the detection method used. The distribution of various viruses among different age groups and seasonal distribution of the viruses were also determined.

Conclusions

RSV and human adenovirus were the most common respiratory viruses detected by rt-RT-PCR. Co-infections were found to be frequent among children and the vast majority of co-infections were detected by nucleic acid-based detection assays.

Community-Acquired Pneumonia in the Conjugate Vaccine Era

Community-acquired pneumonia (CAP) remains one of the most common serious infections encountered among children worldwide. In this review, we highlight important literature and recent scientific discoveries that have contributed to our current understanding of pediatric CAP. We review the current epidemiology of childhood CAP in the developed world, appraise the state of diagnostic testing for etiology and prognosis, and discuss disease management and areas for future research in the context of recent national guidelines.

Impact of the 7-valent pneumococcal conjugate vaccine on the incidence of childhood pneumonia

In September 2006, the 7-valent pneumococcal conjugate vaccine (PCV7) was added to the UK immunization programme. We aimed to evaluate the impact of PCV7 on the incidence of all-cause community-acquired pneumonia (CAP) in children. A prospective survey was undertaken in 2008-2009 at 11 hospitals in North East England of children aged 0-16 years with radiologically confirmed pneumonia. Data were compared to those from a similar survey undertaken in the same hospitals in 2001-2002. A total of 542 children were enrolled, of which 74% were aged <5 years. PCV7 uptake was 90∙7%. The incidence of pneumonia was 11∙8/10,000 [95% confidence interval (CI) 10∙9-12∙9], and the hospitalization rate was 9∙9/10,000 (95% CI 9∙0-10∙9). Compared to 2001, there was a 19% (95% CI 8-29) reduction in the rate of CAP in those aged <5 years, and in those <2 years a 33∙1% (95% CI 20-45) reduction in the incidence of CAP and 38∙1% (95% CI 24-50) reduction in hospitalization rates. However, for those unvaccinated aged ≥5 years, there was no difference in the incidence of CAP and hospitalization rate between both surveys. Since 2001, the overall reduction in incidence was 17∙7% (95% CI 8-26) and for hospitalization 18∙5% (95% CI 8-28). For the <5 years age group there was a lower incidence of CAP in PCV7-vaccinated children (25∙2/10,000, 95% CI 22∙6-28∙2) than in those that were not vaccinated (37∙4/10,000, 95% CI 29∙2-47∙1). In conclusion, PCV7 has reduced both incidence and rate of hospitalization of pneumonia in children, particularly in the <2 years age group.

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.

Decline in early childhood respiratory tract infections in the Norwegian mother and child cohort study after introduction of pneumococcal conjugate vaccination

BACKGROUND

The 7-valent pneumococcal conjugate vaccine (PCV7) was introduced into the Norwegian Childhood Immunization Program in 2006. A substantial effectiveness of PCV7 immunization against invasive pneumococcal disease has been demonstrated, whereas evidence of its impact on respiratory tract infections are less consistent.

METHODS

This study included children participating in the Norwegian Mother and Child Cohort Study, which recruited pregnant women between 1999 and 2008. Maternal report of acute otitis media (AOM), lower respiratory tract infections (LRTIs) and asthma in the child was compared by PCV7 immunization status, as obtained from the Norwegian Immunization Registry. Generalized linear models with the log-link function were used to report adjusted relative risks (RRs) and 95% confidence intervals (CIs).

RESULTS

For children who had received 3 or more PCV7 immunizations by 12 months of age, the adjusted RRs of AOM and LRTIs between 12 and 18 months were 0.86 (95% CI: 0.81, 0.91) and 0.78 (95% CI: 0.70, 0.87) respectively, when compared with nonimmunized children. A reduced risk of AOM, RR 0.92 (95% CI: 0.90, 0.94), and LRTIs, RR 0.75 (95% CI: 0.71, 0.80), between 18 and 36 months of age was also identified among children who had received 3 or more immunizations by 18 months of age. No association was seen between PCV7 immunization and asthma at 36 months of age.

CONCLUSION

Reduced incidences of AOM and LRTIs before 36 months of age were observed among children immunized with PCV7 through the childhood immunization program.

Indirect population impact of universal PCV7 vaccination of children in a 2 + 1 schedule on the incidence of pneumonia morbidity in Kielce, Poland

The aim of this study was an analysis of the population effects of a seven-valent pneumococcal conjugate vaccine (PCV7) on pneumonia incidence rates in the 5-year follow-up period after the introduction in 2006 of a universal PCV7 vaccination programme in the city of Kielce, Poland. Vaccinations were carried out according to a 2 + 1 schedule. The vaccination compliance rate amounted to approximately 99 %. The age groups 0-2, 30-49, 50-65 and 65+ years were analysed. The Cochran-Armitage test was used to investigate the significance of observed trends in pneumonia morbidity. The significance of deviations from a linear trend was also tested. The importance of the trend was confirmed by the Mantel test. Between 2005 and 2010, the greatest decline, 82.9 % (2005, 25.31/1,000; 2010, 4.34/1,000), in pneumonia morbidity was observed for children <2 years of age. In the 65+ years age group, this amounted to 43.5 %. Lesser declines, but still of statistical significance, were observed for the other age groups: 16.5 % in the 30-49 years group and 40.4 % in the 50-64 years group. All reductions are statistically significant and confirmed by the Mantel test. Five years after the introduction of a universal PCV7 vaccination programme in Kielce, Poland, its effectiveness in pneumonia prevention has been demonstrated in both the <2 years of age group and indirectly for other groups.

Epidemiology of community acquired pneumonia

Despite efforts in prevention worldwide including recent advances in vaccine therapy, childhood community acquired pneumonia (CAP) remains a major cause of morbidity and mortality both in the developed and the developing world. Traditionally, qualifying the aetiology of CAP proved to be fraught with challenges particularly due to low yields from blood and sputum specimens. In recent years however, new advances in techniques such as enzyme-linked immunosorbent assay and polymerase chain reaction have dramatically improved detection rates of both bacteria and viruses. In addition to qualifying the true burden of disease by known organisms such as Streptococcus pneumoniae it has led to the identification of organisms such as human bocavirus which have not previously been associated with CAP. This article aims to provide a brief update to the clinician on the current epidemiology of CAP in this post-vaccination era. It is based on a combination of recommendations from existing clinical practice guidelines, recent systematic reviews and the current literature.

Laboratory methods for determining pneumonia etiology in children

Laboratory diagnostics are a core component of any pneumonia etiology study. Recent advances in diagnostic technology have introduced newer methods that have greatly improved the ability to identify respiratory pathogens. However, determining the microbial etiology of pneumonia remains a challenge, especially in children. This is largely because of the inconsistent use of assays between studies, difficulties in specimen collection, and problems in interpreting the presence of pathogens as being causally related to the pneumonia event. The laboratory testing strategy for the Pneumonia Etiology Research for Child Health (PERCH) study aims to incorporate a broad range of diagnostic testing that will be standardized across the 7 participating sites. We describe the current status of laboratory diagnostics for pneumonia and the PERCH approach for specimen testing. Pneumonia diagnostics are evolving, and it is also a priority of PERCH to collect and archive specimens for future testing by promising diagnostic methods that are currently under development.

The management of community-acquired pneumonia in infants and children older than 3 months of age: clinical practice guidelines by the Pediatric Infectious Diseases Society and the Infectious Diseases Society of America

Evidenced-based guidelines for management of infants and children with community-acquired pneumonia (CAP) were prepared by an expert panel comprising clinicians and investigators representing community pediatrics, public health, and the pediatric specialties of critical care, emergency medicine, hospital medicine, infectious diseases, pulmonology, and surgery. These guidelines are intended for use by primary care and subspecialty providers responsible for the management of otherwise healthy infants and children with CAP in both outpatient and inpatient settings. Site-of-care management, diagnosis, antimicrobial and adjunctive surgical therapy, and prevention are discussed. Areas that warrant future investigations are also highlighted.

Variations in the management of pneumonia in pediatric emergency departments: compliance with the guidelines

OBJECTIVE

We sought to assess compliance with evidence-based guidelines for the management of pediatric pneumonia, including the variations in tests ordered and antimicrobials prescribed. Our primary hypothesis was that compliance with the treatment recommendations from the most current guidelines would be low for antimicrobial prescriptions.

METHODS

We conducted a chart review at the Children's Hospital in London, Ont., to assess variation in the management of pediatric pneumonia. All patients aged 3 months to 18 years seen at the pediatric emergency department between Apr. 1, 2006, and Mar. 31, 2007, with a diagnosis of pneumonia were eligible for inclusion in the study.

RESULTS

Compliance with management guidelines was 59.7% (95% confidence interval [CI] 53%-66%, n = 211) in children 5-18 years old and 83.0% (95% CI 80%-86%, n = 605) in children 3 months to 5 years old. Significant variation existed in the choice of antimicrobial agent for children with pneumonia, with nonrecommended agents frequently prescribed.

CONCLUSION

Significant variation existed in the management of pediatric pneumonia, and adherence to guidelines was low for the group of patients aged 5-18 years. Future studies should attempt to provide guidance to distinguish between viral and bacterial etiology to allow judicious use of antimicrobials.

Significant decline in pneumonia admission rate after the introduction of routine 2+1 dose schedule heptavalent pneumococcal conjugate vaccine (PCV7) in children under 5 years of age in Kielce, Poland

This study was performed to estimate the effect of heptavalent pneumococcal conjugate vaccine (PCV7) on the pneumonia admission rate in children younger than 5 years of age, after the introduction of routine 2+1 dose schedule immunization. We compared the pneumonia admission rate (number of cases per 1,000 population) 2 years before and 2 years after the introduction of PCV7 in 2006. Only children with radiologically confirmed pneumonia were analyzed. The vaccination rate in the analyzed periods was around 99%. In the period preceding the implementation of PCV7, the average pneumonia admission rate was 41.48/1,000 and 6.15/1,000 for 1-year-old and 2-4-year-old children, respectively. Statistical analysis showed a significant fall in this rate in two consecutive years after PCV7 implementation (p < 0.0000001 for 1-year-old and p = 0.011 for 2-4-year-old children, respectively). In the first year of vaccination, the admission number decreased in these two groups by about 65 and 23%, respectively. In the second year, only a few percent fall in the admission rate was noted. In children younger than 2 years of age, the age group targeted for vaccination, pneumonia-related healthcare utilization declined substantially following PCV7 introduction. These results suggest that PCV7 may play an important role in reducing the burden of pneumonia in Poland.

Etiology of community-acquired pneumonia in hospitalized children based on WHO clinical guidelines

Community-acquired pneumonia (CAP) is a major cause of death in developing countries and of morbidity in developed countries. The objective of the study was to define the causative agents among children hospitalized for CAP defined by WHO guidelines and to correlate etiology with clinical severity and surrogate markers. Investigations included an extensive etiological workup. A potential causative agent was detected in 86% of the 99 enrolled patients, with evidence of bacterial (53%), viral (67%), and mixed (33%) infections. Streptococcus pneumoniae was accounted for in 46% of CAP. Dehydration was the only clinical sign associated with bacterial pneumonia. CRP and PCT were significantly higher in bacterial infections. Increasing the number of diagnostic tests identifies potential causes of CAP in up to 86% of children, indicating a high prevalence of viruses and frequent co-infections. The high proportion of pneumococcal infections re-emphasizes the importance of pneumococcal immunization.

Detection of Haemophilus influenzae type B DNA in a murine pneumonia model by in situ PCR

This study estimated the value of in situ PCR (ISPCR) in the detection of Haemophilus influenzae type b (Hib) DNA in paraffin-embedded lung tissues of a murine pneumonia model. ICR mice were infected with Hib solution intranasally. In study group A (n=20), physiological changes and the number of deaths were recorded for 7 consecutive days after infection. In study group B (n=10), blood samples and lung tissues were obtained from the infected mice on the brink of death. In both groups, portions of the lung tissue were cultured for Hib, while other portions were submitted for histopathological studies. Conventional PCR, PCR followed by Southern blotting and ISPCR were performed to detect Hib in paraffin-embedded lung tissues. In control group A, six mice were inoculated intranasally with the same concentration of heat-inactivated Hib solution. In control group B, six healthy mice served as a blank control. Both control groups were managed using the same methods as those used in the study groups. The white blood cell count of the mice in the study group increased (F=3.295, P<0.01), with a high neutrophil count (F=0.127, P<0.05). In the histopathological study, various stages of pneumonia were found in the lung tissues of the infected mice examined by microscope; 80% of the mice had moderate or severe pneumonia. Cultures of lung tissues in the study groups were all positive for Hib, while no bacteria were found in the control groups. Hib was detected in only 4 of 30 samples (13.3%) of the study groups using conventional PCR, but in all 30 samples (100%) using both Southern blotting and ISPCR. All three methods did not detect Hib in the control groups. Because of its sensitivity and specificity and its ability to locate the micro-organism, ISPCR can be considered suitable for the detection of Hib in paraffin-embedded lung tissues.

The role of Haemophilus influenzae type b in fatal community-acquired pneumonia in Chinese children

To analyze the role of Haemophilus influenzae type b in children's death resulting from severe pneumonia conventional PCR, Southern blotting and in situ PCR were evaluated for the detection of Hib in 202 paraffin-embedded lung tissue autopsy samples from children with fatal outcome of pneumonia in China during the period of 1953-2002. The results indicate that Hib was a cause of fatal pneumonia in 36 (17.8%) of 202 samples.

Medical microbiology: laboratory diagnosis of invasive pneumococcal disease

The laboratory diagnosis of invasive pneumococcal disease (IPD) continues to rely on culture-based methods that have been used for many decades. The most significant recent developments have occurred with antigen detection assays, whereas the role of nucleic acid amplification tests has yet to be fully clarified. Despite developments in laboratory diagnostics, a microbiological diagnosis is still not made in most cases of IPD, particularly for pneumococcal pneumonia. The limitations of existing diagnostic tests impact the ability to obtain accurate IPD burden data and to assess the effectiveness of control measures, such as vaccination, in addition to the ability to diagnose IPD in individual patients. There is an urgent need for improved diagnostic tests for pneumococcal disease--especially tests that are suitable for use in underresourced countries.

Management of community-acquired pneumonia in children

Community-acquired pneumonia (CAP) is a significant cause of childhood morbidity and mortality worldwide. Viral etiology is most common in young children and decreases with age. Streptococcus pneumoniae is the single most common bacterial cause across all age groups. Atypical organisms present similarly across all age groups and may be more common than previously recognized.A bacterial pneumonia should be considered in children presenting with fever >38.5 degrees C, tachypnea, and chest recession. Oxygen therapy is life saving and should be given when oxygen saturation is <92%. For non-severe pneumonia, oral amoxicillin is the antibacterial of choice with low failure rates reported. Severely ill children are traditionally treated with parenteral antibacterials. Penicillin non-susceptible S. pneumoniae prevalence rates are increasing and have been linked to community antibacterial prescribing. Most pneumococci remain sensitive to high-dose penicillin-based antibacterials but macrolide resistance is also a problem in some communities. However, primary combination treatment with macrolides is indicated in areas where there is a high prevalence of atypical organisms. The most common complications in CAP are parapneumonic effusions and empyema. The use of ultrasonography combined with intercostal drainage augmented with the use of fibrinolytic therapy has significantly reduced the morbidity associated with these complications. There is increasing evidence that a preventative strategy with the 7-valent pneumococcal conjugate vaccine (PCV-7) results in a significant fall in CAP in early childhood.

Comparison of oral amoxicillin and intravenous benzyl penicillin for community acquired pneumonia in children (PIVOT trial): a multicentre pragmatic randomised controlled equivalence trial

OBJECTIVE

To ascertain whether therapeutic equivalence exists for the treatment of paediatric community acquired pneumonia by the oral and intravenous (IV) routes.

METHODS

A multicentre pragmatic randomised controlled non-blinded equivalence trial was undertaken in eight paediatric centres in England (district general and tertiary hospitals). Equivalence was defined as no more than a 20% difference between treatments of the proportion meeting the primary outcome measure at any time. 246 children who required admission to hospital and had fever, respiratory symptoms or signs and radiologically confirmed pneumonia were included in the study. Exclusion criteria were wheeze, oxygen saturations <85% in air, shock requiring >20 ml/kg fluid resuscitation, immunodeficiency, pleural effusion at presentation requiring drainage, chronic lung condition (excluding asthma), penicillin allergy and age <6 months. The patients were randomised to receive oral amoxicillin for 7 days (n = 126) or IV benzyl penicillin (n = 120). Children in the IV group were changed to oral amoxicillin after a median of six IV doses and received 7 days of antibiotics in total. The predefined primary outcome measure was time for the temperature to be <38 degrees C for 24 continuous hours and oxygen requirement to cease. Secondary outcomes were time in hospital, complications, duration of oxygen requirement and time to resolution of illness.

RESULTS

Oral amoxicillin and IV benzyl penicillin were shown to be equivalent. Median time for temperature to settle was 1.3 days in both groups (p<0.001 for equivalence). Three children in the oral group were changed to IV antibiotics and seven children in the IV group were changed to different IV antibiotics. Median time to complete resolution of symptoms was 9 days in both groups.

CONCLUSION

Oral amoxicillin is effective for most children admitted to hospital with pneumonia (all but those with the most severe disease who were excluded from this study). Prior to this study, the British Thoracic Society guidelines on childhood pneumonia could not draw on evidence to address this issue. This will spare children and their families the trauma and pain of cannulation, and children will spend less time in hospital.

Currently used nucleic acid amplification tests for the detection of viruses and atypicals in acute respiratory infections

For the detection of respiratory viruses conventional culture techniques are still considered as the gold standard. However, results are mostly available too late to have an impact on patient management. The latest developments include appropriate DNA- and RNA-based amplification techniques (both NASBA and PCR) for the detection of an extended number of agents responsible for LRTI. Real time amplification, the latest technical progress, produces, within a considerable shorter time, results with a lower risk of false positives. As results can be obtained within the same day, patient management with appropriate therapy or reduction of unnecessary antibiotic therapy in LRTI will be possible. A number of technical aspects of these amplification assays, and their advantages are discussed.

The availability and use of these new diagnostic tools in virology has contributed to a better understanding of the role of respiratory viruses in LRTI. The increasing importance of the viral agents, Mycoplasma pneumoniae and Chlamydophila pneumoniae in ARI is illustrated. A great proportion of ARI are caused by viruses, but their relative importance depends on the spectrum of agents covered by the diagnostic techniques and on the populations studied, the geographical location and the season. The discovery of new viruses is ongoing; examples are the hMPV and the increasing number of coronaviruses. Indications for the use of these rapid techniques in different clinical situations are discussed. Depending on the possibilities, the laboratory could optimize its diagnostic strategy by applying a combination of immunofluorescence for the detection of RSV an IFL, and a combination of real-time amplification tests for other respiratory viruses and the atypical agents. When implementing a strategy, a compromise between sensitivity, clinical utility, turn around time and cost will have to be found.

[Pneumococcal infection among community-acquired pneumonia. A retrospective study of 230 hospitalized children]

OBJECTIVES

To find arguments in favour of pneumococcal origin in community-acquired pneumonia.

POPULATION AND METHODS

A retrospective analysis of the files of 230 children hospitalized between January 1st 1999 and June 30th 2001 for community acquired pneumonia was performed. The files were classified into 3 subgroups: I (N=7), confirmed (positive blood culture); II (N=134), probable (biological arguments); III (N=89), possible pneumococcal infection. Age of the children was also taken into consideration.

RESULTS

All children in the subgroup I had fever>39 degrees C at admission and at least 1 of the 3 criteria (WBC> or=20.10(9)/l, neutrophils > or =10.10(9)/l, C-reactive protein level> or =60 mg/l). Dyspnea was more frequently asthmatiform in the subgroup III. Chest X-ray was not contributive. Before admission, 39% of the children were given one or several antibiotics, and so some of patients belonging to the subgroups II and III could have been infected by pneumococcus without possibility to confirm that.

CONCLUSION

Results of this analysis suggest that some criteria may be useful for selecting initial antibiotherapy even though systematic early specific antipneumococcal immunization should reduce the frequency of this infection.

Effective treatment strategies for paediatric community-acquired pneumonia

Pneumonia is the leading cause of death in children under 5 years of age worldwide and a cause of morbidity in a considerable number of children. A number of studies have sought to identify the ideal choice of antibiotics, route of administration and optimum duration of treatment based on the most likely aetiological agents. Emerging bacterial resistance to antibiotics is also an important consideration in treatment. However, inconsistent clinical and radiological definitions of pneumonia make comparison between studies difficult. There is also a lack of well designed adequately powered randomised controlled trials. This review describes the difficulties encountered in diagnosing community-acquired pneumonia, aetiology, treatment strategies with recommendations and highlights areas for further research.

Decline in pneumonia admissions after routine childhood immunisation with pneumococcal conjugate vaccine in the USA: a time-series analysis

BACKGROUND

Routine infant immunisation with seven-valent pneumococcal conjugate vaccine (PCV7) began in the USA in 2000. Although invasive pneumococcal disease has declined substantially, the programme's effect on hospital admissions for pneumonia is unknown. We therefore assessed the effect of the programme on rates of all-cause and pneumococcal pneumonia admissions.

METHODS

Data from the Nationwide Inpatient Sample, the largest inpatient database available in the USA, were analysed with an interrupted time-series analysis that used pneumonia (all-cause and pneumococcal) admission rates as the main outcomes. Monthly admission rates estimated for years after the introduction of PCV7 vaccination (2001-2004) were compared with expected rates calculated from pre-PCV7 years (1997-1999). The year of vaccine introduction (2000) was excluded, and rates of admission for dehydration were assessed for comparison.

FINDINGS

At the end of 2004, all-cause pneumonia admission rates had declined by 39% (95% CI 22-52) for children younger than 2 years, who were the target population of the vaccination programme. This annual decline in all-cause pneumonia admissions of 506 (291-675) per 100,000 children younger than 2 years represented about 41,000 pneumonia admissions prevented in 2004. During the 8 study years, 10,659 (2%) children younger than 2 years admitted with pneumonia were coded as having pneumococcal disease; these rates declined by 65% (47-77). This decline represented about 17 fewer admissions per 100,000 children in 2004. Admission rates for dehydration for children younger than 2 years remained stable over the study period.

INTERPRETATION

The reduction in all-cause pneumonia admissions in children younger than 2 years provides an estimate of the proportion of childhood pneumonias attributable to Streptococcus pneumoniae in the USA that are vaccine preventable. Our results contribute to the growing body of evidence supporting the beneficial effects of the pneumococcal conjugate vaccines in children.

A Comparison of group A Streptococcus versus Streptococcus pneumoniae pneumonia

BACKGROUND

St reptococcus pyogenes is an uncommon cause of community-acquired pneumonia in children. Further, its clinical course in comparison to pneumonia caused by Streptococcus pneumonia has not been previously highlighted.

METHODS

We reviewed medical records of children 0-18 years of age from April 1983 to April 2005, with discharge diagnoses of invasive disease caused by group A streptococcus (GAS) (Streptococcus pyogenes), or Streptococcus pneumonia (SP) or pneumonia. Data were extracted from the charts, and a comparison of clinical characteristics between the 2 etiologies was performed. Confirmed disease required blood or pleural fluid isolates. Patients with single isolates of GAS in tracheobronchial secretions or sputum were classified as having presumed disease caused by GAS. Patients with confirmed disease due to GAS and SP were compared with respect to clinical characteristics.

RESULTS

Of 103 patients with invasive GAS disease, 12 (11.6%) had confirmed GAS lobar pneumonia. In addition 7 patients had presumed GAS pneumonia. There were 54 patients with confirmed SP pneumonia. Most children who had GAS pneumonia were healthy and recovered completely. Compared with patients with confirmed SP pneumonia, those with confirmed GAS pneumonia had more frequent and larger effusions, more culture positive effusions, had prolonged fever, and had longer hospitalizations. There was not an increasing trend to GAS pneumonia over the 22-year period. There was not a predominant serotype responsible for the pneumonias.

CONCLUSIONS

Lobar GAS pneumonia represents approximately 11% of all cases of invasive disease in this institution during a 22-year period. Compared with patients with SP pneumonia, it appears to cause more effusions and morbidity. The organism is also more frequently recovered from pleural fluid.

Community-acquired pneumonia in Shanghai, China: microbial etiology and implications for empirical therapy in a prospective study of 389 patients

The aim of this multicenter study was to identify the causative pathogens of community-acquired pneumonia (CAP) in Shanghai, China, and to determine their susceptibility to antimicrobial agents. Pathogens obtained from 389 patients with documented CAP during 2001-2003 were identified by multiple diagnostic tools that included bacterial culture, polymerase chain reaction (PCR), and specific immunological assays. Susceptibility of the bacterial isolates was tested by the broth microdilution method. A specific pathogen was identified in 39.8% (155/389) of the patients: Haemophilus influenzae (n=80), Klebsiella spp. (n=15), Streptococcus pneumoniae (n=12), Staphylococcus aureus (n=6), Moraxella catarrhalis (n=1), other gram-negative organisms (n=9), and atypical pathogens that comprised Mycoplasma pneumoniae (n=42), Chlamydia pneumoniae (n=17), and Legionella pneumophila (n=2). Most H. influenzae isolates were susceptible to ampicillin (88.3%), and all were susceptible to macrolides. Of the S. pneumoniae isolates, 75% (9/12) were susceptible to penicillin, while 25% (3/12) were intermediately susceptible. H. influenzae and atypical pathogens are among the most important pathogens of CAP. Ampicillin, cephalosporins, and the newer fluoroquinolones can be used as empirical therapy for CAP in the Shanghai area. The efficacy of monotherapy with newer macrolides for CAP caused by S. pneumoniae requires further evaluation.

Influenza pneumonia

BACKGROUND

Influenza and pneumonia are common childhood illnesses, but few studies have been conducted on influenza-related pneumonia in children. The aim of this study was to describe the frequency and characteristics of laboratory-documented and radiologically detected influenza pneumonia in children.

METHODS

This study involved children treated at the Department of Pediatrics, Turku University Hospital, from 1980 through 2003. Influenza A or B infection was documented with the use of antigen detection from nasopharyngeal aspirates. Children with chest radiographs obtained during influenza episodes were identified. Chest radiographs were reevaluated by a pediatric radiologist for verification of pneumonic infiltrates. Clinical and laboratory data were collected from medical records.

RESULTS

Pneumonia was detected in 134 (14%) of 936 children with influenza infection. The most frequent signs of influenza pneumonia were fever and cough. Of these children, 47% had no specific clinical signs or symptoms suggesting pneumonia. White blood cell count was <15 x 10/L in 89% and serum C-reactive protein concentration <80 mg/L in 85% of the children. One-half of the children had solely interstitial infiltrates, one-fourth solely alveolar and one- fourth both alveolar and interstitial infiltrates on the chest radiograph. The hospitalization rate was 68%, and the median duration of hospitalization was 2 days. Complicated pneumonias were rare, and mortality was low (0.7%).

CONCLUSIONS

Pneumonia is detected in a minority of children treated for influenza at a tertiary center. Unlike in adults, influenza pneumonia in children is usually a benign illness, and the mortality is low.

Prevalence of Chlamydophila pneumoniae among Bangladeshi children under age 5 years with acute respiratory infections

Despite major improvements in the diagnosis of pathogenic organisms causing acute respiratory infections (ARIs), details of infections caused by atypical pathogens are not well understood, particularly in developing countries. This clinical and epidemiological research was conducted in Bangladesh to explore the prevalence of atypical pathogens in causing childhood pneumonia. Sixty-four children with ARI were studied at the Pediatric Outpatient Department of Dhaka Medical College Hospital, Bangladesh, during September through December 2000. In addition to clinical examination, hematological, radiological, and bacteriological examinations were performed. Antibody titers from paired sera against Mycoplasma pneumoniae and Legionella spp. in the acute and convalescent phases revealed that none of these children were infected with M. pneumoniae, while only one serum sample was positive for L. pneumophila serogroup 4. Antibody titers against Chlamydophila (Chlamydia) pneumoniae, determined by an indirect microimmunofluorescence method, and by an enzyme-linked immunosorbent assay (ELISA) kit (HITAZYME C. pneumoniae kit) indicated that 13 children (20.3%) were infected with C. pneumoniae. Our results indicate a high prevalence rate of C. pneumoniae, suggesting it is as an important causative pathogen of childhood pneumonia in Bangladesh.

The burden of pneumonia in children: an Australian perspective

The burden of pneumonia in Australian children is significant with an incidence of 5-8 per 1000 person-years. Pneumonia is a major cause of hospital admission in children less than 5 years of age. Indigenous children are at particular risk with a 10-20-fold higher risk of hospitalisation compared to non-Indigenous children. They also have longer admissions and are more likely to have multiple admissions with pneumonia. There are limited data on pathogen-specific causes of pneumonia, however Streptococcus pneumonia is the most common bacterial cause in children under 5 years of age and respiratory syncytial virus (RSV) and influenza are the predominant viral causes in young children. Pneumonia due to Haemophilus influenza type b (Hib) has been virtually eliminated by the introduction of universal Hib immunisation. Further studies are needed to accurately define the epidemiology of pneumonia due to specific pathogens to help target treatment and immunisation strategies.