Lower respiratory tract infection in hospitalized children

Epidemiology of Community-Acquired Respiratory Tract Infections in Patients Admitted at the Emergency Departments

Objectives: Community-acquired respiratory infections (CARTIs) are responsible for serious morbidities worldwide. Identifying the aetiology can decrease the use of unnecessary antimicrobial therapy. In this study, we intend to determine the pathogenic agents responsible for respiratory infections in patients presenting to the emergency department of several Lebanese hospitals. Methods: A total of 100 patients presenting to the emergency departments of four Lebanese hospitals and identified as having CARTIs between September 2017 and September 2018 were recruited. Specimens of upper and lower respiratory tract samples were collected. Pathogens were detected by a multiplex polymerase chain reaction respiratory panel. Results: Of 100 specimens, 84 contained at least one pathogen. Many patients were detected with ≥2 pathogens. The total number of pathogens from these 84 patients was 163. Of these pathogens, 36 (22%) were human rhinovirus, 28 (17%) were Streptococcus pneumoniae, 16 (10%) were metapneumovirus, 16 (10%) were influenza A virus, and other pathogens were detected with lower percentages. As expected, the highest occurrence of pathogens was observed between December and March. Respiratory syncytial virus accounted for 2% of the cases and only correlated to paediatric patients. Conclusion: CARTI epidemiology is important and understudied in Lebanon. This study offers the first Lebanese data about CARTI pathogens. Viruses were the most common aetiologies of CARTIs. Thus, a different approach must be used for the empirical management of CARTI. Rapid testing might be useful in identifying patients who need antibiotic therapy.

Mortality in children hospitalised with respiratory syncytial virus infection in Singapore

INTRODUCTION

This study aimed to investigate the trend and seasonality of infection due to respiratory syncytial virus (RSV) at KK Women's and Children's Hospital (KKH) in Singapore and to examine the risk factors for mortality among children with RSV infection requiring admission to the paediatric intensive care unit (PICU).

METHODS

A retrospective study was conducted at KKH on children with RSV infections who were admitted to the PICU between January 2004 and December 2010. The medical records of children who died from RSV infections were reviewed. Linear regression was performed to determine the risk factors of RSV mortality.

RESULTS

RSV infection was documented in 5,785 children during the study period, occurring throughout the year, with a small increase in prevalence between the months of June and August annually. Among 85 (1.5%) of 5,785 children who were admitted to the PICU for RSV infection, 74 (1.3%) survived and there were 11 (0.2%) deaths. Multivariate logistic regression analysis showed that significant haemodynamically significant cardiac disease (odds ratio [OR] 12.2, 95% confidence interval [CI] 0.9-16.7, p = 0.05), immunodeficiency (OR 71.4, 95% CI 8.2-500, p < 0.001) and metabolic disease (OR 71.4, 95% CI 4.3-1,000, p = 0.003) were independent risk factors for mortality in RSV infections. Prematurity increased the risk of admission to the PICU but was not significantly associated with mortality.

CONCLUSION

Children with haemodynamically significant cardiac disease, immunodeficiency and metabolic disease were at higher risk of death after hospitalisation for RSV-related illnesses. These children should be considered for palivizumab prophylaxis.

Viral etiology of severe acute respiratory infections in hospitalized children in Cameroon, 2011-2013

BACKGROUND

Severe acute respiratory illness (SARI) is recognized as an important cause of morbidity, mortality, and hospitalization among children in developing countries. Little is known, however, in tropical countries like Cameroon about the cause and seasonality of respiratory infections, especially in hospitalized settings.

OBJECTIVES

Our study investigates the viral etiology and seasonality of SARI in hospitalized children in Yaounde, Cameroon.

METHODS

Prospective clinic surveillance was conducted to identify hospitalized children aged ≤15 years presenting with respiratory symptoms ≤5-day duration. Demographic and clinical data, and respiratory specimens were collected. Nasopharyngeal samples were tested for 17 respiratory viruses using a multiplex polymerase chain reaction. The viral distribution and demographic data were statistically analyzed.

RESULTS

From September 2011 through September 2013, 347 children aged ≤15 years were enrolled. At least one virus was identified in each of 65·4% children, of which 29·5% were coinfections; 27·3% were positive for human adenovirus (hAdV), 13·2% for human respiratory syncytial virus (hRSV), 11·5% for rhinovirus/enterovirus (RV/EV), 10·6% for human bocavirus (hBoV), 9·8% for influenza virus (Inf), 6·6% for human parainfluenza virus (hPIV), 5·7% for human coronavirus (hCoV), and 2·3% for human metapneumovirus (hMPV). While hRSV showed seasonal patterns, hAdV and RV/EV were detected throughout the year and no evident temporal patterns were observed for the remaining viruses.

CONCLUSION

Respiratory viruses were associated with a high burden of hospitalizations among children in Cameroon. Nevertheless, additional studies evaluating asymptomatic Cameroonian children will be important in understanding the relationship between viral carriage and disease.

A review of the role of Haemophilus influenzae in community-acquired pneumonia

In an era when Haemophilus influenzae type b (Hib) conjugate vaccine is widely used, the incidence of Hib as a cause of community-acquired pneumonia (CAP) has dramatcally declined. Non-typeable H. influenzae (NTHi) strains and, occasionally, other encapsulated serotypes of H. influenzae are now the cause of the majority of invasive H. influenzae infectons, including bacteraemic CAP. NTHi have long been recognised as an important cause of lower respiratory tract infecton, including pneumonia, in adults, especially those with underlying diseases. The role of NTHi as a cause of non-bacteraemic CAP in children is less clear. In this review the evidence for the role of NTHi and capsulated strains of H. influenzae will be examined.

Viral etiology of hospitalized acute lower respiratory infections in children under 5 years of age -- a systematic review and meta-analysis

AIM

To estimate the proportional contribution of influenza viruses (IV), parainfluenza viruses (PIV), adenoviruses (AV), and coronaviruses (CV) to the burden of severe acute lower respiratory infections (ALRI).

METHODS

The review of the literature followed PRISMA guidelines. We included studies of hospitalized children aged 0-4 years with confirmed ALRI published between 1995 and 2011. A total of 51 studies were included in the final review, comprising 56091 hospitalized ALRI episodes.

RESULTS

IV was detected in 3.0% (2.2%-4.0%) of all hospitalized ALRI cases, PIV in 2.7% (1.9%-3.7%), and AV in 5.8% (3.4%-9.1%). CV are technically difficult to culture, and they were detected in 4.8% of all hospitalized ALRI patients in one study. When respiratory syncytial virus (RSV) and less common viruses were included, at least one virus was detected in 50.4% (40.0%-60.7%) of all hospitalized severe ALRI episodes. Moreover, 21.9% (17.7%-26.4%) of these viral ALRI were mixed, including more than one viral pathogen. Among all severe ALRI with confirmed viral etiology, IV accounted for 7.0% (5.5%-8.7%), PIV for 5.8% (4.1%-7.7%), and AV for 8.8% (5.3%-13.0%). CV was found in 10.6% of virus-positive pneumonia patients in one study.

CONCLUSIONS

This article provides the most comprehensive analysis of the contribution of four viral causes to severe ALRI to date. Our results can be used in further cost-effectiveness analyses of vaccine development and implementation for a number of respiratory viruses.

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.

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.

Survey of childhood empyema in Asia: implications for detecting the unmeasured burden of culture-negative bacterial disease

Background

Parapneumonic empyema continues to be a disease of significant morbidity and mortality among children despite recent advances in medical management. To date, only a limited number of studies have assessed the burden of empyema in Asia.

Methods

We surveyed medical records of four representative large pediatric hospitals in China, Korea, Taiwan and Vietnam using ICD-10 diagnostic codes to identify children <16 years of age hospitalized with empyema or pleural effusion from 1995 to 2005. We also accessed microbiology records of cultured empyema and pleural effusion specimens to describe the trends in the epidemiology and microbiology of empyema.

Results

During the study period, we identified 1,379 children diagnosed with empyema or pleural effusion (China, n = 461; Korea, n = 134; Taiwan, n = 119; Vietnam, n = 665). Diagnoses of pleural effusion (n = 1,074) were 3.5 times more common than of empyema (n = 305), although the relative proportions of empyema and pleural effusion noted in hospital records varied widely between the four sites, most likely because of marked differences in coding practices. Although pleural effusions were reported more often than empyema, children with empyema were more likely to have a cultured pathogen. In addition, we found that median age and gender distribution of children with these conditions were similar across the four countries. Among 1,379 empyema and pleural effusion specimens, 401 (29%) were culture positive. Staphylococcus aureus (n = 126) was the most common organism isolated, followed by Streptococcus pneumoniae (n = 83), Pseudomonas aeruginosa (n = 37) and Klebsiella (n = 35) and Acinetobacter species (n = 34).

Conclusion

The age and gender distribution of empyema and pleural effusion in children in these countries are similar to the US and Western Europe. S. pneumoniae was the second leading bacterial cause of empyema and pleural effusion among Asian children. The high proportion of culture-negative specimens among patients with pleural effusion or empyema suggests that culture may not be a sufficiently sensitive diagnostic method to determine etiology in the majority of cases. Future prospective studies in different countries would benefit from standardized case definitions and coding practices for empyema. In addition, more sensitive diagnostic methods would improve detection of pathogens and could result in better prevention, treatment and outcomes of this severe disease.

Invasive pneumococcal disease in Singapore children

INTRODUCTION

Our retrospective study examined community-acquired invasive pneumococcal disease (IPD) in children admitted to KK Women's and Children's Hospital, Singapore.

METHODS

All pneumococcal isolates from sterile sites from 1997 to 2004 were surveyed.

RESULTS

There were 147 positive pneumococcal isolates with a mean age of 45 months. The estimated incidence of IPD was 13.6 per 10(5) children under 5 years old. Diagnoses at presentation were: Pneumonia 63.3% (included 14.3% empyema), bacteremia 17%, meningitis 15.6% (included 2.8% meningitis and pneumonia), 4.1% others. The morbidity rate was 25.2%, mortality rate was 6.1%. Antibiotic resistance was: Penicillin 44%, ceftriaxone 15%, erythromycin 62%, trimethoprim-sulfamethoxazole 67%. A separate serotype analysis (n=93, 63%) showed that the current 7valent pneumococcal conjugate vaccine (PCV7) would cover 78.1% of vaccine serotypes and 89% of vaccine-related serotypes for children under 5 years old.

Epidemiology of invasive Haemophilus influenzae type b disease in Singapore children, 1994–2003

Invasive Haemophilus influenzae type b (Hib) diseases are major causes of childhood morbidity and mortality. For the period from 1994 to 2003, we retrospectively identified 53 children with invasive Hib disease including 31 with meningitis, 14 with pneumonia, 2 with septic arthritis, 2 with epiglottitis, 1 with neutropenic sepsis, and 3 who were bacteraemic without a focus. Two children died and 22 had serious sequelae; significantly, survivors with sequelae had presented with meningitis (P-value<0.001) or sepsis (P-value=0.001). During the 11-year period, the annual incidence of invasive Hib disease was estimated to be 4.4/100,000 children <5 years old. With rising affluence, decreasing costs of vaccines, and increased costs in caring for survivors, universal infant immunization with Hib vaccine may need to be reconsidered in Singapore.

The epidemiology of hospitalized pneumonia in rural Kenya: the potential of surveillance data in setting public health priorities

INTRODUCTION

Surveillance data from inpatient health facilities can be useful for prioritization of public health initiatives, but often are not collected or analyzed in developing countries. We evaluated data on hospitalized patients diagnosed with pneumonia in rural western Kenya to characterize pneumonia epidemiology and mortality.

METHODS

Data were obtained from admission registers of all inpatient facilities from 2001 to 2003 in Bondo District (estimated 2003 population: 255901), which is holoendemic for malaria and has high HIV rates. Inpatients with diagnoses compatible with acute pneumonia were included, and census data (1999) were used to calculate incidence rates by age, sex, season, and residence.

RESULTS

From 2001 to 2003, a total of 2466 patients diagnosed with pneumonia were hospitalized with 282 deaths (11.4%). Incidence peaked at 698 per 100,000 person-years among children <5 years of age. A second peak occurred among 20-29 year-olds at 356 per 100,000 person-years; rates were twice as high in women as men in this age group (p<0.001). The incidence in persons >65 years was 121 per 100,000 person-years. Pneumonia incidence peaked during the twice-yearly high malaria seasons, 1-2 months after peak rainfall. Rates of pneumonia decreased with increasing distance of residence from the district hospital (p<0.0001).

DISCUSSION

In Bondo District, the pneumonia burden is greatest among young children and middle-aged adults, the latter peak reflecting the area's HIV epidemic. Access to care likely influenced hospital utilization and thus pneumonia rates, particularly among the elderly. Our findings show that hospital-based data can provide useful information for public health priority setting, such as the introduction of new pneumonia vaccines for children and accelerating the introduction of antiretroviral medications.

Serodiagnosis of acute respiratory infections in children in Georgia

OBJECTIVE

To investigate the etiology of acute respiratory infections in hospitalized children.

METHODS

A total of 808 children were studied. Investigation of RSV, Adenovirus, Parainfluenza, Influenza A and B, C.trachomatis, C.pneumoniae, M. pneumonia and Legionella were performed with an ELISA for IgM, IgG and IgA antibodies detection.

RESULTS

There were 496 males and 312 females giving a male: female ratio of 1.6:1. Ages range from 1 month to 15 years. The overall detection rate was 57.9%. The most frequently detected were: parainfluenza 12.6%, adenovirus 11.2%, influenza A 7.3%, RSV 6%, M. pneumoniae 5.4%, C.trachomatis 3.5% and mixed-infections 9.2%. Pneumonia was associated most frequently with adenovirus and mixed-infections; wheezing bronchitis--with adenovirus, RSV and M. pneumoniae; bronchitis--with parainfluenza and adenovirus, diseases of upper respiratory tract--with parainfluenza and adenovirus. Peak of the virus activity was during winter (influenza, parainfluenza, adenovirus, RSV) and autumn (parainfluenza, RSV).

CONCLUSION

Viruses are the main causes of ARI in Georgian children. A better understanding of the etiology of ARI in all of the regions of the world may be helpful for timely decision of specific therapy, which can help pediatricians to estimate and manage children with ARI.

Expression and Activity of β-Defensins and LL-37 in the Developing Human Lung

Immaturity of innate immunity contributes to the increased susceptibility of human neonates to infection. The lung is a major portal of entry for potential pathogens in the neonate, and human beta-defensins (HBDs) and LL-37 participate in pulmonary innate immunity. We hypothesized that these antimicrobial factors would be developmentally regulated, expressed by neonatal pulmonary tissues, and participate in neonatal innate immunity. We found HBD-2 to be the predominant beta-defensin in human neonatal lung. HBD-2 mRNA expression was developmentally regulated, induced by the proinflammatory factor IL-1beta, and decreased by dexamethasone. Additionally, HBD-2 abundance in neonatal tracheal aspirates increased as a function of gestational age. HBD-1 had a lower level of expression compared with HBD-2 and was induced by dexamethasone. HBD-3 and LL-37 messages were not detected in airway epithelial cultures. Additionally, each antimicrobial peptide exhibited a unique spectrum of antimicrobial activity and salt sensitivity against bacteria commonly causing sepsis in the neonate. Lower levels of HBD-2 may be one factor contributing to the increased susceptibility of premature infants to pulmonary infections.

Pneumonia in HIV-infected and HIV-uninfected children in developing countries

PURPOSE OF REVIEW

Pneumonia is a leading cause of illness and death in children younger than 5 years in developing countries, accounting for approximately 20% of childhood deaths. The HIV epidemic has sharply increased the incidence, severity, and mortality of childhood pneumonia in the developing world, particularly in sub-Saharan Africa. This article reviews recent findings on the epidemiology, clinical features, and management of HIV-infected and -uninfected children with pneumonia in developing countries.

RECENT FINDINGS

Bacterial infection remains a major cause of pneumonia mortality; in HIV-infected children, a broader spectrum of pathogens including gram-negative infections and Pneumocystis jiroveci occurs. Mycobacterium tuberculosis is an important cause of acute pneumonia among children from high tuberculosis prevalence areas. Use of case management guidelines substantially reduces neonatal, infant, and under-5 mortality and pneumonia-specific mortality in developing countries. New advances in therapy include the use of short-course antibiotics and high-dose amoxicillin twice daily for ambulatory treatment of HIV-negative children with pneumonia. New preventive interventions include the development of conjugate vaccines against Streptococcus pneumoniae and Haemophilus influenzae, but these are not widely affordable nor available in developing countries. Despite a lower efficacy in HIV-infected children, these vaccines still protect against disease in a significant proportion of children. Available preventive interventions including micronutrient supplementation with zinc and vitamin A, and immunization as contained in the WHO Expanded Program of Immunization can substantially reduce the burden of childhood pneumonia.

SUMMARY

Urgent measures to implement existing available, effective interventions for prevention and treatment of childhood pneumonia and achieve high coverage rates in developing countries are needed.