Epidemiology and etiology of childhood pneumonia

Randomized controlled trial of day care versus hospital care of severe pneumonia in Bangladesh

OBJECTIVE

A randomized controlled trial compared day care versus hospital care management of pneumonia.

METHODS

Children 2 to 59 months of age with severe pneumonia received either day care, with antibiotic treatment, feeding, and supportive care from 8:00 am to 5:00 pm, or hospital care, with similar 24-hour treatment.

RESULTS

In 2006-2008, 360 children were assigned randomly to receive either day care or hospital care; 189 (53%) had hypoxemia, with a mean±SD oxygen saturation of 93±4%, which increased to 99±1% after oxygen therapy. The mean±SD durations of day care and hospital care were 7.1±2.3 and 6.5±2.8 days, respectively. Successful management was possible for 156 (87.7% [95% confidence interval [CI]: 80.9%-90.9%]) of 180 children in the day care group and 173 (96.1% [95% CI: 92.2%-98.1%]) of 180 children in the hospital care group (P=.001). Twenty-three children in the day care group (12.8% [95% CI: 8.7%-18.4%] and 4 children in the hospital care group (2.2% [95% CI: 0.9%-5.6%] required referral to hospitals (P<.001). During the follow-up period, 22 children in the day care group (14.1% [95% CI: 9.5%-20.4%]) and 11 children in the hospital care group (6.4% [95% CI: 3.6%-11%]) required readmission to hospitals (P=.01). The estimated costs per child treated successfully at the clinic and the hospital were US$114 and US$178, respectively.

CONCLUSION

Severe childhood pneumonia without severe malnutrition can be successfully managed at day care clinics, except for children with hypoxemia who require prolonged oxygen therapy.

Frequency of human bocavirus (HBoV) infection among children with febrile respiratory symptoms in Argentina, Nicaragua and Peru

BACKGROUND

Globally, respiratory infections are the primary cause of illness in developing countries, specifically among children; however, an etiological agent for many of these illnesses is rarely identified.

OBJECTIVES

Our study aimed to estimate the frequency of human bocavirus (HBoV) infection among pediatric populations in Argentina, Nicaragua and Peru.

METHODS

We conducted a cross-sectional study using stored samples of an influenza-like illness surveillance program. Irrespective of previous diagnosis, nasopharyngeal or nasal swab specimens were randomly selected and tested using real-time PCR from three sites during 2007 from patients younger than 6 years old.

RESULTS

A total of 568 specimens from Argentina (185), Nicaragua (192) and Peru (191) were tested. The prevalence of HBoV was 10·8% (95% CI: 6·3; 15·3) in Argentina, 33·3% in Nicaragua (95% CI: 26·6; 40·1) and 25·1% in Peru (95% CI: 18·9; 31·3).

CONCLUSIONS

These findings demonstrate circulation of HBoV in Argentina, Nicaragua and Peru among children with influenza-like symptoms enrolled in a sentinel surveillance program.

Metabolomic analysis in severe childhood pneumonia in the Gambia, West Africa: findings from a pilot study

BACKGROUND

Pneumonia remains the leading cause of death in young children globally and improved diagnostics are needed to better identify cases and reduce case fatality. Metabolomics, a rapidly evolving field aimed at characterizing metabolites in biofluids, has the potential to improve diagnostics in a range of diseases. The objective of this pilot study is to apply metabolomic analysis to childhood pneumonia to explore its potential to improve pneumonia diagnosis in a high-burden setting.

METHODOLOGY/PRINCIPAL FINDINGS

Eleven children with World Health Organization (WHO)-defined severe pneumonia of non-homogeneous aetiology were selected in The Gambia, West Africa, along with community controls. Metabolomic analysis of matched plasma and urine samples was undertaken using Ultra Performance Liquid Chromatography (UPLC) coupled to Time-of-Flight Mass Spectrometry (TOFMS). Biomarker extraction was done using SIMCA-P+ and Random Forests (RF). 'Unsupervised' (blinded) data were analyzed by Principal Component Analysis (PCA), while 'supervised' (unblinded) analysis was by Partial Least Squares-Discriminant Analysis (PLS-DA) and Orthogonal Projection to Latent Structures (OPLS). Potential markers were extracted from S-plots constructed following analysis with OPLS, and markers were chosen based on their contribution to the variation and correlation within the data set. The dataset was additionally analyzed with the machine-learning algorithm RF in order to address issues of model overfitting and markers were selected based on their variable importance ranking. Unsupervised PCA analysis revealed good separation of pneumonia and control groups, with even clearer separation of the groups with PLS-DA and OPLS analysis. Statistically significant differences (p<0.05) between groups were seen with the following metabolites: uric acid, hypoxanthine and glutamic acid were higher in plasma from cases, while L-tryptophan and adenosine-5'-diphosphate (ADP) were lower; uric acid and L-histidine were lower in urine from cases. The key limitation of this study is its small size.

CONCLUSIONS/SIGNIFICANCE

Metabolomic analysis clearly distinguished severe pneumonia patients from community controls. The metabolites identified are important for the host response to infection through antioxidant, inflammatory and antimicrobial pathways, and energy metabolism. Larger studies are needed to determine whether these findings are pneumonia-specific and to distinguish organism-specific responses. Metabolomics has considerable potential to improve diagnostics for childhood pneumonia.

Mucosal immunity in resource-limited setting: is the battle ground different?

In many developing countries, populations are under considerable pressure from high bacterial exposure on mucosal surfaces. Immune dysregulation in this setting is multifactorial and is driven by a range of environmental factors, undernutrition and coinfections such as measles, malaria and HIV. Disruption or subversion of respiratory-tract and intestinal epithelial barriers leads to increased invasion by mucosal pathogens and a high frequency of life-threatening bacterial disease. It is our opinion that a process of epithelial barrier dysfunction and immune dysregulation at these mucosal surfaces leads to the much higher rates of pneumonia, meningitis and severe sepsis seen in resource-limited countries.

Two weeks of zinc administration to Nepalese children with pneumonia does not reduce the incidence of pneumonia or diarrhea during the next six months

Diarrhea and pneumonia are the 2 main causes of death in children under 5 y of age. Short courses of zinc administration are now recommended for treatment of childhood diarrhea and some studies have also shown its beneficial effect on treatment of pneumonia. The objective of our study was to assess the efficacy of zinc administration (10 mg/d for children 2-11 mo and 20 mg/d for >or= 12 mo of age) for 14 d on preventing diarrheal and respiratory illnesses for 6 mo of follow-up. This was a randomized, double-blind, placebo-controlled trial in children 2-35 mo of age with community-acquired pneumonia. The number of illness episodes and time until the first episode of various illnesses were compared between the 2 study groups. After 14 d of zinc supplementation, plasma zinc was significantly higher in the group receiving zinc. However, this difference was not detectable at 1 and 2.5 mo after the end of zinc administration. Of 2628 enrolled cases, a total of 2599 (99%) were available for assessment after the completion of zinc supplementation. The number of hospital visits and the median number of days until the first episode of pneumonia, diarrhea, and dysentery was similar in the 2 groups. The hazard ratios (95% CI) were 1.02 (0.92, 1.14) for nonsevere pneumonia, 1.11 (0.72, 1.73) for severe pneumonia, 1.07 (0.91, 1.26) for diarrhea, and 0.96 (0.69, 1.34) for dysentery. A short course of zinc supplementation given during an episode of pneumonia did not prevent diarrheal or respiratory illness over the next 6 mo.

Community-based interventions for diarrhoeal diseases and acute respiratory infections in Nepal

PROBLEM

Acute diarrhoeal diseases and acute respiratory infections (ARIs) are the most common causes of child mortality worldwide. Safe, effective and inexpensive solutions are available for prevention and control, but they do not reach needy communities.

APPROACH

Interventions based on research were designed to train and engage community health volunteers (CHVs) to implement a community-based control programme in Nepal. With the advent of the Integrated Management of Childhood Illnesses (IMCI) strategy, this programme subsequently emerged as a community-based IMCI but retained its mainstream activities. We reviewed and analysed policy decisions and programme development, implementation and expansion.

LOCAL SETTING

Severe resource constraints and difficult terrain limit access to health-care facilities in many parts of Nepal.

RELEVANT CHANGES

In districts with interventions, more cases of acute diarrhoea and of ARIs (including pneumonia) were reported. The proportion of diarrhoea cases with dehydration and the proportion of ARI cases with pneumonia were significantly lower in districts with interventions. Case fatality rates due to acute diarrhoea and the proportion of severe pneumonia among ARI cases across the country showed a significant trend towards a decrease from 2004 to 2007. Nepal has succeeded in training many CHVs and is on course to meet the Millennium Development Goal for child mortality.

LESSONS LEARNT

The burden of acute diarrhoea and ARIs can be reduced by training and engaging CHVs to implement community-based case management and prevention strategies. Monitoring, supervision and logistical support are essential. Policy decisions based on evidence from national research contributed to the success of the programme.

Pneumonia incidence and mortality in Mainland China: systematic review of Chinese and English literature, 1985-2008

Background

Pneumonia is a leading infectious disease killer worldwide, yet the burden in China is not well understood as much of the data is published in the non-English literature.

Methodology/Principal Findings

We systematically reviewed the Chinese- and English-language literature for studies with primary data on pneumonia incidence and mortality in mainland China. Between 1985 and 2008, 37 studies met the inclusion criteria. The quality of the studies was highly variable. For children <5 years, incidence ranged from 0.06–0.27 episodes per person-year and mortality ranged from 184–1,223 deaths per 100,000 population. Overall incidence and mortality were stable or decreased over the study period and were higher in rural compared to urban areas.

Conclusions/Significance

Pneumonia continues to be a major public health challenge in young children in China, and estimates of pneumonia incidence and mortality vary widely. Reliable surveillance data and new prevention efforts may be needed to achieve and document additional declines, especially in areas with higher incidence and mortality such as rural settings.

Incidence of pneumonia, bacteremia, and invasive pneumococcal disease in Pakistani children

OBJECTIVE

To determine the incidence of pneumonia, bacteremia, and invasive pneumococcal disease (IPD) in Pakistani children <5 years old.

METHODS

Household surveillance from 1st February 2007 to 12th May 2008 was conducted in two low-income, coastal communities of Karachi. Community health workers referred each sick child <5 years old to the local clinic. Blood culture was obtained whenever possible from children meeting inclusion criteria.

RESULTS

Overall, 5570 children contributed 3949 observation years. There were 1039 clinical cases of pneumonia, of which 54 were severe pneumonia and four cases of very severe disease according to WHO criteria. The overall pneumonia incidence was 0.26 (95% CI: 0.25-0.28) episodes per child-year. A pathogen was isolated from the blood of 29 (2.8%) pneumonia cases. Bacteremia incidence was 912 (95% CI: 648-1248) episodes per 100,000 child-years with a case fatality rate of 8%. The detected IPD incidence was 25 (95% CI: 1-125) episodes per 100,000 child-years. The under-five mortality rate was 55 per 1000 live births, with pneumonia causing 12 (22%) deaths among children <5 years old.

CONCLUSION

Clinical pneumonia is common in Pakistani children, with one in four deaths attributable to the disease. Bacteremia occurs at a high rate but surveillance for pneumococcus underestimates the burden of IPD.

Community-acquired pneumonia in HIV-infected children: a global perspective

PURPOSE OF REVIEW

Pneumonia is a leading cause of morbidity and death in HIV-infected children. The aim of this study was to review recent advances in the epidemiology, cause, management and prevention of pneumonia in HIV-infected children.

RECENT FINDINGS

Pneumonia remains a major cause of death and hospitalization, particularly in sub-Saharan Africa, where the paediatric HIV epidemic is concentrated. HIV-infected children have a higher risk of developing pneumonia and of more severe disease than immunocompetent children. Bacterial pathogens especially Streptococcus pneumoniae, Staphylococcus aureus and Gram-negative bacteria predominate, with rising rates of antimicrobial resistance. Mycobacterium tuberculosis is increasingly reported to cause acute pneumonia. Pneumocystis jirovecii (PCP) remains an important cause of severe pneumonia especially in infants. Viral infections, especially cytomegalovirus-associated pneumonia are common. Polymicrobial infection is increasingly recognized and associated with a worse prognosis. HIV-exposed, negative children have an increased risk of infection with opportunistic pathogens and a poorer outcome than HIV-unexposed children.Increasing access to highly active antiretroviral therapy (HAART) has reduced the incidence of severe pneumonia, eliminated most opportunistic infections and improved outcome. However, pneumonia remains the major cause of morbidity in HIV-infected children taking HAART. Standard case management guidelines are effective at decreasing mortality but require adaptation for high HIV-prevalence areas. Broad-spectrum antibiotics should be used as empiric therapy. Infants or children who are not taking pneumocystis prophylaxis should be treated for PCP.A number of general or specific preventive strategies are effective including early use of HAART at the time of HIV diagnosis, pathogen-specific immunizations, in particular pneumococcal conjugate vaccine, and antibiotic prophylaxis against PCP.

SUMMARY

Greater access to preventive and treatment strategies, especially PCP prophylaxis, pneumococcal immunization and HAART, are urgently needed in areas of high childhood HIV prevalence.

Impact of HIV on standard case management for severe pneumonia in children

It is estimated that 2 million children under 5 years of age die from pneumonia each year and that half of these deaths occur in sub-Saharan Africa. Over 85% of the more than 2.3 million children living with HIV worldwide reside in sub-Saharan Africa. HIV infection is likely to have a major impact on current recommendations for the standard case management of pneumonia in children and is the rationale for undertaking this review of published studies. The studies identified indicate an overall sixfold (range 2.5-13.5-fold) increase in pneumonia-related fatality in HIV-infected compared with HIV-uninfected African infants and children. They are more likely to have disease due to mixed infection and from a wider range of pathogens including Pneumocystis pneumonia, TB and cytomegalovirus. Scaling-up of the implementation of strategies that prevent HIV and Pneumocystis pneumonia remains an important strategy to reduce the burden of HIV-related pneumonia in the region. Research is urgently required to address the most effective pneumonia case management strategy in HIV-infected infants and children.

Global burden of acute lower respiratory infections due to respiratory syncytial virus in young children: a systematic review and meta-analysis

BACKGROUND

The global burden of disease attributable to respiratory syncytial virus (RSV) remains unknown. We aimed to estimate the global incidence of and mortality from episodes of acute lower respiratory infection (ALRI) due to RSV in children younger than 5 years in 2005.

METHODS

We estimated the incidence of RSV-associated ALRI in children younger than 5 years, stratified by age, using data from a systematic review of studies published between January, 1995, and June, 2009, and ten unpublished population-based studies. We estimated possible boundaries for RSV-associated ALRI mortality by combining case fatality ratios with incidence estimates from hospital-based reports from published and unpublished studies and identifying studies with population-based data for RSV seasonality and monthly ALRI mortality.

FINDINGS

In 2005, an estimated 33.8 (95% CI 19.3-46.2) million new episodes of RSV-associated ALRI occurred worldwide in children younger than 5 years (22% of ALRI episodes), with at least 3.4 (2.8-4.3) million episodes representing severe RSV-associated ALRI necessitating hospital admission. We estimated that 66 000-199 000 children younger than 5 years died from RSV-associated ALRI in 2005, with 99% of these deaths occurring in developing countries. Incidence and mortality can vary substantially from year to year in any one setting.

INTERPRETATION

Globally, RSV is the most common cause of childhood ALRI and a major cause of admission to hospital as a result of severe ALRI. Mortality data suggest that RSV is an important cause of death in childhood from ALRI, after pneumococcal pneumonia and Haemophilus influenzae type b. The development of novel prevention and treatment strategies should be accelerated as a priority.

FUNDING

WHO; Bill & Melinda Gates Foundation.

The effect of Haemophilus influenzae type b and pneumococcal conjugate vaccines on childhood pneumonia incidence, severe morbidity and mortality

Background With the aim of populating the Lives Saved Tool (LiST) with parameters of effectiveness of existing interventions, we conducted a systematic review of the literature assessing the effect of Haemophilus influenzae type b (Hib) and pneumococcal (PC) conjugate vaccines on incidence, severe morbidity and mortality from childhood pneumonia.

Methods We summarized cluster randomized controlled trials (cRCTs) and case–control studies of Hib conjugate vaccines and RCTs of 9- and 11-valent PC conjugate vaccines conducted in developing countries across outcome measures using standard meta-analysis methods. We used a set of standardized rules developed for the purpose of populating the LiST tool with required parameters to promote comparability across reviews of interventions against the major causes of childhood mortality. The estimates could be adjusted further to account for factors such as PC vaccine serotype content, PC serotype distribution and human immunodeficiency virus prevalence but this was not included as part of the LiST model approach.

Results The available evidence from published data points to a summary effect of the Hib conjugate vaccine on clinical pneumonia of 4%, on clinical severe pneumonia of 6% and on radiologically confirmed pneumonia of 18%. Respective effectiveness estimates for PC vaccines (all valent) on clinical pneumonia is 7%, clinical severe pneumonia is 7% and radiologically confirmed pneumonia is 26%.

Conclusions The findings indicated that radiologically confirmed pneumonia, as a severe morbidity proxy for mortality, provided better estimates for the LiST model of effect of interventions on mortality reduction than did other outcomes evaluated. The LiST model will use this to estimate the pneumonia mortality reduction which might be observed when scaling up Hib and PC conjugate vaccination in the context of an overall package of child health interventions.

The effect of case management on childhood pneumonia mortality in developing countries

BACKGROUND

With the aim of populating the Lives Saved Tool (LiST) with parameters of effectiveness of existing interventions, we conducted a systematic review of the literature assessing the effect of pneumonia case management on mortality from childhood pneumonia.

METHODS

This review covered the following interventions: community case management with antibiotic treatment, and hospital treatment with antibiotics, oxygen, zinc and vitamin A. Pneumonia mortality outcomes were sought where available but data were also recorded on secondary outcomes. We summarized results from randomized controlled trials (RCTs), cluster RCTs, quasi-experimental studies and observational studies across outcome measures using standard meta-analysis methods and used a set of standardized rules developed for the purpose of populating the LiST with required parameters, which dealt with the issues of comparability of the studies in a uniform way across a spectrum of childhood conditions.

RESULTS

We estimate that community case management of pneumonia could result in a 70% reduction in mortality from pneumonia in 0-5-year-old children. In contrast treatment of pneumonia episodes with zinc and vitamin A is ineffective in reducing pneumonia mortality. There is insufficient evidence to make a quantitative estimate of the effect of hospital case management on pneumonia mortality based on the published data.

CONCLUSION

The available evidence reinforces the effectiveness of community and hospital case management with World Health Organization-recommended antibiotics and the lack of effect of zinc and vitamin A supportive treatment for children with pneumonia. Evidence from one trial demonstrates the effectiveness of oxygen therapy but further research is required to give higher quality evidence so that an effect estimate can be incorporated into the LiST model. We identified no trials that separately evaluated the effectiveness of other supportive care interventions. The summary estimates of effect on pneumonia mortality will inform the LiST model.

Sialidase-based anti-influenza virus therapy protects against secondary pneumococcal infection

BACKGROUND

DAS181 (Fludase) is a sialidase fusion protein in clinical development as a broad-spectrum anti-influenza virus (IFV) therapeutic agent. Previous reports by other investigators have raised the concern that desialylation of airway epithelium might increase susceptibility to Streptococcus pneumoniae infection.

METHODS

To address whether DAS181 would lead to an increased risk of pneumococcal infection, we tested S. pneumoniae colonization after DAS181 treatment of human A549 cells, healthy mice, and mice challenged with a lethal dose of IFV A/PR/8/34 (H1N1) or A/Victoria/3/75 (H3N2), followed by 10(4) cfu of S. pneumoniae (D39) on day 3 or day 7. DAS181 treatment was given 24-48 h after IFV challenge.

RESULTS

DAS181 treatment did not increase S. pneumoniae colonization in vitro or in vivo in healthy animals. In IFV-infected mice, DAS181 prevented pneumonia and significantly prolonged survival and inhibited the IFV titer by > or = 3 logs. None of the treated animals showed enhanced S. pneumoniae colonization of the lung. In addition, opportunistic infections with Citrobacter species or Klebsiella species occurred only in mice receiving vehicle, not in animals treated with DAS181.

CONCLUSIONS

These data indicate that DAS181 treatment does not exacerbate secondary bacterial infection in mice. DAS181 may reduce the risk of secondary bacterial infection by inhibiting IFV.

The future in paediatric respirology

The authors were given the charge of providing a vision of the future in paediatric respirology. Themes selected for being ripe for this visionary analysis include bronchopulmonary dysplasia (BPD), asthma, cystic fibrosis (CF), lung infections, obstructive sleep disordered breathing (OSDB) and pulmonary diagnostics and monitoring. A profound reduction or elimination of BPD is seen. Given the strong genetic component of this disease, genetic biomarkers will likely be identified that will permit much earlier recognition of BPD susceptibility and potentially the ability to modify disease course by altering gene expression. The ultimate prevention of BPD will be to prevent prematurity, but recognition of both the genetic basis of BPD and the inflammatory background should lead to improved prevention and therapy. A clear understanding and definition of asthma phenotypes will lead to more specific and targeted therapy, earlier detection and prevention, better monitoring of severity and adherence to therapy, lower mortality and decreased inappropriate diagnosis of asthma. The greatest opportunities in asthma care will likely come through tools to improve adherence to effective therapy. Also, areas are identified where better therapies are needed such as in patients with severe mucus hypersecretion (secretory hyperresponsiveness) especially in those with life-threatening asthma. The future of CF is easier to foresee with early successes seen in clinical trials. After the expected ability to correct the CF transmembrane regulator, care will need to change and additional research will be needed. Additionally, the face of CF is changing with more adults than children presently having the disease. This will necessitate changes to our approach to treating this disease in a fortunately aging population. If we are going to affect the worldwide lung health of children, we will need to address respiratory infections particularly pneumonia, tuberculosis and HIV-associated infections. Preventive, diagnostic and treatment strategies will shape the future face of these problems. The availability of inexpensive, readily available, and rapid molecular techniques to identify true infection (including HIV and tuberculosis) may permit earlier use of effective therapy while preventing the inappropriate use of antibiotics for common viral diseases. Sleep medicine will continue to be an important aspect of paediatric pulmonology. The evaluation of OSDB cannot rely on full-night attended polysomnography due to limited access. Identifying reliable markers of end organ dysfunction in children with OSDB may permit more rapid identification of patients in need of intervention like CPAP and assisted breathing. In addition, management options, as an alternative to adenotonsilectomy, are listed with a call for further research. Pulmonary diagnostics and monitoring will see the development and refinement of tools like the lung clearance index and the analysis of exhaled gases, volatiles and dissolved biomarkers of inflammation as techniques that might help clinicians identify both the initiation of inflammation while it is more amenable to therapy, and to identify more readily the early changes associated with chronic lung diseases in children. The authors hope that these visionary articles will generate comments, arguments, inspiration, and perhaps even motivate funding agencies.

Incidence of respiratory pathogens in persons hospitalized with pneumonia in two provinces in Thailand

Although pneumonia is a leading cause of death from infectious disease worldwide, comprehensive information about its causes and incidence in low- and middle-income countries is lacking. Active surveillance of hospitalized patients with pneumonia is ongoing in Thailand. Consenting patients are tested for seven bacterial and 14 viral respiratory pathogens by PCR and viral culture on nasopharyngeal swab specimens, serology on acute/convalescent sera, sputum smears and antigen detection tests on urine. Between September 2003 and December 2005, there were 1730 episodes of radiographically confirmed pneumonia (34·6% in children aged <5 years); 66 patients (3·8%) died. A recognized pathogen was identified in 42·5% of episodes. Respiratory syncytial virus (RSV) infection was associated with 16·7% of all pneumonias, 41·2% in children. The viral pathogen with the highest incidence in children aged <5 years was RSV (417·1/100 000 per year) and in persons aged ⩾50 years, influenza virus A (38·8/100 000 per year). These data can help guide health policy towards effective prevention strategies.

Antibiotics for community-acquired pneumonia in children

BACKGROUND

Pneumonia caused by bacterial pathogens is the leading cause of mortality in children in low-income countries. Early administration of antibiotics improves outcomes.

OBJECTIVES

To identify effective antibiotics for community acquired pneumonia (CAP) in children by comparing various antibiotics.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2009, issue 2) which contains the Cochrane Acute Respiratory Infections Group's Specialised Register; MEDLINE (1966 to September 2009); and EMBASE (1990 to September 2009).

SELECTION CRITERIA

Randomised controlled trials (RCTs) in children of either sex, comparing at least two antibiotics for CAP within hospital or ambulatory (outpatient) settings.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data from full articles of selected studies.

MAIN RESULTS

There were 27 studies, which enroled 11,928 children, comparing multiple antibiotics. None compared antibiotic with placebo.For ambulatory treatment of non-severe CAP, amoxycillin compared with co-trimoxazole had similar failure rates (OR 0.92; 95% CI 0.58 to 1.47) and cure rates (OR 1.12; 95% CI 0.61 to 2.03). (Three studies involved 3952 children).In children hospitalised with severe CAP, oral amoxycillin compared with injectable penicillin or ampicillin had similar failure rates (OR 0.95; 95% CI 0.78 to 1.15). (Three studies involved 3942 children). Relapse rates were similar in the two groups (OR 1.28; 95% CI 0.34 to 4.82).In very severe CAP, death rates were higher in children receiving chloramphenicol compared to those receiving penicillin/ampicillin plus gentamycin (OR 1.25; 95% CI 0.76 to 2.07). (One study involved 1116 children).

AUTHORS' CONCLUSIONS

There were many studies with different methodologies investigating multiple antibiotics. For treatment of ambulatory patients with CAP, amoxycillin is an alternative to co-trimoxazole. With limited data on other antibiotics, co-amoxyclavulanic acid and cefpodoxime may be alternative second-line drugs. For severe pneumonia without hypoxia, oral amoxycillin may be an alternative to injectable penicillin in hospitalised children; however, for ambulatory treatment of such patients with oral antibiotics, more studies in community settings are required. For children hospitalised with severe and very severe CAP, penicillin/ampicillin plus gentamycin is superior to chloramphenicol. The other alternative drugs for such patients are ceftrioxone, levofloxacin, co-amoxyclavulanic acid and cefuroxime. Until more studies are available, these can be used as a second-line therapy.There is a need for more studies with larger patient populations and similar methodologies to compare newer antibiotics.

Pneumococcal conjugate vaccines in the prevention of childhood pneumonia

Lower respiratory tract infections are among the most important causes of childhood mortality worldwide, more than 2 million children die due to pneumonia every year. A number of infections caused by the main pathogens related to pneumonia can be prevented through vaccination ( S. pneumoniae, H. influenzae type-b, morbilli, pertussis, influenza). In the last decade, after the introduction of the 7-valent pneumococcal conjugated vaccine (PCV), the epidemiological background of childhood pneumonia has changed. Recently, several studies have been performed to collect data and evidences about the efficacy of PCV against noninvasive pneumococcal diseases (e.g. pneumonia, otitis media). These investigations showed 10-50% decrease of all pneumonia cases, 10-30% decrease of radiologically diagnosed pneumonia, and 50-70% decrease of the incidence of pneumococcal pneumonia in children. The aim of this review was to determine the role of the PCV in the prevention of childhood pneumonia according to the medical literature, and to summarize the efforts of global organizations (WHO, UNICEF, GAVI) in the fight against pneumonia in children.

Antimicrobial susceptibility of Streptococcus pneumoniae and genotypic characterization of erythromycin-resistant strains in porto alegre, Brazil

The antimicrobial susceptibility of 64 strains of S. pneumoniae obtained from three hospitals in Porto Alegre, Brazil, isolated between 2004 and 2005. was determined, using the agar-dilution method. The prevalence of resistant (intermediate and full resistance) strains to trimethoprim/sulphamethoxazole, penicillin, tetracycline, erythromycin, chloramphenicol, and ceftriaxone were 68%, 28%, 18%, 15%, 3%, and 1%, respectively. All strains were susceptible to vancomycin. Among 18 penicillin-resistant strains, 7 were resistant to at least two other antimicrobial drugs. All erythromycin-resistant strains, except one, contained the erm(B) and/or mef(A/E) genes, with a predominance of the former. The resistance rate to penicillin and erythromycin in Porto Alegre remained stable. The combination of trimethoprim/ sulphamethoxazole should not be recommended to treat pneumococcal infections, because of the high rate of resistant strains.

The burden of acute respiratory infections in crisis-affected populations: a systematic review

Crises due to armed conflict, forced displacement and natural disasters result in excess morbidity and mortality due to infectious diseases. Historically, acute respiratory infections (ARIs) have received relatively little attention in the humanitarian sector. We performed a systematic review to generate evidence on the burden of ARI in crises, and inform prioritisation of relief interventions. We identified 36 studies published since 1980 reporting data on the burden (incidence, prevalence, proportional morbidity or mortality, case-fatality, attributable mortality rate) of ARI, as defined by the International Classification of Diseases, version 10 and as diagnosed by a clinician, in populations who at the time of the study were affected by natural disasters, armed conflict, forced displacement, and nutritional emergencies. We described studies and stratified data by age group, but did not do pooled analyses due to heterogeneity in case definitions. The published evidence, mainly from refugee camps and surveillance or patient record review studies, suggests very high excess morbidity and mortality (20-35% proportional mortality) and case-fatality (up to 30-35%) due to ARI. However, ARI disease burden comparisons with non-crisis settings are difficult because of non-comparability of data. Better epidemiological studies with clearer case definitions are needed to provide the evidence base for priority setting and programme impact assessments. Humanitarian agencies should include ARI prevention and control among infants, children and adults as priority activities in crises. Improved data collection, case management and vaccine strategies will help to reduce disease burden.

10-valent pneumococcal nontypeable Haemophilus influenzae PD conjugate vaccine: Synflorix

The global burden of disease due to Streptococcus pneumoniae remains high. The licensed 7-valent pneumococcal conjugate vaccine (7vCRM, Prevenar/Prevnar) has successfully reduced invasive disease in the USA, but serotype coverage is incomplete and some evidence suggests that serotype replacement has occurred. Recently, a new 10-valent pneumococcal nontypeable Haemophilus influenzae (NTHi) protein D (PD) conjugate vaccine (PHiD-CV, Synflorix) has been licensed in more than 40 countries, including Europe, for the prevention of invasive disease and acute otitis media (AOM) due to pneumococcus in infants and children. PHiD-CV is immunogenic in infants when administered as a three-dose primary vaccination in a range of schedules and has a safety profile comparable to that of 7vCRM. Additional serotypes in PHiD-CV (1, 5 and 7F) increase overall serotype coverage and improve coverage in specific age groups and against specific disease syndromes. The use of the PD carrier, which provided protection against AOM caused by NTHi in a large efficacy trial testing a prototype of the final vaccine formulation, suggests that PHiD-CV will also provide some protection against AOM due to NTHi.

Imaging of Chest Infections in Children

■ Imaging studies have limited value in the differentiation between viral and bacterial lower respiratory tract infections (moderate evidence).

■ CT provides more information than plain radiographs for complicated pulmonary infections with empyema, pleural effusion, or bronchopleural fistula (moderate evidence).

■ In immunocompromised patients, CT has been shown to characterize the type of infection better than plain radiographs (moderate evidence).

■ Ultrasound has an advantage over CT in the identification and characterization of complicated effusions (moderate evidence).

■ Early detection and therefore intervention for pleural complications of pneumonia are critical and can result in better outcomes (moderate evidence).

■ Early surgery (VATS) is more cost-effective than thoracotomy (without or with image guidance) in the treatment of empyemas in children (strong evidence).

Burden and cost of hospital admissions for vaccine-preventable paediatric pneumococcal disease and non-typable Haemophilus influenzae otitis media in New Zealand

INTRODUCTION

Streptococcus pneumoniae (Sp.) is a leading cause of paediatric bacterial meningitis, pneumonia and acute otitis media, as is non-typable Haemophilus influenzae (NTHi) for acute otitis media. In 2008, a 7-valent conjugated pneumococcal vaccine (PCV7) was included in the New Zealand (NZ) childhood immunization schedule.

OBJECTIVE

To estimate the potentially vaccine-preventable annual hospital admissions and cost to the NZ Government of paediatric admissions for pneumococcal disease and NTHi otitis media prior to the immunization programme.

METHODS

Admissions (2000-7) and deaths (2000-5) in children aged<20 years with pneumococcal meningitis or bacteraemia, pneumonia or otitis media were identified in national datasets and linked by unique patient identifiers. New episodes of illness were defined as admissions occurring >30 days after discharge from a previous admission. Informed by the literature, pneumococcal pneumonia episodes were estimated at 33% of all-cause pneumonia admissions; Sp. and NTHi otitis media episodes were estimated jointly at 72% of otitis media admissions. Each episode was assigned a single diagnosis according to the following hierarchy: meningitis>bacteraemia>pneumonia>otitis media. Incidence rates for episodes were determined for 2000-7 (meningitis, bacteraemia and pneumonia) and 2006-7 (otitis media). Annual DRG-based costs for pneumococcal meningitis, bacteraemia, pneumonia and otitis media were estimated as (episode rate)x(DRG cost weight per episode)x(2007 population)x(national price per cost weight).

RESULTS

Episode rates for pneumococcal meningitis, bacteraemia and pneumonia were stable in 2000-7, highest in the second 6 months of life and declined steeply over the first 5 years of life. Mean rates per 100000 in 2000-7 were 18.4, 27.6 and 464 for pneumococcal meningitis, bacteraemia and pneumonia, respectively, for children aged<2 years; 8.4, 14.9 and 295 for children aged<5 years (including those aged<2 years); and 2.2, 4.4 and 97 for children aged<20 years (including those aged<5 years). Mean rates per 100000 in 2006-7 for Sp. and NTHi otitis media combined were 631 (surgical) and 197 (medical) for children aged<2 years; 691 and 116 for children aged<5 years; and 281 and 35 for children aged<20 years. Pacific Island and indigenous Māori children generally had higher rates than European/other children. Rates increased with socioeconomic disadvantage, across all diagnoses. The annual cost to Government of pneumococcal disease and NTHi otitis media admissions for children aged<20 years was estimated at New Zealand dollars ($NZ)9.95 million (range 7.7-12.2 million) [about $US7.1 million]. Most of this cost was shared between pneumococcal pneumonia (48%) and otitis media (45%), and 78% was incurred in the first 2 years of life. Estimated annual paediatric mortality rates per 100 000 for children aged<5 years were 0.48, 0.30 and 0.54 for pneumococcal meningitis, bacteraemia and pneumonia, respectively. The analysis predicted four or five pneumococcal deaths per year (range 1-8) for children aged<5 years.

CONCLUSIONS

Prior to the introduction of a national Sp. immunization programme, hospital admissions for Sp. disease and NTHi otitis media in NZ cost about $NZ10 million annually, mostly for children aged<2 years and particularly for those living in relative socioeconomic deprivation and for Pacific Island and Māori children. There were about five pneumococcal deaths annually. With adjustment for local serotypes, vaccine serotype coverage and uptake, immunization with any of the three available pneumococcal vaccines would reduce this burden substantially.

Empyema hospitalizations increased in US children despite pneumococcal conjugate vaccine

OBJECTIVE

To determine if the incidence of empyema among children in the United States has changed since the introduction of the pneumococcal conjugate vaccine in 2000.

METHODS

We used the nationally representative Kids' Inpatient Database to estimate the annual total number of hospitalizations of children < or = 18 years of age that were associated with empyema in 1997, 2000,2003, and 2006 [corrected]. Using US Census data, estimated counts were converted into annual incidence rates per 100000 children. Incidence rates were compared between 1997 and later years to determine the impact of pneumococcal conjugate vaccine on hospitalization rates.

RESULTS

During 2006, an estimated total of 2898 (95% confidence interval [CI]: 2532-3264) hospitalizations of children <or=18 years of age in the United States were associated with empyema. The empyema-associated hospitalization rate was estimated at 3.7 (95% CI: 3.3-4.2) per 100000 children, an increase of almost 70% from the 1997 empyema hospitalization rate of 2.2 (95% CI: 1.9-2.5) per 100000. The rate of complicated pneumonia (empyema, pleural effusion, or bacterial pneumonia requiring a chest tube or decortication) similarly increased 44%, to 5.5 (95% CI: 4.8-6.1) per 100000. The rate of bacterial pneumonia decreased 13%, to 244.3 (95% CI: 231.1-257.5) per 100000. The rate of invasive pneumococcal disease (pneumonia, sepsis, or meningitis caused by Streptococcus pneumoniae) decreased 50%, to 6.3 (95% CI: 5.7-6.9) per 100000.

CONCLUSIONS

Among children <or=18 years of age, the annual empyema-associated hospitalization rates increased almost 70% between 1997 and 2006, despite decreases in the bacterial pneumonia and invasive pneumococcal disease rates. Pneumococcal conjugate vaccine is not decreasing the incidence of empyema.

Respiratory Infections

Until recently, conventional culture techniques and immunofluorecence assays were considered the gold standard for the detection of respiratory viruses, even though results are mostly available too late or lacked specificity and sensitivity. These methods are now widely replaced with appropriate DNA- and RNA-based amplification techniques, in particular real time PCR amplification, for the detection of an extended number of agents responsible for acute respiratory infections. Real-time PCR offers rapid results, efficiencies in work flow and a reduced risk of false positive results due to contamination. As a result, better patient management or reduction of unnecessary antibiotic administration will be possible leading to enhanced efficiencies in health care. In applying molecular methods to diagnostic use, the laboratory can optimise its diagnostic strategy by applying a combination of real-time amplification tests for respiratory viruses and the non-viral respiratory bacterial pathogens. However this must be done within a context of resource availability, technical expertise available and clinical utility. It seems certain that molecular microbiology will continue to develop, leading to further applications in diagnostic technology, thereby improving our understanding of disease processes and enhancing our knowledge of the pathogens responsible.

Crystallization of dihydrodipicolinate synthase from a clinical isolate of Streptococcus pneumoniae

Dihydrodipicolinate synthase (DHDPS; EC 4.2.1.52) catalyzes the rate-limiting step in the (S)-lysine biosynthesis pathway of bacteria and plants. Here, the cloning of the DHDPS gene from a clinical isolate of Streptococcus pneumoniae (OXC141 strain) and the strategy used to express, purify and crystallize the recombinant enzyme are described. Diffracting crystals were grown in high-molecular-weight PEG precipitants using the hanging-drop vapour-diffusion method. The best crystal, from which data were collected, diffracted to beyond 2.0 A resolution. Initially, the crystals were thought to belong to space group P4(2)2(1)2, with unit-cell parameters a = 105.5, b = 105.5, c = 62.4 A. However, the R factors remained high following initial processing of the data. It was subsequently shown that the data set was twinned and it was thus reprocessed in space group P2, resulting in a significant reduction in the R factors. Determination of the structure will provide insight into the design of novel antimicrobial agents targeting this important enzyme from S. pneumoniae.

Nutritional rickets and vitamin D deficiency--association with the outcomes of childhood very severe pneumonia: a prospective cohort study

BACKGROUND

The association of rickets and vitamin D deficiency (VDD) with pneumonia is well documented, but not with its outcomes.

OBJECTIVES

To investigate whether rickets and VDD predict the outcomes in very severe pneumonia (VSP).

DESIGN

A prospective cohort study conducted at Al-Sabeen hospital in Sana'a, Yemen. A total of 152 children aged 2-59 months with WHO-defined VSP were enrolled, managed, and followed for up to 30 days. Treatment outcome was either successful or failure (antibiotic modification for clinical worsening, death, relapse after 10-day antibiotics, or development of complications). Serum vitamin D (25OHD) was measured in 79 cases. A concentration of <or=30 nmol/L defines VDD.

MAIN OUTCOME MEASURES

Association of rickets with treatment outcome; and VDD with the circulating neutrophils (PMNs), and oxygen saturation% (SpO(2)%), respectively.

RESULTS

Treatment failure occurred in 24 (15.8%), all aged 2-12 months, and 21 (87.5%) were rachitic. Of the 79 subset, 29 had VDD of which 23 (79.3%) had rickets. Treatment failure was significantly higher in the rachitic compared to non-rachitic [20.6% (21/102) vs. 6% (3/50); OR 1.38 (95% CI 1.13-1.69), P = 0.031]. In multivariate regression, rickets significantly predict a reduced successful treatment compared with non-rachitic [79.4% (81/102) vs. 94% (47/50); Adjusted OR 0.41 (95% CI 0.20-0.85); P = 0.02]. VDD was strongly associated with reduced PMNs% [Mean (SD) 37 (17) vs. 47 (17); Adjusted OR 0.71 (95% CI 0.53-0.95), P = 0.02], and reduced SpO(2)% [Mean (SD) 85.9 (7.9) vs. 89.8 (7.1); OR 0.96 (95% CI 0.93-0.99), P = 0.021].

CONCLUSIONS

In VSP, rickets was significantly associated with treatment outcome and VDD significantly predict both reduced circulating PMNs, and Day-5 hypoxemia (SpO(2)%, <88%).

[Children who die--is the millennium goal within reach?]

BACKGROUND

At the beginning of the new millennium the world's leaders agreed on eight MDG's (Millennium Development Goals). This paper addresses the fourth goal: The number of children who die before their fifth birthday should be reduced by two thirds from 1990 to 2015.

MATERIAL AND METHODS

The article is based on literature identified through a non-systematic search in Medline and publications from WHO and UNICEF available on the internet.

RESULTS

From 1990 and up to now childhood mortality has decreased from about 90 to 70 per 1000 live birth. In 2007, 9.2 million children died, 97 % of them in the 68 poorest countries. Six of ten deaths are caused by infectious diseases.

INTERPRETATION

Millennium developmental goal number 4 is not within reach. Despite notable progress, the rate is too slow to achieve the target within time. Many children could have been saved with basic preventive and treatment measures. Challenges in the years up to 2015 are, among others, to reach the poorest people, to coordinate targeted actions for the best possible effect and to maintain the focus both from donors and recipients.

Comparative impact assessment of child pneumonia interventions

OBJECTIVE

To compare the cost-effectiveness of interventions to reduce pneumonia mortality through risk reduction, immunization and case management.

METHODS

Country-specific pneumonia burden estimates and intervention costs from WHO were used to review estimates of pneumonia risk in children under 5 years of age and the efficacy of interventions (case management, pneumonia-related vaccines, improved nutrition and reduced indoor air pollution from household solid fuels). We calculated health benefits (disability-adjusted life years, DALYs, averted) and intervention costs over a period of 10 years for 40 countries, accounting for 90% of pneumonia child deaths.

FINDINGS

Solid fuel use contributes 30% (90% confidence interval: 18-44) to the burden of childhood pneumonia. Efficacious community-based treatment, promotion of exclusive breastfeeding, zinc supplementation and Haemophilus influenzae type b (Hib) and Streptococcus pneumoniae immunization through existing programmes showed cost-effectiveness ratios of 10-60 International dollars (I$) per DALY in low-income countries and less than I$ 120 per DALY in middle-income countries. Low-emission biomass stoves and cleaner fuels may be cost-effective in low-income regions. Facility-based treatment is potentially cost-effective, with ratios of I$ 60-120 per DALY. The cost-effectiveness of community case management depends on home visit cost.

CONCLUSION

Vaccines against Hib and S. pneumoniae, efficacious case management, breastfeeding promotion and zinc supplementation are cost-effective in reducing pneumonia mortality. Environmental and nutritional interventions reduce pneumonia and provide other benefits. These strategies combined may reduce total child mortality by 17%.

Childhood bacterial respiratory diseases: past, present, and future

Pneumonia is the most serious acute respiratory infection and is caused by numerous etiologic agents, bacteria and viruses. Severe pneumonia is a major challenge to survival of children globally. In this article we examine the causes of global childhood mortality, and the distribution of childhood pneumonia mortality and morbidity, as well as the risk factors that affect pneumonia incidence. Although major bacterial and viral respiratory infections, such as diphtheria, measles, Haemophilus influenzae type b (Hib), and pneumococcal infections, are now preventable through vaccination, bacterial pneumonia, including severe pneumonia (those that require hospitalization), still remain a public health challenge in both resource-poor and wealthy countries. We therefore, review the published literature on the available vaccines and their potential effectiveness in further reducing the burden of childhood bacterial respiratory diseases. There is a need to conduct further epidemiologic studies for identifying the disease burden and for urgent implementation of proven cost-effective interventions. These interventions are a necessary part of public health actions to reduce childhood mortality, a major Millennium Development Goal. The role of vaccines in this regard is critical, as they represent a rapid and feasible intervention with an early and sustained impact.

Burden of disease caused by Haemophilus influenzae type b in children younger than 5 years: global estimates

BACKGROUND

Haemophilus influenzae type b (Hib) is a leading cause of childhood bacterial meningitis, pneumonia, and other serious infections. Hib disease can be almost completely eliminated through routine vaccination. We assessed the global burden of disease to help national policy makers and international donors set priorities.

METHODS

We did a comprehensive literature search of studies of Hib disease incidence, case-fatality ratios, age distribution, syndrome distribution, and effect of Hib vaccine. We used vaccine trial data to estimate the proportion of pneumonia cases and pneumonia deaths caused by Hib. We applied these proportions to WHO country-specific estimates of pneumonia cases and deaths to estimate Hib pneumonia burden. We used data from surveillance studies to develop estimates of incidence and mortality of Hib meningitis and serious non-pneumonia, non-meningitis disease. If available, high-quality data were used for national estimates of Hib meningitis and non-pneumonia, non-meningitis disease burden. Otherwise, estimates were based on data from other countries matched as closely as possible for geographic region and child mortality. Estimates were adjusted for HIV prevalence and access to care. Disease burden was estimated for the year 2000 in children younger than 5 years.

FINDINGS

We calculated that Hib caused about 8.13 million serious illnesses worldwide in 2000 (uncertainty range 7.33-13.2 million). We estimated that Hib caused 371,000 deaths (247,000-527,000) in children aged 1-59 months, of which 8100 (5600-10,000) were in HIV-positive and 363,000 (242,000-517,000) in HIV-negative children.

INTERPRETATION

Global burden of Hib disease is substantial and almost entirely vaccine preventable. Expanded use of Hib vaccine could reduce childhood pneumonia and meningitis, and decrease child mortality.

FUNDING

GAVI Alliance and the Vaccine Fund.

Burden of disease caused by Streptococcus pneumoniae in children younger than 5 years: global estimates

BACKGROUND

Streptococcus pneumoniae is a leading cause of bacterial pneumonia, meningitis, and sepsis in children worldwide. However, many countries lack national estimates of disease burden. Effective interventions are available, including pneumococcal conjugate vaccine and case management. To support local and global policy decisions on pneumococcal disease prevention and treatment, we estimated country-specific incidence of serious cases and deaths in children younger than 5 years.

METHODS

We measured the burden of pneumococcal pneumonia by applying the proportion of pneumonia cases caused by S pneumoniae derived from efficacy estimates from vaccine trials to WHO country-specific estimates of all-cause pneumonia cases and deaths. We also estimated burden of meningitis and non-pneumonia, non-meningitis invasive disease using disease incidence and case-fatality data from a systematic literature review. When high-quality data were available from a country, these were used for national estimates. Otherwise, estimates were based on data from neighbouring countries with similar child mortality. Estimates were adjusted for HIV prevalence and access to care and, when applicable, use of vaccine against Haemophilus influenzae type b.

FINDINGS

In 2000, about 14.5 million episodes of serious pneumococcal disease (uncertainty range 11.1-18.0 million) were estimated to occur. Pneumococcal disease caused about 826,000 deaths (582,000-926,000) in children aged 1-59 months, of which 91,000 (63,000-102,000) were in HIV-positive and 735,000 (519,000-825,000) in HIV-negative children. Of the deaths in HIV-negative children, over 61% (449,000 [316,000-501,000]) occurred in ten African and Asian countries.

INTERPRETATION

S pneumoniae causes around 11% (8-12%) of all deaths in children aged 1-59 months (excluding pneumococcal deaths in HIV-positive children). Achievement of the UN Millennium Development Goal 4 for child mortality reduction can be accelerated by prevention and treatment of pneumococcal disease, especially in regions of the world with the greatest burden.

FUNDING

GAVI Alliance and the Vaccine Fund.

Costing of severe pneumonia in hospitalized infants and children aged 2-36 months, at a secondary and tertiary level hospital of a not-for-profit organization

OBJECTIVES

To determine health care provider cost and household cost of the treatment of severe pneumonia in infants and young children admitted to secondary and tertiary level health care facilities.

METHODS

The study was done in a private, not-for-profit medical college hospital, in Vellore, India, in mid-2008. Children aged 2-36 months admitted with severe pneumonia with no underlying chronic disease were included in the study. The relatives were interviewed daily on matters relating to patients' view point of the costs. These were direct medical costs, direct non-medical costs which comprised travel, accommodation and special food during the period of illness, and indirect costs of productivity loss for family members. Patient specific resource consumption and related charges were recorded from charts, nursing records, pharmacy lists and hospital bills, and the providers view point of the costs was estimated. Unit cost estimates for bed days, treatment and investigation inputs were calculated.

RESULTS

Total cost to health care provider for one episode of hospitalized childhood pneumonia treated at secondary level was US$ 83.89 (INR 3524) and US$ 146.59 (INR 6158) at tertiary level. At both levels the greatest single cost was the hospital stay itself, comprising 74% and 56% of the total cost, respectively. Diagnostic investigations were a large expense and supportive treatment with nebulization and oxygen therapy added to the costs. Mean household expenditure on secondary level was US$ 41.35 (INR 1737) and at tertiary level was US$ 134.62 (INR 5655), the largest single expense being medicines in the former and the hospitalization in the latter. (one US$=INR 42.1 at time of study)

CONCLUSIONS

A considerable cost difference exists between secondary and tertiary level treatment. Admission at lowest possible treatment level for appropriate patients could decrease the costs borne by the provider and the patient.

Biomass fuel use and indoor air pollution in homes in Malawi

Background:

Air pollution from biomass fuels in Africa is a significant cause of mortality and morbidity both in adults and children. The work describes the nature and quantity of smoke exposure from biomass fuel in Malawian homes.

Methods:

Markers of indoor air quality were measured in 62 homes (31 rural and 31 urban) over a typical 24 h period. Four different devices were used (one gravimetric device, two photometric devices and a carbon monoxide (HOBO) monitor. Gravimetric samples were analysed for transition metal content. Data on cooking and lighting fuel type together with information on indicators of socioeconomic status were collected by questionnaire.

Results:

Respirable dust levels in both the urban and rural environment were high with the mean (SD) 24 h average levels being 226 μg/m³ (206 μg/m³). Data from real-time instruments indicated respirable dust concentrations were >250 μg/m³ for >1 h per day in 52% of rural homes and 17% of urban homes. Average carbon monoxide levels were significantly higher in urban compared with rural homes (6.14 ppm vs 1.87 ppm; p<0.001). The transition metal content of the smoke was low, with no significant difference found between urban and rural homes.

Conclusions:

Indoor air pollution levels in Malawian homes are high. Further investigation is justified because the levels that we have demonstrated are hazardous and are likely to be damaging to health. Interventions should be sought to reduce exposure to concentrations less harmful to health.

Homeostatic regulation of T effector to Treg ratios in an area of seasonal malaria transmission

An important aspect of clinical immunity to malaria is the ability to down-regulate inflammatory responses, once parasitaemia is under control, in order to avoid immune-mediated pathology. The role of classical (CD4(+)CD25(+)CD127(lo/-)FOXP3(+)) Treg in this process, however, remains controversial. Thus, we have characterized the frequency, phenotype and function of Treg populations, over time, in healthy individuals in The Gambia. We observed that both the percentage and the absolute number of CD4(+)FOXP3(+)CD127(lo/-) T cells were higher among individuals living in a rural village with highly seasonal malaria transmission than among individuals living in an urban area where malaria rarely occurs. These CD4(+)FOXP3(+)CD127(lo/-) T cells exhibited an effector memory and apoptosis-prone phenotype and suppressed cytokine production in response to malaria antigen. Cells from individuals exposed to malaria expressed significantly higher levels of mRNA for forkhead box P3 and T-box 21 (T-BET) at the end of the malaria transmission season than at the end of the non-transmission season. Importantly, the ratio of T-BET to forkhead box P3 was remarkably consistent between populations and over time, indicating that in healthy individuals, a transient increase in Th1 responses during the malaria transmission season is balanced by a commensurate Treg response, ensuring that immune homeostasis is maintained.

Nasopharyngeal carriage of S. pneumoniae among young children in rural Nepal

OBJECTIVES

To provide epidemiologic data on Streptococcus pneumoniae (Spn) carriage in Nepal.

METHODS

Prospective, population-based study among children in Sarlahi, Nepal to estimate carriage prevalence, identify risk factors, and determine antibiotic susceptibility patterns and serotype distribution. Between December 2003 and July 2004, NP specimens were collected from 604 children aged 1-36 months with acute lower respiratory infection (ALRI) and 604 healthy, age- and season-matched controls.

RESULTS

Of the 1100 specimens analysed, carriage prevalence was approximately 80% in both groups. In the multivariate analyses, significant risk factors for Spn carriage in controls were Muslim religion [adjusted odds ratio (AOR): 2.93] and no latrine in the household (AOR: 2.41). Those treated for a recent illness had lower carriage rates (AOR: 0.37). Results were similar for ALRI cases with the addition of age >or=12 months (AOR: 1.68), and symptomatic infection (AOR: 3.78) as risk factors. The antibiotics and proportions of isolates resistant to them were as follows: penicillin 4.5%, cotrimoxazole 89.2%, chloramphenicol 1.4%, erythromycin 1.5% and tetracycline 22.7%. The most prevalent serogroups/types were 6, 19, 23, 15, 9 and 10.

CONCLUSIONS

Young children in rural Nepal experience high rates of Spn carriage. Most isolates were resistant to cotrimoxazole. Current conjugate Spn vaccines may substantially reduce the risk of a severe pneumonia and other Spn infections.

Sortase A confers protection against Streptococcus pneumoniae in mice

Streptococcus pneumoniae sortase A (SrtA) is a transpeptidase that is highly conserved among pneumococcal strains, whose involvement in adhesion/colonization has been reported. We found that intraperitoneal immunization with recombinant SrtA conferred to mice protection against S. pneumoniae intraperitoneal challenge and that the passive transfer of immune serum before intraperitoneal challenge was also protective. Moreover, by using the intranasal challenge model, we observed a significant reduction of bacteremia when mice were intraperitoneally immunized with SrtA, while a moderate decrease of lung infection was achieved by intranasal immunization, even though no influence on nasopharynx colonization was seen. Taken together, our results suggest that SrtA is a good candidate for inclusion in a multicomponent, protein-based, pneumococcal vaccine.

The prevalence of hypoxaemia among ill children in developing countries: a systematic review

Hypoxaemia is a common complication of childhood infections, particularly acute lower respiratory tract infections. In pneumonia-a disease that disproportionately impacts developing countries, and accounts for more than two million deaths of children worldwide-hypoxaemia is a recognised risk factor for death, and correlates with disease severity. Hypoxaemia also occurs in severe sepsis, meningitis, common neonatal problems, and other conditions that impair ventilation and gas exchange or increase oxygen demands. Despite this, hypoxaemia has been overlooked in worldwide strategies for pneumonia control and reducing child mortality. Hypoxaemia is also often overlooked in developing countries, mainly due to the low accuracy of clinical predictors and the limited availability of pulse oximetry for more accurate detection and oxygen for treatment. In this Review of published and unpublished studies of acute lower respiratory tract infection, the median prevalence of hypoxaemia in WHO-defined pneumonia requiring hospitalisation (severe and very severe classifications) was 13%, but prevalence varied widely. This corresponds to at least 1.5 to 2.7 million annual cases of hypoxaemic pneumonia presenting to health-care facilities. Many more people do not access health care. With mounting evidence of the impact that improved oxygen systems have on mortality due to acute respiratory infection in limited-resource health-care facilities, there is a need for increased awareness of the burden of hypoxaemia in childhood illness.

Overview of the disease burden of invasive pneumococcal disease in Asia

This paper represents a collaborative effort by the Asian Strategic Alliance for Pneumococcal Disease Prevention (ASAP) Working Group to collate data on the disease burden due to invasive pneumococcal disease (IPD) in participating Asian countries and territories; namely, Hong Kong, India, Indonesia, Korea, Macau, Malaysia, Pakistan, the Philippines, Singapore, Sri Lanka, Taiwan and Thailand. A review of both published and unpublished data revealed that the incidence of IPD in some countries is well documented by way of large, long-duration studies, while in other countries, much of the available data have been extrapolated from international studies or have come from small population studies of limited geographical coverage. This paper confirms that data regarding the incidence of IPD in Asia are grossly lacking and reinforces the need for urgent and more substantial studies.