Massimiliano Don

The value of clinical features in differentiating between viral, pneumococcal and atypical bacterial pneumonia in children

Objective: To evaluate the value of clinical features in differentiating between viral, pneumococcal and atypical bacterial pneumonia in children.

Aetiology of community-acquired pneumonia: Serological results of a paediatric survey

Serological methods are routinely used in the diagnosis of viral and atypical bacterial respiratory infections. Recently, they have also been applied to typical bacteria, such as Streptococcus pneumoniae. The aim of this study was to determine the aetiology of paediatric community-acquired pneumonia (CAP) in both ambulatory and hospitalized patients, by using antibody assays. During a 15-month prospective surveillance, paired sera were studied for antibodies to 14 microbes in 101 children with symptoms of acute infection and infiltrates compatible with pneumonia on chest radiographs. A potential causative agent was detected in 66 (65%) patients. Evidence of bacterial, viral and mixed viral-bacterial infection was demonstrated in 44%, 42% and 20% of the CAP cases, respectively. The most commonly found agents included Mycoplasma pneumoniae (27%), Pneumococcus (18%) and respiratory syncytial virus (17%). Human metapneumovirus (hMPV) was detected in 5 (5%) children. Pneumococcal infections were evenly distributed among the age groups studied. Our results confirm the role of S. pneumoniae in paediatric CAP at all ages, those of M. pneumoniae at >2 y of age and emphasize the emerging role of hMPV. The high proportion of mixed viral-bacterial infections highlights the need to treat all children with CAP with antibiotics.

Serologically verified human bocavirus pneumonia in children.

Human bocavirus (HBoV) is a newly identified parvovirus frequently found in children suffering from acute respiratory and intestinal infections. The aim of the present study was to evaluate, by using a newly developed antibody assay, the role of HBoV in pediatric community‐acquired pneumonia (CAP) and the seropositivity rate to HBoV in a prospective study in North‐Italian children.

Differentiation of bacterial and viral community‐acquired pneumonia in children

Background:  Microbe‐specific diagnosis of pediatric community‐acquired pneumonia (CAP) and the distinction between typical‐bacterial, atypical‐bacterial and viral cases are difficult. The aim of the present study was to evaluate the role of four serum non‐specific inflammatory markers and their combinations, supplemented by chest radiological findings, in the screening of bacterial etiology of pediatric CAP.

Efficacy of serum procalcitonin in evaluating severity of community-acquired pneumonia in childhood

Microbe-specific diagnosis of community-acquired pneumonia (CAP) in childhood is difficult in clinical practice. Chest radiographs and non-specific inflammatory markers have been used to separate presumably bacterial from viral infection but the results have been inconsistent. The aim of the present study was to evaluate the usefulness of procalcitonin (PCT) in assessing the severity as well as the bacterial or viral aetiology of CAP. Serum PCT was measured by an immunoluminometric assay in 100 patients with CAP; 26 were treated as inpatients and 74 as outpatients. The pulmonary infiltrate was considered to be alveolar in 62 and interstitial in 38 cases, according to the radiological diagnosis. The bacterial and viral aetiology of pneumonia was studied by an extensive serological test panel. No differences were found in PCT concentrations between the 4 aetiological (pneumococcal, atypical bacterial, viral, unknown) and the 3 age (<2, 2–4 and ≥5 y) groups. Serum PCT was >0.5 ng/ml in 69%, >1.0 ng/ml in 54% and >2.0 ng/ml in 47% of all patients. PCT was higher in patients that were admitted than as outpatients (medians 17.81 vs 0.72 ng/ml, respectively, p<0.01) and higher in alveolar than in interstitial pneumonia (medians 9.43 vs 0.53 ng/ml, respectively, p<0.01). In conclusion, serum PCT values were found to be related to the severity of CAP in children even though they were not capable, at any level of serum concentration, to differentiate between bacterial and viral aetiology.

Community-acquired pneumonia in children: what's old? What's new?

Community‐acquired pneumonia (CAP) still remains a significant cause for childhood morbidity worldwide. Streptococcus pneumoniae is the most important causative agent at all ages. Respiratory syncytial virus is common in young children, and Mycoplasma pneumoniae in schoolchildren. Paediatric CAP is universally treated with antibiotics; amoxicillin is the drug of choice for presumably pneumococcal and a macrolide for presumably atypical bacterial cases. Because of globally increased resistances, macrolides are not safety for pneumococcal CAP. At present, available prospective research data on the epidemiology of paediatric CAP in western countries are from 1970s to 1980s; correspondingly, data on bacterial aetiology are mainly from 1980s to 1990s. Current concepts on pneumococcal aetiology are mostly based on poorly validated antibody assays. Most data on clinical characteristics in children’s CAP, as well as on antibiotic treatment come from developing countries, thus not being directly applicable in western communities. Recent viral studies have revealed the role of rhinoviruses, metapneumovirus and bocavirus in the aetiology of paediatric CAP. This review critically summarizes the available data on epidemiology, aetiology, clinical presentation, treatment and outcome of CAP in children, with special focus on the newest microbial findings, the age and applicability of the data and the need of new studies.

Simkania negevensis in community-acquired pneumonia in Italian children

Simkania negevensis, a recently found Chlamydia-like organism, has been associated with respiratory infections in children and adults with pneumonia, but S. negevensis findings have been common also without any infection. The aims of the present paper were to evaluate S. negevensis in the aetiology of paediatric community-acquired pneumonia (CAP), its seroprevalence in north Italian children, and whether there is cross-reactivity between S. negevensis and Chlamydia pneumoniae serology. Antibodies to S. negevensis were measured by microimmunofluorescence (MIF) in 101 frozen paired sera obtained from children with CAP. Serological evidence (>/=4-fold increase or decrease in IgM or IgG) of acute S. negevensis infection was achieved in 5 (5%) cases. Two were mixed infections with Mycoplasma pneumoniae and 1 with respiratory syncytial virus. In total, 20–30% of the children had measurable antibodies to S. negevensis, with no association with age. No cross-reactivity was observed between antibodies to S. negevensis and C. pneumoniae. S. negevensis appears to be a real, though rare, cause of CAP in children.

Human metapneumovirus pneumonia in children: Results of an Italian study and mini-review

Human metapneumovirus (hMPV) is a newly identified paramyxovirus causing lower respiratory tract infections (LRTI). Current knowledge on hMPV is mainly based on retrospective studies performed in stored respiratory and serum samples. We found 15 previous prospective clinical studies on LRTI (11 clinical and 4 epidemiological studies) that have been reviewed. Our aims were to analyse the role of hMPV in community acquired pneumonia (CAP) and the seroconversion rate to hMPV in a prospective study in North Italian children. During a 15-month study period, 124 children were admitted due to presumptive CAP and, in 116 of them, CAP was radiologically confirmed. The aetiology of CAP was assessed by serology to 15 microorganisms, including enzyme immunoassay to hMPV. hMPV infection was found in 5 children (4.9%), being single in 2 and mixed in 3 cases. The seroconversion rate to hMPV increased with age, reaching nearly 100% seropositivity rate at school age. In conclusion, hMPV caused 0% to 17.5% of LRTI cases in children in the mini-review. The figure was about 5% in the present and in the only earlier paediatric CAP study. Thus, hMPV is a real but rare cause of paediatric CAP, although seroconversion to hMPV in most children takes place in early childhood.

Lung ultrasound for paediatric pneumonia diagnosis: internationally officialized in a near future?

Abstract We read with great interest the recent paper about the diagnosis and treatment of pediatric community-acquired pneumonia (CAP) in Finland. [1] Clearly, the standard approaches to diagnosis of this disease may be changing. We suggest, however, that lung ultrasound (LUS) may be preferable to chest radiograph (CXR) for this purpose.

Hyper- and hypoglycemia in children with community-acquired pneumonia.

Clinical conditions characterized by sufficient biological stress may be associated with hyperglycemia. The aim of the present study was to evaluate whether stress induced by community-acquired pneumonia (CAP) is associated with disturbances in glucose metabolism in children. Plasma glucose was measured in 108 children with CAP. The relationships between plasma glucose and clinical/laboratory characteristics of CAP were studied by multiple linear regression. The etiology of CAP was determined by serological methods. Plasma glucose level was 100.3 +/- 21.2 mg/dl (mean +/- SD). Only one patient developed hyperglycemia (167 mg/dl), and hypoglycemia (< 60 mg/dl) was present in four patients (3.7%). Plasma glucose had a significant association only with body temperature. Hyperglycemia was rare, about 1%, and the severity or etiology of CAP was not predictive for plasma glucose levels. However, about 4% of the patients had hypoglycemia, which could be explained by reduced calorie intake during acute infection or by the effect of stress-induced cytokines.