Determination of avidity of IgG against protein antigens from Streptococcus pneumoniae: assay development and preliminary application in clinical settings

The measurement of antibody levels is a common test for the diagnosis of Streptococcus pneumoniae infection in research. However, the quality of antibody response, reflected by avidity, has not been adequately evaluated. We aimed to evaluate the role of avidity of IgG against eight pneumococcal proteins in etiologic diagnosis. Eight pneumococcal proteins (Ply, CbpA, PspA1 and 2, PcpA, PhtD, StkP-C, and PcsB-N) were used to develop a multiplex bead-based avidity immunoassay. The assay was tested for effects of the chaotropic agent, multiplexing, and repeatability. The developed assay was applied to paired samples from children with or without pneumococcal disease (n = 38 for each group), determined by either serology, polymerase chain reaction (PCR), or blood culture. We found a good correlation between singleplex and multiplex assays, with r ≥ 0.94.The assay was reproducible, with mean inter-assay variation ≤ 9% and intra-assay variation < 6%. Children with pneumococcal disease had lower median avidity indexes in the acute phase of disease for PspA1 and 2 (p = 0.042), PcpA (p = 0.002), PhtD (p = 0.014), and StkP-C (p < 0.001). When the use of IgG avidity as a diagnostic tool for pneumococcal infection was evaluated, the highest discriminative power was found for StkP-C, followed by PcpA (area under the curve [95% confidence interval, CI]: 0.868 [0.759-0.977] and 0.743 [0.607-879], respectively). The developed assay was robust and had no deleterious influence from multiplexing. Children with pneumococcal disease had lower median avidity against five pneumococcal proteins in the acute phase of disease compared to children without disease.

Distinct regulation of tonsillar immune response in virus infection

Background

The relationships between tonsillar immune responses, and viral infection and allergy are incompletely known.

Objective

To study intratonsillar/nasopharyngeal virus detections and in vivo expressions of T‐cell‐ and innate immune response‐specific cytokines, transcription factors, and type I/II/III interferons in human tonsils.

Methods

Palatine tonsil samples were obtained from 143 elective tonsillectomy patients. Adenovirus, bocavirus‐1, coronavirus, enteroviruses, influenza virus, metapneumovirus, parainfluenza virus, rhinovirus, and respiratory syncytial virus were detected using PCR. The mRNA expression levels of IFN‐α, IFN‐β, IFN‐γ, IL‐10, IL‐13, IL‐17, IL‐28, IL‐29, IL‐37, TGF‐β, FOXP3, GATA3, RORC2, and Tbet were directly analyzed by quantitative RT‐PCR.

Results

Fifty percentage of subjects reported allergy, 59% had ≥1 nasopharyngeal viruses, and 24% had ≥1 intratonsillar viruses. Tonsillar virus detection showed a strong negative association with age; especially rhinovirus or parainfluenza virus detection showed positive association with IFN‐γ and Tbet expressions. IL‐37 expression was positively associated with atopic dermatitis, whereas IFN‐α, IL‐13, IL‐28, and Tbet expressions were negatively associated with allergic diseases. Network analyses demonstrated strongly polarized clusters of immune regulatory (IL‐10, IL‐17, TGF‐β, FOXP3, GATA3, RORC2, Tbet) and antiviral (IFN‐α, IFN‐β, IL‐28, IL‐29) genes. These two clusters became more distinctive in the presence of viral infection or allergy. A negative correlation between antiviral cytokines and IL‐10, IL‐17, IL‐37, FOXP3, and RORC2 was observed only in the presence of viruses, and interestingly, IL‐13 strongly correlated with antiviral cytokines.

Conclusions

Tonsillar cytokine expression is closely related to existing viral infections, age, and allergic illnesses and shows distinct clusters between antiviral and immune regulatory genes.

Normal behavior of plasma procalcitonin in adolescents undergoing surgery for scoliosis

Background and Aims:

Surgical site infections are relatively common after spinal deformity surgery. Early detection of deep wound infections is important, since it may allow retention of spinal instrumentation. However, serum C-reactive protein and erythrocyte sedimentation rate may remain elevated for almost 6 weeks, making differential diagnosis of systemic inflammatory response and acute deep bacterial wound infection difficult. Plasma procalcitonin has been suggested to be a useful indicator for bacterial infection. However, there are no studies evaluating behavior of procalcitonin in patients undergoing major spine surgery with instrumentation.

Materials and Methods:

A total of 50 consecutive adolescents (37 idiopathic scoliosis and 13 neuromuscular scoliosis, mean age = 15 years at surgery and follow-up time = 21 months (range = 12–29 months)) undergoing scoliosis surgery participated in this prospective follow-up study. White blood cell count, serum C-reactive protein, and plasma procalcitonin levels were measured on the day before surgery, on the day of surgery, and daily thereafter for 1 week. None of the patients developed signs of acute or delayed wound infection during the follow-up period; however, two neuromuscular scoliosis patients developed severe postoperative pneumonia, and their inflammatory parameter data will be reported separately.

Results:

Plasma procalcitonin levels peaked on the first postoperative day (mean = 0.19 ng/mL, range = 0.04–1.29 ng/mL), and mean values were less than 0.5 ng/mL during the whole first postoperative week, while C-reactive protein remained elevated during the whole first postoperative week (highest mean value = 63.8 mg/L (range = 5–248 mg/L) on third postoperative day). Patients with idiopathic scoliosis had lower C-reactive protein levels (p < 0.05 from first to sixth postoperative day) and lower procalcitonin levels (p < 0.05 from third to seventh postoperative day) than neuromuscular scoliosis patients. Two patients with postoperative pneumonia showed elevated procalcitonin values over the whole postoperative week (22.34 ng/mL and 0.72 ng/mL highest values, respectively).

Conclusions:

Elevated plasma procalcitonin levels seem useful when excluding acute deep wound infection from systemic inflammatory response.

Specific antibody deficiency in children with recurrent respiratory infections: a controlled study with follow-up

Specific antibody deficiency (SAD) to unconjugated pneumococcal vaccine (PPV) is an established primary B cell immunodeficiency. The occurrence and natural history of SAD in children is unclear. We conducted an observational study to identify SAD in children with recurrent respiratory infections. Ninety-nine children, mean age 5·9 (range 2-16) years, with recurrent or severe infections were vaccinated with PPV; serum antibody concentrations for serotypes 4, 6B, 9V, 14, 18C, 19F and 23F were measured before and 2 weeks after vaccination with enzyme immunoassay. The retrospective control group consisted of 89 healthy children matched for age and gender. No children had received previous conjugated pneumococcal vaccine (PCV) or PPV. The structured history of infectious diseases of all participants was collected. Ten of 91 (11%) children (eight excluded due to immunoglobulin G subclass deficiency) with recurrent respiratory infections had SAD. In the control group, three children (3%) responded inadequately to PPV (P = 0·05). Most children with SAD also had many other minor immune defects. After 0·5-5 years (medium 3·8), eight children with SAD were revaccinated with PPV; five responded adequately and three inadequately. Two SAD children were revaccinated with PCV, one developed an adequate and one an inadequate response. Two children with SAD received treatment with intravenous immunoglobulin; the remaining eight children recovered without replacement therapy during the follow-up. SAD is common in young children with recurrent respiratory infections, but it is often transient and resolves itself within a few years without specific treatment.

Virus shedding after human rhinovirus infection in children, adults and patients with hypogammaglobulinaemia

The shedding of human rhinovirus (HRV) after an acute, naturally acquired infection has not been described in detail. We determined the duration of HRV shedding in immunocompetent children and adults, and in patients with primary hypogammaglobulinaemia. Subjects with symptoms of respiratory tract infection, and their household contacts, were screened for HRV by reverse transcription PCR. They were followed by serial, self-collected nasal swab specimens until negative for HRV or infected by another HRV type. We followed 62 HRV infections in 54 subjects. The mean (95% CI) duration of HRV shedding was 11.4 (8.2-14.7) days in children, 10.1 (7.4-12.9) days in adults, and 40.9 (26.4-55.4) days in patients with hypogammaglobulinaemia (p <0.001). The duration of respiratory tract symptoms correlated with the duration of virus shedding (p 0.002). A new infection by another HRV type soon after the first episode was common. We conclude that the shedding times of HRV are relatively short in otherwise healthy individuals. In contrast, prolonged shedding over 28 days is frequent in patients with hypogammaglobulinaemia despite immunoglobulin replacement therapy.

Viruses and bacteria in sputum samples of children with community-acquired pneumonia

Clin Microbiol Infect 2012; 18: 300–307

Abstract

Few comprehensive studies have searched for viruses and bacteria in children with community‐acquired pneumonia (CAP). We identified 76 children hospitalized for pneumonia. Induced sputum samples were analysed for 18 viruses by antigen detection and PCR, and for six bacteria by culture and PCR. Viruses were found in 72% of samples, bacteria in 91%, and both in 66%. Rhinovirus (30%), human bocavirus (18%) and human metapneumovirus (14%) were the most commonly detected viruses. Two viruses were found in 22% of samples and three in 8%. The most common bacteria found were Streptococcus pneumoniae (50%), Haemophilus influenzae (38%), and Moraxella catarrhalis (28%). Rhinovirus–S. pneumoniae was the most commonly found combination of virus and bacterium (16%). All six children with treatment failure had both viruses and bacteria detected in the sputum. Otherwise, we found no special clinical characteristics in those with mixed viral–bacterial detections. With modern molecular diagnostic techniques, there are high rates of both viral and bacterial identification in childhood CAP. The clinical significance of mixed viral–bacterial infections remains unclear, although we found a potential association between them and treatment failure.

Admission diagnoses of children 0-16 years of age hospitalized with influenza

The prompt diagnosis of influenza enables the institution of antiviral therapy and adequate cohorting of patients, but scarce data are available to help clinicians correctly suspect influenza in children at the time of admission. This 16-year retrospective study assessed the main admission diagnoses of 401 children aged ≤16 years hospitalized with virologically confirmed influenza. The clinical data were derived from a systematic review of the medical records of the children. Sepsis-like illness was the main reason for admission in 52% of infants aged <6 months and in 7-16% of the older children. Respiratory symptoms accounted for 38% of admissions, and 15% of children were hospitalized due to acute neurologic conditions, primarily febrile convulsions. Wheezing or exacerbation of asthma was the primary reason for admission in 14% of children aged <3 years. No differences were observed in the admission diagnoses between children with influenza A and B infections. The main admission diagnoses vary widely in different age groups of children with influenza, and only a minority of children are hospitalized for respiratory symptoms. The leading role of sepsis-like illness in infants aged <6 months calls for increased efforts to find protective measures against influenza in this age group.

Allergic sensitization is associated with rhinovirus-, but not other virus-, induced wheezing in children

BACKGROUND

Data on the link between atopy and viral wheeze are limited.

AIM

To evaluate the association between IgE sensitization and viral infection in wheezing children.

METHODS

This is an observational study in hospitalized wheezing children (n = 247; median age 1.6 ; interquartile range 1.1, 2.9). Eighteen respiratory viral infections were studied using all available methods. A specific immunoglobulin E (IgE) sensitization for common food and aeroallergens and other atopy-related variables including total IgE, blood and nasal eosinophils, exhaled nitric oxide, eczema and atopic eczema, parental allergy and asthma, number of wheezing episodes, positive asthma predictive index or asthma and use of inhaled corticosteroid were correlated with specific viral etiology.

RESULTS

Atopy was closely associated with sole rhinovirus etiology (n = 58) but not with sole respiratory syncytial virus, sole enterovirus, sole human bocavirus, sole other virus, mixed viral, or virus negative etiology. The number of sensitizations was particularly associated with sole rhinovirus etiology (odds ratio 4.59; 95% confidence interval 1.78, 11.8; adjusted to age and sex), followed by aeroallergen sensitization (respectively; 4.18; 2.00, 8.72), total IgE level (2.06; 1.32, 3.21), food allergen sensitization (2.02; 1.08, 3.78), and nasal eosinophil count (1.52; 1.08, 2.13).

CONCLUSIONS

According to our data, allergic sensitization is positively linked to rhinovirus-, but not other virus-, associated wheezing and calls attention for studies to test rhinovirus-associated wheezing as a part of asthma risk indices.

Recurrent wheezing after respiratory syncytial virus or non-respiratory syncytial virus bronchiolitis in infancy: a 3-year follow-up

BACKGROUND

Recent studies have suggested that rhinovirus-associated early wheezing is a greater risk factor for development of recurrent wheezing in children than is early wheezing associated with respiratory syncytial virus (RSV). We determined the development of recurrent wheezing in young children within 3 years after hospitalization for RSV or non-RSV bronchiolitis.

METHODS

We identified retrospectively all children <2 years of age who were admitted to Turku University Hospital because of bronchiolitis in the months of August-December during 1988-2001. The primary outcome was recurrent wheezing that required long-term asthma medication. Data on asthma medications of the individual children were derived from the Social Insurance Institution of Finland.

RESULTS

Within the first year after hospitalization, 36 of 217 (16.6%) children with non-RSV bronchiolitis developed recurrent wheezing, compared with five of 199 (2.5%) children with RSV bronchiolitis [relative risk (RR) 6.6; 95% confidence interval (CI) 2.6-16.5]. The rates of recurrent wheezing were significantly increased in the non-RSV group also within 2 years (RR 2.9; 95% CI 1.7-5.1) and 3 years (RR 3.4; 95% CI 2.0-5.7) after hospitalization. The increased risk of recurrent wheezing in children with non-RSV-associated bronchiolitis was observed both in boys and girls at all time points of the 3-year follow-up, and it was not explained by the age difference between the RSV and non-RSV groups or any confounding seasonal factors.

CONCLUSION

Children hospitalized with bronchiolitis caused by other viruses than RSV develop recurrent wheezing at substantially higher rates during a 3-year follow-up period than do children with RSV-induced bronchiolitis.

Induced sputum in the diagnosis of childhood community-acquired pneumonia

BACKGROUND

The usefulness of induced sputum in searching for causative agents of pneumonia in children has not been studied.

METHODS

The study involved 101 children, aged 6 months to 15 years, treated for community-acquired pneumonia at Turku University Hospital (Turku, Finland) from January 2006 to April 2007. Nasopharyngeal aspirate samples were first collected through both nostrils. Sputum production was then induced by inhalation of 5.0% hypertonic saline for 5-10 min and a sputum sample was either aspirated or expectorated. The presence and amount of bacteria and viruses in paired nasopharyngeal aspirate and sputum specimens was analysed and compared using semiquantitative bacterial culture and quantitative PCR techniques.

RESULTS

A good quality sputum specimen was obtained from 76 children. The possible causative agent was found in 90% of cases. Streptococcus pneumoniae (46%) and rhinovirus (29%) were the most common microbes detected. Newly discovered viruses human bocavirus and human metapneumovirus were detected in 18% and 13% of the children, respectively. One-quarter of all bacterial findings were only detected in sputum, and the amount of bacteria in the remainder of the sputum specimens compared with nasopharyngeal aspirate was higher in 14% and equal in 70%. The amount of rhinovirus in sputum was higher than in nasopharyngeal aspirate in 82%.

CONCLUSIONS

Sputum induction provides good quality sputum specimens with high microbiological yield in children with community-acquired pneumonia. Induced sputum analysis can be useful in the microbiological diagnosis of childhood community-acquired pneumonia.

A randomized, controlled trial of tonsillectomy in periodic fever, aphthous stomatitis, pharyngitis, and adenitis syndrome

OBJECTIVE

We carried out a prospective, randomized, controlled trial to clarify the effect of tonsillectomy on the clinical course of periodic fever, aphthous stomatitis, pharyngitis, and adenitis (PFAPA) syndrome.

STUDY DESIGN

Twenty-six consecutive children (mean age 4.1 years) with at least 5 PFAPA attacks were recruited from 3 tertiary care pediatric hospitals during 1999-2003 and randomly allocated to tonsillectomy or follow-up alone. They were all followed up with symptom diaries for 12 months. Tonsillectomy was allowed after 6 months in the control group if the attacks recurred.

RESULTS

Six months after randomization all 14 children in the tonsillectomy group and 6/12 children in the control group (50%) were free of symptoms (difference 50%, 95% confidence interval 23% to 75%, P < .001). Tonsillectomy was performed on 5/6 of the patients in the control group who still had symptoms after 6 months. The remaining unoperated child in the control group had recurrences of the fever episodes throughout the follow-up, but the symptoms became less severe, and the parents did not choose tonsillectomy.

CONCLUSION

Tonsillectomy appeared to be effective for treating PFAPA syndrome. The fever episodes ceased without any intervention in half of the control subjects. We conclude that although the mechanisms behind this syndrome are unknown, tonsillectomy can be offered as an effective intervention for children with PFAPA.

Pneumolysin polymerase chain reaction for diagnosis of pneumococcal pneumonia and empyema in children

Streptococcus pneumoniae is the most important cause of childhood pneumonia and empyema, yet the diagnosis of pneumococcal infections by conventional methods is challenging. In this study, the clinical value of the pneumolysin-targeted real-time polymerase chain reaction (PCR) method for the diagnosis of pneumococcal pneumonia and empyema was evaluated with 33 whole blood samples and 12 pleural fluid samples. The analytical sensitivity of the PCR assay was 4 fg of pneumococcal DNA, corresponding to two genome equivalents of pneumococcal DNA per reaction. The PCR assay correctly detected all clinical isolates of S. pneumoniae tested, whereas all nonpneumococcal bacterial organisms tested were negative by PCR. In a clinical trial, S. pneumoniae was detected by PCR in the pleural fluid of 75% of children with empyema, increasing the detection rate of pneumococcus almost tenfold that of pleural fluid culture. However, in whole blood samples, PCR detected S. pneumoniae in only one child with pneumonia and one child with pneumococcal empyema and failed to detect S. pneumoniae in three children with blood cultures positive for S. pneumoniae. The present data indicate that pneumolysin-targeted real-time PCR of pleural fluid is a valuable method for the etiologic diagnosis of pneumococcal empyema in children. The ease and rapidity of the LightCycler technology (Roche Diagnostics, Mannheim, Germany) make real-time PCR an applicable tool for routine diagnostics. In the evaluation of blood samples, blood culture remains the superior method for the diagnosis of bacteremic pneumococcal disease.

Bacterial coinfections in children with viral wheezing

Bacterial coinfections occur in respiratory viral infections, but the attack rates and the clinical profile are not clear. The aim of this study was to determine bacterial coinfections in children hospitalized for acute expiratory wheezing with defined viral etiology. A total of 220 children aged 3 months to 16 years were investigated. The viral etiology of wheezing was confirmed by viral culture, antigen detection, serologic investigation, and/or PCR. Specific antibodies to common respiratory bacteria were measured from acute and convalescent serum samples. All children were examined clinically for acute otitis media, and subgroups of children were examined radiologically for sinusitis and pneumonia. Rhinovirus (32%), respiratory syncytial virus (31%), and enteroviruses (31%) were the most common causative viruses. Serologic evidence of bacterial coinfection was found in 18% of the children. Streptococcus pneumoniae (8%) and Mycoplasma pneumoniae (5%) were the most common causative bacteria. Acute otitis media was diagnosed in 44% of the children. Chest radiographs showed alveolar infiltrates in 10%, and paranasal radiographs and clinical signs showed sinusitis in 17% of the older children studied. Leukocyte counts and serum C-reactive protein levels were low in a great majority of patients. Viral lower respiratory tract infection in children is often associated with bacterial-type upper respiratory tract infections. However, coexisting bacterial lower respiratory tract infections that induce systemic inflammatory response are seldom detected.

Radiographic follow-up of pneumonia in children

This study assessed the clinical value of routine follow-up chest radiographs in hospitalized children with community-acquired pneumonia. The study population consisted of 196 children hospitalized for community-acquired pneumonia diagnosed between 1993-1995. Seventeen infective agents (10 viruses and 7 bacteria) were sought. Chest radiographs were taken on admission and 3-7 weeks later. All children were treated with antibiotics. Data on the course of illness over the following 8-10 years were obtained from patient files and questionnaires sent to parents. A potential causative agent was found in 165 (84%) of 196 cases. On follow-up chest radiographs, residual or new changes were seen in 30% of cases. The residual changes tended to be more common after mixed viral-bacterial infection (43%) than after sole viral (25%) or sole bacterial (20%) infection. Interstitial infiltrates (66%), atelectasis (46%), and enlarged lymph nodes were the most common sequelae seen on follow-up. Residual findings on follow-up radiographs did not affect the treatment of the children. No further chest radiographs were taken. During the 8-10-year follow-up of 194 children, no illnesses appeared that were associated with previous pneumonia. Twenty-six children had a new episode of pneumonia, 7 of them had asthma, and 6 had different underlying illnesses. In conclusion, routine follow-up chest radiographs are not needed in childhood community-acquired pneumonia if the child has a clinically uneventful recovery.

Hospital admission of high risk infants for respiratory syncytial virus infection: implications for palivizumab prophylaxis

OBJECTIVES

To determine the rates of hospital admission for respiratory syncytial virus (RSV) infection among children born at different gestational ages. To assess the theoretical impact of palivizumab prophylaxis on admissions for RSV infection.

DESIGN

Retrospective cohort study of children born in 1991-2000.

SETTING

Tertiary care university hospital.

METHODS

Data on all children born during the 10 year period were combined with information on laboratory confirmed RSV infections in these children until the end of 2002. The theoretical impact of palivizumab on RSV associated admissions was estimated by applying the current recommendations for prophylaxis to the study population and using the observed rates of admission in the calculations.

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

Rates of RSV infection and hospital admission in different subgroups of children.

RESULTS

Children with chronic lung disease (CLD) were admitted for RSV infection at a rate of 12.0%. The corresponding rates in children born at </=28 or 29-32 weeks gestation were 7.1% and 6.8% respectively. Children born at </=32 weeks gestation accounted for 6.6% of all admissions due to RSV. Of 586 children who would have met the criteria for palivizumab prophylaxis, 27 (4.6%) were admitted with RSV during the presumed prophylactic period. The number needed to treat to prevent one admission for RSV infection was 15 for children with CLD (with a total cost of 75 000) and 43 for children without CLD born at </=32 weeks gestation (with a total cost of 215 000).

CONCLUSIONS

The rates of hospital admission for RSV infection in premature infants were substantially lower than those in most previous reports from other countries. Determination of the local rates of RSV admissions in different groups of children would be useful in making decisions about the use of palivizumab.

Differentiation of bacterial and viral pneumonia in children

BACKGROUND

A study was undertaken to investigate the differential diagnostic role of chest radiographic findings, total white blood cell count (WBC), erythrocyte sedimentation rate (ESR), and serum C reactive protein (CRP) in children with community acquired pneumonia of varying aetiology.

METHODS

The study population consisted of 254 consecutive children admitted to hospital with community acquired pneumonia diagnosed between 1993 and 1995. WBC, ESR, and CRP levels were determined on admission. Seventeen infective agents (10 viruses and seven bacteria) were searched for. Chest radiographs were retrospectively and separately reviewed by three paediatric radiologists.

RESULTS

A potential causative agent was found in 215 (85%) of the 254 cases. Bacterial infection was found in 71% of 137 children with alveolar infiltrates on the chest radiograph, while 72% of the 134 cases with a bacterial pneumonia had alveolar infiltrates. Half of the 77 children with solely interstitial infiltrates on the chest radiograph had evidence of bacterial infection. The proportion of patients with increased WBC or ESR did not differ between bacterial and viral pneumonias, but differences in the CRP levels of >40 mg/l, >80 mg/l, and >120 mg/l were significant although the sensitivity for detecting bacterial pneumonia was too low for use in clinical practice.

CONCLUSIONS

Most children with alveolar pneumonia, especially those with lobar infiltrates, have laboratory evidence of a bacterial infection. Interstitial infiltrates are seen in both viral and bacterial pneumonias.

Pulmonary imaging and function in the common cold

The common cold is generally considered to be an upper respiratory tract infection. We studied the lower respiratory tract in 76 otherwise healthy young adults with the common cold. Viral infection was diagnosed in 56 (74%) of the 76 subjects. Rhinovirus was detected in 42 (55%) subjects. Chest radiography (CR) and high-resolution computerized tomography (HRCT) were carried out in 40 subjects on day 7, and pulmonary function testing with bronchodilator challenge was carried out in 36 patients on days 7 and 21 of the study. Clinical examinations were carried out on days 1, 7 and 21. The subjects recorded their symptoms on a diary card for 20 d. The mean duration of cough was 8.4 (SD 6.5) d and that of sputum production 5.9 (SD 6.4) d. No abnormal findings were detected in the lungs on auscultation. CR and HRCT showed no pulmonary changes associated with the common cold. No clinically remarkable increases were seen in peak expiratory flow, forced expiration volume in 1 s or forced vital capacity after bronchodilator challenge on either days 7 or 21. All patients made a clinical recovery without antimicrobial therapy within 21 d. We conclude that the common cold in young otherwise healthy adults is an upper respiratory tract infection and that clinically important abnormalities in the lower respiratory tract are rare.

Clinical profile of serologically diagnosed pneumococcal pneumonia

OBJECTIVE

To describe the characteristics of serologically diagnosed pneumococcal pneumonia and compare them with those of respiratory syncytial virus (RSV) pneumonia and bacteremic pneumococcal pneumonia.

METHODS

IgG antibodies to pneumococcal pneumolysin and C-polysaccharide as well as immune complexes containing IgG antibodies to pneumolysin and C-polysaccharide were measured from acute and convalescent sera of 254 children with community-acquired pneumonia. Evidence of pneumococcal infection was found in 93 children. Clinical and laboratory data were retrospectively collected from the records of 38 children with sole (all tests for 16 other microbes negative) pneumococcal pneumonia and compared with 26 sole RSV-induced pneumonia from the present series and with the data of our 85 bacteremic pneumococcal pneumonia cases reported earlier.

RESULTS

Serologically diagnosed sole pneumococcal pneumonia clinically overlapped with RSV pneumonia, but RSV pneumonia was more often associated with tachypnea (45% vs. 17%, P < 0.05) and low white blood cell counts (means, 12.0 x 109/l vs. 20.8 x 109/l; P < 0.001) as well as low serum C-reactive protein levels (means, 28 mg/l vs. 137 mg/l; P < 0.001). Alveolar infiltrates were found in 15% of chest radiographs of children with RSV pneumonia compared with 76% of those in children with sole pneumococcal pneumonia (P < 0.001). Patients with bacteremic pneumonia more often appeared ill (79% vs. 50%, P < 0.001) and more often had typical pneumococcal pneumonia with high fever, leukocytosis and lobar infiltrates in their chest radiographs (70% vs. 34%, P < 0.05) than those with serologically diagnosed pneumococcal pneumonia.

CONCLUSIONS

Serologically detected pneumococcal pneumonia differs significantly from RSV pneumonia in laboratory and chest radiography findings, but the clinical signs and symptoms overlap considerably. Bacteremic pneumococcal pneumonia is a more severe illness than the serologically diagnosed one.

Diagnostic findings in 95 Finnish patients with common variable immunodeficiency

Common variable immunodeficiency is the most frequent of the primary hypogammaglobulinemias. It is manifested by a wide variety of clinical signs and symptoms. In this retrospective, nationwide survey data were collected on all patients with common variable immunodeficiency who were receiving immunoglobulin replacement therapy in Finland to study the prediagnostic clinical picture, diagnostic delay, and diagnostic findings. Ninety-five patients were identified. The median age of the patients was 33 years. Sixteen of the patients were children. Sinopulmonary infections were the most common prediagnostic signs and symptoms; 66% had suffered from recurrent pneumonia, 60% from recurrent maxillary sinusitis, and 45% from recurrent bronchitis. There was a considerable delay in diagnosis. The mean delay was 8 years. At the time of diagnosis chronic pulmonary complications had already developed in 17% of the patients. The diagnosis was based on low serum immunoglobulin concentrations. This study showed that the awareness of common variable immunodeficiency is low. To improve the recognition of hypogammaglobulinemia, it should be suspected in every patient with recurrent bacterial infections. In addition to a low serum IgG concentration, measurement of specific antibody production is recommended to establish the diagnosis before initiation of a life-long and costly replacement therapy.

Validity of ultrasonography in diagnosis of acute maxillary sinusitis

BACKGROUND

Accurate diagnosis of maxillary sinusitis is difficult on the basis of clinical examination only because the signs and symptoms of sinusitis are nonspecific. A simple, rapid, and readily available method for diagnosing maxillary sinusitis in primary care would increase the accuracy of the diagnoses and thus reduce unnecessary antibiotic treatment.

OBJECTIVE

To investigate the validity of ultrasonography compared with radiography and magnetic resonance imaging (MRI) in detection of maxillary sinusitis.

DESIGN

Ultrasonography and plain-film radiography of the paranasal sinuses were performed on all patients and MRI was performed on 40 randomly selected patients on day 7 of the study.

SETTING

Study office at the Department of Pediatrics of Turku University Hospital, Turku, Finland.

PATIENTS

One hundred ninety-seven young adults who contacted the study office within 48 hours of the onset of symptoms of the common cold.

MAIN OUTCOME MEASURES

Detection rates of maxillary sinusitis by ultrasonography, radiography, and MRI.

RESULTS

Acute maxillary sinusitis was diagnosed in 24% of the sinuses by radiography and in 28% by MRI. Compared with MRI findings, the sensitivity of ultrasonography for detection of maxillary sinusitis was 64% (specificity, 95%). Using a 2-step diagnostic approach in which radiological findings were additionally considered in cases of negative ultrasound findings, a sensitivity of 86% (specificity, 95%) was observed.

CONCLUSIONS

The high specificity of ultrasonography indicates that a positive ultrasound finding can be regarded as evidence of maxillary sinusitis. The addition of plain-film radiography in cases of negative ultrasound findings increases the diagnostic sensitivity to clinically acceptable levels without loss in specificity. Active use of ultrasonography would substantially decrease the need for radiological imaging of the sinuses and also help reduce unnecessary antibiotic treatment in primary care. Arch Otolaryngol Head Neck Surg. 2000;126:1482-1486

Streptococcus pneumoniae and Mycoplasma pneumoniae coinfection in community acquired pneumonia

The characteristics of nine children with community acquired pneumonia with evidence of Streptococcus pneumoniae and Mycoplasma pneumoniae coinfection are described.

Intranasal fluticasone propionate does not prevent acute otitis media during viral upper respiratory infection in children

BACKGROUND

Acute otitis media (AOM) is the most common complication of a viral upper respiratory infection (URI) in children. The virus-induced host inflammatory response in the nasopharynx plays a key role in the pathogenesis of AOM. Suppression of this inflammatory process might prevent the development of AOM as a complication.

OBJECTIVE

We sought to assess the effect of intranasally administered fluticasone propionate on prevention of AOM during a viral respiratory infection.

METHODS

A total of 210 children (mean age, 2.1 years; range, 0.7-3.9 years) with normal middle ear status and URI of 48 hours' duration or less were randomly allocated to receive either fluticasone (100 microg twice daily) or placebo for 7 days. The specific viral cause of the infection was determined from nasopharyngeal aspirates obtained at the first visit. The children were re-examined at the end of the 7-day medication period.

RESULTS

In the fluticasone group AOM developed in 40 (38.1%) of 105 children compared with 29 (28.2%) of 103 children receiving placebo (P =.13). The viral cause of the respiratory infection was determined in 167 (86.1%) of 194 children from whom a nasopharyngeal aspirate was obtained. In children with rhinovirus infection, AOM developed significantly more often in the fluticasone group (45.7%) than in the placebo group (14.7%, P =.005).

CONCLUSION

Intranasally administered fluticasone does not prevent the development of AOM during URI but may increase the incidence of AOM during rhinovirus infection.

Serum procalcitonin, C-reactive protein and interleukin-6 for distinguishing bacterial and viral pneumonia in children

OBJECTIVE

Serum procalcitonin (PCT), C-reactive protein (CRP) and interleukin-6 (IL-6) concentrations were measured in 126 children hospitalized for community-acquired, radiologically confirmed pneumonia to assess whether these host response values could be used to distinguish bacterial from viral pneumonia.

METHODS

The samples for PCT, CRP and IL-6 measurements were obtained on admission or the first day of hospitalization. The etiology of pneumonia was studied with an extensive panel of methods that detected 6 bacteria and 11 viruses.

RESULTS

In all, 54% had evidence of bacterial pneumonia, and 32% had evidence of sole viral pneumonia. In 14% of the cases the etiology could not be determined. Children with bacterial pneumonia had significantly higher PCT (median 2.09 ng/ml vs. 0.56 ng/ml, P = 0.019) and CRP concentrations (96 mg/l vs. 54 mg/l, P = 0.008) than those with sole viral etiology. However, the values markedly overlapped. No significant difference in IL-6 concentrations was seen between the two patient groups. Using PCT > or = 2.0 ng/ml, CRP > or = 150 mg/l or IL-6 > or = 40 pg/ml, the specificity was > or =80% for bacterial pneumonia. The sensitivities with these cutoff values were 50% for PCT, 31% for CRP and 34% for IL-6.

CONCLUSIONS

The results indicate that the measurement of serum PCT, CRP and IL-6 has little value in the differentiation of bacterial and viral pneumonia in children. However, in some patients with very high serum PCT, CRP or IL-6 values, bacterial pneumonia is probable.

Bacteremic urinary tract infection in children

OBJECTIVE

To assess the clinical characteristics of bacteremic urinary tract infection (UTI) in children.

DESIGN

Clinical data of Finnish children with bacteremic UTI (n = 134) from 1985 to 1994 were analyzed. Their symptoms, laboratory and imaging findings were compared with those of age- and sex-matched patients hospitalized for blood culture negative UTI.

RESULTS

Generally, no major differences were seen in clinical findings between bacteremic and nonbacteremic patients. Bacteremic children had more frequent feeding problems (P = 0.02), and children > or =12 months of age tended more often to have abdominal pain and vomiting than did nonbacteremic patients. Fever was the major initial symptom in both study groups, but no significant difference occurred in the mean highest temperature or in the mean of duration of fever before admission to the hospital. The mean concentration of serum C-reactive protein on admission was significantly higher in bacteremic patients (116 vs. 76 mg/l; P < 0.01). After onset of antimicrobial treatment fever lasted significantly longer in bacteremic patients than in control patients (means, 2.3 vs. 1.1 days; P < 0.01). Anatomic or functional abnormalities in the urinary tract were detected in 51% vs. 46%, respectively. Obstruction of the urinary tract (9% vs. 1%, P < 0.01) and Grade 3 to 5 vesicoureteral reflux (30% vs. 16%, P = 0.02) were significantly more frequent in bacteremic patients with UTI. Obstruction or vesicoureteral reflux was found in 46% of children with bacteremic UTI caused by Escherichia coli vs. 89% of children with non-E. coli infection (P < 0.01).

CONCLUSIONS

Clinical symptoms do not significantly distinguish bacteremic from nonbacteremic children with UTI. Outcome of bacteremic UTI was comparable with that of nonbacteremic UTI. Bacteremic children, especially those with non-E. coli UTI, more often had anatomical or functional abnormalities in the urinary tract.

Etiology of community-acquired pneumonia in 254 hospitalized children

BACKGROUND

Childhood community-acquired pneumonia is a common illness, but there have been relatively few comprehensive studies of the viral and bacterial etiology in developed countries. The aim of the present investigation was to determine the etiology of community-acquired pneumonia in hospitalized children by several laboratory methods.

METHODS

In a 3-year prospective study a nasopharyngeal aspirate for viral studies and acute and convalescent serum samples for viral and bacterial serology were taken from 254 children with symptoms of acute infection and infiltrates compatible with pneumonia in the chest radiograph. The role of 17 microbes was investigated.

RESULTS

A potential causative agent was detected in 215 (85%) of the 254 patients. Sixty-two percent of the patients had viral infection, 53% had bacterial infection and 30% had evidence of concomitant viral-bacterial infection. Streptococcus pneumoniae (37%), respiratory syncytial virus (29%) and rhinovirus (24%) were the most common agents associated with community-acquired pneumonia. Only one patient had a positive blood culture (S. pneumoniae) of 125 cultured. A dual viral infection was detected in 35 patients, and a dual bacterial infection was detected in 19 patients.

CONCLUSIONS

The possible causative agent of childhood community-acquired pneumonia can be detected in most cases. Further studies are warranted to determine what etiologic investigations would aid in the management of pneumonia. With effective immunization for S. pneumoniae and respiratory syncytial virus infections, more than one-half of the pneumonia cases in this study could have been prevented.

Direct amplification of rRNA genes in diagnosis of bacterial infections

A broad-range bacterial PCR targeting rRNA genes (rDNAs) was used to directly analyze 536 clinical samples obtained from 459 hospitalized patients during a 4-year study period. The molecular diagnosis based on DNA sequencing of the PCR product was compared to that obtained by bacterial culture. The bacteriological diagnosis was concordant for 447 (83%) specimens. Broad-range rDNA PCR was the only method that yielded an etiologic diagnosis for 11 (2.4%) of 459 patients. Compared to culture and clinical assessment, the sensitivity of the PCR method combined with sequencing was 74.2%, and the specificity was between 98.7 and 99.6%. At present, the described molecular approach proved superior to bacterial culture in two clinical situations: infections caused by bacteria with unusual growth requirements and specimens taken during antimicrobial treatment of the patient.

Pulmonary abnormalities in patients with primary hypogammaglobulinemia

BACKGROUND

Pulmonary complications are common in patients with primary hypogammaglobulinemia. Intravenous immunoglobulin replacement therapy has been thought to reduce the occurrence of pulmonary complications, yet they do occur.

OBJECTIVE

The purpose of this study was to evaluate pulmonary abnormalities in 22 patients with primary hypogammaglobulinemia (18 with common variable immunodeficiency, 4 with X-linked agammaglobulinemia) and to conduct a prospective 3-year follow-up study to assess the possible progression of pulmonary abnormalities.

METHODS

Pulmonary changes were evaluated with use of pulmonary imaging (chest radiographs, high-resolution computed tomography), and pulmonary function testing.

RESULTS

High-resolution computed tomography revealed pulmonary abnormalities in 21 patients. Bronchiectasis was present in 16 patients, whereas chest radiographs revealed bronchiectasis in only 3 patients. Pulmonary function testing showed obstruction in 5 patients. A prospective 3-year follow-up was conducted in 14 patients. It showed silent progression of bronchiectasis in 5 of the 14 patients, all of whom were receiving intravenous immunoglobulin replacement therapy and had preinfusion serum IgG concentrations of 5 g/L or more.

CONCLUSIONS

Pulmonary abnormalities develop in most patients with primary hypogammaglobulinemia. A new finding is that silent and asymptomatic progression of pulmonary changes may occur in patients despite an adequate immunoglobulin replacement therapy. High-resolution computed tomography is the method of choice in monitoring pulmonary changes.

Bacteremic pneumococcal pneumonia in children

We carried out a nationwide retrospective study on bacteremic pneumococcal pneumonia diagnosed from 1985 to 1994 in Finland. The records of 85 children were reviewed for symptoms, signs, laboratory data, and response to antibiotic therapy. The chest radiographs were reevaluated. Bacteremic pneumococcal pneumonia was characterized by high fever (> or =39.0 degrees C in 93%), leukocytosis (WBC count on admission of > or =15x10(9)/L in 84%), and ill appearance (in 79%). Lobar or segmental consolidation was found in 79% of the chest radiographs. Of the patients, 28% had no respiratory symptoms, 6% presented with only gastrointestinal symptoms in addition to fever, and 4% had fever only. Tachypnea was recorded in 19% and rales in 14% of the patients. After onset of antimicrobial treatment, children became afebrile within an average of 22 hours. One patient developed pleural empyema, and none of the patients died.

Homozygous deletion of the CYP21A-TNXA-RP2-C4B gene region conferring C4B deficiency associated with recurrent respiratory infections

The central class III region of the human major histocompatibility complex contains highly polymorphic genes that are associated with immune disorders and may serve as susceptibility factors for viral infections. Many HLA haplotype specific rearrangements, duplications, conversions and deletions, occur frequently in the C4 gene region. Genetic deficiencies of complement components are associated with recurrent occurrence of bacterial infections. We have studied the complement profile and the class III genes 5'-RP1-C4A-CYP21A-TNXA-RP2-C4B-CYP21B-TNXB -3' in a 4-year-old Caucasian patient. He has suffered from several pneumonias caused by respiratory viruses, eight acute otitis media, prolonged respiratory infections and urinary tract infection. Complement C4 was constantly low, but the other complement components, from C1 to C9, C1INH, factor B and properdin, were within normal limits. Immunological evaluation gave normal lymphocyte numbers and functions with the exception of subnormal T cell response to pokeweed mitogen. Molecular studies of the C4 gene region in the patient revealed homozygous deletion of CYP21A-TNXA-RP2-C4B generating total deficiency of C4B and the flanking 5' region up to C4A, and in the father a missing CYP21A gene. Further investigations are needed to elucidate the relationship between C4B deficiency and susceptibility to infections.