Pneumococcal Pneumonia In Children Research Articles

Post-marketing effectiveness of Prevnar [pneumococcal 7-valent conjugate vaccine (diphtheria CRM197 protein)] and implications for adult immunization

Pneumococcal pneumonia is a significant health concern for pediatric, healthy adult, and elderly populations. The newly licensed pneumococcal 7-valent conjugate (diphtheria CRM197 protein) vaccine, Prevnar, and a second generation experimental 9-valent product have demonstrated, for the first time, a clear and significant impact on pneumococcal pneumonia in children. The potential for saccharide-conjugate vaccines to help prevent pneumococcal pneumonia in adult and elderly populations and potential barriers to the introduction of a conjugate vaccine in adults are discussed.

Serologically indicated pneumococcal pneumonia in children: a population-based study in primary care settings.

The aim of the study was to assess age-specific incidences of community-acquired pneumonia (CAP) caused by Streptococcus pneumoniae and diagnosed serologically in a child population. The study was population-based, and prospective, and performed in primary health care settings. During a surveillance period of 12 months from 1981-1982, all pneumonia cases in a defined child population (57% urban residents) were registered prospectively. In total, 201 CAP cases were diagnosed (mean age 5.6 years; 57% boys; 58% urban residents). S. pneumoniae etiology was studied by antibody and immune complex (IC) assays to C-polysacchride (C-PS), type-specific capsular polysaccharides (CPS), and to pneumolysin (Ply), in acute and convalescent sera. Serologic evidence of S. pneumoniae etiology was indicated in 57(28%) cases, 35(61%) being mixed infections with other microbes. The distribution of pneumococcal cases was 44%, 30% and 26% in the three 5-year age groups, respectively. There were 33 (58%) males and 34 (60%) urban residents. In total, 26 cases were identified by antibody assays and 35 cases by IC assays, 26/35 being positive in acute sera. Responses to C-PS, CPS and Ply, when antibody and IC results are combined, were found equally often in 23-25 cases. The total annual incidence of pediatric S. pneumoniae CAP was 6.4/1000/year. S. pneumoniae etiology was found in 28% of the children and was similar at all ages. The incidence of pneumococcal CAP was assessed for the first time, being high (19/1000/year) in 0- to 4-year-old urban boys and rather stable (5-9/1000/year) in all other groups by age, sex and residence.

Serum procalcitonin in pneumococcal pneumonia in children

Serum procalcitonin (PCT), a marker of bacterial infection, was measured in children with pneumonia to examine whether PCT can be used to screen pneumococcal (PNC) from viral pneumonia. The number of patients was 132; mean age 3.0 yrs, and 64% were males. In all cases, pneumonia was radiologically confirmed, being alveolar in 46 and interstitial in 86 cases. The aetiology of infection was studied by a panel of serological tests for PNC, for five other respiratory bacteria and for seven common respiratory viruses. PNC infection was found in 25, mixed viral-PNC infections in 13 and viral infection in 17 cases. In general, serum PCT was not associated with the type or aetiology of pneumonia. PCT values were >1.0 mg.L(-1) in 40% of PNC cases, as compared to 12-15% in viral or mixed cases, respectively (p<0.05). PCT values were significantly higher in >2 yrs old children than in younger ones. The cut-off limits of 0.5 ng.mL(-1), 1.0 ng.mL(-1) and 2.0 ng.mL(-1) were tested for screening between PNC and viral pneumonia. The highest sensitivity of 55% was found at the 0.5 ng.mL(-1) cut-off level, whereas the highest specificity of 88% was reached at the level of 1.0 ng.mL(-1). The likelihood ratios, however, were far from optimal for both the positive and negative results. Although marginally higher in pneumococcal pneumonia than in viral pneumonia, serum procalcitonin cannot be used to discriminate between these two types of pneumonia.

Parenteral Antibiotics for Bacteremia-Associated Pneumococcal Pneumonia in Children

Streptococcus pneumoniae, the most common bacterial cause of pneumonia in early childhood, is sometimes complicated by bacteremia, which can lead to

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.

White blood cells, C-reactive protein and erythrocyte sedimentation rate in pneumococcal pneumonia in children.

We evaluated the applicability of C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), white blood cell count (WBC), and absolute neutrophil count (ANC), in the screening of pneumococcal (PNC) pneumonia in children. In 1981-1982, 161 children were treated for radiologically verified community-acquired pneumonia in the hospital during a period of 12 months. The Streptococcus pneumoniae aetiology of infection was studied by antigen, antibody and immune complex assays in acute and convalescent sera. In acute blood samples, CRP was measured by the immunonephelometric method, ESR by the Westergren method, WBC using an automatic cell counter, and thereafter the ANC was calculated after microscopic examination of peripheral smears. CRP and ESR were significantly higher in patients with alveolar (n=53) than in those with interstitial (n=108) pneumonia. CRP, ESR and ANC were significantly higher in PNC (n=29) than in viral (n=23) pneumonia. The values in mixed PNC and viral infections (n=17) were approximately midway between PNC and viral cases. All cases with serologic evidence of S. pneumoniae aetiology were combined (n=46) for calculation of diagnostic parameters. When a cut-off limit of 60 mg x L(-1) was used, CRP had a sensitivity of 26% and a specificity of 83% in the screening of PNC pneumonia. We conclude that C-reactive protein and erythrocyte sedimentation rate have a limited capacity to differentiate between pneumococcal and nonpneumococcal pneumonia. C-reactive protein is recommended as the first-line method of screening, and the value of 60 mg x L(-1) as the cut-off limit.

Latex agglutination test for diagnosing pneumococcal pneumonia in children in developing countries.

To prepare and assess the sensitivity and specificity of a latex agglutination test specific for the serotype of antigen in diagnosing pneumococcal pneumonia in Gambian children. Comparison of agglutination test specific for serotype with culture of blood and lung aspirates, countercurrent immunoelectrophoresis, and commercial latex agglutination tests in diagnosing pneumococcal pneumonia. Cross reaction studies and investigation of 102 control children to determine specificity of agglutination test specific for serotype. General medical ward of Medical Research Council laboratories, The Gambia. 101 Gambian children aged between 2 months and 10 years admitted with severe pneumonia. Serum samples were boiled and treated with edetic acid, and urine samples were boiled and concentrated 25 times before testing. A latex agglutination test specific for the serotype of pneumococcal antigen that is sensitive and highly specific for detecting pneumococcus in the urine of patients with pneumococcal pneumonia. Concentrated urine samples from 16 of the 21 children (76%) with pneumococcal pneumonia established by results of culture of blood or lung aspirates gave a positive result with the agglutination test specific for serotype, whereas only four of the 102 urine samples obtained from control children without pneumonia gave positive results. The serotypes of antigens detected in the urine of children with pneumococcal pneumonia and the serotypes of pneumococci isolated from cultures of blood or lung aspirates were the same in all cases. When performed on urine samples the agglutination test specific for serotype has a high specificity and is more sensitive than culture of blood or lung aspirates, commercial agglutination tests, or countercurrent immunoelectrophoresis in identifying pneumococcal pneumonia. It is easy to use and should be especially useful in communities with limited laboratory facilities.

URINE COUNTERCURRENT IMMUN0ELECTROPH0RESIS FOR THE DIAGNOSIS OF PNEUMOCOCCAL PNEUMONIA

We report the results of a prospective trial in which counterimmunoelectrophoresis (CIE) and coagglutination (COA) have been used for the detection of specific pneumococcal capsular antigens in urine of 215 community-acquired pneumonia. Urines were studied unconcentrated and concentrated by ethanol precipitation and by anultrafilter system (Minicon B 15 concentrator Amicon). CIE was positive in 18 patients. Three of them,had untreated urine positive, 14 ethanol precipitated urine and 12 Amicon concentrated urine. COA was positive in none of these 18 CIE positive patients, and blood cultures only in two. In 3 children coexisted other etiology with a positive CIE. CONCLUSION: Althoug COA of urine does not apper to work sufficiently well to warrant its use, CIE can be useful in the diagnosis of pneumococcal pneumonia in children.

Countercurrent immunoelectrophoresis for the diagnosis of pneumococcal pneumonia in children

blood count, 13,500, with 65% lymphocytes, 20% polymorphonu cleocytes, 2% bands, 2% metamyelocytes, 2% monoeytes, and 6% eosinophils. Serum concentrations of calcium and phosphorus were normal. The urine spot examination for VMA was 15/~g/mg creatinine. The chest roentgenogram showed a posterior superior mediasfinal mass separate from a normal thymic shadow. Results of an WP, bone survey, and Gallium scan were normal. At thoracotomy a 3 • 5 • 2 cm mass resembling normal thymic tissue was located posterior to the superior vena cava lying along the right side of the trachea. After a normal thymus gland was identified in its usual location, the mass was removed. Histologic examination revealed thymic tissue in involution.

STOSSTHERAPY IN ACUTE RESPIRATORY INFECTION IN CHILDREN

STOSSTHERAPY is a word of Germanic origin, Stoss referring to "a thrust" or "a push." The term has been used to describe a method of treating rickets with a single massive dose of vitamin D. In a recent article (Brit. M. J., 1:487, March 1, 1958) the author "thrusts" antibacterial agents at children and compares the results with conventional treatment by antibacterial agents over a period of some days. The chief contribution of this paper is to remind the reader that careful earlier studies showed that a single massive dose of sulfonamide can be curative of pneumococcal pneumonia in children, a fact established almost 20 years ago. In the debit side is the introduction of a burdensome word in a paper remarkably devoid of appropriate documentation. Between October, 1952, and October, 1954, 174 children with acute lower-respiratory-tract infection were treated at the Evelina Children's Hospital of Guy's Hospital, London, with penicillin by injection or oral sulfonamide, or a combination of both. The personal preferences of no less than 14 doctors who admitted these patients dictated the decisions regarding therapy.