Antigen detection for the diagnosis of pneumonia

Abstract

Streptococcus pneumoniae and Haemophilus influenzae type b are the main agents of bacterial community-acquired pneumonia in developing countries, although a definite etiologic diagnosis cannot be established in most cases. This study was carried out to assess the performance of a latex particle agglutination test (LPAT) from a commercial kit (Slidex Méningite Kit trade mark, BioMérieux, France) in diagnosing pneumococcal and H. influenzae type b pneumonia. One hundred and seven children (45 ill subjects and 62 healthy controls) were enrolled. All 45 cases had a presumptive diagnosis of bacterial pneumonia based on clinical (WHO criteria), laboratory (white blood cell count > or = 15.000/mm3, polymorphonuclear leukocytes > or = 70%, bands > or = 500/mm3, and C-reactive protein > or = 40 mg/l), and radiological findings, i.e., two or more positive points in the scoring system described by Khamapirad and Glezen (Semin Respir Infect 1987;2:130-144). Clinical, laboratory, and radiological assessments were performed in a blinded manner. LPAT was performed in urine samples after concentration through an ethanol-acetone solution. Sensitivity, specificity, and positive and negative predictive values were 77.3% (95% CI, 61.8-88.0%), 90.3% (95% CI, 79.5-96.0%), 85.0% (95% CI, 69.5-93.8%), and 84.8% (95% CI, 73.4-92.1%), respectively. Results suggest that LPAT is a useful diagnostic tool for the etiologic diagnosis of S. pneumoniae and H. influenzae type b pneumonia, especially in the developing world.

Impact of antibiotic therapy on laboratory analysis of parapneumonic pleural fluid in children

“…As a result, the development of alternative, more sensitive laboratory techniques has been encouraged (polymerase chain reaction, detection of capsular antigens) [9,27,28]. Our study confirms that previous antibiotic therapy may significantly influence culture results in pleural fluid and blood: bacteria were more easily identified in the absence of previous antibacterial treatment.…”

A Systematic Review on the Diagnosis of Pediatric Bacterial Pneumonia: When Gold Is Bronze

“…Five studies [25], [30]–[33] used a chest radiograph either alone or with other variables as the gold standard, measuring the validity of seven index tests. These index tests included: PCT with three cutoff points, WBC count, CRP, serology by complement fixation in 2 studies, latex particle agglutination, and nested PCR.…”

Rapid Diagnosis of Bacterial Pneumonia in Under-five Children by Latex Particle Agglutination Test in Urine

“…Similarly, Nunes et al (2004) reported that among 45 children with pneumonia, who had positive X-ray findings and high leukocyte count, LPAT were positive in 77.3% cases and negative in 22.7%. 15 Another study in India by Bahl et al (1995) showed the highest diagnostic yield with LPAT showing 52 (41.2%) cases positive by LPAT. 23 One study in USA found 24% antigenuria, in children with acute lower respiratory tract infection.…”

“…14 S. pneumoniae and H. influenzae type b are main the agents among community-acquired pneumonia in developing countries. 15 Organisms responsible for pneumonia occasionally cause bacteremia. Lung aspiration culture is the most sensitive and reliable method for isolation of bacterial agents in children but lung aspiration is invasive and exposes the child to potentially dangerous complications.…”