Pleural effusion with negative culture: a challenge for pneumococcal diagnosis in children

Parapneumonic Empyema Complicating Community-acquired Pneumonia: Etiology in the Era of Pneumococcal Vaccination and Role of Molecular Diagnosis

BACKGROUND

Impact of pneumococcal conjugate vaccines (PCVs) on pneumococcal disease is well described; pneumococcus is infrequently identified by culture in pneumonia. Yield is higher when pleural fluid is cultured. Polymerase chain reaction (PCR) in pleural fluid samples improves pathogen identification, particularly in the case of S. pneumoniae.

METHODS

Healthy children with empyema who underwent pleural fluid drainage were eligible. Demographics and PCV immunization status were collected. Blood/pleural fluid cultures were obtained. Pleural fluid samples were sent for PCR for pathogen. Serotyping was done by Neufeld-Quellung reaction on pneumococcus isolates, and PCR in culture negative cases.

RESULTS

From December 2018 to September 2023, 74 patients were enrolled. Pathogens were cultured in 22 patients (29.7%), with pneumococcus found in 6 (27.3%). PCR identified additional pathogens in 23 patients (31.1%), including 18 pneumococci (81.8%) and real-time PCR identified 5 more pneumococci, totaling 29 pneumococci, with 23 (79.3%) detected by PCR only. Serotype information was available for 27 (93.1%) pneumococci; 22 (81.5%) were identified as PCV-13 serotypes, with serotype 3 being present in 17 (63%) cases. Among patients with a PCV-13 serotype detected through culture or molecular methods, 15 (68.2%) were fully vaccinated with PCV-13, including 11 of 17 (65%) with serotype 3.

CONCLUSION

S. pneumoniae, particularly serotype 3, is the leading bacterial pathogen in children ≤18 years old. Molecular diagnosis enhances pathogen detection. Ongoing surveillance is crucial to monitor etiology changes as new pneumococcal vaccines are introduced.

Necrotizing Pneumonia In Children: A Review

The objective of the review was to determine the long-term outcomes of necrotising pneumonia (NP). Studies published since 1990 in English, Portuguese, or Spanish, published on PubMed and Scielo were evaluated. Our findings showed ultrasound scanning is the diagnostic modality of choice. Despite prolonged hospitalisation (median 13-27 days) and fever (median 9-16 days), most patients recover completely. Empyema and bronchopleural fistulae are frequent in bacterial NP. Streptococcus pneumoniae is the most prevalent cause. Seventeen studies with 497 patients followed for 30 days to 8.75 years showed that most patients were clinically asymptomatic and had normal lung function. X-ray or CT chest imaging demonstrated that almost all lung lesions recovered within 4-6 months. We suggest that it is not necessary to request frequent chest X-rays during the treatment and recovery process. Chest CT scans should be reserved for specific cases not following the expected clinical course.

Two Cases of Group A Streptococcus-Induced Right Empyema: Rare Occurrences in Adult Medicine

Group A Streptococcus (GAS) empyema, though rare in adults, poses serious clinical challenges. We present two cases of GAS-induced right empyema in immunocompetent patients. Case 1 involved a 45-year-old female Chinese healthcare worker with persistent pleural effusion despite antibiotic therapy. GAS was isolated from her sputum and bronchoalveolar lavage, necessitating a treatment shift to clindamycin and co-amoxiclav. Case 2 featured a 55-year-old Filipino domestic helper exhibiting right lower chest consolidation and effusion. Thoracocentesis confirmed empyema, prompting intrapleural fibrinolytic administration. Both cases highlight the diagnostic complexity and therapeutic intricacies of adult GAS empyema, underscoring the importance of early recognition and tailored management strategies for optimal patient outcomes.

Detection of Streptococcus pneumoniae antigen in pleural fluid: usefulness of an immunofluorescence-based lateral flow assay for the diagnosis of pneumococcal pneumonia

The performance of an immunofluorescence-based Streptococcus pneumoniae antigen detection test in pleural fluid (IF-PF) was evaluated. For proven and possible pneumococcal pneumonias global sensitivity and specificity were 92.6 (95 CI 76.6-97.9) and 80 (95 CI 62.7-90.5), respectively, with no significant differences between children and adults. Global diagnostic accuracy of IF-PF was 86% (74.2-93.7), and a substantial k index of concordance with culture/RT-PCR of 0.716 (0.535-0.896). IF-PF might be useful as a rapid complementary test for the etiologic diagnosis of pneumococcal pneumonia.

Identifying pneumococci in parapneumonic pleural effusion: Is there a role for culture-independent methods?

OBJECTIVE

To evaluate culture-independent procedures (immunochromatography and quantitative polymerase chain reaction [qPCR]) in the detection and susceptibility of Streptococcus pneumoniae directly from culture-negative pleural fluid (PF) in children.

METHOD

Detection of S. pneumoniae in PF of children with parapneumonic effusion and/or empyema by using two culture-independent methods: an immunochromatographic membrane test (IMT) which identifies the pneumococcal C antigen, and a real-time PCR test to detect pneumococcal genes lytA and pbp2b, a marker of susceptibility of β-lactam agents, in PF samples.

RESULTS

We tested 36 PF specimens and recorded the previous use of antimicrobials. In the final analysis, 34 samples were included. IMT and qPCR presented positive results in 23 (67.6%) and 24 (70.6%) of the samples, respectively, showing a moderate agreement (k = 0.518) between the two methods. From the 36 children included, 34 (94.4%) had antibiotic data available by the time when PFs were collected. Thirty-four (100%) children had been given treatment before PF sampling, with 33 (97%) receiving β-lactam antibiotics administered empirically. Of the 24 lytA real-time positive samples, 21 (87.5%) were also positive for pbp2b, a marker of β-lactam susceptibility.

CONCLUSION

The reduced sensitivity of culture for pneumococcal detection can be improved through the addition of IMT and qPCR analysis. The utility of qPCR combining detection of lytA and a marker of β-lactam susceptibility should be explored further.

Paediatric thoracic empyema in the tropical North Queensland region of Australia: Epidemiological trends over a decade

AIM

The Townsville Hospital and Health Service is the regional referral centre for children in the north of Queensland. Aboriginal and Torres Strait Islander (ATSI) people make up 7-10% of the population. Increasing numbers of children with paediatric thoracic empyema (pTE) are being referred to Townsville Hospital and Health Service for management. This study aims to describe the incidence rates, epidemiology, microbiology and trends of this disease in North Queensland over a 10-year period.

METHODS

A retrospective chart review of all children (1 month to 16 years), admitted in the years 2007-2016, with community-acquired pTE was conducted. International Classification of Diseases codes were used to identify the patients. Epidemiological and microbiological data were extracted from records.

RESULTS

Of the 123 cases identified, incidence rates per 100 000 were 8.5 (95% confidence interval (CI) 8.4-8.6) in all children and much higher at 19.8 (95% CI: 19.5-21.9) in ATSI children. The under 5 years age group had the highest rate (24.5; 95% CI: 24.4-24.6). There was a progressive rise in incidence during the 10-year period, with the highest incidence of 15.2 (95% CI: 15.1-15.2) occurring in 2016. A pathogen was isolated in 76% of cases. Non-multi-resistant methicillin-resistant Staphylococcus aureus was the most common pathogen isolated in 22 of 64 ATSI children (34%), while Streptococcus pneumoniae was the most common pathogen isolated in 27 of 59 non-ATSI children (46%).

CONCLUSIONS

A high and increasing incidence of pTE in North Queensland is being observed. ATSI children have higher incidence rates and are more likely to have non-multi-resistant methicillin-resistant Staphylococcus aureus as a causative agent.

When should parapneumonic pleural effusions be drained in children?

Pneumonia is an important health problem in children, and parapneumonic pleural effusion (PPE) is a frequent complication. There is no standard strategy for treating PPE, reflected in the few international guidelines that have been published on the issue. Compared to adults, there is no consensus on the utility of pleural fluid analysis in paediatric PPE. This is because of the lack of good evidence either in favour or against it and the risks of procedural sedation for acquiring pleural fluid for analysis to guide management. In this paper we provide a succinct review of the different approaches to the management of PPE, including diagnosis, pleural fluid analysis (Light's criteria) and treatment, both medical and surgical.