12 years active surveillance for pediatric pleural empyema in a Mexican hospital: effectiveness of pneumococcal 13-valent conjugate vaccine, and early emergence of methicillin-resistant Staphylococcus aureus

Invasive pneumococcal disease in Latin America and the Caribbean: Serotype distribution, disease burden, and impact of vaccination. A systematic review and meta-analysis

BACKGROUND

Invasive pneumococcal diseases (IPD) are associated with high morbidity, mortality, and health costs worldwide, particularly in Latin America and the Caribbean (LAC). Surveillance about the distribution of serotypes causing IPD and the impact of pneumococcal vaccination is an important epidemiological tool to monitor disease activity trends, inform public health decision-making, and implement relevant prevention and control measures.

OBJECTIVES

To estimate the serotype distribution for IPD and the related disease burden in LAC before, during, and after implementing the pneumococcal vaccine immunization program in LAC.

METHODS

Systematic literature review following Cochrane methods of studies from LAC. We evaluated the impact of the pneumococcal vaccine on hospitalization and death during or after hospitalizations due to pneumococcal disease and serotype-specific disease over time. We also analyzed the incidence of serotyped IPD in pneumococcal conjugate vaccine PCV10 and PCV13. The protocol was registered in PROSPERO (ID: CRD42023392097).

RESULTS

155 epidemiological studies were screened and provided epidemiological data on IPD. Meta-analysis of invasive diseases in children <5 years old found that 57%-65% of causative serotypes were included in PCV10 and 66%-84% in PCV13. After PCV introduction, vaccine serotypes declined in IPD, and the emergence of non-vaccine serotypes varied by country.

CONCLUSIONS

Pneumococcal conjugate vaccines significantly reduced IPD and shifted serotype distribution in Latin America and the Caribbean. PCV10/PCV13 covered 57-84% of serotypes in children under 5, with marked decline in PCV serotypes post-vaccination. Continuous surveillance remains crucial for monitoring evolving serotypes and informing public health action.

Systematic review on the impact of the pneumococcal conjugate vaccine ten valent (PCV10) or thirteen valent (PCV13) on all-cause, radiologically confirmed and severe pneumonia hospitalisation rates and pneumonia mortality in children 0-9 years old

Background

There is an ongoing need to assess the impact of pneumococcal conjugate vaccines (PCVs) to guide the use of these potentially valuable but under-utilized vaccines against pneumonia, which is one of the most common causes of post-neonatal mortality.

Methods

We conducted a systematic review of the literature on PCV10 and PCV13 impact on all-cause, radiologically confirmed and severe pneumonia hospitalisation rates as well as all-cause and pneumonia-specific mortality rates. We included studies that were published from 2003 onwards, had a post-licensure observational study design, and reported on any of our defined outcomes in children aged between 0-9 years. We derived incidence rates (IRs), incidence rate ratios (IRRs) or percent differences (%). We assessed all studies for risk of bias using the Effective Public Health Practice Project (EPHPP) quality assessment tool.

Results

We identified a total of 1885 studies and included 43 comparing one or more of the following hospitalised outcomes of interest: all-cause pneumonia (n = 27), severe pneumonia (n = 6), all-cause empyema (n = 8), radiologically confirmed pneumonia (n = 8), pneumococcal pneumonia (n = 7), and pneumonia mortality (n = 10). No studies evaluated all-cause mortality. Studies were conducted in all WHO regions except South East Asia Region (SEAR) and low- or middle-income countries (LMICs) in the Western Pacific Region (WPR). Among children <5 years old, PCV impact ranged from 7% to 60% for all-cause pneumonia hospitalisation, 8% to 90% for severe pneumonia hospitalisation, 12% to 79% for radiologically confirmed pneumonia, and 45% to 85% for pneumococcal confirmed pneumonia. For pneumonia-related mortality, impact was found in three studies and ranged from 10% to 78%. No obvious differences were found in vaccine impact between PCV10 and PCV13. One study found a 17% reduction in all-cause pneumonia among children aged 5-9 years, while another found a reduction of 81% among those aged 5-17 years. A third study found a 57% reduction in all-cause empyema among children 5-14 years of age.

Conclusion

We found clear evidence of declines in hospitalisation rates due to all-cause, severe, radiologically confirmed, and bacteraemic pneumococcal pneumonia in children aged <5 years, supporting ongoing use of PCV10 and PCV13. However, there were few studies from countries with the highest <5-year mortality and no studies from SEAR and LMICs in the WPR. Standardising methods of future PCV impact studies is recommended.

Systematic review on the impact of the pneumococcal conjugate vaccine ten valent (PCV10) or thirteen valent (PCV13) on all-cause, radiologically confirmed and severe pneumonia hospitalisation rates and pneumonia mortality in children 0-9 years old

Background

There is an ongoing need to assess the impact of pneumococcal conjugate vaccines (PCVs) to guide the use of these potentially valuable but under-utilized vaccines against pneumonia, which is one of the most common causes of post-neonatal mortality.

Methods

We conducted a systematic review of the literature on PCV10 and PCV13 impact on all-cause, radiologically confirmed and severe pneumonia hospitalisation rates as well as all-cause and pneumonia-specific mortality rates. We included studies that were published from 2003 onwards, had a post-licensure observational study design, and reported on any of our defined outcomes in children aged between 0-9 years. We derived incidence rates (IRs), incidence rate ratios (IRRs) or percent differences (%). We assessed all studies for risk of bias using the Effective Public Health Practice Project (EPHPP) quality assessment tool.

Results

We identified a total of 1885 studies and included 43 comparing one or more of the following hospitalised outcomes of interest: all-cause pneumonia (n = 27), severe pneumonia (n = 6), all-cause empyema (n = 8), radiologically confirmed pneumonia (n = 8), pneumococcal pneumonia (n = 7), and pneumonia mortality (n = 10). No studies evaluated all-cause mortality. Studies were conducted in all WHO regions except South East Asia Region (SEAR) and low- or middle-income countries (LMICs) in the Western Pacific Region (WPR). Among children <5 years old, PCV impact ranged from 7% to 60% for all-cause pneumonia hospitalisation, 8% to 90% for severe pneumonia hospitalisation, 12% to 79% for radiologically confirmed pneumonia, and 45% to 85% for pneumococcal confirmed pneumonia. For pneumonia-related mortality, impact was found in three studies and ranged from 10% to 78%. No obvious differences were found in vaccine impact between PCV10 and PCV13. One study found a 17% reduction in all-cause pneumonia among children aged 5-9 years, while another found a reduction of 81% among those aged 5-17 years. A third study found a 57% reduction in all-cause empyema among children 5-14 years of age.

Conclusion

We found clear evidence of declines in hospitalisation rates due to all-cause, severe, radiologically confirmed, and bacteraemic pneumococcal pneumonia in children aged <5 years, supporting ongoing use of PCV10 and PCV13. However, there were few studies from countries with the highest <5-year mortality and no studies from SEAR and LMICs in the WPR. Standardising methods of future PCV impact studies is recommended.

Continuous Effectiveness of Pneumococcal 13-Valent Conjugate Vaccine on Pediatric Pneumococcal Otomastoiditis: Results of 15 Years of Active/Prospective Surveillance in a Mexican Hospital on the Mexico-US Border

Introduction

The effectiveness of the 13-valent pneumococcal conjugate vaccine (PCV13) on sepsis, meningitis, pneumonia, and even acute otitis media has been proved in many studies. Nonetheless, the impact of PCV13 on otomastoiditis (OM) in children has barely been reviewed. In the past, we published a 13 years pneumococcal OM study from our hospital. This is a continuation of our active surveillance and is the first Latin American, prospective study examining the effectiveness of this vaccine on pneumococcal pediatric OM.

Methods

Active surveillance identifying patients < 16 years of age with OM admitted at the “Hospital General de Tijuana” was performed from October 1, 2005, to September 30, 2019. Diagnosis of OM was based on clinical exam (postauricular tenderness, erythema, and swelling causing protrusion of the auricle) and computerized tomographic signs (opacification of the mastoid air cells and middle ear). We used either conventional culturing or PCR to isolate bacterial pathogens, while to further Streptococcus pneumoniae serotype identification we used the Quellung Reaction (Statens Serum Institute^®) or PCR. To assess pneumococcal conjugate vaccines effectiveness (VE), we counted cases per month before any pneumococcal conjugate vaccine was implemented (19 months surveillance), during the 7-valent pneumococcal conjugate vaccine (PCV7) use in the pediatric community (61 months surveillance), after PCV13 implementation in children (100 months surveillance), and calculated as follows: VE = 1 -(cases per month with specific pneumococcal conjugate vaccination/cases per month without any pneumococcal conjugate vaccination).

Results

Following 15 years of active surveillance, we identified 21 cases of OM. At admission the median age of patients was 38 months (six months to 15 years old), the median hospitalization days was 12 (5 to 115). All patients underwent mastoidectomy. Identification of bacterial pathogens was possible in 19 (90.5%), among which. Streptococcus pneumoniae was the leading cause with 15 cases (79%). PCV7 VE was 27.8%, however, after PCV13 introduction, VE increased to 68%, with only one case of pneumococcal OM in the last two years, without incremental OM cases by other bacteriae.

Conclusion

After 15 years of active/prospective surveillance in our hospital, a continuous and high VE (68%) of PCV13 on pediatric OM caused by Streptococcus pneumoniae has been found, with only one case in the last two years.

Surveillance of pediatric parapneumonic effusion/empyema in New Zealand

AIM

The incidence of childhood empyema has been increasing in some developed countries despite the introduction of pneumococcal vaccination. This study aimed to document the incidence, bacterial pathogens, and morbidity/mortality of parapneumonic effusion/empyema in New Zealand.

METHODS

A prospective study of 102 children <15 years of age requiring hospitalization with parapneumonic effusion/empyema between May 1, 2014 and May 31, 2016 notified via the New Zealand Paediatric Surveillance Unit. Parapneumonic effusion/empyema was defined as pneumonia and pleural effusion persisting ≥7 days, and/or any pneumonia, and pleural effusion necessitating drainage. Notifying pediatricians completed standardized questionnaires.

RESULTS

Annual pediatric parapneumonic effusion/empyema incidence was 5.6/100,000 (95% confidence interval [CI]: 4.7-6.9). Most children (80%) required surgical intervention and 31% required intensive care. A causative organism was identified in 71/102 (70%) cases. Although Staphylococcus aureus (25%) and Streptococcus pneumoniae (25%) infection rates were equal, prolonged hospitalization and intensive care admission were more common in children with S. aureus PPE/E. Māori and Pasifika children were over-represented at 2.2 and 3.5 times, their representation in the New Zealand pediatric population. Pneumococcal vaccination was incomplete, with only 61% fully immunized and 30% unimmunized. Haemophilus influenzae type b vaccine uptake was near complete at 89/94 (95%), with influenza immunization only 3/78 (4%).

CONCLUSIONS

New Zealand has a high incidence of pediatric complicated parapneumonic effusion/empyema with significant morbidity. S. aureus was a significant cause of severe empyema in New Zealand, particularly for Māori and Pasifika children. Improvements in vaccine coverage are needed along with strategies to reduce S. aureus disease morbidity.

Complications in community acquired pneumonia: magnitude of problem, risk factors, and management in pediatric age

Introduction: In the last decades, the large use of several effective vaccines has dramatically reduced the incidence of community acquired pneumonia (CAP) in infants and children. Moreover, the availability of new antibiotics effective against emerging resistant strains of bacteria has greatly improved the early and long-term prognosis of this disease.Areas covered: The aim of this manuscript is to evaluate the burden of complicated CAP in pediatric age and to discuss its appropriate management.Expert opinion: Complicated CAP remains a problem for children in industrialized and developing countries. A larger use of lung ultrasonography (US) as first diagnostic approach could significantly improve early identification of cases at higher risk of complications. Difficult to solve, is the problem of the use of an antibiotic therapy able to assure adequate control in all the CAP cases, including those at high risk of or with already established complications. All these findings reveal that control of the incidence of complicated CAP remains difficult and will not be significantly changed in the next few years. Any attempt to improve complicated CAP management must be made. Consensus documents on better definition of the use of corticosteroids, fibrinolytic agents, and interventional procedures (including surgery) can allow us to reach this goal.

Molecular Characterization of Staphylococcus aureus Obtained from Blood Cultures of Paediatric Patients Treated in a Tertiary Care Hospital in Mexico

Purpose

Staphylococcus aureus is one of the main causative agents of hospital-acquired (HA) infections. In Mexico, information about the characteristics of clinical S. aureus isolates is limited. Our aim was to characterize S. aureus strains obtained from blood cultures of paediatric patients treated in a tertiary care hospital.

Materials and Methods

We analysed 249 S. aureus isolates over the period from 2006 to 2019, and their resistance profiles were determined. The isolates were classified into methicillin-resistant S. aureus (MRSA) or methicillin-sensitive S. aureus (MSSA). Staphylococcal cassettes chromosome mec (SCCmec) were detected. Virulence genes (cna, clfA, clfB, eta, etb, fnbA, fnbB, hla, pvl, sec, and tsst) were amplified, and their clonal relationships were established by pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST) and clonal complex (CC) typing. We reviewed one hundred medical files to collect clinical information.

Results

Thirty-eight percent of the isolates were MRSA and showed an expanded profile of resistance to other non-beta-lactam antibiotics, while MSSA strains presented a reduced resistance profile. SCCmec-II was the most frequent element (86.3%). Eight virulence factors were detected in MSSA and six in MRSA. The pvl gene was detected in four MRSA-SCCmec-IV isolates (P≤0.0001). MRSA isolates were distributed among 14 clones and were classified into 15 sequence types (ST); the most frequent was ST1011 (17%). The most common CC in MRSA was CC5 (69%, P≤0.0001), and in MSSA, it was CC30 (30%, P≤0.0001). Eighty-seven percent of MRSA isolates were HA-MRSA, and 13% were community-acquired MRSA (CA-MRSA). Of 21 HA-MRSA isolates, 17 had SCCmec-II, while two CA-MRSA isolates had SCCmec-IV. Of MSSA isolates, 77% were derived from HA infections and 23% from CA infections.

Conclusion

MSSA isolates had more virulence factors. MRSA isolates were resistant to more non-beta-lactam antibiotics, and those with SCCmec-IV expressed a greater variety of virulence factors. Most S. aureus isolates belonged to CC5.

Control of Methicillin-Resistant Staphylococcus aureus Strains Associated With a Hospital Outbreak Involving Contamination From Anesthesia Equipment Using UV-C

Methicillin-resistant Staphylococcus aureus (MRSA) is considered an opportunistic pathogen in humans and is mainly associated with healthcare-associated infections (HCAIs). This bacterium colonizes the skin and mucous membranes of healthy people and causes frequent hospital outbreaks. The aim of this study was to perform molecular typing of the staphylococcal cassette chromosome mec (SCCmec) and agr loci as wells as to establish the pulsotypes and clonal complexes (CCs) for MRSA and methicillin-sensitive S. aureus (MSSA) outbreaks associated with the operating room (OR) at a pediatric hospital. Twenty-five clinical strains of S. aureus (19 MRSA and 6 MSSA strains) were recovered from the outbreak (patients, anesthesia equipment, and nasopharyngeal exudates from external service anesthesia technicians). These clinical S. aureus strains were mainly resistant to benzylpenicillin (100%) and erythromycin (84%) and were susceptible to vancomycin and nitrofurantoin. The SCCmec type II was amplified in 84% of the S. aureus strains, and the most frequent type of the agr locus was agrII, which was amplified in 72% of the strains; however, the agrI and agrIII genes were mainly detected in MSSA strains. A pulsed-field gel electrophoresis (PFGE) analysis grouped the 25 strains into 16 pulsotypes (P), the most frequent of which was P1, including 10 MRSA strains related to the anesthesia equipment, external service anesthesia technicians, and hospitalized patients. Multilocus sequence typing (MLST) identified 15 sequence types (STs) distributed in nine CCs. The most prevalent ST was ST1011, belonging to CC5, which was associated with the SCCmec type II and agrII type. We postulate that the external service anesthesia technicians were MRSA carriers and that these strains were indirectly transmitted from the contaminated anesthesia equipment that was inappropriately disinfected. Finally, the MRSA outbreak was controlled when the anesthesia equipment disinfection was improved and hand hygiene was reinforced.