Heptavalent Pneumococcal Vaccine Research Articles

Burden of pneumococcal disease in children in Cuba before the introduction of a novel pneumococcal conjugate vaccine

# Background The Cuban heptavalent conjugate pneumococcal vaccine will be introduced for children beginning in 2020. We estimated the burden of pneumococcal cases and deaths in children 1-59 months in 2015. # Methods Mortality and morbidity attributable to pneumococcus were estimated for each of the three primary syndromes commonly associated with pneumococcus: pneumonia, meningitis, and invasive non-pneumonia, non-meningitis (NPNM). Vaccine randomized clinical trial data were used to estimate the proportion of pneumonia deaths attributable to pneumococcus. Data from Cuba were obtained from two domestic sources: National Bacterial Meningitis Surveillance System and the laboratory register from the National Reference Laboratory. Syndrome-specific pneumococcal mortality proportions were applied to all-cause pneumonia and meningitis death estimates prepared by the World Health Organization Maternal Child Epidemiology Estimation (WHO/MCEE) collaboration. The proportion of pneumonia cases attributable to pneumococcus was applied to estimates of all-cause clinical and severe pneumonia also prepared by the WHO/MCEE collaboration. Pneumococcal NPNM morbidity and mortality estimates were prepared using the ratio pneumococcal meningitis to pneumococcal invasive disease. Estimates were adjusted for HIV prevalence and access to health care. # Results In 2015, pneumococcus was estimated to cause 970 severe cases (uncertainty range, UR=692-1209) and 39 deaths (UR=23-59) among children 1-59 months. The estimated incidence rate of severe pneumonia was 149 (UR=112-170) per 100,000 children 1-59 months. The estimated case fatality ratio (CFR) was 2% (UR=1-2%). Over a period of one year, 22 deaths were attributed to pneumococcal pneumonia (UR=16-23), 9 (UR=14-19) to pneumococcal meningitis, and 8 (UR=3-17) to pneumococcal bacteremia. The CFR due pneumococcal meningitis was 18% (UR= 8-37%) in 2015. # Conclusions Reduced morbidity and mortality due to pneumococcal disease in Cuba could be achieved with the accelerated introduction of a novel PCV product in children.

Trend of invasive pneumococal disease (IPD) in a South Western, Nigerian hospital.

The recent introduction of the Heptavalent-pneumococcal vaccine (PCV-7) by private pharmaceutical companies in Nigeria, has generated interest in invasive bacterial diseases particularly IPD. Our objective in this study is to investigate the trend and occurrence rate of IPD in Abeokuta, Nigeria. Suspected IPD cases were assessed from Jan 2010 to Dec 2010 for demographic and Microbiological characteristics. Bacterial isolations and antibiotics susceptibility testing followed standard bacteriological procedure. Overall 471 cases of probable IPD was assessed, with 21(4.5%) cases of suspected pneumonia, 109(23.1%) cases of suspected meningitis, and 341(72.4%) cases of suspected septicaemia. Confirmed IPD cases were 9 with 2 cases of meningitis, 3 cases of septicaemia and 4 cases of pneumonia. Age range distribution showed, high distribution of IPD cases among children >1 with 5(55.6%) there was a statistically significant difference in gender p< 0.05 (X2 test) with females recording a higher occurrence than males. We conclude by advocating for better detection methods against IPD meningitis cases, and continuous surveillance into the serotypes of streptococcus pneumonia as well inclusion of the PCV vaccine into our childhood immunization program.

Trends in orbital complications of pediatric rhinosinusitis in the United States.

Several studies have documented the prevalence and treatment of orbital complications secondary to pediatric rhinosinusitis, but to our knowledge, none have investigated the national health care burden of this disease since the introduction of the heptavalent pneumococcal vaccine (PCV-7). To identify the current public health burden of orbital complications of pediatric rhinosinusitis, and to determine if the introduction of the PCV-7 has resulted in a change in national practice patterns. Population-based study using the 2000 and 2009 Kids' Inpatient Databases to gather data on a sample of all pediatric discharges in the United States during the years 2000 and 2009. Children diagnosed as having orbital complications of sinusitis were identified by corresponding International Classification of Diseases, Ninth Revision (ICD-9) codes. Database analyses generated national estimates of summary statistics and comparison of trends over the 9-year period. Database analysis. National health care trends according to year. End points assessed included prevalence, age, sex, length of hospital stay, and treatment of disease. The estimated prevalence of orbital complications of sinusitis requiring hospitalization in the United States has slightly decreased from 5338 (95% CI, 4956-5720) admissions in 2000 to 4511 (95% CI, 4165-4858) in 2009. However, the mean age has increased from 4.77 (95% CI, 4.56-4.97) years to 6.07 (95% CI, 5.87-6.26) years. The proportion of children undergoing surgical treatment increased from 0.108 (95% CI, 0.093-0.123) to 0.195 (95% CI, 0.176-0.213). Total charges increased from $4,140,000 (95% CI, $3,440,000-$4,830,000) to $10,000,000 (95% CI, $8,480,000-$11,600,000) with a mean charge per admission increasing from $8390 (95% CI, $7096-$9685) in 2000 to $22,656 (95% CI, $19,997-$25,314) in 2009. The mean length of stay remained stable at 3.67 (95% CI, 3.37-3.97) to 4.05 (95% CI, 3.81-4.29) hospital days. The public health impact of orbital complications of pediatric rhinosinusitis continues to be substantial. Since the institution of the PCV-7 vaccine, national trends demonstrate a slightly decreased prevalence of hospital admissions. However, there is a shifting trend toward an older age at admission and a higher proportion of children undergoing surgical treatment.

Immunogenicity and safety of 23-valent pneumococcal polysaccharide vaccine as a booster dose in 12- to 18-month-old children primed with 3 doses of 7-valent pneumococcal conjugate vaccine

The current study examined the safety and immunogenicity of 23-valent pneumococcal capsular polysaccharide vaccine (Pneumo23® [PPV23], Sanofi Pasteur) as a booster dose in 12- to 18-month-old children primed with heptavalent pneumococcal vaccine (PCV7; Prevnar®, Pfizer). This was a randomized, observer-blinded, 2-arm, controlled, multicenter phase III study performed in Thailand to assess and describe the immunogenicity and safety of PPV23 as a booster dose in children who had received the 3 primary doses of PCV7, the pneumococcal vaccine available during the study period. Children primed with 3 doses of PCV7 were randomized 1:1 to receive a booster immunization with PPV23 or PCV7. Pneumococcal antibody concentrations were measured by enzyme-linked immunosorbent assay and functional antibody levels by multiplex opsonophagocytosis assay on day 30. A total of 339 children were enrolled. Geometric mean serum antibody concentrations against serotypes common to PCV7 and PPV23 (4, 6B, 9V, 14, 18C, 19F, and 23F) increased in both groups but they were higher for serotypes 4, 9V, 18C, and 19F in the PPV23 group. Opsonization indices increased in both groups for all measured serotypes (1, 6B, 14, 19A, and 23F) and were higher for serotypes 6B, 14, and 23F in the PCV7 group and for serotypes 1 and 19A in PPV23 group. Solicited reactions and unsolicited adverse events were similar in the 2 groups and generally mild and transient. No treatment-related serious adverse events were reported. These results confirm that boosting with PPV23 is immunogenic and well tolerated in healthy toddlers primed with PCV7.

Prevalence of Heptavalent Vaccine-related Pneumococcal Serotypes in Nasopharyngeal carrier in children under five years old in Shahrekord, Iran by Multiplex-PCR during 2010- 2011.

Heptavalent pneumococcal vaccine which included pneumococcal serotypes 4, 6B, 9V,14, 18C, 19F and 23F has been regularly used and is effective on preventing invasive pneumococcal infection. This study aimed to determine vaccine-related serotype distribution in nasopharyngeal carrier and healthy children under five years old. In this cross-sectional study from September 2010 to September 2011, 363 nasopharyngeal specimens were collected from healthy children in day care centers. In positive cultures of streptococcus pneumoniae (S. pneumonia) distribution, serotypes were detected by Multiplex polymerase chain reaction (PCR). Electrophoresis of PCR products was used for detection of serotypes of S. pneumoniae. The carrier rate of S. pneumoniae was 29.5% with 95% confidence interval as 24.8- 34.5%. Electrophoresis of PCR products for detection of serotypes of S. pneumonia revealed 430, 220, 753, 189, 573, 304, and 384 bp (s) for 4, 6B, 9V, 14, 18C, 19F, and 23F serotypes of S. pneumoniae, respectively. The frequency of 23F, 6B, 19F, and 18C serotypes were 43%, 34%, 18%, and 5% respectively, but other serotypes (4, 9V and 14) were not detected. Based on the 30% carrier rate and high prevalence of most of heptavalent pneumococcal conjugate vaccine serotypes in our study, this vaccine should be used for prevention of invasive infection in Iranian children.

On the nature of pleural involvement in necrotizing pneumonia: A report of two cases of life threatening late complications

Suppurative complications of pneumonia such as empyema, lung abscess, pyopneumothorax, and necrotizing pneumonia (NP) are uncommon in children. Over the last decade an increasing incidence of NP has been reported. Streptococcus pneumoniae continues to be the predominant causative organism of NP, and while sporadic cases were reported prior to routine administration of heptavalent pneumococcal vaccine, a marked increase in NP appears to relate to replacement pneumococcal strains. Pleural involvement is almost universal in NP, and the course of pleural disease often determines its duration and outcome, particularly as it relates to complication of bronchopleural fistula. Cavities are formed in NP within the lung parenchyma and in the pleural space as the fibrosing pleural process organizes. The similarity of the radiologic appearance of parenchymal and pleural space cavities often makes the differentiation of pneumatocele versus residua of loculated pneumothorax challenging. The prevailing perception from most reports on childhood NP is of a favorable outcome with conservative approach. We report two pediatric cases with pneumonia who presented with prolonged fever despite antibiotic treatment, eventually diagnosed with NP. After stabilization on prolonged IV antibiotics, and weeks after discharge, they presented with unexpected acute respiratory failure due to a life-threatening tension air collection. In this article we discuss the nature of NP, its typical presentation, benign course and outcome, albeit its potential to cause serious late complications in the light of our recent experiences. Increasing awareness of such complications will result in more careful follow-up and in providing appropriate recommendations to parents of patients recovering from NP.

Carriage-Associated Streptocccus pneumoniae Serotype 1 in Brussels, Belgium

Streptococcus pneumoniae serotype 1 presents a high invasiveness index and is seldom isolated from its niche, the nasopharynx. We report an unusual serotype 1 carriage in a healthy pediatric population at the time of the heptavalent pneumococcal vaccine adoption in Belgium. Our sampling period coincides with an epidemic wave of serotype 1 invasive pneumococcal infections. Invasive and colonizing isolates were characterized by both antibiotic resistance profile and multilocus sequence typing and were shown to share the same backbone (ST306 and ST350).

Nasopharyngeal carrier rate of Streptococcus pneumoniae in children: serotype distribution and antimicrobial resistance.

This study aimed to define the nasopharyngeal carrier rates, serotype distribution, and antimicrobial resistance patterns of Streptococcus pneumoniae in healthy children less than ten years-old in Tehran. This was a cross-sectional study conducted from November 2008 until January 2009. Nasopharyngeal specimens were collected by trained investigators from 1300 healthy children recruited from 20 randomly selected day care centers and 50 elementary schools in Tehran and inoculated into blood agar. Positive cultures that grew alpha-hemolytic colonies were gram-stained and serotypes of the isolates identified by the Quellung reaction. All isolated pneumococci were tested for sensitivity to different antibiotics by the disc diffusion method. The carrier rate for Streptococcus pneumoniae was 44.1%. Serotypes 19, 6, 14, 17, 20, 23, and 21 were most common, found in decreasing order from 11.9% to 6.1%. Only 38.56% of isolates belonged to strains covered by the heptavalent pneumococcal vaccine. Most (69.4%) were resistant to one or more antimicrobial agents: tetracycline (69.85%), clarithromycin (57.2%), azithromycin (54.9%), co-trimoxazole (11.8%), penicillin (9.2%), and vancomycin (1.5%). All isolates were sensitive to rifampin and meropenem. This study has revealed the nasopharyngeal carrier rate, serotype distribution and antibiotic sensitivities of Streptococcus pneumoniae strains in children from Tehran. Our findings may have implications on the type and efficacy of pneumococcal conjugate vaccines that should be used for prevention of pneumococcal invasive disease in Iranian children.

Derrame pleural en pacientes hospitalizados en la era de la vacuna antineumocócica heptavalente

Introduction: Invasive pneumococcal disease is one of the diseases with higher morbidity and mortality in children. Despite expectations created, we discuss the role of the heptavalent vaccine in the incidence of complicates pneumonia. Our goal is to determine if it has increased in our hospital.Patients and methods: We studied 9068 patients admitted with the diagnosis of pneumonia in the Hospital Niño Jesús between 1996 and 2010. A retrospective, observational study, analyzing the total or partial introduction of the vaccine.Results: Sample segregation in 3 groups according to the non introduction and the total or partial introduction of the vaccine. We confirmed an increase in pleural effusion (p< 0.005) in vaccine groups.Conclusions: After the introduction of heptavalent pneumococcal vaccine it has been found in our sample an increase in complicated pneumonia with pleural effusion.

PspA Family Distribution, unlike Capsular Serotype, Remains Unaltered following Introduction of the Heptavalent Pneumococcal Conjugate Vaccine

Pneumococcal conjugate vaccines (PCVs) are recommended for the prevention of invasive pneumococcal disease (IPD) in young children. Since the introduction of the heptavalent pneumococcal vaccine (PCV7) in 2000, IPD caused by serotypes in the vaccine has almost been eliminated, and previously uncommon capsular serotypes now cause most cases of pediatric IPD in the United States. One way to protect against these strains would be to add cross-reactive protein antigens to new vaccines. One such protein is pneumococcal surface protein A (PspA). Prior to 2000, PspA families 1 and 2 were expressed by 94% of isolates. Because PCV7 vaccine pressure has resulted in IPD caused by capsular serotypes that were previously uncommon and unstudied for PspA expression, it was possible that many of the new strains expressed different PspA antigens or even lacked PspA. Of 157 pediatric invasive pneumococcal isolates collected at a large pediatric hospital in Alabama between 2002 and 2010, only 60.5% had capsular serotypes included in PCV13, which came into general use in Alabama after our strains were collected. These isolates included 17 serotypes that were not covered by PCV13. Nonetheless, pneumococcal capsular serotype replacement was not associated with changes in PspA expression; 96% of strains in this collection expressed PspA family 1 or 2. Continued surveillance will be critical to vaccine strategies to further reduce IPD.

Local Vaccine Site Reactions and Contact Allergy to Aluminum

Childhood vaccines are a routine part of pediatric care in the United States; clinicians must be able to recognize and interpret associated localized adverse reactions. Redness and induration at the site of injection are commonly reported and are considered to be the result of local inflammation or hematoma formation, although other atypical reactions can occur. We report the case of a 6-month-old infant who developed subcutaneous nodules at the sites of his 4- and 6-month Pentacel (DTaP/Hib/IPV, diphtheria, tetanus, acellular pertussis, Haemophilus b conjugate, and inactivated poliovirus vaccine) and 6-month Prevnar (heptavalent pneumococcal vaccine) injections. Infectious disease and immunodeficiency examinations were unremarkable. Aluminum contact allergy was considered, and contact allergy testing confirmed sensitivity to aluminum. Although rare, aluminum contact allergy after routine immunization can occur and should be considered in the differential diagnosis of persistent subcutaneous nodules after vaccination.

Pneumococcal vaccination in children at risk of developing recurrent acute otitis media – a randomized study

Acute otitis media (AOM) is a common childhood disease, which often becomes recurrent (rAOM). A small reduction in AOM episodes has been noted in unselected child cohorts after vaccination with heptavalent conjugate pneumococcal vaccine (PCV7). The purpose of this study was to investigate how vaccination affects young children at risk of developing rAOM. Ninety-six children with an AOM onset before 6 months of age, implying a high risk for rAOM, were closely monitored until the age of 2 years. Forty-six were vaccinated with PCV7 and 50 were not. All episodes of AOM, emergency visits and ventilation tube insertions were registered. A total of 363 AOM episodes were diagnosed. The incidence was reduced by 26% (p = 0.03), the number of emergency visits because of suspected AOM by 36% (p = 0.01) and the proportion of children who received ventilation tubes was halved in the vaccine group (p = 0.02). During the first 2 years of life, PCV7 significantly reduced AOM episodes, emergency visits and ventilation tube insertions in children with rAOM. Pneumococcal vaccine may be a future route to reduce antibiotic use and health care consumption in otitis-prone children.

Increased incidence of bronchopulmonary fistulas complicating pediatric pneumonia

The frequency of complicated pneumococcal disease, including necrotizing pneumonia, has increased over the last decade. During 2008-2009, we noted an increase in the number of children whose empyema was complicated by the development of a bronchopleural fistula and air leak. We studied these children to see if there was an associated cause. This was a retrospective case note and database review of children admitted to our tertiary unit with a parapneumonic effusion or empyema from 2002 to 2007, compared with 2008 to 2009. For the latter period, we also compared the outcomes of those with a bronchopleural fistula to those without. During the 8-year period, 310 children were admitted. In the first 6 years, the frequency of air leaks was 1% (2/258) rising to 33% (16/49) in the last 2 years (P<0.0001). Three children were excluded as their fistulas were possibly iatrogenic. This was associated with a significant increase in median hospital stay (7 vs. 10 days, P<0.0001) and surgical intervention rate (2% vs. 14%, P=0.001). In the latter 2 years, S. pneumoniae serotype 3 was identified in 10/16 (91%) of those with a bronchopleural fistula compared to 1/33 (3%) of those without. The frequency of bronchopleural fistulas increased markedly in the 2 years 2008-2009. Although these cases were associated with pneumococcal serotype 3 infection, which was not covered by the heptavalent pneumococcal vaccine Prevenar® in use at that time, we do not know whether the increased incidence of fistulas was due to a change in serotype 3 prevalence.

Vaccination of SCT recipients

Last year several scientific organizations collaborated in drafting the guidelines for prevention of infections after hematopoietic SCT (HSCT).1, 2 One set of guidelines dealt with vaccination of transplant recipients and in these guidelines the conjugated heptavalent pneumococcal vaccine (PCV7; Prevnar; Pfizer Inc.) was recommended based on several studies showing both immunogenicity and safety of this vaccine in HSCT recipients. Earlier this year, a 13-valent vaccine (Prevnar13; Pfizer Inc., New York, NY, USA), which is produced in a similar way to the 7-valent vaccine, was licensed in both the USA and Europe after the completion of large clinical trials in healthy children. This vaccine contains the same seven pneumococcal serotype antigens contained in the PCV7 together with antigens from additional six serotypes. After licensure, it was decided that the heptavalent vaccine will be withdrawn from the market and therefore the published recommendations cannot be followed. Presently, a clinical trial is ongoing with this 13-valent vaccine in allogeneic HSCT recipients. In addition, a 10-valent pneumococcal vaccine (Synflorix; GlaxoSmithKline, London, UK) conjugated to another carrier protein has also been licensed in Europe for which no data yet exist in immunocompromised patients. The alternative to these conjugated vaccines is polysaccharide vaccines that have shown decreased immunogenicity compared with conjugate vaccines in allogeneic HSCT recipients. Despite the lack of data, we recommend that the 13-valent vaccine be used as replacement for the heptavalent vaccine when this is no longer available, until additional studies are performed.

Modified sequential multiplex PCR for determining capsular serotypes of invasive pneumococci recovered from Seville

The heptavalent pneumococcal vaccine’s introduction resulted in a decline in invasive disease caused by Streptococcus pneumoniae, but was accompanied by an increase in non-vaccine serotypes. We evaluated a modified scheme of the sequential multiplex PCRs adapted to the prevalence of serotypes in Seville (Spain) for determining capsular serotypes of S. pneumoniae invasive clinical isolates. In adults, the modified scheme allowed us to type 73% with the first three reactions, and 92% with two additional PCRs. In paediatric patients, it allowed us to type 73.5% with the first three reactions, and 90% with the two additional PCRs. The multiplex PCR approach was successfully adapted to target the serotypes most prevalent in Seville.

Invasive pneumococcal disease after implementation of a reduced three-dose pneumococcal conjugate vaccine program: a pediatric tertiary care center experience

Following the implementation of a government-sponsored reduced three-dose (2 + 1) heptavalent conjugate pneumococcal vaccine (PCV7) program, we report a 61.4% decrease in the number of cases of invasive pneumococcal diseases (IPD) treated at our institution. Four years after the implementation of the three-dose reduced vaccine program, only 7.4% of IPD were caused by PCV7 serotypes, and there was an increase in the proportion of IPD caused by nonPCV7 serotypes; serotype 19A represented 40.7% of the strains isolated during the last year of the study. These results, similar to those previously observed with a regular four-dose (3 + 1) PCV7 schedule, are reassuring as to the effectiveness of a reduced three-dose (2 + 1) PCV7 program. Increasing numbers of IPD caused by nonPCV7 serotypes warrant the use of a new conjugate pneumococcal vaccine that contains serotype 19A.

Report on Invasive Disease and Meningitis due toHaemophilus influenzaeandStreptococcus pneumoniafrom the Network for Surveillance of Pneumococcal Disease in the East African Region

Pneumococcal disease in young children has not been as well characterized in East Africa as it has been in industrialized countries. Although pneumococci are likely to cause substantial mortality and morbidity, universal diagnostic challenges plus the rudimentary nature of public health surveillance make the true epidemiological characteristics of these diseases difficult to ascertain with these methods alone. However, local data are critical to inform the debate on vaccine deployment and assess vaccine impact. The Network for Surveillance of Pneumococcal Disease in the East African Region has worked to expand the World Health Organization Paediatric Bacterial Meningitis Surveillance Network-initiated surveillance process aimed at Haemophilus influenza type b to perform surveillance on pneumococcal diseases. A total of 119 H. influenzae isolates from children aged >2 years but <5 years of age have been confirmed. Eighty-three isolates (69.75%) were serotype b, 19 belonged to other capsular antigen groups, and 17 were nontypable. For Streptococcus pneumoniae, a total of 442 isolates were confirmed to be pneumococci; 302 isolates were from blood cultures, and 140 were from cultures of cerebrospinal fluid. Most of the isolates were obtained from patients in the 6-29-month age group; in this age group, overall coverage by the heptavalent vaccine was 56% (increasing to 67% with the addition of cross-protection due to serotype 6A). S. pneumoniae isolates are susceptible to most commonly used antibiotics, with the exception of trimethoprim-sulfamethoxazole, and have exhibited no resistance to penicillin. A surveillance network is in place to provide local data on the importance of S. pneumoniae as a cause of both meningitis and bacteremia. Serotypes in the currently available heptavalent conjugate pneumococcal vaccine and related serotypes account for two-thirds of invasive pneumococcal disease among children aged 6-29 months.

Safety experience with heptavalent pneumococcal CRM 197-conjugate vaccine (Prevenar ®) since vaccine introduction

Documentation of the safety of any vaccine is of paramount importance given the nature and scale of vaccination as a public health intervention. Prevenar ® was first approved for use in 2000, and includes seven pneumococcal serotypes conjugated to CRM 197, a carrier protein that has been used safely in multiple conjugate vaccines for more than 20 years. The safety profile of Prevenar ® was established prior to licensure in 5 clinical trials involving more than 18,000 infants and children. The largest postmarketing study of the safety of Prevenar ® given concomitantly with other recommended vaccines was conducted in the United States, and included more than 162,000 subjects. This analysis did not suggest any new safety consideration that would alter the risk–benefit balance of the vaccine, and demonstrated the favorable safety profile of Prevenar ®. To date, global surveillance of spontaneously reported adverse events to the manufacturer after more than 198 million doses distributed has confirmed these findings. The WHO has recommended the priority inclusion of this vaccine in national childhood immunization programs based on both its documented efficacy and safety. We will discuss the importance of monitoring vaccine safety and the methodologies by which this may be done, using Prevenar ® as an illustrative example.

Empyema associated with community-acquired pneumonia: A Pediatric Investigator's Collaborative Network on Infections in Canada (PICNIC) study

BackgroundAlthough the incidence of serious morbidity with childhood pneumonia has decreased over time, empyema as a complication of community-acquired pneumonia continues to be an important clinical problem. We reviewed the epidemiology and clinical management of empyema at 8 pediatric hospitals in a period before the widespread implementation of universal infant heptavalent pneumococcal vaccine programs in Canada.MethodsHealth records for children < 18 years admitted from 1/1/00–31/12/03 were searched for ICD-9 code 510 or ICD-10 code J869 (Empyema). Empyema was defined as at least one of: thoracentesis with microbial growth from pleural fluid, or no pleural fluid growth but compatible chemistry or cell count, or radiologist diagnosis, or diagnosis at surgery. Patients with empyemas secondary to chest trauma, thoracic surgery or esophageal rupture were excluded. Data was retrieved using a standard form with a data dictionary.Results251 children met inclusion criteria; 51.4% were male. Most children were previously healthy and those ≤ 5 years of age comprised 57% of the cases. The median length of hospitalization was 9 days. Admissions occurred in all months but peaked in winter. Oxygen supplementation was required in 77% of children, 75% had chest tube placement and 33% were admitted to an intensive care unit. While similarity in use of pain medication, antipyretics and antimicrobial use was observed, a wide variation in number of chest radiographs and invasive procedures (thoracentesis, placement of chest tubes) was observed between centers. The most common organism found in normally sterile samples (blood, pleural fluid, lung biopsy) was Streptococcus pneumoniae.ConclusionEmpyema occurs most commonly in children under five years and is associated with considerable morbidity. Variation in management by center was observed. Enhanced surveillance using molecular methods could improve diagnosis and public health planning, particularly with regard to the relationship between immunization programs and the epidemiology of empyema associated with community-acquired pneumonia in children.

¿Por qué hay más empiemas pediátricos en España?

There is a widespread perception among Spanish pediatricians that the incidence of empyema has significantly increased in the last few years, even though the objective information available is limited, and there is no specific active epidemiological surveillance system for this condition. In the present article, we review the situation of empyema in Spain, and discuss the main hypotheses put forward in the international literature to explain this increase, as well as the limitations of the sources available. Despite the scarcity of information, we draw the following conclusions: 1) the incidence of pediatric empyema is increasing in Spain, both generally and when caused by pneumococcus in particular; 2) the reason for this increase remains unknown, and to date no firm link has been established between this phenomenon and the heptavalent conjugate pneumococcal vaccine; and 3) this situation justifies the establishment of prospective systems for the surveillance and control of empyema and, once again, highlights the importance of developing active surveillance systems for pneumococcal disease.