Failures of 13-Valent Conjugated Pneumococcal Vaccine in Age-Appropriately Vaccinated Children 2-59 Months of Age, Spain.

Vaccination with the 13-valent conjugated pneumococcal disease (PCV13) has reduced invasive pneumococcal disease (IPD), but there have been reports of vaccine failures. We performed a prospective study in children aged 2-59 months who received diagnoses of IPD during January 2012-June 2016 in 3 pediatric hospitals in Catalonia, Spain, a region with a PCV13 vaccination coverage of 63%. We analyzed patients who had been age-appropriately vaccinated but who developed IPD caused by PCV13 serotypes. We detected 24 vaccine failure cases. The serotypes involved were 3 (16 cases); 19A (5 cases); and 1, 6B, and 14 (1 case each). Cases were associated with children without underlying conditions, with complicated pneumonia (OR 6.65, 95% CI 1.91-23.21), and with diagnosis by PCR (OR 5.18, 95% CI 1.84-14.59). Vaccination coverage should be increased to reduce the circulation of vaccine serotypes. Continuous surveillance of cases of IPD using both culture and PCR to characterize vaccine failures is necessary.

Invasive Pneumococcal Disease and Influenza Activity in a Pediatric Population: Impact of PCV13 Vaccination in Pandemic and Nonpandemic Influenza Periods.

The objective of this study was to analyze the incidence, clinical presentation, and severity of invasive pneumococcal disease (IPD)-causing serotypes and the impact of the 13-valent pneumococcal conjugate vaccination during epidemic and nonepidemic influenza periods in Catalonia, Spain. This was a prospective study in persons aged <18 years diagnosed with IPD between 2012 and 2015 in three Catalan pediatric hospitals. IPD was defined as clinical infection together with isolation of Streptococcus pneumoniae by culture and/or detection by reverse transcription-PCR in a normally sterile sample. Incidence rate ratios (IRRs) and the fraction of IPD prevented associated with 13-valent pneumococcal conjugate vaccine (PCV13) were calculated. The bivariate analysis used the χ2 test and the multivariate analysis nonconditional logistic regression. A total of 229 cases of IPD were recorded. The incidence was higher during influenza epidemic periods (IRR, 2.7; 95% confidence interval [CI], 2.05 to 3.55; P < 0.001), especially for pneumonia (IRR, 3.25; 95% CI, 2.36 to 4.47; P < 0.001), with no differences in the distribution of pneumococcal serotypes. Complications during admission and sequel at discharge were greater during epidemic periods (adjusted odds ratio [aOR], 2.00; 95% CI, 1.06 to 3.77; P = 0.03) than at nonepidemic periods (aOR, 3.38; 95% CI, 1.37 to 8.29; P = 0.01). The prevented fraction for the population (PFp) of IPD in children aged 7 to 59 months was 48% to 49.4%. The PFp was higher in influenza epidemic than nonepidemic periods and increased when ≥2 doses of PCV13 or ≥1 after 24 months were administered. Influenza virus circulation increases the incidence of IPD in persons aged <18 years. In influenza epidemic periods, IPD cases were more severe. Increased PCV13 coverage might increase the fraction of IPD prevented in epidemic and nonepidemic periods.

Multidisciplinary, evidence-based consensus guidelines for human papillomavirus (HPV) vaccination in high-risk populations, Spain, 2016.

INTRODUCTION: Although human papillomavirus (HPV) routine vaccination programmes have been implemented around the world and recommendations have been expanded to include other high-risk individuals, current recommendations often differ between countries in Europe, as well as worldwide. AIM: To find and summarise the best available evidence of HPV vaccination in high-risk patients aiding clinicians and public health workers in the day-to-day vaccine decisions relating to HPV in Spain. METHODS: We conducted a systematic review of the immunogenicity, safety and efficacy/effectiveness of HPV vaccination in high-risk populations between January 2006 and June 2016. HPV vaccination recommendations were established with levels of evidence according to the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system. RESULTS: A strong recommendation about HPV vaccination was made in the following groups: HIV infected patients aged 9-26 years; men who have sex with men aged 9-26 years; women with precancerous cervical lesions; patients with congenital bone marrow failure syndrome; women who have received a solid organ transplant or hematopoietic stem cell transplantation aged 9-26 years; and patients diagnosed with recurrent respiratory papillomatosis. CONCLUSIONS: Data concerning non-routine HPV vaccination in populations with a high risk of HPV infection and associated lesions were scarce. We have developed a document to evaluate and establish evidence-based guidelines on HPV vaccination in high-risk populations in Spain, based on best available scientific evidence.

[Pertussis vaccine. Reemergence of the disease and new vaccination strategies]. / Vacuna de la tos ferina. Reemergencia de la enfermedad y nuevas estrategias de vacunación.

Pertussis continues to be a public health problem despite the significant decrease in its incidence due to routine vaccination. Resurgence of the disease in countries that have maintained high vaccination coverage has been observed in recent years. Although vaccination is the most effective preventive control measure, both natural and artificial immunity wane over time, and thus the protection offered by current vaccines is not long-lasting. Furthermore, acellular vaccines are less effective. The implementation of new vaccine strategies is required. Vaccination of pregnant women is the most effective strategy for preventing pertussis in young infants, who are the most vulnerable, and should be recommended together with cocooning, ie vaccination of future household and extra-domiciliary contacts who are the main transmitters of the disease.

[Pertussis in fully vaccinated infants and children. Are new vaccination strategies required?]. / Tos ferina en lactantes y niños bien vacunados. ¿Son necesarias nuevas estrategias de vacunación?

OBJECTIVE: To analyse the vaccination status of children diagnosed with pertussis and to compare the clinical manifestations of fully vaccinated with unvaccinated, or incompletely-vaccinated, children. METHODS: The clinical histories and vaccination cards of patients under 16years of age seen in the Emergency Room of the University Hospital Vall d'Hebron, Barcelona (Spain), for pertussis confirmed by a microbiological study were reviewed. The study period lasted from January 1, 2009 to December 31, 2011. RESULTS: Two hundred and twelve cases were studied: 35 in 2009, 28 in 2010 and 149 in 2011. RT-PCR was positive in 210 patients, and 73 had a positive culture. Infants under 6months of age account for 36.8% of all cases. Forty-four patients (21.5%) were not vaccinated. Forty-four (21.5%) children were between 2 and 5months of age and had received 1-2vaccine doses. One hundred and seventeen (57%) children were fully vaccinated; 76.9% (90cases) had received the last dose less than 4years ago. When clinical manifestations of the fully vaccinated patients were compared with those of the non-vaccinated or incompletely-vaccinated children, only cyanosis was found with a higher frequency in the latter group (P<.001). The age-adjusted probability of hospitalisation was significantly associated with non-vaccination (P=.001). The case mortality rate among inpatients was 1.3%. CONCLUSIONS: The number of pertussis cases seen in our centre has risen significantly in the last year. More than half (57%) of the patients were fully vaccinated, and 76.9% had received the last dose in the previous 4years. Other vaccination strategies, such as vaccination of adolescents, adults, and pregnant women, as well as a cocoon strategy are required to protect infants under 6months of age. More effective vaccines need to be developed.

[Carbapenem antibiotics in hospitalised paediatric patients. Adherence to a therapeutic protocol]. / Uso de antibióticos carbapenémicos en enfermos pediátricos hospitalizados. Adecuación de su prescripción a un protocolo terapéutico.

OBJECTIVE: To describe the use of carbapenems in children hospitalised outside intensive care and onco-haematology units, and assess adherence to a therapeutic protocol. PATIENTS AND METHODS: A retrospective observational study was conducted on the use of carbapenems between January 2009 and December 2010. The study included children with a community-acquired infectious disease or a health care-associated infectious disease, and who were admitted to paediatric areas of the Vall d'Hebron University Hospital (Barcelona, Spain), other than intensive care, neonatology and onco-haematology units. Clinical data were collected and antibiotic consumption data were provided by the Pharmacy Department. RESULTS: A total of 51 episodes fulfilled the inclusion criteria. Carbapenem as initial empirical treatment was indicated in 31.4%, and applied as rescue therapy in the remainder. The instructions of the protocol were adhered to in 70.6% of the empirical and 87.5% of the targeted prescriptions (77.6% overall). A better match was found for empirical carbapenem in patients with a previous admission or underlying condition. Factors such as diagnosis, age or antibiotic use prior to admission did not affect the empirical indication of carbapenem. CONCLUSIONS: The establishment of a treatment protocol with carbapenem indications in our centre since 2007 has yielded significantly better results on the appropriateness of the prescription than those obtained in other studies.

[Whooping cough in Spain. Current epidemiology, prevention and control strategies. Recommendations by the Pertussis Working Group]. / Tos ferina en España. Situación epidemiológica y estrategias de prevención y control. Recomendaciones del Grupo de Trabajo de Tos ferina.

A large increase of pertussis incidence has been observed in recent years in countries with high vaccination coverage. Outbreaks of pertussis are increasingly being reported. The age presentation has a bipolar distribution: infants younger 6months that have not initiated or completed a vaccination schedule, and adolescents and adults, due to the lost of natural or vaccine immunity over time. These epidemiological changes justify the need to adopt new vaccination strategies in order to protect young infants and to reduce pertussis incidence in all age groups. Adolescents and adults immunization must be a priority. In the first group, strategy is easy to implement, and with a very low additional cost (to replace dT vaccine by dTap one). Adult vaccination may be more difficult to implement; dT vaccine decennial booster should be replaced by dTap. The immunization of household contacts of newborn infants (cocooning) is the strategy that has a most important impact on infant pertussis. Recently, pregnant women vaccination (after 20weeks of gestation) has been recommended in some countries as the most effective way to protect the newborn.

Changes in Invasive Pneumococcal Disease in the Paediatric Population in the Second COVID-19 Pandemic Year.

Incidence of invasive pneumococcal disease (IPD) decreased worldwide in 2020, coinciding with the implementation of measures to reduce COVID-19 transmission. We evaluated the impact of the COVID-19 pandemic on healthcare demand and IPD in children in 2021 compared to the pre-pandemic period (2018-2019) and the early pandemic period (2020) in a study carried out during 2018-2021 in Catalonia. Incidence rates were compared by calculating the incidence rate ratio (IRR), and expressing percentage changes in IRR as (1-IRR)x100. Compared to 2018-2019, emergency room (ER) visits declined by 21% in 2021 (p < 0.001), mainly in the first quarter (-39%), and compared to 2020, ER visits increased by 22% in 2021 (p < 0.001), except in the first quarter. IPD incidence overall was 11.0 in 2018-2019 and 4.6 in 2021 (-58%, p < 0.001); the reduction in incidence was similar in the 0-4 age group and was higher in the first quarters. Compared to 2020, in 2021, IPD incidence decreased during the first quarter (-86%, p < 0.001), but increased from 0.0 to 1.2 in the second quarter (p = 0.02) and from 0.6 to 2.1 (p=0.03) in the fourth quarter. The decreased IPD incidence observed in 2021 compared to 2018-2019 (most especially in the first quarter) was greater than the decrease in healthcare demand and PCR test requests. Compared to 2020, IPD incidence decreased in the first quarter when a second state of alarm was in force. In 2021, compared to 2018-2019, there was a greater reduction in PCV13 serotypes than in non-PCV13 serotypes.

Impact of vaccinating pregnant women against pertussis on hospitalizations of children under one year of age in a tertiary hospital in Catalonia.

INTRODUCTION: The recommendation for pertussis vaccination in pregnancy was established in Catalonia in February 2014. The objective of this study was to compare the hospitalisation rate for pertussis in children under one year of age before and after the implementation of the vaccination programme. METHODS: Observational and retrospective study of patients under one year of age admitted to hospital with a diagnosis of pertussis. The hospitalisation rate of patients under one year of age of the period prior to the vaccination programme (2008-2013) was compared with the period with vaccination programme (2014-2019) in the total of children under one year of age and in 2 subgroups: children under 3 months and between 3-11 months. RESULTS: Hospitalization rate was significantly lower in the period with vaccination programme in children under one year of age and specifically in children under 3 months (2.43 vs. 4.72 per 1000 person-years and 6.47 vs. 13.11 per 1000 person-years, respectively). The rate ratios were: 0.51 (95% CI 0.36-0.73) for children under one year of age; 0.49 (95% CI 0.32-0.75) for those younger than 3 months and 0.56 (95% CI 0.30-1.03) for those with 3-11 months. No statistically significant differences were observed in the clinical severity between both periods. CONCLUSION: The introduction of the pertussis vaccination programme in pregnancy was associated with a global lower hospitalisation rate for pertussis in children under one year of age and specifically in those under 3 months of age.

Invasive pneumococcal disease in children under 60 months before and after availability of 13-valent conjugate vaccine.

BACKGROUND: Invasive pneumococcal disease (IPD) is the most important bacterial infection in young children, and the introduction of pneumococcal conjugate vaccines has changed its presentation. This study compared the incidence, characteristics and serotype distribution of IPD before and after the introduction of the pneumococcal conjugate vaccine (PCV13). METHODS: Prospective enrolment of patients with IPD aged less than 60 months and admitted to either of 2 tertiary care hospitals between January 2007 and December 2009 (pre-PCV13 period) and January 2012 and June-2016 (PCV13 period). RESULTS: We identified 493 cases, 319 in the pre-PCV13 period and 174 in the PCV13 period. The incidence of IPD decreased from 89.7 to 34.4 casos per 100 000 habitantes ( -62%; P < .001). This decrease was observed in all forms of disease except necrotising pneumonia (increase from 0.8 to 3.7 casos/100 000 population). There was a significant reduction in all serotypes included in the PCV13 and not included in the PCV7. We did not find significant differences in length of stay, mortality or the frequency of sequelae between both periods, but in the PCV13 period, the length of stay in the paediatric intensive care unit and the duration of mechanical ventilation were longer (P = .00). The incidence of serotype 3 decreased from 10.4 to 6.9 casos per 100 000 population, although it was the serotype involved most frequently in patients with severe disease. CONCLUSIONS: After the introduction of the PCV13, there has been a significant decrease in IPD cases. Serotype 3 continues to be an important cause of severe IPD.

[Rotavirus vaccines: a long and difficult journey]. / Vacunas antirrotavirus. Un largo y difícil camino.

Diarrhea is the second cause of death worldwide. The main causative agent in infants and children less than 5 years is rotavirus. Consequently, for the World Health Organization and the Global Alliance for Vaccines and Immunization (GAVI), rotavirus vaccination is an urgent priority. The global distribution of rotavirus serotypes varies from country to country, but in 80-90% of cases is caused by five types: G1P[8], G2P[4], G3P[8], G4P[8] and G9P[8]. Currently, two rotavirus vaccines are available, an attenuated monovalent G1P[8] vaccine, and a pentavalent human-bovine recombinant vaccine containing five strains of bovine WC3 rotavirus, four with a gene codifying the VP7 protein of human rotaviruses G1, G2, G3 and G4, and a fifth expressing the VP4 P[8] genotype.

[Characteristics of patients with invasive pneumococcal disease requiring admission to intensive care units]. / Características de los pacientes con enfermedad neumocócica invasora que requieren ingreso en la unidad de cuidados intensivos.

INTRODUCTION: Patients with invasive pneumococcal disease (IPD) may require admission into paediatric intensive care units (PICU). The aim of this study is to analyse the epidemiological, clinical, and microbiological characteristics associated with IPD that may require admission to the PICU. MATERIAL AND METHODS: A prospective study was conducted on cases of IPD diagnosed in three Paediatric Hospitals in Barcelona between January 2012 and June 2016. An analysis was made of the associations between the admission to PICU and the epidemiological, clinical, and microbiological variables. RESULTS: A total of 263 cases with IPD were included, of which 19% (n = 50) required admission to PICU. Patients with septic shock (7; 100%), meningitis (16; 84.2%), and those with complicated pneumonia (23; 15.2%) were admitted to the PICU. The most frequent complications were pulmonary (35.2%) and neurological (39.5%). The ratio between admission and non-admission to PICU was 4.7 times higher in subjects with an underlying disease. The serotypes associated with PICU admission were 19A (23% of the total of this serotype), serotype 14 (20%), serotype 3 (17%), and serotype 1 (12.5%). CONCLUSIONS: IPD required PICU admission in cases of septic shock and meningitis, and less so with complicated pneumonia. The percentage of admissions is greater in children with an underlying disease. Admission into the PICU involves a longer stay, complications during the acute phase, as well as sequelae, particularly neurological ones. The serotypes of the patients that were admitted to PICU were predominantly vaccine serotypes.

Impact of vaccinating pregnant women against pertussis on hospitalizations of children under one year of age in a tertiary hospital in Catalonia. / Impacto de la vacunación de las embarazadas frente a la tosferina en las hospitalizaciones de menores de un año en un hospital de tercer nivel de Cataluña.

INTRODUCTION: The recommendation for pertussis vaccination in pregnancy was established in Catalonia in February 2014. The objective of this study was to compare the hospitalization rate for pertussis in children under one year of age before and after the implementation of the vaccination program. METHODS: Observational and retrospective study of patients under one year of age admitted to hospital with a diagnosis of pertussis. The hospitalization rate of patients under one year of age of the period prior to the vaccination program (2008-2013) was compared with the period with vaccination program (2014-2019) in the total of children under one year of age and in 2subgroups: children under 3 months and between 3-11 months. RESULTS: Hospitalization rate was significantly lower in the period with vaccination program in children under one year of age and specifically in children under 3 months (2.43 vs. 4.72 per 1,000 person-years and 6.47 vs. 13.11 per 1,000 person-years, respectively). The rate ratios were: 0.51 (95% CI 0.36-0.73) for children under one year of age; 0.49 (95% CI 0.32-0.75) for those younger than 3 months and 0.56 (95% CI 0.30-1.03) for those with 3-11 months. No statistically significant differences were observed in the clinical severity between both periods. CONCLUSION: The introduction of the pertussis vaccination program in pregnancy was associated with a global lower hospitalization rate for pertussis in children under one year of age and specifically in those under 3 months of age.

Necrotizing pneumonia due to Streptococcus pneumoniae in children during the period of non-systematic use of PCV13 in Catalonia, Spain.

BACKGROUND: Some studies have observed an increased incidence of necrotizing pneumonia (NP) in recent years. This might be related to the emergence of non-vaccine S. pneumoniae serotypes after PCV7 introduction although it is suggested that evolutionary factors may have modified the virulence and the interactions of pneumococci. The aim of this study was to clinically and microbiologically define NP in the population served by the three major paediatric hospitals in Barcelona (Catalonia, Spain). METHODS: A prospective observational study was conducted in patients <18 years hospitalized due to invasive pneumococcal disease (January 2012-June 2016). Data of confirmed cases of pneumococcal NP (diagnosed by culture or DNA detection and serotyped) were collected. PCV13 was not systematically administered in Catalonia during the study period, but was available in the private market so the vaccination coverage in children increased from 48.2% to 74.5%. RESULTS: 35 cases of NP were identified. 77.1% of cases were associated with empyema. In the first 4 years, a trend to a decrease in NP incidence was observed (p=0.021), especially in children <5 years (p=0.006). Serotype 3 was responsible for 48.6% of NP cases. Five patients with NP due to serotype 3 were fully vaccinated for their age with PCV13. CONCLUSIONS: Serotype 3 has a preeminent role in pneumococcal NP and was associated with all PCV13 vaccination failures. Although in our series the incidence does not seem to be increasing, evolution of pneumococcal NP rates should be monitored after inclusion of PCV13 in the systematic calendar.

[Invasive pneumococcal disease in children under 60 months before and after availability of 13-valent conjugate vaccine]. / Enfermedad neumocócica invasiva en niños menores de 60 meses, antes y después de la introducción de la vacuna conjugada 13-valente.

BACKGROUND: Invasive pneumococcal disease (IPD) is the most important bacterial infection in young children, and the introduction of pneumococcal conjugate vaccines has changed its presentation. This study compared the incidence, characteristics and serotype distribution of IPD before and after the introduction of the pneumococcal conjugate vaccine (PCV13). METHODS: Prospective enrolment of patients with IPD aged less than 60 months and admitted to either of 2 tertiary care hospitals between January 2007 and December 2009 (pre-PCV13 period) and January 2012 and June-2016 (PCV13 period). RESULTS: We identified 493 cases, 319 in the pre-PCV13 period and 174 in the PCV13 period. The incidence of IPD decreased from 89.7 to 34.4 cases per 100,000 population (-62%; P<.001). This decrease was observed in all forms of disease except necrotising pneumonia (increase from 0.8 to 3.7 cases/100,000 population). There was a significant reduction in all serotypes included in the PCV13 and not included in the PCV7. We did not find significant differences in length of stay, mortality or the frequency of sequelae between both periods, but in the PCV13 period, the length of stay in the paediatric intensive care unit and the duration of mechanical ventilation were longer (P=.00). The incidence of serotype 3 decreased from 10.4 to 6.9 cases per 100,000 population, although it was the serotype involved most frequently in patients with severe disease. CONCLUSIONS: After the introduction of the PCV13, there has been a significant decrease in IPD cases. Serotype 3 continues to be an important cause of severe IPD.

[Community-acquired methicillin-resistant Staphylococcus aureus infections in children]. / Infecciones por Staphylococcus aureus resistente a meticilina adquirido en la comunidad en niños.

INTRODUCTION: Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) infections were first reported in the 1990s. Young, healthy individuals are frequently affected. The incidence of CA-MRSA in Spain is increasing. METHODS: All children seen between August 2006 and January 2009 with CA-MRSA infections were included. The S. aureus isolates were studied by conventional techniques, their antibiotic susceptibility by agar disk diffusion, the presence of mecA gene was detected by multiplex polymerase chain reaction (PCR) and the gene encoding the Panton-Valentine leukocidin (PVL) by conventional PCR. CA-MRSA colonization was studied both in patients and their family members. RESULTS: CA-MRSA was isolated in 15 samples from 12 patients, aged between 6 days and 14 years. Half of them were not native. Eight patients required hospital admission. The most common clinical presentation was skin and soft tissue infection (92%). Secondary CA-MRSA bacteraemia was present in two patients. All strains were PVL producers and two were resistant to macrolides associated to methicillin resistance and one of them was also resistant to lincosamides. An intra-familial transmission was identified. The clinical outcome was favourable in all patients. CONCLUSION: CA-MRSA infections are emerging in Spain. Empirical treatment of skin and soft tissue infections should not be changed, since their incidence is still low. The drainage of CA-MRSA suppurative infections plays an important role in their treatment. Clindamycin or trimethoprim-sulfamethoxazole should be used for mild or moderate skin and soft tissue infections. Controlling the spread of these strains presents a challenge in the community today.

[Serogroup C invasive meningococcal disease in the post-vaccine era and vaccine failures]. / Enfermedad meningocócica invasiva por serogrupo C en la era posvacunal y fallos vacunales.

INTRODUCTION: The incidence of serogroup C invasive meningococcal disease (IMD) has decreased since the introduction of systematic vaccination in 2000. The aim of this study is to determine the number of serogroup C IMD cases diagnosed since then and the vaccine failures. PATIENTS AND METHODS: A retrospective analysis was performed on patients diagnosed with IMD by culture or polymerase chain reaction (PCR) in a maternity and childhood hospital in Barcelona between 2001 and 2018. An analysis was made of the number of vaccine doses and the age received, as well as on the medical records and vaccine cards. RESULTS: There were 128 confirmed cases of IMD (7.1 cases/year; 70.3 in <5 years). The serogroup was studied in 125 (97.6%) cases, in which 103 (82.4%) were B, 10 (8%) were C, one (0.8%) was 29E, and one (0.8%) was Y, and only 10 (8%) were not able to be serogrouped. Of the 10 patients with serogroup C, 4 were not vaccinated, and in 3, the course was not complete as regards the number of doses. The other 3 received the complete course according to age and current calendar, and thus were considered vaccine failures. A total of 6 patients died (mortality rate: 4.7%), 5 due to serogroup B (mortality: 4.8%), and one due to serogroup C (mortality: 10%). CONCLUSIONS: Serogroup C only represented 8% of IMD cases in the period studied, with 30% of cases due to this serogroup being vaccine failures.

Impact of the 13-Valent Conjugated Pneumococcal Vaccine on the Direct Costs of Invasive Pneumococcal Disease Requiring Hospital Admission in Children Aged < 5 Years: A Prospective Study.

The lack of invasive pneumococcal disease (IPD) cost studies may underestimate the eect ofpneumococcal polysaccharide conjugated vaccines (PCV). The objective of this study was to estimatethe direct costs of hospitalized IPD cases. A prospective study was made in children aged <5 yearsdiagnosed with IPD in two high-tech hospitals in Catalonia (Spain) between 2007-2009 (PCV7 period)and 2012-2015 (PCV13 period). Costs were calculated according to 2014 Catalan Health Service ratesusing diagnostic-related groups. In total, 319 and 154 cases were collected, respectively. Pneumoniahad the highest cost (65.7% and 62.0%, respectively), followed by meningitis (25.8% and 26.1%,respectively). During 2007-2015, the costs associated with PCV7 serotypes (Pearson coecient (Pc) =?0.79; p = 0.036) and additional PCV13 serotypes (Pc = ?0.75; p = 0.05) decreased, but those of otherserotypes did not (Pc = 0.23 p = 0.62). The total mean cost of IPD increased in the PCV13 period by31.4% (¿3016.1 vs. ¿3963.9), mainly due to ICU stay (77.4%; ¿1051.4 vs. ¿1865.6). During the PCV13period, direct IPD costs decreased due to a reduction in the number of cases, but cases were more severe and had a higher mean cost. During 2015, IPD costs increased due to an increase in the costsassociated with non-PCV13 serotypes and serotype 3 and this requires further investigation.

Necrotizing pneumonia due to Streptococcus pneumoniae in children during the period of non-systematic use of PCV13 in Catalonia, Spain.

BACKGROUND: Some studies have observed an increased incidence of necrotizing pneumonia (NP) in recent years. This might be related to the emergence of non-vaccine S. pneumoniae serotypes after PCV7 introduction although it is suggested that evolutionary factors may have modified the virulence and the interactions of pneumococci. The aim of this study was to clinically and microbiologically define NP in the population served by the three major paediatric hospitals in Barcelona (Catalonia, Spain). METHODS: A prospective observational study was conducted in patients <18 years hospitalized due to invasive pneumococcal disease (January 2012-June 2016). Data of confirmed cases of pneumococcal NP (diagnosed by culture or DNA detection and serotyped) were collected. PCV13 was not systematically administered in Catalonia during the study period, but was available in the private market so the vaccination coverage in children increased from 48.2% to 74.5%. RESULTS: 35 cases of NP were identified. 77.1% of cases were associated with empyema. In the first 4 years, a trend to a decrease in NP incidence was observed (p=0.021), especially in children <5 years (p=0.006). Serotype 3 was responsible for 48.6% of NP cases. Five patients with NP due to serotype 3 were fully vaccinated for their age with PCV13. CONCLUSIONS: Serotype 3 has a preeminent role in pneumococcal NP and was associated with all PCV13 vaccination failures. Although in our series the incidence does not seem to be increasing, evolution of pneumococcal NP rates should be monitored after inclusion of PCV13 in the systematic calendar.