[Epidemiology of pneumococcal pneumonia among middle-aged and older adults in Catalonia, 2017-2018]

OBJECTIVE

To analyse population-based incidence and lethality of pneumococcal pneumonia (PP) requiring hospitalisation among Catalonian adults after universal vaccination implementation in infants.

DESIGN

Population-based cohort study.

SETTING

Primary care/hospital, Catalonia.

PARTICIPANTS

2,059,645 individuals ≥50 years old affiliated to the Institut Catala de la Salut retrospectively followed between 01/01/2017 and 31/12/2018.

MAIN OUTCOME MEASURES

The Catalonian information system for the development of research in primary care (SIDIAP, Sistema de Información para el Desarrollo de la Investigación en Atención Primaria) was used to establish baseline characteristics and risk-strata of cohort members at study start: low-risk (immunocompetent persons without risk conditions), intermediate-risk (immunocompetent persons with at-risk condition) and high-risk (immunocompromising conditions). PP requiring hospitalisation among cohort members across study period were collected from CMBD (Conjunto Mínimo Básico de Datos) discharge data of 64 reference Catalonian hospitals.

RESULTS

An amount of 3592 episodes of HPP were observed, with an incidence density of 90.7 cases per 100,000 person-years (95% CI: 85.2-96.5), being 11.9 bacteremic (95% CI: 10.8-13.1) and 78.8 non-bacteremic (95% CI: 74.0-83.8). Incidence rates substantially increased by age (37.3 in 50-64 years vs. 98.3 in 65-79 years vs. 259.8 in ≥80 years) and baseline-risk stratum (42.1, 120.7 and 238.6 in low-, intermediate- and high-risk stratum, respectively). Overall case-fatality rate was 7.6% (10.8% in invasive cases vs. 7.1% in non-invasive cases; pP=.004). In multivariable analyses, high-risk stratum and oldest age were the strongest predictors for invasive and non-invasive cases, respectively.

CONCLUSION

Incidence and lethality of PP remained moderate among adults >50 years in Catalonia during 2017-2018 (earlier period after universal vaccination introduction for infants).

Community-acquired pneumonia in hospitalised patients: changes in aetiology, clinical presentation, and severity outcomes in a 10-year period

BACKGROUND AND OBJECTIVE

Community-acquired pneumonia (CAP) is a frequent cause of hospitalisation. Several factors, such as pandemics, vaccines and globalisation may lead to changes in epidemiology, clinical presentation, and outcomes of CAP, which oblige to a constant actualisation. We performed this study to analyse how these factors have evolved over a 10-year period.

MATERIALS AND METHODS

Patients diagnosed with CAP for two 1-year periods that were 10 years apart (2007-2008 and 2017-2018) were included. We compared microbiological information, clinical data and evolutive outcomes in the two periods. A mortality analysis was performed.

RESULTS

1043 patients were included: 452 during the first period (2007- 2008), and 591 during the second period (2017-2018). Bacterial aetiology did not change during the 10-year period, besides a slight increase in Staphylococcus aureus (0.9% vs 2.9%, p = 0.026). There was a decline in the proportion of bacteraemia in the second period (14.8% vs 9.6%, p = 0.012). The incidence of complicated pleural effusion and septic shock declined too (6.4% vs 3.6%, p = 0.04 and 15.5% vs 6.3%, p < 0.001). Respiratory failure and Intensive care unit (ICU) admission were similar in both periods. Variables independently associated with mortality were age and septic shock. Influenza vaccine was a protective factor against mortality in the second period.

CONCLUSIONS

We have not found relevant differences in the bacterial aetiology of CAP over this 10-year period. There has been a decline in septic complications of CAP such as septic shock, bacteraemia, and complicated pleural effusion. Influenza vaccination is an important tool to reduce mortality.KEY MESSAGESThere were no differences in the bacterial pathogens causing CAP among the 10-year study period. There has been a decline in septic complications of CAP such as septic shock, bacteraemia, and complicated pleural effusion.

Genomic features of predominant non-PCV13 serotypes responsible for adult invasive pneumococcal disease in Spain

BACKGROUND

Although pneumococcal conjugate vaccines (PCVs) effectively prevent invasive pneumococcal disease (IPD), serotype replacement has occurred.

OBJECTIVES

We studied the pangenome, antibiotic resistance mechanisms and presence of mobile elements in predominant non-PCV13 serotypes causing adult IPD after PCV13 vaccine introduction in Spain.

METHODS

We conducted a multicentre study comparing three periods in six Spanish hospitals and analysed through whole genome sequencing representative strains collected in the pre-PCV13, early-PCV13 and late-PCV13 periods.

RESULTS

Among 2197 cases of adult IPD identified, 110 pneumococci expressing non-PCV13 capsules were sequenced. Seven predominant serotypes accounted for 42.6% of IPD episodes in the late-PCV13 period: serotypes 8 (14.4%), 12F (7.5%), 9N (5.2%), 11A (4.1%), 22F (3.9%), 24F (3.9%) and 16F (3.6%). All predominant non-PCV13 serotypes were highly clonal, comprising one or two clonal complexes (CC). In general, CC538, CC4048, CC3016F, CC43322F and CC669N, related to predominant non-PCV13 serotypes, were antibiotic susceptible. CC15611A was associated with resistance to co-trimoxazole, penicillin and amoxicillin. CC23024F was non-susceptible to penicillin and resistant to erythromycin, clindamycin, and tetracycline. Six composite transposon structures of the Tn5252-family were found in CC23024F, CC98912F and CC3016F carrying different combinations of erm(B), tet(M), and cat. Pangenome analysis revealed differences in accessory genomes among the different CC, with most variety in CC3016F (23.9%) and more conservation in CC15611A (8.5%).

CONCLUSIONS

We identified highly clonal predominant serotypes responsible for IPD in adults. The detection of not only conjugative elements carrying resistance determinants but also clones previously associated with vaccine serotypes (CC15611A and CC23024F) highlights the importance of the accessory genome.

Evaluation of the indirect impact of the 10-valent pneumococcal Haemophilus influenzae protein D conjugate vaccine in a cluster-randomised trial

Background

In the nation-wide double-blind cluster-randomised Finnish Invasive Pneumococcal disease trial (FinIP, ClinicalTrials.gov NCT00861380, NCT00839254), we assessed the indirect impact of the 10-valent pneumococcal Haemophilus influenzae protein D conjugate vaccine (PHiD-CV10) against five pneumococcal disease syndromes.

Methods

Children 6 weeks to 18 months received PHiD-CV10 in 48 clusters or hepatitis B/A-vaccine as control in 24 clusters according to infant 3+1/2+1 or catch-up schedules in years 2009―2011. Outcome data were collected from national health registers and included laboratory-confirmed and clinically suspected invasive pneumococcal disease (IPD), hospital-diagnosed pneumonia, tympanostomy tube placements (TTP) and outpatient antimicrobial prescriptions. Incidence rates in the unvaccinated population in years 2010―2015 were compared between PHiD-CV10 and control clusters in age groups <5 and ≥5 years (5―7 years for TTP and outpatient antimicrobial prescriptions), and in infants <3 months. PHiD-CV10 was introduced into the Finnish National Vaccination Programme (PCV-NVP) for 3-month-old infants without catch-up in 9/2010.

Results

From 2/2009 to 10/2010, 45398 children were enrolled. Vaccination coverage varied from 29 to 61% in PHiD-CV10 clusters. We detected no clear differences in the incidence rates between the unvaccinated cohorts of the treatment arms, except in single years. For example, the rates of vaccine-type IPD, non-laboratory-confirmed IPD and empyema were lower in PHiD-CV10 clusters compared to control clusters in 2012, 2015 and 2011, respectively, in the age-group ≥5 years.

Conclusions

This is the first report from a clinical trial evaluating the indirect impact of a PCV against clinical outcomes in an unvaccinated population. We did not observe consistent indirect effects in the PHiD-CV10 clusters compared to the control clusters. We consider that the sub-optimal trial vaccination coverage did not allow the development of detectable indirect effects and that the supervening PCV-NVP significantly diminished the differences in PHiD-CV10 vaccination coverage between the treatment arms.

Burden of pneumococcal disease among adults in Southern Europe (Spain, Portugal, Italy, and Greece): a systematic review and meta-analysis

The aim was to summarize pneumococcal disease burden data among adults in Southern Europe and the potential impact of vaccines on epidemiology. Of 4779 identified studies, 272 were selected. Invasive pneumococcal disease (IPD) incidence was 15.08 (95% CI 11.01-20.65) in Spain versus 2.56 (95% CI 1.54-4.24) per 100,000 population in Italy. Pneumococcal pneumonia incidence was 19.59 (95% CI 10.74-35.74) in Spain versus 2.19 (95% CI 1.36-3.54) per 100,000 population in Italy. Analysis of IPD incidence in Spain comparing pre-and post- PCV7 and PCV13 periods unveiled a declining trend in vaccine-type IPD incidence (larger and statistically significant for the elderly), suggesting indirect effects of childhood vaccination programme. Data from Portugal, Greece and, to a lesser extent, Italy were sparse, thus improved surveillance is needed. Pneumococcal vaccination uptake, particularly among the elderly and adults with chronic and immunosuppressing conditions, should be improved, including shift to a higher-valency pneumococcal conjugate vaccine when available.

National surveillance of antimicrobial susceptibilities to dalbavancin, telavancin, tedizolid, eravacycline, omadacycline and other comparator antibiotics and serotype distribution of invasive Streptococcus pneumoniae isolates in adults: results from the Surveillance of Multicenter Antimicrobial Resistance in Taiwan (SMART) programme in 2017-2020

Objectives

The aim of this study was to investigate the trends in serotypes and in vitro antimicrobial susceptibility of Streptococcus pneumoniae causing adult invasive pneumococcal disease (IPD) to dalbavancin, telavancin, tedizolid, eravacycline, omadacycline and other comparator antibiotics from 2017–2020 following implementation of the 13-valent pneumococcal conjugate vaccine (PCV-13) and during the COVID-19 (coronavirus disease 2019) pandemic.

Methods

During the study period, 237 S. pneumoniae isolates were collected from non-duplicate patients, covering 15.0% of IPD cases in Taiwan. Antimicrobial susceptibility testing was performed using a Sensititre® system. A latex agglutination method (ImmuLex™ Pneumotest Kit) was used to determine serotypes.

Results

Susceptibility rates were high for vancomycin (100%), teicoplanin (100%) and linezolid (100%), followed by ceftaroline (non-meningitis) (98.3%), moxifloxacin (94.9%) and quinupristin/dalfopristin (89.9%). MIC₅₀ and MIC₉₀ values of dalbavancin, telavancin, tedizolid, eravacycline and omadacycline were generally low. Non-vaccine serotype 23A was the leading cause of IPD across the adult age range. Isolates of serotype 15B were slightly fewer than those of PCV-13 serotypes in patients aged ≥65 years. The overall case fatality rate was 15.2% (36/237) but was especially high for non-PCV-13 serotype 15B (21.4%; 3/14). Vaccine coverage was 44.7% for PCV-13 and 49.4% for the 23-valent pneumococcal polysaccharide vaccine (PPSV-23), but was 57% for both PCV-13 and PPSV-23.

Conclusion

The incidence of IPD was stationary after PCV-13 introduction and only dramatically decreased in the COVID-19 pandemic in 2020. The MIC₅₀ and MIC₉₀ values of dalbavancin, telavancin, tedizolid, eravacycline, omadacycline were generally low for S. pneumoniae causing adult IPD.

A historical perspective of MDR invasive pneumococcal disease in Spanish adults

OBJECTIVES

To analyse the clonal dynamics and clinical characteristics of adult invasive pneumococcal disease (IPD) caused by MDR and penicillin-non-susceptible (PNS) pneumococci in Spain.

METHODS

All adult IPD episodes were prospectively collected (1994-2018). Streptococcus pneumoniae isolates were serotyped, genotyped and tested for antimicrobial susceptibility. Changes in the incidence of IPD were analysed and risk factors contributing to MDR were assessed by logistic regression.

RESULTS

Of 2095 IPD episodes, 635 (30.3%) were caused by MDR/PNS isolates. Over the study period, the incidence of MDR/PNS-IPD decreased (IRR 0.70; 95% CI 0.53-0.93) whereas that of susceptible isolates remained stable (IRR 0.96; 95% CI 0.80-1.16). A reduction of resistance rates to penicillin (-19.5%; 95% CI -37% to 2%) and cefotaxime (-44.5%; 95% CI -64% to -15%) was observed. Two clones, Spain9V-ST156 and Denmark14-ST230, accounted for 50% of current resistant disease. Among current MDR/PNS isolates, 45.8% expressed serotypes not covered by the upcoming PCV15/PCV20 vaccines. MDR/PNS episodes were associated with older patients with comorbidities, nosocomial acquisition and higher 30 day mortality. MDR/PNS pneumococci were not independently associated with 30 day mortality in multivariate analysis [OR 0.826 (0.648-1.054)].

CONCLUSIONS

Our study shows an overall reduction of MDR/PNS isolates in adults after the introduction of pneumococcal conjugate vaccines. However, a significant proportion of current resistant isolates are not covered by any of the upcoming PCV15/PCV20 vaccines. The burden of resistant disease is related to older patients with underlying conditions and caused by two major clones. Our data show that MDR is not a statistically significant factor related to increased mortality.

Non-bacteremic pneumococcal pneumonia: general characteristics and early predictive factors for poor outcome

Purpose: Nowadays, most cases of pneumococcal community-acquired pneumonia (PCAP) are diagnosed by positive urinary antigen. Our aims were to analyse process of care in patients hospitalised with non-bacteremic PCAP (NB-PCAP) and identify factors associated with poor outcome (PO) in this population.Methods: We conducted a prospective study, including patients hospitalised for NB-PCAP (positive urinary antigen and negative blood culture) over a 15 year period. We performed multivariate analysis of predisposing factors for PO, defined as need for mechanical ventilation and/or shock and/or in-hospital death.Results: Of the 638 patients included, 4.1% died in hospital and 12.8% had PO. Host-related factors were similar in patients with and without PO, but patients with PO had higher illness severity on admission. Adjusted analysis revealed the following independent factors associated with PO: being a nursing home resident (OR: 6.156; 95% CI: 1.827-20.750; p = .003), respiratory rate ≥30 breaths/min (OR: 3.030; 95% CI: 1.554-5.910; p = .001), systolic blood pressure <90 mmHg (OR: 4.789; 95% CI: 1.967-11.660; p = .001), diastolic blood pressure <60 mmHg (OR: 2.820; 95% CI: 1.329-5.986; p = .007), pulse rate ≥125 beats/min (OR: 3.476; 95% CI: 1.607-7.518; p = .002), pH <7.35 (OR: 9.323; 95% CI: 3.680-23.622; p < .001), leukocytes <4000/µL (OR: 10.007; 95% CI: 2.960-33.835; p < .001), and severe inflammation (OR: 2.364; 95% CI 1.234-4.526; p = .009). The area under the curve for predicting PO was 0.890 (95% CI: 0.851-0.929).Conclusions: Since patients with PO seem different and had worse in-hospital course, we identified eight independent risk factors for PO measurable on admission.

Estimating the Impact of Switching from a Lower to Higher Valent Pneumococcal Conjugate Vaccine in Colombia, Finland, and The Netherlands: A Cost-Effectiveness Analysis

INTRODUCTION

Widespread use of ten-valent (Synflorix™, GSK) or 13-valent (Prevenar 13™; Pfizer) conjugate vaccination programs has effectively reduced invasive pneumococcal disease (IPD) globally. However, IPD caused by serotypes not contained within the respective vaccines continues to increase, notably serotypes 3, 6A, and 19A in countries using lower-valent vaccines. Our objective was to estimate the clinical and economic benefit of replacing PCV10 with PCV13 in Colombia, Finland, and The Netherlands.

METHODS

Country-specific databases, supplemented with published and unpublished data, informed the historical incidence of pneumococcal disease as well as direct and indirect medical costs. A decision-analytic forecasting model was applied, and both costs and outcomes were discounted. The observed invasive pneumococcal disease (IPD) trends from each country were used to forecast the future number of IPD cases given a PCV13 or PCV10 program.

RESULTS

Over a 5-year time horizon, a switch to a PCV13 program was estimated to reduce overall IPD among 0-2 year olds by an incremental - 37.6% in Colombia, - 32.9% in Finland, and - 26% in The Netherlands, respectively, over PCV10. Adults > 65 years experienced a comparable incremental decrease in overall IPD in Colombia (- 32.2%), Finland (- 15%), and The Netherlands (- 3.7%). Serotypes 3, 6A, and 19A drove the incremental decrease in disease for PCV13 over PCV10 in both age groups. A PCV13 program was dominant in Colombia and Finland and cost-effective in The Netherlands at 1 × GDP per capita (€34,054/QALY).

CONCLUSION

In Colombia, Finland, and The Netherlands, countries with diverse epidemiologic and population distributions, switching from a PCV10 to PCV13 program would significantly reduce the burden of IPD in all three countries in as few as 5 years.

Epidemiology of pneumococcal diseases in Spain after the introduction of pneumococcal conjugate vaccines

In Spain, the use of pneumococcal conjugate vaccines (PCVs) has led to a decrease in the incidence of vaccine serotypes causing invasive and non-invasive disease in vaccinated and unvaccinated children and adults. Further, the coverage of most of the resistant serotypes by vaccines resulted in an overall decline in antibiotic resistance. As an undesirable effect, there was an increase in the non-vaccine serotypes causing infection, especially serotypes 1, 7F and 19A after PCV7 and serotype 8 after PCV13 approval, this making the beneficial effect of vaccination less apparent. The inclusion of PCVs in childhood vaccination schedules, its approval for use in healthy adults and the increasing number of serotypes covered by the vaccines in development are strong strategies in the fight against pneumococcal disease. Nonetheless, the epidemiology of Streptococcus pneumoniae infections must be still under surveillance to detect new changes, given the high capacity for recombination and adaptability of this always-surprising microorganism.

Emerging non-13-valent pneumococcal conjugate vaccine (PCV13) serotypes causing adult invasive pneumococcal disease in the late-PCV13 period in Spain

OBJECTIVE

An early reduction of adult invasive pneumococcal disease (IPD) was observed after the 13-valent pneumococcal conjugate vaccine (PCV13) introduction for children in Spain. We analysed the epidemiology of adult IPD in the late-PCV13 period.

METHODS

This was a prospective multicentre study of adult IPD involving six hospitals. Strains were serotyped, genotyped and studied for antimicrobial susceptibility. The late-PCV13 period was compared with the pre- and early-PCV13 periods.

RESULTS

A total of 2197 episodes were collected-949 in 2008-2009, 609 in 2012-2013 and 639 in 2015-2016. The initial decrease of IPD observed (from 12.3/100 000 to 8.1/100 000; 2008-2009 versus 2012-2013) plateaued in 2015-2016 (8.3/100 000). IPD due to PCV13 serotypes decreased (from 7.7 to 3.5 to 2.3/100 000; p < 0.05), whereas IPD caused by non-PCV13 serotypes increased (from 4.5 to 4.6 to 6.0/100 000; p < 0.05). The most frequent serotypes in the late-PCV13 period were: 8 (15.1%), 3 (10.5%), 12F (7.9%) and 9N (5.4%). These serotypes were related to major genotypes: CC53 (59.8%) and CC404 (30.4%) for serotype 8, CC180 (64.1%) and CC260 (28.1%) for serotype 3, CC989 (91.7%) for serotype 12F and CC67 (84.8%) for serotype 9N. Penicillin-non-susceptibility (21.2%) was associated with serotypes 11A (CC156), 14 (CC156) and 19A (CC320), and macrolide-resistance was related to serotypes 24F and 19A. Rates of pneumococcal meningitis remained stable throughout the periods (ranges 0.9, 0.8 and 1.0/100 000).

CONCLUSIONS

The initial decrease of adult IPD observed after PCV13 introduction for children has been balanced by the rise of non-PCV13 serotypes. The spread of antibiotic-resistant lineages related to non-PCV13 serotypes (11A and 24F) could be a threat for the treatment of serious pneumococcal diseases.

Evolution of the β-lactam-resistant Streptococcus pneumoniae PMEN3 clone over a 30 year period in Barcelona, Spain

Objectives

To analyse the epidemiology and genetic evolution of PMEN3 (Spain9V-156), a penicillin-non-susceptible clone of Streptococcus pneumoniae, causing invasive pneumococcal disease (IPD) in Barcelona during 1987-2016.

Methods

WGS was performed on 46 representative isolates and the data were used to design additional molecular typing methods including partial MLST, PCR-RFLP and detection of surface-exposed proteins and prophages, to assign the remaining isolates to lineages. The isolates were also subjected to antimicrobial susceptibility testing.

Results

Two hundred and twenty-seven adult cases of IPD caused by PMEN3 were identified. PMEN3 caused mainly pneumonia (84%) and the 30 day mortality rate was 23.1%. Evidence of recombination events was found, mostly in three regions, namely the capsular operon (associated with capsular switching) and adjacent regions containing pbp2x and pbp1a, the murM gene and the pbp2b-ddl region. Some of these genetic changes generated successful new variant serotype lineages, including one of serotype 11A that is not included in the current PCV13 vaccine. Other genetic changes led to increased MICs of β-lactams. Notably, most isolates also harboured prophages coding for PblB-like proteins. Despite these adaptations, the ability of this clone to cause IPD remained unchanged over time, highlighting the importance of its core genetic background.

Conclusions

Our study demonstrated successful adaptation of PMEN3 to persist over time despite the introduction of broader antibiotics and conjugate vaccines. In addition to enhancing understanding of the molecular evolution of PMEN3, these findings highlight the need for the development of non-serotype-based vaccines to fight pneumococcal infection.

Blood‒Brain Barrier Pathology and CNS Outcomes in Streptococcus pneumoniae Meningitis

Streptococcus pneumoniae is a major meningitis-causing pathogen globally, bringing about significant morbidity and mortality, as well as long-term neurological sequelae in almost half of the survivors. Subsequent to nasopharyngeal colonisation and systemic invasion, translocation across the blood‒brain barrier (BBB) by S. pneumoniae is a crucial early step in the pathogenesis of meningitis. The BBB, which normally protects the central nervous system (CNS) from deleterious molecules within the circulation, becomes dysfunctional in S. pneumoniae invasion due to the effects of pneumococcal toxins and a heightened host inflammatory environment of cytokines, chemokines and reactive oxygen species intracranially. The bacteria‒host interplay within the CNS likely determines not only the degree of BBB pathological changes, but also host survival and the extent of neurological damage. This review explores the relationship between S. pneumoniae bacteria and the host inflammatory response, with an emphasis on the BBB and its roles in CNS protection, as well as both the acute and long-term pathogenesis of meningitis.

Overview of pneumococcal serotypes and genotypes causing diseases in patients with chronic obstructive pulmonary disease in a Spanish hospital between 2013 and 2016

Background

Streptococcus pneumoniae is an important pathogen in chronic obstructive pulmonary disease (COPD). We aimed at showing the recent changes in the epidemiology of pneumococcal diseases in patients with COPD, especially after the introduction of the 13-valent pneumococcal conjugate vaccine (PCV13).

Methods

From 2013 to 2016, strains causing invasive pneumococcal disease (IPD), non-bacteremic pneumococcal pneumonia (non-BPP), and acute exacerbation of COPD (AE-COPD) were prospectively included. Antimicrobial susceptibility testing, serotyping, and genotyping were analyzed.

Results

We collected 345 pneumococci from 286 COPD patients (57 IPD, 78 non-BPP, and 210 AE-COPD). The most frequent serotypes were serotypes 3 (14.0%), 8 (14.0%), and 12F (8.8%) in IPD; serotypes 3 (16.7%), 11A (9%), 9L/N (7.7%), and 23A (7.7%) in non-BPP; and serotypes 11A (11%), nontypeable (11%), and 6C (10%) in AE-COPD. Resistance rates were highest among AE-COPD strains. Penicillin resistance was associated with serotypes 11A (CC156) and 19A (CC320 and CC230). Compared with previous studies, fluoroquinolone resistance in AE-COPD increased (9.5%), PCV13 serotypes decreased (31.6%, 26.9%, and 16.7% for IPD, non-BPP, and AE-COPD, respectively), and serotype 11A-CC156 in AE-COPD and serotype 8 in IPD increased.

Conclusion

The epidemiology of pneumococcal disease in COPD changed after the introduction of PCV13 in children. Increases in the highly invasive serotype 8 among patients with IPD and in serotype 11A-CC156 among patients with AE-COPD could compromise the ability of current PCVs to prevent diseases. Vaccines with a greater coverage could improve the benefits of adult vaccination.

Spatial Variability in the Persistence of Pneumococcal Conjugate Vaccine-targeted Pneumococcal Serotypes Among Adults

Invasive pneumococcal disease is a leading cause of morbidity worldwide. Pneumococcal conjugate vaccine effectively reduces the number of cases caused by vaccine-targeted serotypes among children who receive the vaccine and adults who are not directly vaccinated. Recently, there has been a debate as to whether adults should receive the same conjugate vaccine as children. In settings where vaccine uptake in children is high, the vaccine serotypes cause a small fraction of disease cases, and direct vaccination might have a small effect. However, direct vaccination might be warranted if geographic regions or subpopulations exist where the targeted serotypes persist at higher levels than expected. To detect such geographic variability, new methodology is required. We introduce an innovative, spatially varying change points model, combined with spatially varying intercepts and slopes, to jointly determine whether the beginning date of the vaccine-associated decline, the initial baseline proportion of invasive pneumococcal disease cases caused by vaccine-targeted serotypes, and/or the rate of decline of vaccine-targeted serotypes vary in the adult population across Connecticut, 1998-2009. Results indicate that there is substantial spatial variability in the pattern with which vaccine-targeted serotypes decline, suggesting that the fraction of invasive pneumococcal disease cases that could have been preventable by direct vaccination of adults in Connecticut during the study period differed over time and space. The newly developed model is shown to outperform a number of competitors in terms of explanatory and predictive ability.

A model for predicting bacteremia in patients with community-acquired pneumococcal pneumonia: a retrospective observational study

Background

Pneumococcal pneumonia causes high morbidity and mortality among adults. This study aimed to identify risk factors for bacteremic pneumococcal pneumonia, and to construct a prediction model for the development of bacteremia in patients with community-acquired pneumococcal pneumonia.

Methods

We retrospectively analyzed data from patients hospitalized with community-acquired pneumococcal pneumonia between April 2007 and August 2015. Logistic regression models were applied to detect risk factors for pneumococcal bacteremia, and a receiver operating characteristic curve was used to devise a prediction model.

Results

Based on the results of sputum cultures, urine antigen tests, and/or blood cultures, 389 patients were diagnosed with pneumococcal pneumonia, 46 of whom had bacteremia. In the multivariate analysis, age < 65 years, serum albumin level < 3.0 g/dL, need for intensive respiratory or vasopressor support (IRVS), and C-reactive protein level > 20 mg/dL were identified as independent risk factors for the development of pneumococcal bacteremia. The bacteremia prediction score based on receiver operating characteristic curve analysis had a sensitivity of 0.74 and a specificity of 0.78 in patients with two risk factors. The area under the receiver operating characteristic curve was 0.77 (95% confidence interval (CI), 0.70–0.85).

Conclusions

Age < 65 years, hypoalbuminemia, IRVS, and high C-reactive protein level on admission are independent risk factors for the development of bacteremia in patients with community-acquired pneumococcal pneumonia. A prediction model based on these four risk factors could help to identify patients with community-acquired pneumococcal pneumonia at high risk of developing bacteremia; this can be used to guide antibiotic choices.

Trial registration

UMIN-CTR UMIN 000004353. Registered 7 October 2010. Retrospectively registered.

The Alere BinaxNOW Pneumococcal Urinary Antigen Test: Diagnostic Sensitivity for Adult Pneumococcal Pneumonia and Relationship to Specific Serotypes

Little is known about the sensitivity of the BinaxNOW pneumococcal urinary antigen (PUA) test for adult pneumococcal pneumonia caused by different serotypes. In this study, we aimed to analyze the trends in the sensitivity of the PUA test over a 15-year period (2001 to 2015) and to analyze its sensitivity for pneumococcal pneumonia caused by different serotypes. In total, we analyzed 1,096 pneumococcal isolates from adults with pneumococcal pneumonia who had a PUA test performed at the onset of the episode. Three periods were analyzed: 2001 to 2005 (early use of the seven-valent pneumococcal conjugate vaccine [early PCV7]), 2006 to 2010 (late PCV7), and 2011 to 2015 (early PCV13). The sensitivity of the PUA test varied from 76.4% (95% confidence interval [CI], 70.5% to 82.4%) in the period from 2001 to 2005 to 77.9% in 2006 to 2010 (95% CI, 74.4% to 81.4%) and decreased to 60.5% (95% CI, 55.4% to 65.6%) in 2011 to 2015. This decrease was observed in 560 proven (83.2% in 2001 to 2005, 86.5% in 2006 to 2010, and 78.1%) and 536 probable (70.0% in 2001 to 2005, 68.7% in 2006 to 2010, and 41.5% in 2011 to 2015) episodes of pneumococcal pneumonia. Differences were observed in the sensitivity of the PUA test for diagnosing pneumonia caused by certain serotypes, being highest for the 9V (90.6%), 14 (86.8%), 18C (100%), and 20 (100%) serotypes and lowest for the 8 (55.2%), 9L/N (39.1%), 11A (48.8%), 23B (33.3%), and nontypeable (47.8%) serotypes. Comparing 2001 to 2005, 2006 to 2010, and 2011 to 2015, the prevalence of serotypes 9V (3.1%, 3.7%, and 1.7%, respectively) and 14 (7.2%, 5.1%, and 3.1%, respectively) decreased, while the prevalence of serotypes 23B (0%, 0.7%, and 1.4%, respectively), 9L/N (1.0%, 1.6%, and 3.4%, respectively), 11A (2.6%, 4.2%, and 3.7%, respectively), and 8 (1.5%, 1.5%, and 5.1%, respectively) increased. The PUA test sensitivity varied by pneumococcal pneumonia serotype, and these differences and the changes in serotype distribution were associated with an overall decrease in the sensitivity of the PUA test.

[Immunisation schedule of the Spanish Association of Paediatrics: 2018 recommendations]

The Advisory Committee on Vaccines of the Spanish Association of Paediatrics annually publishes the immunisation schedule considered optimal for children resident in Spain, according to available evidence on current vaccines. Regarding funded immunisations, 2+1 strategy (2, 4, 11-12 months) with hexavalent (DTPa-IPV-Hib-HB) and 13-valent pneumococcal vaccines are recommended. Administration of the 6-year booster dose with DTPa is recommended, and a poliomyelitis dose for children who had received the 2+1 scheme, as well as Tdap vaccine for adolescents and pregnant women in every pregnancy between 27 and 32 weeks' gestation. The two-dose scheme should be used for MMR (12 months and 2-4 years) and varicella (15 months and 2-4 years). MMRV vaccine could be applied as the second dose if available. Coverage of human papillomavirus vaccination in girls aged 12 with a two dose scheme (0, 6 months) should be improved. Information and recommendation for male adolescents about potential beneficial effects of this immunisation should be provided as well. The new 9 genotypes vaccine is now available, expanding the coverage for both gender. Regarding non-funded immunisations, Committee on Vaccines of the Spanish Association of Paediatrics recommends meningococcal B vaccination, with a 3+1 schedule, and requests to be included in the National Immunisation Program. Tetravalent meningococcal vaccine (MenACWY) is recommended to adolescents (14-18 years) who are going to live in countries with systematic vaccination against ACWY serogroups, and people >6 weeks of age with risk factors or travellers to countries with very high incidence. Vaccination against rotavirus is recommended in all infants.

Pre-vaccine serotype composition within a lineage signposts its serotype replacement - a carriage study over 7 years following pneumococcal conjugate vaccine use in the UK

Serotype replacement has been reported in carriage and disease after pneumococcal conjugate vaccine (PCV) introductions in the UK and globally. We previously described concurrent expansion and decline of sequence types associated with serotype replacement over 5 years following PCV introductions in the UK. Here we use whole-genome sequencing to fully characterise the population structure of pneumococcal isolates collected over seven winters encompassing PCV7 and PCV13 introductions in the UK, investigating the importance of lineages in serotype replacement. We analysed 672 pneumococcal genomes from colonised children of 4 years old or less. The temporal prevalence of 20 lineages, defined by hierarchical Bayesian analysis of population structure (BAPS), was assessed in the context of serotype replacement. Multiple serotypes were detected in the primary winter of sampling within three vaccine-type (VT) lineages BAPS4, BAPS10 and BAPS11, in which serotype replacement were observed. In contrast, serotype replacement was not seen in the remaining three VT lineages (BAPS1, BAPS13 and BAPS14), that expressed a single serotype (6B, 6A and 3, respectively) in the primary winter. One lineage, BAPS1 serotype 6B was undetectable in the population towards the end of the study period. The dynamics of serotype replacement, in this UK population, was preceded by the presence or absence of multiple serotypes within VT lineages, in the pre-PCV population. This observation could help predict which non-vaccine types (NVTs) may be involved in replacement in future PCV introductions here and elsewhere. It could further indicate whether any antibiotic resistance associated with the lineages is likely to be affected by replacement.

Indirect (herd) protection, following pneumococcal conjugated vaccines introduction: A systematic review of the literature

BACKGROUND

Pneumococcal diseases are major causes of morbidity among adults, especially those over 50years of age. While pneumococcal conjugated vaccines (PCV's) impact on pneumococcal disease rates among children is well established, the extent of its impact on adult pneumococcal related illness remains unclear. The aim of this systematic literature review was to describe the impact of PCV introduction to childhood national immunization programs worldwide on PCV-naive adult population.

METHODS

A systematic literature search was performed using the PubMed database. The search was limited to articles written in English and published between January 2000 and February 2016. Studies evaluating pneumococcal disease rates in individuals over 5years of age were included. Independent extraction of articles was performed by the two authors. Search terms included: Pneumococcal conjugated vaccine, herd, indirect, adults, and pneumonia.

RESULTS

Forty-nine articles meeting the selection criteria were identified, 39 regarding invasive pneumococcal disease (IPD, one on meningitis only), 8 regarding pneumonia, and 2 on both IPD and pneumonia. The majority of reports were from the US, UK and Canada. Considerable variability in the data sources, quality and completeness was observed. While most studies reported either statistically significant reduction or insignificant changes in IPD and pneumonia disease rates in adults following PCV nationwide implementation, few studies reported statistically significant increase in pneumococcal disease rates, these were mainly from countries with low PCV coverage rates and/or inadequate surveillance.

CONCLUSION

Invasive pneumococcal diseases and pneumonia rates among the adult population decreased in most countries following PCV introduction into the NIP. This indirect effect on older population seems to be dependent on PCV coverage rates and time from PCV nationwide implementation. Adults >65years old seem to benefit the most from PCV introduction.

Decrease of invasive pneumococcal disease (IPD) in adults after introduction of pneumococcal 13-valent conjugate vaccine in Spain

A prospective laboratory-based multicenter study that collected all adult invasive pneumococcal disease (IPD) episodes from 6 Spanish hospitals before (2008-2009) and after (2012-2013). The 13-valent pneumococcal conjugate vaccine (PCV13) licensure was conducted in order to analyze the impact of PCV13 introduction for children on adult IPD. A total of 1558 IPD episodes were detected. The incidence of IPD decreased significantly in the second period by -33.9% (95% CI, -40.3% to -26.8%). IPD due to PCV7 serotypes (-52.7%; 95% CI, -64.2% to -37.5%) and to PCV13 additional serotypes (-55.0% 95% CI, -62.0% to -46.7%) significantly decreased whereas IPD due to non-PCV13 serotypes remained stable (1.0% 95% CI, -12.9% to 17.2%). IPD due to all PCV13 additional serotypes significantly declined with the exception of serotype 3 (-11.3%; 95%CI -35.0% to 21.1%). IPD due to two non-PCV13 serotypes varied: serotype 6C that rose (301.6%; 95%CI, 92.7% to 733.3%, p<0.001), related to the expansion of ST3866C, and serotype 8 that decreased (-34.9%, 95%CI, -57.1 to -1.2, p = 0.049), related to a decline of the ST638. The recombinant clone ST652111A (variant of ST1569V) increased in frequency. The decrease of serotype 19A IPD was linked to a fall in those antibiotic susceptible clones. In the last period, rates of penicillin- and cefotaxime-resistance remained under 10% and 4%, respectively. Adult IPD decreased after the PCV13 introduction in Spain due to herd protection. The spread of multidrug resistant clones (ST3866C, ST652111A) related to non-PCV13 serotypes needs further surveillance.

The rise and fall of pneumococcal serotypes carried in the PCV era

Streptococcus pneumoniae is a major cause of meningitis, sepsis and pneumonia worldwide. Vaccination using pneumococcal conjugate vaccines (PCV) has therefore been part of the UK's childhood immunisation programme since 2006. Here we describe pneumococcal carriage rates in children under five years of age attending the paediatric department of a large UK hospital in response to vaccine implementation over seven winter seasons from 2006 to 2013. S. pneumoniae (n=696) were isolated from nasopharyngeal swabs (n=2267) collected during seven consecutive winters, October to March, 2006/7 to 2012/13. This includes the period immediately following the introduction of the seven-valent pneumococcal conjugate vaccine (PCV7) in 2006 in addition to pre- and post-PCV13 introduction in 2010. We show a decrease in PCV13 vaccine serotypes (VT) in the three years following PCV13 vaccine implementation (2010/11 to 2012/13). Serotype 6A represented the only observed VT following PCV13 implementation with all others (including PCV7 serotypes) absent from carriage. Overall pneumococcal carriage, attributable to non-VT (NVT), was consistent across all sampling years with a mean of 31·1%. The ten most frequently isolated NVTs were 6C, 11A, 15B, 23B, 15A, 21, 22F, 35F, 23A and 15C. Fluctuations in the prevalence of each were however noted. Comparing prevalence at 2006/07 with 2012/13 only 15A was shown to have increased significantly (p value of 0·003) during the course of PCV implementation. These data support the increasing evidence that the primary effect of PCVs is due to population immunity by reducing or eliminating the carriage of invasive VT serotypes. With IPD being increasingly attributed to non-vaccine serotypes, surveillance of carriage data continues to act as an early warning system for vaccine design and public health policy that require continual data of both carried pneumococcal serotypes and IPD attributed serotype data.

Pneumococcal serotype distribution in adults with invasive disease and in carrier children in Italy: Should we expect herd protection of adults through infants' vaccination?

The 7-valent pneumococcal conjugate vaccine (PCV7) produced a significant herd protection in unvaccinated adult population mostly because of pneumococcus carriage decrease in vaccinated children. It is not known if the 13-valent pneumococcal vaccine can give similar effect on adults. Aims of the work were to evaluate whether the 6 additional serotypes are present in nasopharynx of children and serotype distribution in invasive pneumococcal infections (IPD) in adults.  Realtime-PCR was used to evaluate pneumococcal serotypes in adults with confirmed IPD and in nasopharyngeal swabs (NP) from 629 children not vaccinated or vaccinated with PCV7 and resident in the same geographical areas.    Two hundred twenty-one patients (116 males, median 67.9 years) with IPD were studied (pneumonia n = 103, meningitis n = 61 sepsis n = 50, other n = 7). Two hundred twelve were serotyped. The most frequent serotypes were 3, (31/212; 14.6%), 19A, (19/212; 9.0%), 12 (17/212; 8.0%), 7F, (14/212; 6.6%). In NP of children, the frequency of those serotypes causing over 50% of IPD in adults was very low, ranging from 0.48% for serotype 7F to 7.9% for serotype 19A. On the other side serotype 5, very frequent in NP (18.7%) caused <1% IPD. In conclusion serotypes causing IPD in adults are very rarely found in children NP. We suggest that herd protection obtainable with the additional 6 serotypes included in PCV13 may be more limited than that demonstrated with PCV7 in the past. In order to reduce the burden of disease in adults, adults should be offered a specific vaccination program with highly immunogenic PCV.

Pneumococcal vaccination

PURPOSE OF REVIEW

Pneumococcal diseases (invasive diseases, pneumonia, otitis media, and sinusitis) are among the most frequent preventable infectious diseases carrying a very high morbidity and case fatality rate worldwide. Pneumococcal vaccination is a key element to reduce the global burden of the disease in children and adult population. Our aim is to discuss current knowledge of the epidemiology of pneumococcal disease and pneumococcal vaccines.

RECENT FINDINGS

After the introduction of conjugate vaccines (PCV7 and PCV13), rates of pneumococcal diseases because of vaccine serotypes have decreased considerably among children in the vaccine target and among nonvaccinated children and adults. Results of the Community-Acquired Pneumonia Immunization Trial in Adults demonstrated 45.6% efficacy of PCV13 against the first episode of pneumonia, 45% against first-episode nonbacteremic pneumococcal pneumonia, and 75% against the first episode of invasive pneumococcal diseases in adults older than 65 years. Recommendations for pneumococcal vaccination have changed recently in both the United States and Europe.

SUMMARY

The changing epidemiology of pneumococcal diseases should be closely investigated to assess the effectiveness and the usefulness of the current vaccination policies, and to identify future directions for preventing pneumococcal infections.

Population Structure of Streptococcus pneumoniae Causing Invasive Disease in Adults in Portugal before PCV13 Availability for Adults: 2008-2011

Among the 1660 isolates recovered from invasive pneumococcal disease (IPD) in adults (> = 18 yrs) in 2008–2011, a random sample of ≥50% of each serotype (n = 871) was chosen for MLST analysis and evaluation for the presence and type of pilus islands (PIs). The genetic diversity was high with 206 different sequence types (STs) detected, but it varied significantly between serotypes. The different STs represented 80 clonal complexes (CCs) according to goeBURST with the six more frequent accounting for more than half (50.6%) of the isolates—CC156 (serotypes 14, 9V and 23F), CC191 (serotype 7F), CC180 (serotype 3), CC306 (serotype 1), CC62 (serotypes 8 and 11A) and CC230 (serotype 19A). Most of the isolates (n = 587, 67.3%) were related to 29 Pneumococcal Molecular Epidemiology Network recognized clones. The overall proportion of isolates positive for any of the PIs was small (31.9%) and declined gradually during the study period (26.6% in 2011), mostly due to the significant decline of serotype 1 which is associated with PI-2. The changes in serotypes that occurred in adult IPD after the introduction of the seven-valent pneumococcal conjugate vaccine (PCV7) for children were mostly due to the expansion of previously circulating clones, while capsular switching was infrequent and not related to vaccine use. The reduction of IPD caused by PCV7 serotypes in the years following PCV7 implementation did not result in a decline of antimicrobial resistance in part due to the selection of resistant genotypes among serotypes 14 and 19A.

Invasive group B streptococcal infection in a patient with post splenectomy for hypersplenism secondary to liver cirrhosis and portal hypertension

BACKGROUND

Splenectomy in patients with liver cirrhosis (LC) is expected to become more common owing to its efficacy on portal hemodynamics. In this report we describe an alarming case of group B streptococcus (GBS) infection after splenectomy in a patient with LC.

METHODS

A 72-year-old woman with a history of LC was admitted to our emergency department because of respiratory failure. The patient had received left lateral segmentectomy of the liver and splenectomy three months before admission. Pulmonary examination revealed significant wheezing during inspiration and expiration, but no crackles and stridor. Chest radiography and CT showed no infiltrates. A presumptive diagnosis of bronchial asthma caused by upper respiratory infection was made. Four days after admission, GBS infection was confirmed by blood culture and penicillin G was administered. Antibiotics were given intravenously for a total of 12 days.

RESULTS

The patient was discharged on the 12th day after admission.

CONCLUSIONS

Although efficacy of splenectomy in patients with LC has been reported, immune status should be evaluated for a longer period. Patients who have undergone splenectomy are highly susceptible to bacteria; moreover, LC itself is an independent risk factor for mortality in patients with sepsis. Since prophylaxis against GBS has not been established, immediate action should be taken. Emergency physicians should be aware of invasive GBS infection in the context of the critical risk factors related to splenectomy and LC, particularly the expected increase of splenectomy performed in LC patients.

[Bacterial etiology of acute otitis media in Spain in the post-pneumococcal conjugate vaccine era]

INTRODUCTION

Acute otitis media (AOM) is common in children aged <3 years. A pneumococcal conjugate vaccine (PCV) (PCV7; Prevenar, Pfizer/Wyeth, USA) has been available in Spain since 2001, which has a coverage rate of 50-60% in children aged <5 years.

MATERIALS AND METHODS

Children aged ≥3 to 36 months with AOM confirmed by an ear-nose-throat specialist were enrolled at seven centers in Spain (February 2009-May 2012) (GSK study identifier: 111425). Middle-ear-fluid samples were collected by tympanocentesis or spontaneous otorrhea and cultured for bacterial identification. Culture-negative samples were further analyzed using polymerase chain reaction (PCR).

RESULTS

Of 125 confirmed AOM episodes in 124 children, 117 were analyzed (median age: 17 months (range: 3-35); eight AOM episodes were excluded from analyses. Overall, 69% (81/117) episodes were combined culture- and PCR-positive for ≥1 bacterial pathogen; 44% (52/117) and 39% (46/117) were positive for Haemophilus influenzae (Hi) and Streptococcus pneumoniae (Spn), respectively. 77 of 117 episodes were cultured for ≥1 bacteria, of which 63 were culture-positive; most commonly Spn (24/77; 31%) and Hi (32/77; 42%). PCR on culture-negative episodes identified 48% Hi- and 55% Spn-positive episodes. The most common Spn serotype was 19F (4/24; 17%) followed by 19A (3/24; 13%); all Hi-positive episodes were non-typeable (NTHi). 81/117 AOM episodes (69%) occurred in children who had received ≥1 pneumococcal vaccine dose.

CONCLUSIONS

NTHi and Spn were the main etiological agents for AOM in Spain. Impact of pneumococcal vaccination on AOM requires further evaluation in Spain, after higher vaccination coverage rate is reached.

Serotypes and Clonal Diversity of Streptococcus pneumoniae Causing Invasive Disease in the Era of PCV13 in Catalonia, Spain

The aim of this study was to study the serotypes and clonal diversity of pneumococci causing invasive pneumococcal disease in Catalonia, Spain, in the era of 13-valent pneumococcal conjugate vaccine (PCV13). In our region, this vaccine is only available in the private market and it is estimated a PCV13 vaccine coverage around 55% in children. A total of 1551 pneumococcal invasive isolates received between 2010 and 2013 in the Molecular Microbiology Department at Hospital Sant Joan de Déu, Barcelona, were included. Fifty-two serotypes and 249 clonal types-defined by MLST-were identified. The most common serotypes were serotype 1 (n = 182; 11.7%), 3 (n = 145; 9.3%), 19A (n = 137; 8.8%) and 7F (n = 122; 7.9%). Serotype 14 was the third most frequent serotype in children < 2 years (15 of 159 isolates). PCV7 serotypes maintained their proportion along the period of study, 16.6% in 2010 to 13.4% in 2013, whereas there was a significant proportional decrease in PCV13 serotypes, 65.3% in 2010 to 48.9% in 2013 (p<0.01). This decrease was mainly attributable to serotypes 19A and 7F. Serotype 12F achieved the third position in 2013 (n = 22, 6.4%). The most frequent clonal types found were ST306 (n = 154, 9.9%), ST191 (n = 111, 7.2%), ST989 (n = 85, 5.5%) and ST180 (n = 80, 5.2%). Despite their decrease, PCV13 serotypes continue to be a major cause of disease in Spain. These results emphasize the need for complete PCV13 vaccination.

Emergence of Amoxicillin-Resistant Variants of Spain9V-ST156 Pneumococci Expressing Serotype 11A Correlates with Their Ability to Evade the Host Immune Response

Capsular switching allows pre-existing clones of Streptococcus pneumoniae expressing vaccine serotypes to escape the vaccine-induced immunity by acquisition of capsular genes from pneumococci of a non-vaccine serotype. Here, we have analysed the clonal composition of 492 clinical isolates of serotype 11A causing invasive disease in Spain (2000–2012), and their ability to evade the host immune response. Antibiograms, serotyping and molecular typing were performed. The restriction profiles of pbp2x, pbp1a and pbp2b genes were also analysed. Interaction with the complement components C1q, C3b, C4BP, and factor H was explored whereas opsonophagocytosis assays were performed using a human cell line differentiated to neutrophils. Biofilm formation and the polymorphisms of the major autolysin LytA were evaluated. The main genotypes of the 11A pneumococci were: ST62 (447 isolates, 90.6%), followed by ST6521 (35 isolates, 7.3%) and ST838 (10 isolates, 2.1%). Beta lactam resistant serotype 11A variants of genotypes ST838 and ST6521 closely related to the Spain^9V-ST156 clone were first detected in 2005. A different pattern of evasion of complement immunity and phagocytosis was observed between genotypes. The emergence of one vaccine escape variant of Spain^9V-ST156 (ST6521^11A), showing a high potential to avoid the host immune response, was observed. In addition, isolates of ST6521^11A showed higher ability to produce biofilms than ST838^11A or ST62^11A, which may have contributed to the emergence of this PEN-resistant ST6521^11A genotype in the last few years. The emergence of penicillin-resistant 11A invasive variants of the highly successful ST156 clonal complex merits close monitoring.

Association Between Local Pediatric Vaccination Rates and Patterns of Pneumococcal Disease in Adults

BACKGROUND

Pneumococcal conjugate vaccine (PCV) is now recommended for use in adults in the United States. Because vaccination of children with PCVs protects adults from the targeted serotypes, local variations in PCV uptake among children could influence disease patterns in adults.

METHODS

We obtained ZIP code-level data on invasive pneumococcal disease (IPD) from an active population-based surveillance system in Connecticut (study interval, 1998-2009) and ZIP code-level data on immunization with at least 3 or at least 4 doses of 7-valent PCV (PCV7) from the state immunization registry. We fit logistic regression models to estimate the proportion of IPD cases among adults aged >40 years that were caused by PCV7-targeted serotypes. Covariates included ZIP code-level socioeconomic indicators (eg, percentage of the population that was black and income per capita), the percentage of the population that received 3 or 4 doses of PCV7 (mean centered), and a linear spline to control for the average rate of decline across all ZIP codes.

RESULTS

ZIP codes that had a higher proportion of children that did not complete the 4-dose PCV7 series had a higher proportion of adult IPD cases caused by PCV7 serotypes.

CONCLUSIONS

Local variations in PCV uptake (and receipt of the booster dose) might influence the effectiveness of PCVs in preventing pneumococcal disease in adults.

Temporal trends and clonal diversity of penicillin non-susceptible pneumococci from meningitis cases from 1996 to 2012, in Salvador, Brazil

Background

Hospital-based surveillance for pneumococcal meningitis has been conducted since January 1996 in the city of Salvador, Brazil. The purpose of this study was to describe the temporal evolution of Penicillin Non-Susceptible Streptococcus pneumoniae (PNSSP) in regards to serotype distributions and clonal diversity recovered from meningitis cases over 17 years.

Methods

Broth microdilution was used to identify pneumococcal isolates that were PNSSP (Minimum Inhibitory Concentration > 0.12 μg/ml). The annual incidence rate of meningitis cases was calculated. Serotyping was defined using multiplex polymerase chain reaction assays and quellung reaction. Genetic diversity of PNSSP isolates was assessed using both pulsed-field gel electrophoresis (PFGE) and Multilocus Sequence Typing (MLST) analyses.

Results

A total of 854cerebrospinal fluid (CSF) culture pneumococcal isolates were tested by broth microdilution method and serotyped. A total of 173 (20.3 %) were penicillin non-susceptible (PNSSP) (Minimum Inhibitory concentration ≥ 0.12 μg/ml). The annual incidence of meningitis cases declined from 1.65/100,000 population (1996) to 0.2/100,000 population in 2012 and the rate due to PNSSP declined 82 % over the 17-years of surveillance. PNSSP isolates were restricted to 13 serotypes, being the most common ones serotypes14 (45.1 %; 78/173), 23 F (19.1 %; 33/173), 6B (14.4 %; 25/173), 19 F (9.2 %; 16/173) and 19A (5.2 %; 9/173). Among the PNSSP isolates, 94 % had serotypes represented in the 10-valent conjugate vaccine (PCV10). The predominant serotype 14 clonal groups were identified as PFGE group A/multilocus sequence type 66 (ST66) [35.3 % (61/173)] and PFGE group GK/ST156 [4.6 % (8/173)], the latter one associated with high level resistance to penicillin and ceftriaxone.

Conclusions

Our results show sustained reductions in pneumococcal meningitis cases in the Metropolitan region of Salvador from 1996 to 2012. This might reflect a beneficial impact of conjugate vaccines. Continued surveillance and further studies need to be conducted to better understanding on PCV10 vaccine impact.

A Bivalent Vaccine Based on a PB2-Knockout Influenza Virus Protects Mice From Secondary Pneumococcal Pneumonia

BACKGROUND

Secondary bacterial infections after influenza can be a serious problem, especially in young children and the elderly, yet the efficacy of current vaccines is limited. Earlier work demonstrated that a replication-incompetent PB2-knockout (PB2-KO) influenza virus possessing a foreign gene in the coding region of its PB2 segment can serve as a platform for a bivalent vaccine.

METHODS

In the current study, we generated the PB2-KO virus expressing pneumococcal surface protein A (PspA), PB2-KO-PspA virus, the replication of which is restricted to PB2-expressing cells. We then examined the protective efficacy of intranasal immunization with this virus as a bivalent vaccine in a mouse model.

RESULTS

High levels of influenza virus-specific and PspA-specific antibodies were induced in the serum and airways of immunized mice. The intranasally immunized mice were protected from lethal doses of influenza virus or Streptococcus pneumoniae. These mice were also completely protected from secondary pneumococcal pneumonia after influenza virus infection.

CONCLUSIONS

These findings indicate that our recombinant influenza virus serves as a novel and powerful bivalent vaccine against primary and secondary pneumococcal pneumonia as well as influenza.

Spread of Streptococcus pneumoniae serotype 8-ST63 multidrug-resistant recombinant Clone, Spain

This clone has spread throughout this country and caused invasive pneumococcal disease.

Since 2004, a total of 131 isolates of Streptococcus pneumoniae multidrug-resistant invasive serotype 8 have been detected in Spain. These isolates showed resistance to erythromycin, clindamycin, tetracycline, and ciprofloxacin. All isolates were obtained from adult patients and shared a common genotype (sequence type [ST]63; penicillin-binding protein 1a [pbp1a], pbp2b, and pbp2x gene profiles; ermB and tetM genes; and a ParC-S79F change). Sixty-eight isolates that required a ciprofloxacin MIC ≥16 μg/mL had additional gyrA gene changes. Serotype 8-ST63 pbp2x sequences were identical with those of antimicrobial drug–susceptible serotype 8-ST53 isolates. Serotype 8-ST63 pbp2b sequences were identical with those of the multidrug-resistant Sweden 15A-ST63 clone. Recombination between the capsular locus and flanking regions of an ST53 isolate (donor) and an ST63 pneumococcus (recipient) generated the novel 15A-ST63 clone. One recombination point was upstream of pbp2x and another was within pbp1a. A serotype 8-ST63 clone was identified as a cause of invasive disease in Spain.

Interaction of Vaccination and Reduction of Antibiotic Use Drives Unexpected Increase of Pneumococcal Meningitis

Antibiotic-use policies may affect pneumococcal conjugate-vaccine effectiveness. The reported increase of pneumococcal meningitis from 2001 to 2009 in France, where a national campaign to reduce antibiotic use was implemented in parallel to the introduction of the 7-valent conjugate vaccine, provides unique data to assess these effects. We constructed a mechanistic pneumococcal transmission model and used likelihood to assess the ability of competing hypotheses to explain that increase. We find that a model integrating a fitness cost of penicillin resistance successfully explains the overall and age-stratified pattern of serotype replacement. By simulating counterfactual scenarios of public health interventions in France, we propose that this fitness cost caused a gradual and pernicious interaction between the two interventions by increasing the spread of nonvaccine, penicillin-susceptible strains. More generally, our results indicate that reductions of antibiotic use may counteract the benefits of conjugate vaccines introduced into countries with low vaccine-serotype coverages and high-resistance frequencies. Our findings highlight the key role of antibiotic use in vaccine-induced serotype replacement and suggest the need for more integrated approaches to control pneumococcal infections.

Influence of chronic illnesses and underlying risk conditions on the incidence of pneumococcal pneumonia in older adults

OBJECTIVE

To investigate hospitalizations from pneumococcal pneumonia in older adults with specific underlying chronic conditions, evaluating the influence of these conditions in developing pneumonia.

METHODS

Population-based cohort study involving 27,204 individuals ≥ 60 years old in Southern Catalonia, Spain. All cases of hospitalization from pneumococcal pneumonia (bacteremic and nonbacteremic) were collected since 01/12/2008 until 30/11/2011. Cox regression was used to calculate hazards ratio (HR) and estimate the association between baseline conditions and the risk of developing pneumococcal pneumonia.

RESULTS

Maximum incidences (per 1000 person-years) appeared among patients with history of prior pneumonia (14.6), nursing home residents (12.8), persons with immunodeficiency/asplenia (7.7) and patients with chronic pulmonary disease (7.6). In multivariable analysis, age (HR: 1.05), nursing home residence (HR: 4.59), history of prior pneumonia (HR: 3.58), stroke (HR: 2.50), chronic heart disease (HR: 1.53), chronic pulmonary disease (HR: 4.09), diabetes mellitus (HR: 1.66), smoking (HR: 1.69) and immunosuppressive medication (HR: 1.87) appeared significantly associated with an increased risk of pneumococcal pneumonia.

CONCLUSION

Our data support that nursing home residence, chronic pulmonary disease and immunocompromising conditions are the underlying conditions most strongly associated with an increasing risk of pneumococcal pneumonia in older adults. This data underline the need for better prevention strategies among these persons.

[Streptococcus pneumoniae: serotype distribution, antimicrobial susceptibility, risk factors and mortality in Galicia over a two year-period]

INTRODUCTION

To examine the epidemiology of pneumococcal infection in Galicia (Spain) after the incorporation of the pneumococcal conjugate vaccine, and to determine serotype distribution, antibiotic susceptibility, risk factors and associated mortality in cases of invasive pneumococcal disease (IPD) during 2011 and 2012.

METHODS

All strains causing IPD in Galicia were studied. Serotyping was performed by agglutination and Quellung reaction. Antibiotic sensitivity to penicillin, cefotaxime, erythromycin, vancomycin, and levofloxacin was determined. The risk factors considered were chronic respiratory disease, heart disease, liver disease, kidney disease, diabetes mellitus, and HIV and non-HIV immunodeficiency.

RESULTS

A total of 555 strains were collected, with 43 different serotypes being found. The most frequently isolated ones were: serotype3 (17.5%), serotype7F (12.6%), serotype19A (9.4%), serotype14 (4.1%), serotype6C (4.1%), serotype11A (4%) and serotype22F (3.8%). 57.1% of isolates were serotypes included in VNC-13V. Two non-penicillin-sensitive strains and two others were not sensitive to cefotaxime, and 24.7% of the strains were not susceptible to erythromycin (26.9% in 2011 and 22.5% in 2012). The case fatality rate was 16.5%, reaching 23.3% in patients over 75years. Diseases with a statistically significant risk of mortality were: liver, kidney and immunodeficiency without HIV.

CONCLUSIONS

Serotype3 was the most frequent in Galicia. Very few strains were not susceptible to penicillin. Erythromycin resistance decreased from 2011 to 2012. It is highlighted that mortality increases with age. Liver disease, renal disease and non-HIV immunodeficiency increases the mortality risk.

[Incidence and lethality of invasive pneumococcal disease in Tarragona, Spain, 2006-2009]

An epidemiological study was conducted on all cases of invasive pneumococcal disease (IPD) diagnosed in Tarragona, Spain, between 1 January 2006 and 31 December 2009. A total of 286 IPD cases were observed, which was an overall incidence of 21.2 episodes per 100,000 persons-year (95% CI: 16.6-26.9). Incidence rates were 26.3/100,000 (95% CI: 14.4-44.3) among children, 12.2/100,000 (95% CI: 8.2-17.6) among patients between 15-64 years and 59.6/100,000 (95% CI: 40.0-85.8) in those ≥65 years. Overall lethality rate was 7.3% (none in children, 3.4% among patients 15-64 years, and 14.8% among patients ≥65 years; p<0.001).

Serotypes and genotypes of invasive Streptococcus pneumoniae before and after PCV10 implementation in southern Brazil

To reduce the burden of pneumococcal diseases, different formulations of pneumococcal conjugate vaccines (PCV) have been introduced in many countries. In Brazil, PCV10 has been available since 2010. We aimed to analyze the serotype and genetic composition of invasive pneumococci from Brazil in pre- and post- vaccination periods (2007–2012). Antibiotic susceptibility was determined and genotypes of macrolide and fluoroquinolone resistance were characterized. The genotypes of isolates of the most frequent serotypes were determined by multilocus sequence typing. The study included 325 isolates, which were primarily recovered from blood. The most common serotypes recovered were 14, 3, 4, 23F, 7F, 9V, 12F, 20, 19F, 8, 19A, and 5. Thirty-eight pneumococci (11.7%) were from children ≤5 years old. Considering the overall population, PCV10 and PCV13 serotype coverage was 50.1% and 64.9%, respectively. During the pre-vaccine period, isolates with serotypes belonging to the PVC10 represented 51.5% (100/194), whereas in the post vaccine they represented 48.0% (63/131). PCV13 serotypes represented 67.5% (131/194) and 59.2% (77/131) of total for pre- and post-vaccination periods, respectively. Seventy different sequence types [STs] were found, accounting for 9 clonal complexes [CCs] and 45 singletons. Eight STs (156, 180, 218, 8889, 53, 191, 770, and 4967) represented the majority (51.5%) of isolates. Fifty STs were associated with the pre-vaccination period (27 exclusive) and 43 (20 exclusive) with the post-vaccination period; 23 STs were identified in both periods. Some serotypes were particularly clonal (7F, 8, 12F, 20). Non-susceptibility to penicillin was associated with serotype 19A, CC320. Erythromycin resistance was heterogeneous when considering serotype and ST. A single serotype 23F (ST4967) isolate was resistant to levofloxacin. Continued surveillance is required to determine vaccine impact and to monitor changes in pneumococcal population biology post-PCV10 introduction in Brazil.

Effectiveness of 23-valent pneumococcal polysaccharide vaccine in adults aged 60 years and over in the Region of Madrid, Spain, 2008-2011

Invasive pneumococcal disease (IPD) is a notifiable disease in the Region of Madrid. The 23-valent pneumococcal polysaccharide vaccine (PPV23) is recommended for children and adults aged two years or over with a high risk of disease, and for all adults aged 60 and over. We describe the evolution of IPD incidence from 2008 to 2011 in people aged 60 years and over and PPV23 vaccine effectiveness (VE). VE is estimated using both the screening method and indirect cohort method. The incidence of IPD varied from 20.0 in 2008 to 15.2 per 100,000 inhabitants in 2011 (RR: 0.8; 95% CI: 0.6–0.9). Adjusted VE estimated with the screening method was 68.2% (95% CI: 56.2–76.9). VE with the Broome method was 44.5% (95% CI: 23.8–59.6) for all PPV23 serotypes, and 64.4% (95% CI: 45.2–76.8) for PPV23 serotypes not included in conjugate vaccines. VE was lower in patients aged 80 years and older (25.5%; 95% CI:-23.2 to 55.0) and those with highrisk medical conditions (31.7%; 95% CI: -2.2 to -54.4). Adjusted VE was 44.5% (95% CI: 19.4-61.8) within 5 years of vaccination and 32.5% (95% CI: -5.6 to 56.9) after 5 years. These results are compatible with current recommendations for PPV23.

Clinical burden of multi-cause and pneumococcal pneumonia, meningitis, and septicemia in Hungary. Results of a retrospective study (2006–2011)

Introduction: Assessment of the impact of pneumococcal conjugate vaccines on the burden of pneumonia, meningitis, and septicemia in Hungary is limited. Aim: The aim of this retrospective study was to quantify rates of hospitalized multi-cause and pneumococcal pneumonia, meningitis, and septicemia in all age groups in Hungary between 2006 and 2011. Method: Aggregate data were obtained from the Hungarian National Healthcare Fund using pre-specified ICD-10 codes. Comparisons included average rates pre-vaccine (2006–2007) versus post-vaccine (2010–2011) using a χ2test. Results: Hospitalization rates among children aged 0–4 years significantly declined for multi-cause pneumonia and meningitis, but increased for septicemia. There were significant increases in multi-cause pneumonia and septicemia in other age groups. In-hospital mortality rates increased with age. Limited use of pneumococcal-specific codes led to inconclusive findings for pneumococcal diseases. Conclusions: Declines in multi-cause pneumonia and meningitis in children aged 0–4 years suggest direct effects of pneumococcal conjugate vaccination on hospitalization rates. Orv. Hetil., 2014, 155(36), 1426–1436.