Impact of 13-valent pneumococcal conjugate vaccination on invasive pneumococcal disease in children under 15 years old in Madrid, Spain, 2007 to 2016: The HERACLES clinical surveillance study.

Streptococcus pneumoniae is a major cause of morbidity and mortality worldwide. Using the data from the HERACLES clinical surveillance study (2007-2016), we describe the population impact of the 13-valent pneumococcal conjugate vaccine (PVC13) on invasive pneumococcal disease (IPD) in children <15 years of age in the Community of Madrid, Spain. After six years of the inclusion of PCV13 in the vaccination calendar (2010-2016), and despite changes in the Regional Immunization Programme that limited its availability, the net benefit incidence rate (IR) of IPD fell by 70.1% (IRR 0.3 [95% CI: 0.22-0.4]; p ≤ 0.001), mainly due to a significant reduction (91%) in the PCV13 serotypes (IRR 0.09 [95% CI: 0.05-0.16], p ≤ 0.001). Furthermore, no significant changes were detected in the IR of IPD caused by non-PCV13 serotypes. The IRs of the aggressive, resistant and most prevalent serotype in the analysed population, the 19A serotype, dramatically decreased from the beginning to the end of the study (98%) [IRR 0.03 (95% CI: 0.00-0.19), p ≤ 0.001], to its almost total disappearance. Remarkably, this reduction led to a pronounced decline in the percentage of cefotaxime-resistant isolates and the incidence of meningitis cases. Assessment of the clinical impact revealed a reduction in the number of all clinical presentations of IPD, confirming the effectiveness of the PCV13. Finally, PCV13 detected by PCR is predicted to have a stronger impact than the one based on culture methods, which can overlook more than 20% of cases of IPD, mainly pleural empyemas.

Hospitalization rates and outcome of invasive bacterial vaccine-preventable diseases in Tuscany: a historical cohort study of the 2000-2016 period.

BACKGROUND: Invasive bacterial diseases (IBD) are a serious cause of hospitalization, sequelae and mortality. Albeit a low incidence, an increase in cases due to H. influenzae was registered in the past 4 years and, in the Tuscany region, an excess of cases due to N. meningitidis since 2015 is alarming. The purpose of this study is to deepen the knowledge of IBD epidemiology in Tuscany with particular attention to temporal trends. METHODS: Tuscan residents hospitalized for IBD from January 1st 2000 to March 18th 2016 were selected from the regional hospital discharge database based on ICD-9-CM codes. Age-specific and standardized hospitalization rates were calculated together with case-fatality rates (CFRs). A time-trend analysis was performed; whereas, prognostic factors of death were investigated through univariable and multivariable analyses. RESULTS: The average standardized hospitalization rates for invasive meningococcal diseases (IMD), invasive pneumococcal diseases and invasive diseases due to H. influenzae from 2000 to 2016 were 0.6, 1.8, and 0.2 per 100,000, respectively. The average CFRs were 10.5%, 14.5% and 11.5% respectively with higher values in the elderly. Older age was significantly associated with higher risk of death from all IBD. A significant reduction in hospitalization rates for IMD was observed after meningococcal C conjugate vaccine introduction. The Annual Percentage Change (APC) was -13.5 (95% confidence interval (CI) -22.3; -3.5) in 2005-2013 but has risen since that period. Furthermore, a significant increasing trend of invasive diseases due to H. influenzae was observed from 2005 onwards in children 1-4 years old (APC 13.3; 95% CI 0; 28.3). CONCLUSIONS: This study confirms changes in the epidemiology of invasive diseases due to H. influenzae and IMD. Furthermore, attention is called to the prevention of IBD in the elderly because of the age group's significantly higher rate of hospitalizations and deaths for all types of IBD.

The Emergence of Antimicrobial Resistance as a Public Matter of Concern: A Swedish History of a "Transformative Event".

ArgumentThis article examines how antimicrobial resistance (AMR) came to be constituted as a matter of public concern in Sweden in conjunction with the development of an inter-professional organization called Strama, founded to promote rational prescription of antibiotics. An outbreak of penicillin-resistant pneumococci in the mid-1990s was crucial for this development, because it brought attention to AMR as an urgent public threat. This outbreak fuelled the constitution of AMR as caused by consumption of antibiotics and as a matter of disease control. As a consequence, Strama was able to mobilize the Swedish health officers responsible for disease control. The outbreak is conceptualized as a "transformative event" - an event that makes an issue and its associated risks concrete and urgent. Transformative events play the crucial role of expediting the transformation of issues into matters of public concern.

Invasive pneumococcal disease in children under 16 years of age: Incomplete rebound in incidence after the maximum effect of PCV13 in 2012/13 in Germany.

OBJECTIVE: To identify a potential nadir of the impact of pneumococcal conjugate vaccination (PCV) in infancy on invasive pneumococcal diseases (IPD) in children under 16 in Germany. METHODS: Active surveillance on IPD based on two independent data sources with capture-recapture correction for underreporting. Annual incidence rates by age group, serotypes, site of infection, and relative incidence reduction compared to pre-vaccination period (1997-2001) at nadir and for the most recent season are reported. We calculated vaccine coverage at the age of 24 months using health insurance claims data. RESULTS: 96-97% of children had received at least two doses of PCV since 2009. The maximum impact on overall IPD incidence was achieved in 2012/13 (-48% [95% CI: -55%; -39%]) with a rebound to -26% [95% CI: -36%; -16%] in 2015/16. Non-PCV13 serotypes accounted for 84.1% of the IPD cases in 2015/16. The most frequent non-PCV serotypes in IPD in 2014/15 and 2015/16 were 10A, 24F, 15C, 12F, 38, 22F, 23B, and 15B. The impact at nadir was highest in children 0-1 years of age both in meningitis and non-meningitis cases, whereas the impact for other age groups was higher for meningitis cases. The rebound mainly pertained to non-meningitis cases. CONCLUSION: The maximum impact of pneumococcal conjugate vaccination has been attained and signs of a rebound are apparent. Sustained surveillance for IPD in children is warranted to assess whether these trends will continue. There may be a need for vaccines using antigens common to all serotypes.

Long-term Impact of a "3 + 0" Schedule for 7- and 13-Valent Pneumococcal Conjugate Vaccines on Invasive Pneumococcal Disease in Australia, 2002-2014.

BACKGROUND: Australia introduced universal 7-valent pneumococcal conjugate vaccine (PCV7) from 2005, replaced by 13-valent PCV (PCV13) in 2011, uniquely among high-income countries giving doses at 2, 4, and 6 months (3 + 0 schedule). Data on impact of a timely 3 + 0 PCV schedule with high coverage are sparse, with none for PCV13. METHODS: We used national surveillance of invasive pneumococcal disease (IPD) from 2002 for baseline and appropriate later comparison periods to calculate incidence rate ratios (IRRs) by serotype and age using a Poisson model. PCV coverage was assessed from the Australian Childhood Immunisation Register. RESULTS: After 9 years of timely 3-dose PCV coverage of >92%, all-age IPD in Australia almost halved (IRR, 0.53; 95% confidence interval [CI], .50-.57), but differed by PCV era. Reductions in IPD due to vaccine serotypes from PCV7 (IRR, 0.20; CI, .17-.22) were about 2-fold greater than for IPD due to extra serotypes in PCV13 (13v-non7v) in a similar period (IRR, 0.58; CI, .51-.66). Post-PCV13 declines in serotype 19A IPD in persons aged <2 years (IRR, 0.23; CI, .13-.35) and ≥2 years (IRR, 0.35; CI, .28-.44) differed from other 13v-non7v IPD (IRR, 0.73; CI, .35-1.48 for those aged <2 years and IRR, 0.96; CI, .81-1.15 for those ≥2 years). Meningitis due to vaccine serotypes nearly disappeared in children eligible for 3 PCV13 doses. IPD due to non-PCV13 serotypes increased by 30% compared with 76% for non-PCV7 serotypes in equivalent period of vaccine use. CONCLUSIONS: Reductions in vaccine-type IPD post-PCV13 were inferior to Australian experience with PCV7 and reports from high-income countries giving a PCV booster dose. Applicability of findings to other settings would depend on age of IPD onset, serotype profile, and timeliness of vaccination.

Invasive Pneumococcal Disease Surveillance, 1 April to 30 June 2017.

The number of notified cases of invasive pneumococcal disease (IPD) in the second quarter of 2017 was greater than the previous quarter and also the second quarter of 2016. Following the July 2011 replacement of the 7-valent pneumococcal conjugate vaccine (7vPCV) in the childhood immunisation program with the 13-valent pneumococcal conjugate vaccine (13vPCV), there was an initial relatively rapid decline in disease due to the additional six serotypes covered by the 13vPCV across all age groups, however more recently this rate of decline has slowed. Additionally, over this period the number of cases due to the eleven serotypes additionally covered by the 23-valent pneumococcal polysaccharide vaccine (23vPPV) and also those serotypes not covered by any available vaccine has been increasing steadily across all age groups.

Invasive Pneumococcal Disease Surveillance, 1 January to 31 March 2017.

The number of notified cases of invasive pneumococcal disease (IPD) in the first quarter of 2017 was less than the previous quarter, but greater than the number of notified cases in the first quarter of 2016. Overall, the decline in disease due to the serotypes targeted by the 13-valent pneumococcal conjugate vaccine (13vPCV) has been maintained across all age groups since the 13vPCV replaced the 7-valent pneumococcal conjugate vaccine (7vPCV) in the childhood immunisation program from July 2011 (Figure 1).

Streptococcus pneumoniae Serotypes 9 and 14 Circulating in Brazil over a 23-Year Period Prior to Introduction of the 10-Valent Pneumococcal Conjugate Vaccine: Role of International Clones in the Evolution of Antimicrobial Resistance and Description of a Novel Genotype.

Antimicrobial-resistant pneumococcal strains have been detected worldwide since the 1960s. In Brazil, the first penicillin-nonsusceptible pneumococci (PNSP) were reported in the 1980s, and their emergence and dissemination have been mainly attributed to serogroup 9 and serotype 14 strains, especially those highly related to recognized international clones. In the present study, antimicrobial susceptibility testing and multilocus sequence typing were performed on 315 pneumococcal isolates belonging to serogroup 9 (n = 99) or serotype 14 (n = 216), recovered from patients or asymptomatic carriers between 1988 and 2011 in Brazil, in order to trace changes in antimicrobial resistance and genotypes prior to the full introduction of the pneumococcal conjugate vaccine in the country. Over the 23-year study period, the PNSP levels increased, and four clonal complexes (CC156, CC66, CC15, and CC5401) have played important roles in the evolution and dissemination of pneumococcal isolates belonging to serogroup 9 and serotype 14, as well as in the emergence of antimicrobial resistance, in the pre-pneumococcal-vaccination era. The earliest PNSP strains detected in this study belonged to serotype 9N/ST66 and were single locus variants of the international clone Tennessee14-18 ST67 (CC66). The first serotype 14 PNSP isolates were identified in 1990 and were related to the England14-9 ST9 (CC15) clone. Serotype 14 PNSP variants of the Spain9V-3 ST156 clone with elevated penicillin MICs and nonsusceptibility to other beta-lactams were detected in 1995 and showed an increasing trend over the years. The results also indicated that introduction of ST156 in our region was preceded by the emergence of trimethoprim-sulfamethoxazole resistance and by the dissemination of ST162. In addition to the presence of successful international clones, a novel regional serotype 14 genotype (CC5401) has emerged in 1996.

Invasive pneumococcal disease in Australia, 2011 and 2012.

In Australia, there were 1,883 cases (8.3 per 100,000 population) of invasive pneumococcal disease (IPD) notified to the National Notifiable Diseases Surveillance System (NNDSS) in 2011 and 1,823 cases (8.0 per 100,000) in 2012. The overall rate of IPD in Indigenous Australians was 9 times the rate of IPD in non-Indigenous Australians in 2011 and 7 times in 2012. Following the July 2011 introduction of the 13-valent pneumococcal conjugate vaccine (13vPCV) to the National Immunisation Program, rates of IPD in children aged less than 5 years decreased from 19.5 per 100,000 in 2011 to 12.6 per 100,000 in 2012. In Indigenous adults aged 50 years or over the rates of IPD caused by serotypes included in the 23-valent pneumococcal polysaccharide vaccine (23vPPV) continued to increase in both 2011 (47.2 per 100,000) and 2012 (51.2 per 100,000). The rates of IPD in non-Indigenous adults aged 65 years or over caused by serotypes included in the 23vPPV also increased in 2011 (10.1 per 100,000) and 2012 (11.2 per 100,000). There were 134 deaths attributable to IPD in 2011 and 126 in 2012, although it should be noted that deaths may be under-reported. The number of invasive pneumococcal isolates with reduced penicillin susceptibility remained low and reduced susceptibility to ceftriaxone/cefotaxime continued to be rare.

Genomic analysis of nontypeable pneumococci causing invasive pneumococcal disease in South Africa, 2003-2013.

BACKGROUND: The capsular polysaccharide is the principal virulence factor of Streptococcus pneumoniae and a target for current pneumococcal vaccines. However, some pathogenic pneumococci are serologically nontypeable [nontypeable pneumococci (NTPn)]. Due to their relative rarity, NTPn are poorly characterized, and, as such, limited data exist which describe these organisms. We aimed to describe disease and genotypically characterize NTPn causing invasive pneumococcal disease in South Africa. RESULTS: Isolates were detected through national, laboratory-based surveillance for invasive pneumococcal disease in South Africa and characterized by whole genome analysis. We predicted ancestral serotypes (serotypes from which NTPn may have originated) for Group I NTPn using multilocus sequence typing and capsular region sequence analyses. Antimicrobial resistance patterns and mutations potentially causing nontypeability were identified. From 2003-2013, 39 (0.1 %, 39/32,824) NTPn were reported. Twenty-two (56 %) had partial capsular genes (Group I) and 17 (44 %) had complete capsular deletion of which 15 had replacement by other genes (Group II). Seventy-nine percent (31/39) of our NTPn isolates were derived from encapsulated S. pneumoniae. Ancestral serotypes 1 (27 %, 6/22) and 8 (14 %, 3/22) were most prevalent, and 59 % (13/22) of ancestral serotypes were serotypes included in the 13-valent pneumococcal conjugate vaccine. We identified a variety of mutations within the capsular region of Group I NTPn, some of which may be responsible for the nontypeable phenotype. Nonsusceptibility to tetracycline and erythromycin was higher in NTPn than encapsulated S. pneumoniae. CONCLUSIONS: NTPn are currently a rare cause of invasive pneumococcal disease in South Africa and represent a genetically diverse collection of isolates.

Epidemiology of Serotype 1 Invasive Pneumococcal Disease, South Africa, 2003-2013.

In South Africa, 7-valent pneumococcal conjugate vaccine (PCV) was introduced in April 2009 and replaced with 13-valent PCV in April 2011. We describe the epidemiology of serotype 1 Streptococcus pneumoniae disease during the pre- and post-PCV eras (2003-2013). Using laboratory-based invasive pneumococcal disease (IPD) surveillance, we calculated annual incidences, identified IPD clusters, and determined serotype 1-associated factors. Of 46,483 IPD cases, 4,544 (10%) were caused by serotype 1. Two clusters of serotype 1 infection were detected during 2003-2004 and 2008-2012, but incidence decreased after 2011. Among children <5 years of age, those who had non-serotype 1 IPD had shorter hospital stays, fewer cases of penicillin-nonsusceptible disease, and lower HIV prevalence and in-hospital death rates than did those with serotype 1 IPD; similar factors were noted for older patients. Serotype 1 IPD had distinctive clinical features in South Africa, and annual incidences fluctuated, with decreases noted after the introduction of PCV13.

Prevalence of antimicrobial resistant Streptococcus pneumoniae serotype 11A isolates in Korea, during 2004-2013, due to the increase of multidrug-resistant clone, CC166.

Since the introduction of the pneumococcal conjugate vaccine (PCV7) in Korea in 2003, the proportion of non-vaccine serotypes has increased. Among non-vaccine serotypes, serotype 11A is highly prevalent in Korea. We investigated the prevalence and characteristics of Streptococcus pneumoniae serotype 11A isolates in a Korean tertiary-care hospital, during 2004-2013. A total of 1579 non-duplicate clinical S. pneumoniae isolates, collected from 2004 to 2013, were included in this study. Serotype was determined by the capsular Quellung method, and in vitro susceptibility testing was performed by broth microdilution method. Multilocus sequence typing was performed to determine the genotypes of the S. pneumoniae isolates. We identified 90 serotype 11A isolates (5.7%). During this period, the proportion of serotype 11A has increased from 3.2% up to 13.2% (in 2012). Among the serotype 11A isolates, two main clonal complexes (CCs), CC166 and CC99, were identified. The increase of serotype 11A was mainly due to the increase of CC166 isolates, which have high antimicrobial resistance rates. In addition, we identified that 14 isolates, belonging to ST8279, ST9875, and ST3598 of CC166, were non-susceptible to all antimicrobial agents tested in this study. We identified the increase of S. pneumoniae serotype 11A in Korea, which mainly due to the expansion of a resistant clonal group, CC166.

Vaccine Serotypes of Streptococcus pneumoniae with High-level Antibiotic Resistance Isolated More Frequently Seven Years After the Licensure of PCV7 in Beijing.

BACKGROUND: Streptococcus pneumoniae 7-valent conjugate vaccine (PCV7) was made available in China in the private sector in September 2008. METHODS: This study investigated the serotype distribution, antibiotic resistance, and molecular characteristics of S. pneumoniae in hospitalized pediatric patients. Pneumococcal isolates were collected from hospitalized children younger than 14 years. Their serotypes were determined using Quellung reactions with antisera; antibiotic resistance against 13 antimicrobials was tested using the E-test method or disc diffusion. The sequence types (STs) were analyzed with multilocus sequence typing. RESULTS: A total of 187 pneumococcal specimens were collected, including 21 invasive and 166 noninvasive isolates. The prevailing serotypes were 19F (31.6%), 19A (19.8%), 23F (11.2%), 6A (9.1%), 14 (9.1%) and 15B (5.9%). The coverage rates of PCV7, PCV10 and PCV13 were 56.2% (105/187), 56.7% (106/187) and 86.1% (161/187), respectively. The overall nonsusceptibility rate against penicillin was 8.0%; however, this rate would have been 91.5% if based on an oral breakpoint. All but one of the isolates were highly resistant to erythromycin. Multidrug resistance was exhibited by 177 (94.7%) isolates. The 5 predominant multilocus sequence typings for all pneumococci were ST271 (24.1%), ST320 (18.2%), ST81 (7.5%), ST876 (7%) and ST3397 (5.3%), which were primarily related to serotypes 19F, 19A, 23F, 14 and 15B, respectively. CC271 was the most frequent antibiotic-resistant complex clone. CONCLUSIONS: The coverage rates of PCVs were high, and the antibiotic resistance rates were of serious concern among hospitalized children. Universal immunization using PCVs would likely prevent episodes of S. pneumoniae diseases and the spread of antibiotic resistance in Beijing.