Epidemiology Of Invasive Pneumococcal Disease Research Articles

The impact of pneumococcal serotype replacement on the effectiveness of a national immunization program: a population-based active surveillance cohort study in New Zealand

In Aotearoa New Zealand (NZ) PCV7 was introduced in 2008, then PCV10 in 2011 and PCV13 in 2014. In 2017 PCV10 was re-introduced, replacing PCV13. In the present study, we investigate the resultant rapidly changing invasive pneumococcal disease (IPD) epidemiology. We compare the IPD incidence rate ratio (IRR) in NZ (2022 versus 2020) with other countries, and describe the IPD epidemiology (including trends in overall IPD and serotype 19A, and antimicrobial resistance) within NZ. Additionally, we performed a genomic-epidemiology investigation identifying the most common 19A sequence types and associated risk factors. Though IPD incidence rates have increased in the US and Australia (2021-22) after declines in 2020, in NZ the incidence rate is the highest since 2011 with a significantly higher IRR than US (p<0.01). Incidence rates among children <2 and adults 65 or over in 2022 are the highest since 2009, driven by significant increases of serotype 19A (p=0.01). Māori and Pacific peoples are experiencing the highest rates since 2009. Further, penicillin resistance among 19A isolates has increased from 39% (2012) to 84% (2021) (p=0.02). Genomic sequencing identified the more virulent ST-2062 as most common among 19A isolates sequenced, increasing from 5% (2010) to 55% (2022). With very high incidence rates of IPD in NZ, inadequate protection against 19A, increasing resistance, and a more virulent 19A clade, targeted public health campaigns and increased PCV13 availability are needed. The NZ Ministry of Health funds IPD surveillance and typing in NZ.

Invasive pneumococcal disease 3 years after introduction of a reduced 1 + 1 infant 13-valent pneumococcal conjugate vaccine immunisation schedule in England: a prospective national observational surveillance study

The UK transition from a 2 + 1 to a 1 + 1 infant immunisation schedule with the 13-valent pneumococcal conjugate vaccine (PCV13) on Jan 1, 2020, coincided with the start of the COVID-19 pandemic. We describe the epidemiology of invasive pneumococcal disease (IPD) in England over 6 financial years (April 1 to March 31) between 2017-18 and 2022-23. We used prospective national surveillance data, including serotyping and whole-genome sequencing of invasive isolates, to analyse IPD trends in England by age and financial year. We compared breakthrough infections and vaccine failure rates in 2022-23 among children eligible for the 1 + 1 schedule with rates in cohorts of children eligible for the 2 + 1 schedule between 2017-18 and 2019-20. We assessed genomic changes over time by comparing Global Pneumococcal Sequencing Clusters and multilocus sequence types among PCV13 serotypes causing IPD. There were 4598 laboratory-confirmed IPD cases in 2022-23, 3025 in 2021-22, 1240 in 2020-21, and 5316 in 2019-20. IPD incidence in 2022-23 was 14% lower than in 2019-20 (incidence rate ratio [IRR] 0·86, 95% CI 0·81-0·91; p<0·001). IPD incidence in 2022-23 compared with 2019-20 was 34% higher in children (aged <15 years) (378 cases vs 292 cases; IRR 1·34, 95% CI 1·08-1·68; p=0·009) and 17% lower in adults (aged 15 years and older; 4220 vs 5024; 0·83, 0·78-0·88; p<0·001). The proportion of PCV13-type IPD increased from 19·4% (95% CI 18·2-20·4; 957 of 4947) in 2019-20 to 29·7% (28·3-31·0; 1283 of 4326) in 2022-23, mainly due to serotype 3, but also serotypes 19F, 19A, and 4, alongside a decrease in non-PCV13 serotypes 8, 12F, and 9N. The increase in IPD incidence due to serotypes 3, 19A, and 19F was driven by clonal expansion of previously circulating strains, whereas serotype 4 expansion was driven by newer strains (ie, sequence types 801 and 15603). Breakthrough infections and vaccine failure rates were similar in children eligible for the 1 + 1 (1·08 per 100 000 person-years) and 2 + 1 (0·76 per 100 000 person-years; IRR 1·42, 95% CI 0·78-2·49; p=0·20) PCV13 schedules. Overall, IPD incidence in England was lower in 2022-23, 2 years after removal of pandemic restrictions, than in 2019-20. Breakthrough and vaccine failure rates were not significantly different between children who received the 1 + 1 compared with the 2 + 1 PCV13 immunisation schedule. The post-pandemic increase in childhood IPD incidence and especially PCV13-type IPD will require close monitoring. None.

Invasive Pneumococcal Disease After 2 Decades of Pneumococcal Conjugate Vaccine Use.

We sought to describe the evolving epidemiology of invasive pneumococcal disease (IPD) among children in Massachusetts, United States, over the last 2 decades during which sequential 7-valent pneumococcal conjugate vaccines (PCV7) and 13-valent PCVs (PCV13) were implemented. Cases of IPD in children aged <18 years were detected between 2002 and 2021 through an enhanced population-based, statewide surveillance system. Streptococcus pneumoniae isolates from normally sterile sites were serotyped and evaluated for antimicrobial susceptibility. IPD incidence rates and rate ratios with 95% confidence intervals (CIs) were calculated. We identified 1347 IPD cases. Incidence of IPD in children aged <18 years declined 72% over 2 decades between 2002 and 2021 (incidence rate ratios 0.28, 95% CI 0.18-0.45). IPD rates continued to decline after replacement of PCV7 with PCV13 (incidence rate ratios 0.25, 95% CI 0.16-0.39, late PCV7 era [2010] versus late PCV13 era [2021]). During the coronavirus disease 2019 pandemic years, 2020 to 2021, the rate of IPD among children aged <18 years reached 1.6 per 100 000, the lowest incidence observed over the 20 years. In PCV13 era, approximately one-third of the IPD cases in children aged >5 years had at least 1 underlying condition (98, 30.3%). Serotypes 19A and 7F contributed 342 (48.9%) of all cases before implementation of PCV13 (2002-2010). Serotype 3 (31, 8.6%), and non-PCV13 serotypes 15B/C (39, 10.8%), 33F (29, 8.0%), 23B (21, 0.8%), and 35B (17, 4.7%) were responsible for 37.8% of cases in PCV13 era (2011-2021). Penicillin nonsusceptibility continued to decline (9.8% vs 5.3% in pre-/late PCV13 era, P = .003), however has become more common among non-PCV13 serotypes compared with vaccine serotypes (14.8% vs 1.4%, P < .001). Robust ongoing surveillance networks are critical for identifying emerging serotypes and development of next-generation vaccine formulations.

2606. Epidemiology of invasive pneumococcal disease in adults with and without underlying lung disease in Ontario, Canada

Abstract Background The advent of enhanced conjugate pneumococcal vaccines for adults has created a need to assess the burden of pneumococcal disease in different populations to support recommendations for vaccination. We assessed the epidemiology of invasive pneumococcal disease (IPD) in adults with underlying lung disease in Ontario, Canada. Methods Ontario introduced PCV7 and PCV13 for children in 2007 and 2010, and PCV13 for immunocompromised adults over 50 years in 2014. TIBDN performs population (pop’n)-based surveillance for IPD in a pop’n of ∼4.5 million. Microbiology laboratories serving area residents report sterile site isolates of Streptococcus pneumoniae; annual audits ensure completeness. Isolates are serotyped at the National Microbiology Laboratory. Population data are from Statistics Canada, with estimates of prevalence of underlying conditions from ICES. Results From 2014-2022, 2769 episodes of IPD occurred in adults; detailed clinical data are available for 2366 (85%), and serotyped isolates for 88%. Of these, 573 (24%) had no chronic underlying illness (undill); 1155 (49%) had an undill not affecting the lungs, 165 (7%) had asthma only, 409 (17%) had COPD (with/without asthma or other lung disease (OLD), 64 (2.7%) had OLD alone (most commonly ILD or bronchiectasis). Among those with asthma, 87 (53%) had another undill predisposing to IPD; compared to 290 (71%) of those with COPD and 45 (70%) of those with OLD. Persons with asthma were younger (median age 56y) than those with no or other undill (64y and 61y), and those with COPD or OLD (70 and 71y). Persons with lung disease were more likely to present with bacteremic pneumonia and less likely to have primary bacteremia or meningitis that those without or with other chrill. ICU admission and case fatality rates are in Table 1. The distribution of serotypes causing disease by conjugate vaccine types did not differ among those with lung disease and others (Figure 1). The incidence of disease in persons with asthma and COPD by age group is shown in Figure 2. Conclusion The epidemiology of IPD differs somewhat in persons with lung disease compared to others, but conditions other than lung disease have a greater impact on incidence and outcome of IPD in adults. Enhanced PCVs likely provide cost-effective protection for 50-64 year olds with asthma/COPD. Disclosures All Authors: No reported disclosures

Invasive Pneumococcal Disease and Potential Impact of Pneumococcal Conjugate Vaccines Among Adults, Including Persons Experiencing Homelessness-Alaska, 2011-2020.

Adults aged ≥65 years, adults with certain underlying medical conditions, and persons experiencing homelessness are at increased risk for invasive pneumococcal disease (IPD). Two new pneumococcal conjugate vaccines, 15-valent pneumococcal conjugate vaccine (PCV15) and 20-valent pneumococcal conjugate vaccine (PCV20), were recently approved for use in US adults. We describe the epidemiology of IPD among Alaska adults and estimate the proportion of IPD cases potentially preventable by new vaccines. We used statewide, laboratory-based surveillance data to calculate and compare IPD incidence rates and 95% confidence intervals (CIs) among Alaska adults aged ≥18 years during 2011-2020 and estimate the proportion of IPD cases that were caused by serotypes in PCV15 and PCV20. During 2011-2020, 1164 IPD cases were reported among Alaska adults for an average annual incidence of 21.3 cases per 100 000 adults per year (95% CI, 20.1-22.5). Incidence increased significantly during the study period (P < .01). IPD incidence among Alaska Native adults was 4.7 times higher than among non-Alaska Native adults (95% CI, 4.2-5.2). Among adults experiencing homelessness in Anchorage, IPD incidence was 72 times higher than in the general adult population (95% CI, 59-89). Overall, 1032 (89%) Alaska adults with IPD had an indication for pneumococcal vaccine according to updated vaccination guidelines; 456 (39%) and 700 (60%) cases were caused by serotypes in PCV15 and PCV20, respectively. Use of PCV15 and PCV20 could substantially reduce IPD among adults in Alaska, including Alaska Native adults and adults experiencing homelessness.

Comparison of the epidemiology of invasive pneumococcal disease between Australia and New Zealand in 2017–2021: an observational study based on surveillance data

The Australian immunisation schedule uses 13-valent pneumococcal conjugate vaccine (PCV13), while New Zealand (NZ) changed from PCV13 to 10-valent PCV (PCV10) in 2017. In NZ, cases of serotype 19A (not in PCV10) have been increasing since 2017. We compared invasive pneumococcal disease (IPD) epidemiology between Australia and NZ in 2017-2021. We collated IPD notification data from national surveillance systems. Between Australia and NZ, we compared IPD incidence rates and assessed the proportion of serotype 19A, and stratified for ethnicity and age. Between 2017 and 2021, the crude IPD incidence per 100,000 in Australia ranged from 4.3 to 8.4, and ranged from 6.9 to 11.4 in NZ. The highest age-adjusted IPD rates were observed in Australian Indigenous people (range: 27.3-35.5) followed by NZ Māori/Pacific peoples (range 19.7-30.4). For children <2 years, ethnicity-adjusted IPD rates were similar between Australia and NZ in 2017-2020. In 2021, however, the ethnicity-adjusted incidence in children <2 years was higher in NZ (30.2; 95% CI 21.1-39.4) than in Australia (23.3 95% CI: 19.5-27.1) (p<0.01). In Australia, the proportion of serotype 19A remained 5%, whereas in NZ serotype 19A increased from 11.5% to 29.5% with the largest increase in children <2 years and 2-4 years. Despite higher risks in Indigenous populations in Australia compared to all other groups, the overall IPD rate in NZ is increasing, particularly among children. The numbers and proportions of IPD due to serotype 19A are increasing in NZ especially in children. These data support the NZ decision from December 2022 to change to PCV13. This research received no specific funding.

Peritonitis primaria por neumococo en un hospital pediátrico de Argentina

Pneumococcal peritonitis represents a small subset of patients suffering from invasive pneumococcal disease (IPD). We describe 5 cases of primary peritonitis documented in the pediatric hospital over 15 years (2005-2020) of IPD surveillance. The patients, 3girls and 2boys with a mean age of 5 years, experienced peritoneal signs and symptoms; 3of them suffered from nephrotic syndrome. Based on the local resistance profiles, all isolates were sensitive to beta-lactams, one strain showed resistance to cotrimoxazole and tetracycline while another strain, to cotrimoxazole only. Serotypes found in 4/5 strains (one was non-viable) were: 1, 19F, 15C and 23A. Children were treated with third-generation cephalosporins or ampicillin, gentamicin and metronidazole and all of them evolved favorably. Pneumococcal etiology should be included in the differential diagnosis of acute abdominal pain in children. Our study aims to contribute to the knowledge of this condition and to the local epidemiology of IPD.

Changing Trends of Invasive Pneumococcal Disease in the Era of Conjugate Pneumococcal Vaccination in Olmsted County: A Population-Based Study

ObjectiveTo estimate the incidence of invasive pneumococcal disease (IPD) in the pre–13-valent pneumococcal conjugate vaccine (pre-PCV13; 7-valent pneumococcal conjugate vaccine era, 2002-2010) and post-PCV13 (2011-2018) time periods. Patients and MethodsUsing the Rochester Epidemiology Project, we conducted a population-based cohort study of all IPD cases in Olmsted County, Minnesota, from January 1, 2002, to December 31, 2018. ResultsOverall, 187 cases of IPD were identified. The incidence of IPD decreased significantly from 11.1 (95% CI, 9.1 to 13.2) to 5.6 (95% CI, 4.3 to 6.9) per 100,000 person-years when the pre- and post-PCV13 periods (2002-2010 vs 2011-2018) were compared (P<.001). Of the 187 patients with IPD, 112 (59.9%) had previously received at least 1 dose of pneumococcal vaccine. Among the IPD cases in the post-PCV13 period, there was an increase in non-PCV13 serotypes, mainly 11A (from 1.0% [1 of 105] to 6.2% [4 of 64]) and 33F (from 2.9% [3 of 105] to 15.6% [10 of 64]), while PCV13/non–7-valent pneumococcal conjugate vaccine serotypes declined from 38.1% (40 of 105) to 15.6% (10 of 64). At 30 days after an IPD diagnosis, the survival rate was 88.8% (95% CI, 84.4% to 93.4%). ConclusionA marked decline in IPD incidence occurred during the post-PCV13 era. Because of the observed increase in non-PCV13 serotypes, coupled with multiple factors that impact the epidemiology of IPD, ongoing surveillance of patients with IPD, particularly due to non-PCV13 serotypes, is warranted.

Impact of national pneumococcal vaccination program on invasive pneumococcal diseases in South Korea

Following the introduction of pneumococcal conjugate vaccines (PCVs), the rate of invasive pneumococcal disease (IPD) declined, however, IPDs replaced by serotypes that are not included in the vaccine have emerged. We describe the epidemiology of IPD in South Korea over a 4.5-year period, encompassing the impact following introduction of PCV10/13 and PPSV23 into the public immunization program, and assess serotype dynamics in pediatric and adult population. This was a nationwide, retrospective review of surveillance of all IPD cases in Korea between September 2014 to December 2019. We analyzed VT13 (serotypes included in 13-valent conjugate vaccine) and NVT (nonvaccine type) cases by age, sex, IPD type, vaccination status, and deaths. A total of 893 cases with serotype data were included; 306 (34%) VT13 cases and 587 (66%) NVT cases. Serotype 3 (n = 155) was the most common VT13 serotype, followed by serotypes 19A (n = 70) and 14 (n = 28). Among the NVTs, serotype 10A (n = 74) was the most common serotype, followed by serotypes 23A (n = 60) and 34 (n = 58). Persons who had PCV13 vaccination were at lower risk (aOR = 0.11, 95% CI 0.02–0.73, P = 0.022) of death compared to unvaccinated persons. Introduction of PCV10/13 and PPSV23 vaccination program has had different impacts on the serotype-specific IPD across age groups. The most common serotypes included serotypes 3 and 19A (VT13), and 10A, 23A, and 34 (NVT). Our findings suggest continued monitoring in the midst of new vaccine development, and a need to develop novel strategies to mitigate the IPDs from emerging pneumococcal serotypes.

Molecular epidemiology of paediatric invasive pneumococcal disease in Andalusia, Spain.

This study aimed to assess the impact of the introduction of pneumococcal conjugate vaccine 13 (PCV13) on the molecular epidemiology of invasive pneumococcal disease (IPD) in children from Andalusia. A population-based prospective surveillance study was conducted on IPD in children aged <14 years from Andalusia (2018-2020). Pneumococcal invasive isolates collected between 2006 and 2009 in the two largest tertiary hospitals in Andalusia were used as pre-PCV13 controls for comparison of serotype/genotype distribution. Overall IPD incidence rate was 3.55 cases per 100 000 in 2018; increased non-significantly to 4.20 cases per 100 000 in 2019 and declined in 2020 to 1.69 cases per 100 000 (incidence rate ratio 2020 vs. 2019: 0.40, 95% confidence interval (CI) 0.20-0.89, P = 0.01). Proportion of IPD cases due to PCV13 serotypes in 2018-2020 was 28% (P = 0.0001 for comparison with 2006-2009). Serotypes 24F (15%) and 11A (8.3%) were the most frequently identified non-PCV13 serotypes (NVT) in 2018-2020. Penicillin- and/or ampicillin-resistant clones mostly belonged to clonal complex 156 (serotype 14-ST156 and ST2944 and serotype 11A-ST6521). The proportion of IPD cases caused by PCV13 serotypes declined significantly after the initiation of the PCV13 vaccination programme in 2016. Certain NVT, such as serotypes 24F and 11A, warrant future monitoring in IPD owing to invasive potential and/or antibiotic resistance rates.

Comparison of the Epidemiology of Invasive Pneumococcal Disease between Australia and Aotearoa New Zealand in 2017-2021: An Observational Study Based on Surveillance Data

Comparison of the Epidemiology of Invasive Pneumococcal Disease between Australia and Aotearoa New Zealand in 2017-2021: An Observational Study Based on Surveillance Data

1309. Incidence and Epidemiology of Invasive Pneumococcal Disease due to Serotype 3 in South-Central Ontario

BackgroundIn our population, the most common serotype (ST) of S. pneumoniae causing invasive pneumococcal disease (IPD) is now ST 3. We undertook an analysis of population based surveillance for IPD to examine the incidence and epidemiology of ST 3 disease over the last 25 years.MethodsThe Toronto Invasive Bacterial Diseases Network has performed population-based surveillance for IPD in Toronto/Peel region (pop’n 4.5M) since 1995. All sterile site isolates of S. pneumoniae are reported to a central study laboratory, isolates are serotyped, and clinical and vaccination data are collected via patient and physician interview and chart review. Population data are obtained from Statistics Canada.ResultsFrom 1995-2020, 11032 episodes of IPD occurred; 10015 had STs available, and 10484 clinical data. Overall, ST 3 comprised 9.2% of cases (N=931). Compared to other patients with IPD, those with ST 3 IPD were older (median age 65 vs. 58.5, P< .001), more likely to have underlying lung (22.7% v 16.0%, P< .0001) and cardiac (21.7 v 18.4, P=.02) disease and less likely to be immunocompromised (IC) (23.1% v 29.0% P< .0001). ST3 episodes were more likely to be pneumonia (81% v 65%), less likely to be bacteremia without focus (7.6% v 18.9%), and more likely to require ICU admission (42.3% v 25.1%) and to die (27.1% v 16.6%). In multivariable analysis, patients with ST 3 disease remained more likely to die (OR 1.65; 95%CI1.3-2.0). Over time, the proportion of patients with ST 3 IPD who were nursing home (NH) residents (18/171 in 1995-2000 vs. 4/215 in 2016-2020, P=.0002), and who were IC (46/169 in 1995-2000 vs 39/204 in 2016-2020, P=.007) decreased significantly; in IPD due to other STs, the proportion who were NH residents declined, but the proportion IC increased significantly. The case fatality rate (CFR) declined significantly in IPD due to ST3 but not other STs (Figure 1). Changes in incidence are shown in Figure 2.Figure 2: Incidence of serotype 3 IPD over time, Toronto/Peel, 1995-2020 The incidence of ST3 IPD in children and adults under 65 did not change significantly from 1995/96 to 2019/20. In older adults, the annual incidence of disease declined from 4.98 per 100,000 per year in 1995-2000 to 3.53 per 100,000 per year in 2001-2010 (IRR 0.71, 95%CI 0.56-0.90), then to 2.23 per 100,000 per year in 2011-2020 (IRR compared to 2001-2010 0.63, 95%CI 0.50-0.79)FIgure 2: Case fatality rate of IPD due to serotype 3 and other serotypes over time, 1995-2020, Toronto-Peel The case fatality rate of IPD due to ST3 declined from 37.6% (56/149) in 1995-2000 to 50/235 (21.3%) in 2015-2020 (P<.0001). The CFR in other serotypes did not change.ConclusionThe epidemiology of IPD due to ST3 has changed significantly over time and the CFR has declined. The incidence of ST3 disease in children and younger adults has not changed significantly, although the power to detect change is low in children. In older adults the incidence of ST3 disease declined significantly after PPV23 introduction in 1995/6 and again after PCV13 introduction for children.Disclosures All Authors: No reported disclosures

The Impact of Pneumococcal Conjugate Vaccine (PCV) Coverage Heterogeneities on the Changing Epidemiology of Invasive Pneumococcal Disease in Switzerland, 2005-2019.

Pneumococcal conjugate vaccines (PCVs) have lowered the incidence of invasive pneumococcal disease (IPD) worldwide. However, the influence of regional vaccine uptake differences on the changing epidemiology of IPD remains unclear. We aimed to examine the overall impact of both seven- and 13-valent PCVs (PCV7 and PCV13) on IPD in Switzerland. Three-year periods from 2005–2010 and 2011–2019 were considered, respectively, as (early and late) PCV7 eras and (early, mid and late) PCV13 eras. Vaccine coverage was estimated from a nationwide survey according to east (German-speaking) and west (French/Italian-speaking) regions for each period. Reported incidence rate ratios (IRRs) were compared between successive periods and regions using nationwide IPD surveillance data. Overall IPD incidence across all ages was only 16% lower in the late PCV13 era compared to the early PCV7 era (IRR 0.83, 95% CI 0.79–0.88), due to increasing incidence of non-PCV-type IPD (2.59, 2.37–2.83) in all age groups, except children <5 years. PCV uptake rates in swiss children were slightly higher in the west than the east (p < 0.001), and were accompanied by lower IPD incidences across all age groups in the former region. Post-PCV13, non-PCV serotypes 8, 22F and 9N were the major cause of IPD in adults ≥65 years. Increased PCV coverage in both areas of Switzerland resulted in a decrease in vaccine-type and overall IPD incidence across all age groups, in a regionally dependent manner. However, the rising incidence of non-vaccine-type IPD, exclusive to older adults, may undermine indirect beneficial effects.

Burden of invasive pneumococcal disease (IPD) over a 10-year period in Bogotá, Colombia

BackgroundInvasive pneumococcal disease (IPD) is the leading cause of infectious death worldwide. This study aimed to describe the epidemiology of IPD and the impact of pneumococcal conjugate vaccine-10 (PCV-10) over a 10-year period in Bogotá, Colombia. MethodsThis was a laboratory-based surveillance study of Streptococcus pneumoniae isolated from patients with IPD from 82 hospitals over 10 years in Bogotá, Colombia. Data were compared between two periods: 2007–2011 (before the introduction of PCV-10) and 2012–2017 (after the introduction of PCV-10). ResultsIn total, 1670 patients with IPD were included in the study between 2007 and 2017. Between 2007 and 2011, the most common serotypes were 14, 1, 6B, 6A and 3. Between 2012 and 2017, the most common serotypes were 19A, 3, 14 and 1. A decrease in the incidence of IPD, particularly in children aged 0–4 years, was noted after the introduction of PCV-10. Importantly, this reduction in incidence was not observed in patients aged ≥50 years. ConclusionsThe IPD burden in Bogotá remained stable between 2007 and 2017. The incidence of IPD decreased in children but not in older adults. The introduction of PCV-10 led to a change in the most prevalent serotypes to serotypes that are not included in PCV-10.

The impact of the changing pneumococcal national immunisation program among older Australians

Australia has a universal infant pneumococcal conjugate vaccination program and until recently a universal pneumococcal polysaccharide vaccine program for non-Indigenous adults aged ≥65 years and Indigenous adults aged ≥50 years. We documented the impacts of infant and adult vaccination programs on the epidemiology of invasive pneumococcal disease (IPD) in Indigenous and non-Indigenous adults.IPD notifications from the National Notifiable Disease Surveillance System were analysed from 2002 to 2017, grouped by age, vaccine serotype group and Indigenous status. Since the universal funding of infant and elderly pneumococcal vaccination programs in January 2005, total IPD decreased by 19% in non-Indigenous adults aged ≥65 years but doubled in Indigenous adults aged ≥50 years. Vaccine uptake was suboptimal in both groups but lower in Indigenous adults. IPD due to the serotypes contained in the pneumococcal conjugate vaccines (PCV) except for serotype 3 declined markedly over the study period but were replaced by non-PCV serotypes. Serotype 3 is currently the most common in older adults. In the populations eligible for the adult 23-valent pneumococcal polysaccharide vaccine (23vPPV) program, IPD rates due to its exclusive serotypes increased to a lower extent than non-vaccine types. In 2017, non-vaccine serotypes accounted for most IPD in the older population eligible for the 23vPPV program, while it's eleven exclusive serotypes accounted for the majority of IPD in younger adults.Infant and adult pneumococcal vaccination programs in Australia have shaped the serotype-specific epidemiology of IPD in older adults. IPD remains a significant health burden for the Indigenous population. Herd immunity impact is clear for PCV serotypes excluding serotype 3 and serotype replacement is evident for non-PCV serotypes. The adult 23vPPV immunisation program appears to have partially curbed replacement with IPD due to its eleven exclusive serotypes, highlighting a potential benefit of increasing adult 23vPPV coverage in Australia.

Invasive Pneumococcal Disease in People With Human Immunodeficiency Virus in England, 1999–2017

The 7-valent and 13-valent pneumococcal conjugate vaccines (PCVs) were introduced into the UK childhood immunization program in 2006 and 2010, respectively, with high effectiveness and resulting in both direct and indirect protection. We describe the epidemiology of invasive pneumococcal disease (IPD) in adults with human immunodeficiency virus (HIV) in England following the introduction of both PCVs. Data on a national cohort of people with HIV were linked to confirmed IPD cases in adults aged ≥ 15 years during 1999-2017. Date of HIV infection was estimated using a CD4 slope decline algorithm. Among 133 994 adults with HIV, 1453 developed IPD during 1999-2017, with 70% (1016/1453) developing IPD ≥ 3 months after their HIV diagnosis. IPD and HIV were codiagnosed within 90 days in 345 (24%) individuals. A missed opportunity for earlier HIV diagnosis was identified in 6% (89/1453), mostly in earlier years. IPD incidence in people with HIV increased from 147/100 000 in 1999 to 284/100 000 in 2007 before declining and stabilizing between 92 and 113/100 000 during 2014-2017. Mean annual IPD incidence was lower among those receiving antiretroviral therapy during 2014-17 (68 vs 720/100 000; incidence rate ratio [IRR] 9.3; 95% confidence interval [CI], 7.3-11.8; P < .001) and was markedly lower in those with a suppressed viral load (50 vs 523/100 000; IRR 10.4; 95% CI, 7.6-14.1; P < .001). The latter group still had 4.5-fold higher (95% CI, 3.8-5.3; P < .001) IPD incidence compared to the general population (11.2/100 000). IPD incidence among people with HIV reduced after PCV13 introduction and has remained stable. Adults presenting with IPD should continue to be tested for HIV infection.

The Role of Streptococcus pneumoniae in Community-Acquired Pneumonia.

With the notable exceptions of the United States and Canada in particular, the global burden of disease in adults due to invasive infection with the dangerous respiratory, bacterial pathogen, Streptococcus pneumoniae (pneumococcus) remains. This situation prevails despite the major successes of inclusion of polysaccharide conjugate vaccines (PCVs) in many national childhood immunization programs and associated herd protection in adults, as well as the availability of effective antimicrobial agents. Accurate assessment of the geographic variations in the prevalence of invasive pneumococcal disease (IPD) has, however, been somewhat impeded by the limitations imposed on the acquisition of reliable epidemiological data due to reliance on often insensitive, laboratory-based, pathogen identification procedures. This, in turn, may result in underestimation of the true burden of IPD and represents a primary focus of this review. Other priority topics include the role of PCVs in the changing epidemiology of IPD in adults worldwide, smoking as a risk factor not only in respect of increasing susceptibility for development of IPD, but also in promoting pneumococcal antibiotic resistance. The theme of pneumococcal antibiotic resistance has been expanded to include mechanisms of resistance to commonly used classes of antibiotics, specifically β-lactams, macrolides and fluoroquinolones, and, perhaps somewhat contentiously, the impact of resistance on treatment outcome. Finally, but no less importantly, the role of persistent antigenemia as a driver of a chronic, subclinical, systemic proinflammatory/procoagulant phenotype that may underpin the long-term sequelae and premature mortality of those adults who have recovered from an episode of IPD, is considered.

Impact of vaccination on invasive pneumococcal disease in Italy 2007-2017: surveillance challenges and epidemiological changes.

Surveillance of new cases of invasive pneumococcal disease (IPD) in Italy was started in 2007 by the Ministry of Health (MoH). In 2012, pneumococcal childhood vaccination was introduced at the national level and, in 2017, for citizens aged 65 years and over. We describe here IPD epidemiology in Italy over the past 10 years investigating the impact of the vaccine programme on disease burden. Reports of IPD cases, data on serotype and vaccination coverage (VC) data were obtained from MoH annual reports, for the period 2007-2017. IPD notification rate and proportion by year, region, age and serotype were calculated. In 2007, 525 cases were reported (rate 0.88/100 000), rising to 1703 cases (rate 2.82/100 000) in 2017. The distribution of IPD cases by age group over time registered the largest share among individuals aged 65 years and over. A decreasing trend in notification rate was observed among those aged 0-4 years. During the same period, the 24-month VC increased, ranging from 80.9% to 96.7% in 2017. Molecular data indicated re-emergence of PPSV23-specific serotypes and non-vaccine serotypes. We observed an increase in IPD notifications during 2007-2017, likely due to an improved surveillance system, at least in some regions, with the relative quota of IPD notifications decreasing among vaccinated children cohorts. Further strengthening of IPD surveillance system, including molecular and vaccine coverage data, would be needed to assess and inform pneumococcal vaccination strategies in Italy.

Changing Epidemiology and Predisposing Factors for Invasive Pneumococcal Disease at Two Australian Tertiary Hospitals.

Invasive pneumococcal disease (IPD) is associated with significant morbidity and mortality in children. Universal pneumococcal conjugate vaccination has changed the epidemiology of IPD. In vaccinated children, IPD can be a marker of an underlying immunodeficiency. This is a retrospective audit of children younger than 18 years with IPD admitted to 2 tertiary pediatric hospitals in Australia between 2011 and 2017. Data on predisposing conditions, immunologic evaluation, pneumococcal serotype, antibiotic susceptibility and treatment were collected. During the 7-year period, there were 131 presentations with IPD in 127 children; 3 children had recurrent IPD. Patients presented with sepsis (41%), empyema (29%), meningitis (18%), mastoiditis (12%), pneumonia (10%) and septic arthritis (4%). In 19 (15%) presentations, risk factors for IPD were present, including malignancy, hematologic disorder, chronic liver disease, chronic kidney disease and cochlear implant. Pneumococcal serotypes were determined in 78/131 (60%) of presentations: the most frequent serotypes were 19A (19%), 3 (13%), 7F (10%) and 19F (8%) and non-vaccine serotypes 22F (8%), 35B (6%), 15A (4%) and 38 (4%). Overall, 11% of isolates were non-susceptible to ceftriaxone. Only 36 patients (32%) had an immunologic evaluation, and 4 patients had proven or probable immunodeficiency. Although pneumococcal conjugate vaccine serotypes 19A, 3, 19F and 7F remain frequent causes of IPD, non-vaccine serotypes are emerging. Our data support vancomycin treatment for children with pneumococcal meningitis given 11% of our isolates were not susceptible to ceftriaxone. It is important to consider underlying conditions predisposing to IPD in a population with high rates of pneumococcal vaccination.

Invasive Pneumococcal Disease in People with HIV in England, 1999-2017

Background: The 7-valent and 13-valent pneumococcal conjugate vaccines (PCVs) were introduced into the United Kingdom childhood immunisation programme in 2006 and 2010 respectively, with high effectiveness and resulting in both direct and indirect protection. We describe the epidemiology of invasive pneumococcal disease (IPD) in adults with HIV in England following the introduction of both PCVs. Methods: Data on a national cohort of people with HIV were linked to confirmed IPD cases in adults aged ≥15 years during 1999-2017. Date of HIV infection was estimated using a CD4 slope decline algorithm. Findings: Among 133,994 adults with HIV, 1,453 developed IPD during 1999-2017, with 70% (1,016/1,453) developing IPD ≥3 months after their HIV diagnosis. IPD and HIV were co-diagnosed within 90 days in 345 (24%) individuals. A missed opportunity for earlier HIV diagnosis was identified in 6% (89/1,453), mostly in earlier years. IPD incidence in people with HIV increased from 147/100,000 in 1999 to 284/100,000 in 2007 before declining and stabilising between 92-113/100,000 during 2014-2017. Mean annual IPD incidence was lower among those receiving ART during 2014-17 (720 vs. 68/100,000; IRR 9.3; 95%CI, 7.3-11.8; P<0.001) and was markedly lower in those with a suppressed viral load (523 vs. 50/100,000; IRR 10.4; 95%CI, 7.6-14.1; P<0.001). The latter group still had 4.5-fold higher (95%CI, 3.8-5.3; P<0.001) IPD incidence compared to the general population (11.2/100,000). Interpretation: IPD incidence among people with HIV reduced after PCV13 introduction and has remained stable. Adults presenting with IPD should continue to be tested for HIV infection. Funding Statement: The authors are employed by PHE. There was no additional funding for this study. Declaration of Interests: PDK, ZAC, SEC, CS, NF and VCD declare no conflicts of interest. SNL performs contract research on behalf of St. George’s University of London (SGUL) and Public Health England (PHE) for vaccine manufacturers but receives no personal remuneration. The Immunisation Department has provided vaccine manufacturers with post-marketing surveillance reports on pneumococcal and meningococcal infection which the companies are required to submit to the UK Licensing authority in compliance with their Risk Management Strategy. A cost recovery charge is made for these reports. Ethics Approval Statement: PHE has legal permission, provided by Regulation 3 of The Health Service (Control of Patient Information) Regulations 2002, to process patient confidential information for national surveillance of communicable diseases (http://www.legislation.gov.uk/uksi/2002/1438/regulation/3/made). This includes PHE’s responsibility to monitor the safety and effectiveness of vaccines.