Invasive Pneumococcal Disease Surveillance Research Articles

Risk of invasive pneumococcal disease during pregnancy and postpartum and association with adverse maternal and foetal outcomes: a prospective cohort study, England, 2014-19

BackgroundPneumococcal infections are associated with significant morbidity and mortality, especially at the extremes of age and in those with underlying conditions. Little is known about the risks, presentations or outcomes of invasive pneumococcal disease (IPD) during pregnancy or the postpartum period. MethodsThe UK Health Security Agency conducts enhanced national surveillance of IPD in England. We used national surveillance data to calculate IPD risk and outcomes in pregnant, postpartum and non-pregnant women of childbearing age with IPD over a five-year period in England. FindingsThere were 1,701 IPD cases in women aged 15-44 years between 1 July 2014 and 30 June 2019, including 123 (7.2%) pregnant, 38 (2.1%) postpartum and 1,540 (90.7%) non-pregnant women. IPD incidence in pregnant women (0.048/1,000 woman-years) was not significantly different compared to non-pregnant women (0.041/1,000 woman-years; Incidence Rate Ratio [IRR]: 1.17; 95%CI 0.96-1.40; p=0.11). When stratified by trimester, however, women in their third trimester had a 2.27-fold (95%CI 1.79-2.85, p<0.001) increased risk of IPD, compared to non-pregnant women (IRR 2.27, 95%CI 1.78-2.85, p<0.001), while those in the first (IRR 0.49, 95%CI 0.28-0.80) and second trimester (IRR 0.71, 95%CI 0.47-1.04) had a lower risk, albeit only statistically significant for the first trimester. Postpartum women (0.144 per 1,000 woman-years), on the other hand, had a 3.49-fold (95%CI 2.46-4.81, p<0.001) higher IPD risk than non-pregnant women.Most pregnant women developed IPD during their third trimester (80/123, 65.0%), with all but one pregnancy resulting in a live birth. IPD in the second trimester was associated with live birth in 77.8% cases (21/27), while 22.2% experienced a miscarriage (5/27, 18.5%) or stillbirth (1/27, 3.7%). IPD in the first trimester was associated with live birth in 41.7% cases (5/12), miscarriages in 41.7% (5/12), and termination in 16.7% (2/12) cases. Only three neonates (3/142) had confirmed IPD. There were no deaths in pregnant women with IPD compared to 5.5% (85/1,540) in non-pregnant women. InterpretationWhile pregnant women overall did not appear to have an increased risk of IPD compared to non-pregnant women, those infected in third trimester appeared to have more than three times the incidence. Most pregnant and postpartum women had a live birth and subsequent neonatal infection was rare, occurring in 2% live births.

Estimating the potential impact of pneumococcal vaccination for new residents entering care homes for older adults in England

BackgroundThe incidence of invasive pneumococcal disease (IPD) increases exponentially in older adults, with very high case fatality rates. In the UK, the 23-valent pneumococcal polysaccharide vaccine (PPV23) is offered to all adults at age 65. PPV23 has moderate vaccine effectiveness against 23 pneumococcal serotypes in older adults, with rapid waning after 5–10 years. The median resident age in care homes for older adults is 86 years, therefore no longer protected by their PPV23 dose, despite increased risk due to advanced age, underlying comorbidities and living in closed settings. We used national surveillance data to estimate the potential impact of vaccinating new care home residents with PPV23 additional to existing national immunisation programme for 65-year-olds. MethodsThe UK Health Security Agency conducts enhanced IPD surveillance in England. National IPD incidence of IPD and care home resident population and life expectancy data were used to calculate the numbers needed to vaccinate (NNV) new care home residents with PPV23 to prevent one IPD case compared to 65-year-olds receiving PPV23 as part of the national immunisation programme. The study did not involve collection of primary data and did not meet the UK Medical Research Council definition of research and therefore no ethical approval was required. Furthermore, UKHSA has legal permission to process confidential information for the purpose of national surveillance of communicable diseases without individual patient consent (Regulation 3 of Health Service Regulations 2002). FindingsIn 2022/23, there were 2574 IPD cases among 603 109 ≥65-year-olds including 1786 (69%) caused by PPV23 serotypes, after correcting for missing serotypes, among confirmed IPD cases. With national vaccine uptake of 71% and PPV23 effectiveness of 36%, the NNV was 3706 to prevent one IPD case in the national immunisation programme for 65-year-olds. Among 121 587 new residents entering English care homes annually, the NNV was 3026. InterpretationVaccinating residents when they enter care homes for older adults with PPV23 has potential to prevent more cases per dose than the national PPV23 programme for 65-year-olds. Pneumococcal conjugate vaccines, such as the recently licensed PCV20, are expected to have higher vaccine effectiveness with longer duration of protection so could prevent even more cases in this vulnerable population. FundingNone.

Characteristics of children with invasive pneumococcal disease eligible for the 1+1 compared with the 2+1 PCV13 infant immunisation schedule in England: a prospective national observational surveillance study

On Jan 1, 2020, the UK transitioned from a 2+1 to a 1+1 national infant immunisation schedule with the 13-valent pneumococcal conjugate vaccine (PCV13). We assessed whether the 1+1 PCV13 schedule had any impact on incidence, disease characteristics, or outcomes after invasive pneumococcal disease (IPD) in eligible children aged 0-3 years. The UK Health Security Agency conducts IPD surveillance and serotyping of invasive pneumococcal isolates via whole-genome sequencing in England. IPD was defined as identification of Streptococcus pneumoniae in a sterile site. We compared IPD incidence, demographics, clinical presentation, comorbidity prevalence, serotype distribution, and case-fatality rates (CFRs) in children from a single birth cohort eligible for the 1+1 schedule (born between Jan 1, 2020, and Dec 31, 2022) who developed IPD in the 2022-23 financial year (April to March) with children from three equivalent historical birth cohorts (born between Jan 1, 2015, and Dec 31, 2019) eligible for the 2+1 schedule who developed IPD during three respective pre-pandemic financial years: 2017-18, 2018-19, and 2019-20. There were a total of 702 IPD episodes in 697 children, including 158 (incidence 8·99 per 100 000 person-years) in the single 1+1 birth cohort and 544 (incidence 9·39 per 100 000 person-years) in the 2+1 birth cohorts, with no significant difference in the incidence of overall IPD (incidence rate ratio 0·96, 95% CI 0·80-1·14, p=0·63), PCV13-type IPD (1·21, 0·71-2·00, p=0·45), or pneumococcal meningitis (0·97, 0·66-1·40, p=0·88). Comorbidity prevalence, clinical presentation, and CFRs were also similar between the two cohorts, as was the percentage of cases in infants too young to be vaccinated (<2 months old) and infants aged 5-11 months who received one or two PCV13 priming doses, in the 1+1 and 2+1 cohorts respectively. After 3 years, the 1+1 schedule continues to provide direct and indirect protection against PCV13-type IPD in children, with no significant change in overall IPD incidence, serotype distribution, clinical presentation, or CFRs in children eligible for the 1+1 compared with the 2+1 schedule. Ongoing surveillance will be important to assess longer-term direct and indirect population protection. None.

Long-term effect of pneumococcal conjugate vaccines on invasive pneumococcal disease incidence among people of all ages from national, active, laboratory-based surveillance in South Africa, 2005–19: a cohort observational study

In South Africa, 7-valent pneumococcal conjugate vaccine (PCV7) was introduced in 2009 and 13-valent PCV (PCV13) was introduced in 2011, both in a two plus one schedule. We evaluated the ongoing effects of PCV on the prevention of invasive pneumococcal disease (IPD) over 15 years of sustained surveillance in South Africa before the COVID-19 pandemic. We conducted national, active, laboratory-based surveillance for IPD among all ages in South Africa, including isolate serotyping and susceptibility testing. We fitted linear regression models with vaccine covariates to imputed IPD case counts each year by serotype and age to compare expected and actual IPD cases in 2019, which was the main outcome. Vaccine effects were set to zero to identify expected incidence after the introduction of PCV7 and PCV13. From Jan 1, 2005, to Dec 31, 2019, surveillance identified 52 957 IPD cases. Among the 50 705 individuals with age data available, 9398 (18·5%) were infants aged younger than 2 years. Compared with expected case numbers (no vaccination) predicted using all available data, overall IPD rates among children younger than 2 years declined by 76·0% (percentage risk difference; 95% CI -79·0 to -72·8%) in 2019; notably, PCV7 and additional PCV13 serotype IPD rates declined by 95·5% (-97·0 to -93·4%) and 93·8% (-96·2 to-90·5%), respectively, whereas non-vaccine serotypes (NVTs) did not change significantly. Among adults aged 25-44 years, overall IPD declined by 50·4% (-54·2 to -46·3%), and PCV7 and additional PCV13 serotype IPD rates declined by 86·1% (-88·7 to -83·1%) and 77·2% (-80·9 to -73·0%), respectively, whereas NVTs increased by 78·5% (56·8 to 103·4%). Individuals aged older than 64 years also benefited from declines in IPD (-30·2%; -41·9 to -16·2%), but NVTs increased (234·9%; 138·1 to 379·4%). We documented sustained direct and indirect benefits of PCV across age groups, and NVT increases in adults older than 24 years. Higher valency PCVs would have the added benefit of preventing this residual disease. National Institute for Communicable Diseases of the National Health Laboratory Service (South Africa) and US Agency for International Development Antimicrobial Resistance Initiative, US Centers for Disease Control and Prevention.

Potential impact of replacing the 13-valent pneumococcal conjugate vaccine with 15-valent or 20-valent pneumococcal conjugate vaccine in the 1 + 1 infant schedule in England: a modelling study

Paediatric pneumococcal conjugate vaccine (PCV) programmes in England using seven-valent PCV (PCV7) in 2006 and 13-valent PCV (PCV13) in 2010 have reduced vaccine-type invasive pneumococcal disease, but the overall effect has been reduced by an increase in invasive pneumococcal disease due to non-vaccine serotypes and serotype 3. We developed pneumococcal transmission models to investigate the potential effect on invasive pneumococcal disease of higher valency PCVs covering an additional two (ie, 15-valent PCV [PCV15]) or seven serotypes (ie, 20-valent PCV [PCV20]) in England. We conducted a modelling study using realistic, age-structured, and compartmental deterministic models fitted to carriage data from before the introduction of PCVs and invasive pneumococcal disease data from before and after the introduction of PCV7 and PCV13 in England from the UK Heath Security Agency invasive pneumococcal disease surveillance system. We estimated key parameters, including PCV7 and PCV13 efficacy against vaccine-type carriage and invasiveness of PCV7 serotypes; the additional serotypes in PCV13, PCV15 and PCV20; and non-vaccine serotypes. We simulated the effect of transitioning from PCV13 to PCV15 or PCV20 in infants under the current 1 + 1 vaccination schedule and investigated the effect of reduced carriage protection against PCV13 serotypes due to attenuation of immunogenicity in higher valency vaccines. Our results suggest that PCV15 might increase overall invasive pneumococcal disease as the reduction in vaccine-type invasive pneumococcal disease would be counterbalanced by an increase in non-PCV15 invasive pneumococcal disease. By contrast, PCV20 is projected to have a substantial impact on overall invasive pneumococcal disease due to higher invasiveness of the additional serotypes covered by PCV20 than the replacing non-vaccine serotypes. Reduced carriage protection against PCV13 serotypes with higher valency vaccines would amplify these effects. Replacing PCV13 with PCV20 is likely to have a substantial public health benefit, but PCV15 could potentially increase the overall burden of disease. UK Health Security Agency and National Institute of Health Research.

Assessing the Impact of Pneumococcal Conjugate Vaccine Immunization Schedule Change From 3+0 to 2+1 in Australian Children: A Retrospective Observational Study.

In mid-2018, the Australian childhood 13-valent pneumococcal conjugate vaccine schedule changed from 3+0 to 2+1, moving the third dose to 12 months of age, to address increasing breakthrough cases of invasive pneumococcal disease (IPD), predominantly in children aged >12 months. This study assessed the impact of this change using national IPD surveillance data. Pre- and postschedule change 3-dose 13-valent pneumococcal conjugate vaccine breakthrough cases were compared by age group, serotype, and clinical syndrome. Annual rates of breakthrough cases were calculated (per 100 000) using respective birth cohort sizes and 3-dose vaccine coverage. Using time-series modelling, observed IPD rates in children aged <12 years were compared to that expected if the 3+0 schedule were continued. Over 2012-2022, rate of 3-dose breakthrough cases in children aged >12 months was 2.8 per 100 000 (n = 557; 11 birth cohorts). Serotype 3 replaced 19A as predominant breakthrough serotype (respectively, 24% and 65% in 2013 to 60% and 20% in 2022) followed by 19F. In breakthrough cases, the most frequent clinical phenotype was bacteremic pneumonia (69%), with meningitis accounting for 3%-4%. In cohorts eligible for 2+1 versus 3+0 schedules, rate of breakthrough cases was lower for all vaccine serotypes, except type 3 (incidence rate ratio, 0.50 [95% confidence interval, .28-.84] and 1.12 [0.71-1.76], respectively). Observed compared to expected IPD was 51.7% lower (95% confidence interval, -60.9 to -40.7%) for vaccine serotypes, but the change for nonvaccine types was not significant 12% (-9.6 to 39.7). The 2+1 schedule is likely superior to 3+0 for overall IPD control, a finding that may be worth consideration for other countries considering or using 3+0 PCV schedules.

Serotype distribution of invasive pneumococcal disease from countries of the WHO Africa, Americas, Eastern Mediterranean, South-East Asia, and Western Pacific regions: a systematic literature review from 2010 to 2021.

Most publications on invasive pneumococcal disease (IPD) serotype distribution are from about 20 countries (Australia, Canada, China, European Union members, Japan, New Zealand, South Korea, and USA). Here, we reviewed the literature among underrepresented countries in the Americas (AMRO), Africa (AFRO), Eastern Mediterranean (EMRO), South-East Asia (SEARO), and Western Pacific (WPRO) WHO regions. We performed a systematic review of the most recent IPD serotype surveillance publications (from 01/01/2010 to 31/12/2021, Medline/Embase) in those WHO regions. Selection criteria were delineated by contemporality, within-country geographical scope, and number of samples. Reported serotype distributions for each country were stratified by age group, pneumococcal conjugate vaccine (PCV) serotype category (considering undifferentiated serotypes), and PCV program period (pre-PCV, intermediate, or PCVhv [higher valency PCV formulation]). Pre-PCV period pooled data estimated PCV serotype category distribution by age group across WHO regions, while for the PCVhv period, country-level dataset tables were prepared. Of 2,793 publications screened, 107 were included (58 pediatric, 11 adult, 37 all ages, and one comprising every age group). One-third of eligible countries (51/135) published serotype distribution, ranging from 30 to 43% by WHO region. Considering number of samples per WHO region, a few countries prevailed: AMRO (Brazil), AFRO (South Africa, Malawi, and Burkina Faso), and WPRO (Taiwan). In the pre-PCV period, PCV13 formulation serotypes predominated: ranging from 74 to 85% in children and 58-86% in adults in the different WHO regions. The PCVhv period represented half of the most recent IPD surveillance by countries (26/51). Undifferentiated serotypes represented >20% of IPD from most countries (34/51). Ubiquity of undifferentiated serotypes among the publications could constrain estimates of PCV program impact and of serotype coverage for newer PCVhv formulations; consequently, we recommend that countries favor techniques that identify serotypes specifically and, rather than reporting PCV formulation serotype distributions, provide serotype results individually. The protocol has been prospectively registered at PROSPERO, identifier: CRD42021278501. https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=278501.

Invasive pneumococcal disease surveillance in Canada, 2021-2022.

Invasive pneumococcal disease (IPD, Streptococcus pneumoniae) has been a nationally notifiable disease in Canada since 2000. The use of conjugate vaccines has caused a shift in the distribution of serotypes over time. This report is a summary of the demographics, serotypes and antimicrobial resistance of IPD isolates collected in Canada in 2021 and 2022. The National Microbiology Laboratory (NML) of the Public Health Agency of Canada in Winnipeg, Manitoba collaborates with provincial and territorial public health laboratories to conduct national surveillance of IPD. There were 1,999 isolates reported in 2021 and 3,775 isolates in 2022. Serotype was determined by the Quellung reaction or whole-genome sequencing (WGS). Antimicrobial susceptibilities were determined by WGS methods, broth microdilution, or data shared by collaborators in the Canadian Antimicrobial Resistance Alliance program at the University of Manitoba. Population-based IPD incidence rates were obtained through the Canadian Notifiable Disease Surveillance System. The incidence of IPD in Canada was 5.62 cases per 100,000 population in 2021, decreasing from the peak of 10.86 cases per 100,000 population in 2018. Serotypes with increasing trends (p<0.05) between 2018 and 2022 included: 4 (6.1%-12.4%), 9V (1.0%-5.1%) and 12F (4.8%-5.4%). The overall prevalence of PCV13 serotypes increased over the same period (31.2%-41.5%, p<0.05) while the prevalence of non-vaccine types decreased significantly (27.3%-21.5%, p<0.0001). The highest rates of antimicrobial resistance in 2021 and 2022 were seen with clarithromycin (21%, 2021; 24%, 2022) and erythromycin (22%, 2021; 24%, 2022). Multidrug-resistant IPD continued to increase from 2018 to 2022 (6.7%-12.6%, p<0.05). The number of cases of IPD continued to decrease in 2021 in comparison to previous years, however, 2022 saw a return to pre-COVID-19 levels. Disease due to PCV13 serotypes 3, 4, 9V and 19F, as well as non-PCV13 serotypes 12F and 20, is increasing in prevalence. Surveillance of IPD to monitor changing serotype distribution and antimicrobial resistance is essential.

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.

Long-term surveillance of invasive pneumococcal disease: The impact of 10-valent pneumococcal conjugate vaccine in the metropolitan region of Salvador, Brazil

BackgroundIn 2010, Brazil introduced the ten-valent pneumococcal conjugate vaccine (PCV10) in the national infant immunization program. Limited data on the long-term impact of PCV10 are available from lower-middle-income settings. We examined invasive pneumococcal disease (IPD) in Salvador, Bahia, over 11 years. MethodsProspective laboratory-based surveillance for IPD was carried out in 9 hospitals in the metropolitan region of Salvador from 2008 to 2018. IPD was defined as Streptococcus pneumoniae cultured from a normally sterile site. Serotype was determined by multiplex polymerase chain reaction and/or Quellung reaction. Incidence rates per 100,000 inhabitants were calculated for overall, vaccine-type, and non-vaccine-type IPD using census data as the denominator. Incidence rate ratios (IRRs) were calculated to compare rates during the early (2010–2012), intermediate (2013–2015), and late (2016–2018) post-PCV10 periods in comparison to the pre-PCV10 period (2008–2009). ResultsPre-PCV10, overall IPD incidence among all ages was 2.48/100,000. After PCV10 introduction, incidence initially increased (early post-PCV10 IRR 3.80, 95% CI 1.18–1.99) and then declined to 0.38/100,000 late post-PCV10 (IRR 0.15; 95% CI 0.09–0.26). The greatest reductions in the late post-PCV10 period were observed in children aged ≤2 years, with no cases (IRR not calculated) and those ≥60 years (IRR 0.11, 95% CI 0.03–0.48). Late post-PCV10, significant reductions were observed for both PCV10 serotypes (IRR 0.02; 95% CI 0.0–0.15) and non-PCV10 serotypes (IRR 0.27; 95%CI 0.14–0.53). Non-PCV10 serotypes 15B, 12F, 3, 17F, and 19A became predominant late post-PCV10 without a significant increase in serotype-specific IPD incidence compared to pre-PCV10. ConclusionSignificant declines in IPD, including among adults not eligible for vaccination, suggest direct and indirect protection up to nine years after PCV10 introduction, without evidence of significant replacement disease. Continued surveillance is needed to monitor changes in non-vaccine serotypes and inform decisions about introducing higher valent PCVs.

Dynamics of invasive pneumococcal disease in infants < 2 years old following PCV7/13 implementation using two infant and a booster dose schedule: evidence for indirect protection of young infants, Israel, 2004 to 2019.

BackgroundPneumococcal conjugated vaccine (PCV)7 and PCV13 programmes started in Israel from July 2009 and November 2010 respectively, with a 2+1 schedule (one dose at 2 months old, one at 4 months old, and a booster dose at 12 months old). Thereafter, invasive pneumococcal disease (IPD) rates substantially declined in children. Uptake of all three doses in < 2-year-olds since 2012 is > 90%. For still incompletely vaccinated infants (≤ 12 months old), how well the PCV 2+1 programme shields from IPD is not fully resolved.AimTo assess the adequacy of protection conferred by the 2+1 schedule PCV vaccination programme, particularly among incompletely-vaccinated infants.MethodsThis was a population-based, prospective, nationwide active IPD surveillance study in Israel, 2004-2019, in children < 24 months old. We estimated annual incidence rates (IR) of overall IPD, IPD caused by PCV13 serotypes (VT13), and non-PCV13 serotypes (NVT13). Annual IPD IRs were stratified by age: < 4 months (receiving ≤ 1 dose), 4-6 months (immediately post dose 2), 7-12 months (a few months post dose 2), and 13-23 months (post dose 3). Late-PCV (2004-2008) to pre-PCV13 (2016-2019) mean annual IR ratios (IRRs) were calculated.Results2,569 IPD episodes were recorded. VT13 decreased > 90% in all age groups, while NVT13 seemed to increase. All-IPD rates declined in all age groups by 56-70%. The 2+1 schedule impact on 7-12-month-old infants (pre-booster) was similar to that on 13-23-month-old children (post booster), with PCV13 IPD reductions of 97% and 98%, respectively.ConclusionsIndirect (herd) protection of infants, including < 4 month-olds with ≤ 1 PCV dose, was achieved by the 2+1 PCV schedule programme which thus seems adequate.

The impact of introduction of the 10-valent pneumococcal conjugate vaccine on pneumococcal carriage in Nigeria

Pneumococcal conjugate vaccines (PCVs) protect against invasive pneumococcal disease (IPD) among vaccinees. However, at population level, this protection is driven by indirect effects. PCVs prevent nasopharyngeal acquisition of vaccine-serotype (VT) pneumococci, reducing onward transmission. Each disease episode is preceded by infection from a carrier, so vaccine impacts on carriage provide a minimum estimate of disease reduction in settings lacking expensive IPD surveillance. We documented carriage prevalence and vaccine coverage in two settings in Nigeria annually (2016–2020) following PCV10 introduction in 2016. Among 4,684 rural participants, VT carriage prevalence fell from 21 to 12% as childhood (<5 years) vaccine coverage rose from 7 to 84%. Among 2,135 urban participants, VT carriage prevalence fell from 16 to 9% as uptake rose from 15 to 94%. Within these ranges, carriage prevalence declined with uptake. Increasing PCV10 coverage reduced pneumococcal infection at all ages, implying at least a comparable reduction in IPD.

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.

Increase of invasive pneumococcal disease in children temporally associated with RSV outbreak in Quebec: a time-series analysis

Respiratory viruses have been previously suspected to trigger invasive pneumococcal disease (IPD). After progressive non-pharmaceutical interventions (NPI) lifting, an unusual RSV outbreak has been observed in the Fall 2021, raising concerns about the possible consequences on IPD. We aimed to analyse the evolution of IPD incidence across age-groups since NPI lifting, and its temporal association with respiratory viral infections. We conducted a time-series analysis using 1) population-based IPD surveillance data and 2) statistics from the laboratory surveillance network of respiratory viruses in the province of Quebec, Canada, from January 2013 to January 2022. The monthly IPD incidence was analysed by quasi-Poisson regression models across age-groups. The fraction of IPD incidence change potentially attributable to different viruses in 2021-2022 was estimated. A total of 7712 IPD cases were included. After a major decrease in IPD incidence from April 2020, IPD rate started to increase in <5-year-old children in October 2021, exceeding the pre-NPI trend (+62%). This was temporally associated with an unusual surge in RSV cases (+53% versus pre-NPI trend). During this 2021-22 surge, the fraction of IPD attributable to RSV dynamics in children was 77% (95% CI [33-100]). By contrast, the IPD incidence in older age-groups remained low, and was temporally associated with influenza dynamics. These results provide new evidence on the role of respiratory viruses in driving IPD dynamics, with possible differences between children and adults. In the coming future, the potential benefit of interventions targeting RSV, such as vaccines, for IPD prevention should be considered. The study was supported by a grant from the Quebec Ministry of Health and Social Services ('ministère de la Santé et des Services sociaux du Québec'). Publication was supported by a grant from "Fondation de l'Assistance Publique - Hôpitaux de Paris et de l'Alliance«Tous Unis contre le Virus » (Fondation de France/Institut Pasteur/APHP)". N.O. was supported by the ESPID (European Society of Pediatric Infectious Diseases) 2021-2023 Fellowship Award and the 2022 ISPPD (International Symposium on Pneumococci and Pneumococcal Diseases) Robert Austrian Research award.

Invasive pneumococcal disease in patients from a pediatric hospital in Peru, 2017-2020.

Motivation for the study: there are few reports describing cases of invasive pneumococcal disease after the introduction of the 13-valent conjugate vaccine in Peru. Main findings: cases of invasive pneumococcal disease are still reported in children, more frequently in children under five years of age. The most frequent clinical form was bacteremia and there was greater antibiotic resistance to erythromycin, trimethoprim-sulfamethoxazole, and penicillin. Implications: our findings suggest the need to maintain epidemiological surveillance of invasive pneumococcal disease and to measure the impact of vaccination against pneumococcus in children. This study aimed to describe the clinical characteristics, serotypes, and antibiotic susceptibility in patients with invasive pneumococcal disease (IPD). The medical records of patients with IPD who were hospitalized at the Instituto Nacional de Salud del Niño-Breña (Lima, Peru) were reviewed. We evaluated 29 patients. The median age was 1.9 years (interquartile range: 1 to 4 years). Of the sample, 51.7% were women and the most frequent clinical form of IPD was bacteremia in 18 (62.1%) patients; 65.5% had a complete vaccination schedule, according to the Peruvian Ministry of Health. Germ isolation was performed from blood samples in 82.8% of patients. Antibiotic resistance to erythromycin (55.2%) was the most frequent, followed by resistance to trimethoprim-sulfamethoxazole (48.3%) and penicillin (24.1%). The isolated serotypes were 6C, 19A, 23A and 24F. One patient died of meningitis. In conclusion, IPD was more frequent in children aged one to five years and the most frequent clinical form was bacteremia. Five serotypes reported in previous studies were found to be resistant to penicillin and erythromycin.

Invasive pneumococcal disease surveillance in Canada, 2020

Invasive pneumococcal disease surveillance in Canada, 2020

Changing Incidence of Invasive Pneumococcal Disease in Infants Less Than 90 Days of Age Before and After Introduction of the 13-Valent Pneumococcal Conjugate Vaccine in Blantyre, Malawi: A 14-Year Hospital Based Surveillance Study.

Background:Invasive pneumococcal disease (IPD) in young infants is uncommon but associated with high morbidity and mortality. Accurate data on the burden of IPD in young infants in low-income countries are lacking. We examined the burden of IPD in infants <90 days old in Blantyre, Malawi over a 14-year period and evaluated the indirect impact of the 13-valent pneumococcal conjugate vaccine (PCV13) on vaccine-serotype IPD (VT-IPD) in this population.Methods:We conducted laboratory-based prospective IPD surveillance in infants <90 days of age admitted to Queen Elizabeth Central Hospital in Blantyre between 2005 and 2018, including 7 years pre-PCV13 and 7 years post-PCV13 introduction. IPD was defined as Streptococcus pneumoniae identified by culture from blood or cerebrospinal fluid. Serotypes were determined by multiplex polymerase chain reaction and latex agglutination testing.Results:We identified 130 cases of culture-confirmed IPD in infants <90 days old between 2005 and 2018. Total IPD incidence was declining before PCV13 introduction. The mean incidence of IPD was significantly lower in the post-PCV13 era. Serotypes 5 (27.8%) and 1 (15.6%) were most prevalent. Even after PCV13 introduction, VTs remained the primary cause of IPD, with serotype 5 accounting for 17.4% and serotype 1 for 13.0% of cases in young infants.Conclusion:Vaccine serotypes 1 and 5 were the main cause of IPD in neonates and young infants, both before and after PCV13 introduction. This suggests incomplete indirect protection with persisting VT carriage across the population despite vaccination in this setting. Alternative vaccine schedules and other vaccine introduction approaches need to be considered to protect this vulnerable population.

Dynamic changes in clinical characteristics and serotype distribution of invasive pneumococcal disease among adults in Japan after introduction of the pediatric 13-valent pneumococcal conjugate vaccine in 2013–2019

Nationwide population-based surveillance for invasive pneumococcal disease (IPD) is being conducted in few Asian countries. We aimed to evaluate the clinical characteristics and serotype distribution among Japanese adult patients with IPD after introduction of the pediatric 13-valent pneumococcal conjugate vaccine (PCV13) in 2013. IPD surveillance was conducted among adults between 2013 and 2019, and 1,995 patients were analyzed by time period (early, 2013–2015; middle, 2016–2017; late, 2018–2019). We found that the period of 2018–2019 was independently associated with a lower risk of fatal outcome, compared with the period of 2013–2015. The proportion of those with serotype PCV13-nonPCV7 decreased significantly in patients aged 15–64 years and in those aged ≥ 65 years within 3 years after the introduction of pediatric PCV13. By contrast, the proportion of those with nonvaccine serotype increased significantly in those aged ≥ 65 years, but not in those aged 15–64 years. No significant change was found in the proportion of 23-valent polysaccharide pneumococcal vaccine (PPSV23)-nonPCV13 in both of adults aged 15–64 years and ≥ 65 years. The proportions of PCV15-, PCV20- and PCV24-covered serotypes were 38%, 56% and 58% in adult patients with IPD aged ≥ 65 years during the late period. Our data on the serotype distribution support an indirect effect from pediatric PCV13 use among adults, and afford a basis for estimates of protection against IPD by vaccination with newly developed PCVs in older adults in Japan.

Reemergence of Invasive Pneumococcal Disease in Germany During the Spring and Summer of 2021.

BackgroundThe incidence of invasive pneumococcal disease (IPD) decreased worldwide in 2020 and the first quarter of 2021, concurrent with nonpharmaceutical interventions (NPIs) intended to stymie transmission of SARS-CoV-2. In 2021, the stringency of these NPI strategies has varied. We investigated age- and serotype-specific variations in IPD case counts in Germany in 2020–2021.MethodsIPD cases through 30 November 2021 were stratified by age group, serotype, or geographic location. IPD surveillance data in 2020–2021 were compared with (1) IPD surveillance data from 2015–2019, (2) mobility data during 2020 and 2021, and (3) NPI stringency data in 2020 and 2021.ResultsIPD incidence began to return toward baseline among children 0–4 years old in April 2021 and exceeded baseline by June 2021 (a 9% increase over the average monthly values for 2015–2019). Children aged 5–14 years and adults aged 15–34 or ≥80 years showed increases in IPD cases that exceeded baseline values starting in July 2021, with increases also starting in spring 2021. The age distribution and proportion of vaccine-serotype IPD remained comparable to those in previous years, despite lower overall case counts in 2020 and 2021. The percentage change in IPD incidence compared with the previous 5 years was correlated with changes in mobility and with NPI stringency.ConclusionsIPD levels began to return to and exceed seasonal levels in spring and summer 2021 in Germany, following sharp declines in 2020 that coincided with NPIs related to the coronavirus disease 2019 pandemic. Proportions of vaccine serotypes remained largely consistent throughout 2020–2021.

International links between Streptococcus pneumoniae vaccine serotype 4 sequence type (ST) 801 in Northern European shipyard outbreaks of invasive pneumococcal disease

BackgroundPneumococcal disease outbreaks of vaccine preventable serotype 4 sequence type (ST)801 in shipyards have been reported in several countries. We aimed to use genomics to establish any international links between them. MethodsSequence data from ST801-related outbreak isolates from Norway (n = 17), Finland (n = 11) and Northern Ireland (n = 2) were combined with invasive pneumococcal disease surveillance from the respective countries, and ST801-related genomes from an international collection (n = 41 of > 40,000), totalling 106 genomes. Raw data were mapped and recombination excluded before phylogenetic dating. ResultsOutbreak isolates were relatively diverse, with up to 100 SNPs (single nucleotide polymorphisms) and a common ancestor estimated around the year 2000. However, 19 Norwegian and Finnish isolates were nearly indistinguishable (0–2 SNPs) with the common ancestor dated around 2017. ConclusionThe total diversity of ST801 within the outbreaks could not be explained by recent transmission alone, suggesting that harsh environmental and associated living conditions reported in the shipyards may facilitate invasion of colonising pneumococci. However, near identical strains in the Norwegian and Finnish outbreaks does suggest that transmission between international shipyards also contributed to those outbreaks. This indicates the need for improved preventative measures in this working population including pneumococcal vaccination.