William Schaffner, United States of America

Vanderbilt University Department of Health Policy

Author Of 4 Presentations

 Conference Calendar

EVOLVING RISK PROFILE OF PATIENTS WITH INVASIVE PNEUMOCOCCAL DISEASE DURING THE PNEUMOCOCCAL CONJUGATE VACCINE ERA (ID 1144)

Session Name
Population Sciences - Epidemiology, Economics, and Mathematical Modelling
Presenter
Authors

Abstract

Background

The incidence of invasive pneumococcal disease (IPD) due to serotypes covered by pneumococcal conjugate vaccines (PCVs) has declined since PCVs introduction. Whether the risk profile of IPD cases have changed following PCVs introduction is unclear.

Methods

We examined the comorbidity profile of all laboratory-confirmed IPD cases identified in Tennessee through active population and laboratory-based surveillance (1998-2017). Comorbidities were identified through chart review, and classified as high-risk and at-risk, as previously described (Figure). We examined changes in the proportion of patients with relevant comorbidities over time, and stratified estimates according to serotype information.

Results

pngfigure.pngThe proportion of IPD cases with high-risk and at-risk comorbidities increased over time from 9% (1998-1999) to 26% (2016-2017) and from 22% to 59%, respectively. For IPD caused by vaccine-covered serotypes (PCV7 or those only covered by PCV13), increases in comorbidities prevalence were attenuated during recent years, but estimates’ precision was limited. For IPD caused by serotypes not in PCV13, the prevalence of comorbidities increased continuously (Figure).

Conclusions

After widespread use of PCVs, patients with residual IPD in Tennessee have a higher prevalence of relevant comorbidities than in previous years. These risk profile changes need to be considered in future prevention plans.

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IMPACT OF 13-VALENT PNEUMOCOCCAL CONJUGATE VACCINE (PCV13) ON NON-BACTEREMIC PNEUMOCOCCAL PNEUMONIA (NBPP) IN THE UNITED STATES 2013-2017 (ID 222)

Session Name
Vaccines - Impact of Vaccine programs and Serotype Replacement
Presenter
Authors

Abstract

Background

PCV13 was recommended for U.S. children in 2010 and for adults ≥65 years in 2014. Vaccine coverage among adults ≥65 years was 43% in 2017. We evaluated PCV13 impact on NBPP among adults.

Methods

NBPP cases (clinically or radiographically-confirmed pneumonia and a positive pneumococcal urine antigen test in a hospitalized adult aged ≥18 years) were identified at select hospitals in 10 sites within CDC’s Active Bacterial Core surveillance during 2013-2017. NBPP rates (cases per 100,000) were estimated using U.S. Census Bureau population denominators and adjusted for the proportion of pneumonia patients tested by UAT and the number of pneumonia admissions in the catchment area.

Results

Between 2013 and 2017, 4,430 NBPP cases were identified. From 2013 to 2014, rates of NBPP declined from 153 to 90 (41% reduction, 95%CI 30%, 51%) in ≥65 year-olds; 60 to 40 (34% reduction, 95%CI 22%, 45%) in 50-64 year-olds; and 15 to 10 (36% reduction, 95%CI 25%, 47%) in 18-49 year-olds. From 2014 to 2017, rates of NBPP increased in all ages but remained below 2013 rates (Figure).

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Conclusions

Reductions in NBPP among adults were primarily due to indirect effects of PCV13 use in children, with no additional declines following PCV13 introduction for adults aged ≥65 years.

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Long-term Impact of Pneumococcal Conjugate Vaccine (PCV) on Antibiotic Resistant Invasive Pneumococcal Disease (IPD) in the United States (ID 892)

Session Name
Vaccines - Impact of Vaccine programs and Serotype Replacement
Presenter
Authors

Abstract

Background

PCVs have been recommended for U.S. children since 2000 and for adults aged ≥65 years since 2014. We evaluated impact of PCVs on antibiotic non-susceptible (NS) IPD.

Methods

IPD cases were identified through CDC’s Active Bacterial Core surveillance during 1998-2018. Isolates were serotyped and classified as PCV13 or non-vaccine type (NVT). We applied 2019 Clinical and Laboratory Standards Institute breakpoints to minimum inhibitory concentrations (using broth microdilution or whole genome sequencing) to classify isolates as NS to >1 antibiotic (NS-IPD) or to >3 drug classes (multi-drug-NS). Incidence rates (per 100,000) were calculated using U.S. Census Bureau population denominators.

Results

From 1998-1999 to 2017-2018, penicillin-NS IPD incidence decreased from 12 to 0.4 among children <5 years-old and from 5 to 0.8 among adults ≥65 years-old. Incidence of PCV13-type NS-IPD decreased among all ages, while incidence of NVT NS-IPD increased for all ages (Figure). In 2018, serotypes 19A (37%), 23A (13%) and 23B (13%) and serotypes 35B (42%), 19A (19%), and 15A (12%) accounted for most penicillin NS and multi-drug-NS IPD, respectively.

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Conclusions

NS-IPD incidence decreased following 18 years of PCV use among children, driven by reductions in PCV serotypes. Increases in NVTs have started to erode PCV benefits on NS-IPD, especially among adults.

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EPIDEMIOLOGY OF INVASIVE PNEUMOCOCCAL DISEASE (IPD) FOLLOWING 18 YEARS OF PNEUMOCOCCAL CONJUGATE VACCINE (PCV) USE IN THE UNITED STATES (ID 849)

Session Name
Vaccines - Impact of Vaccine programs and Serotype Replacement
Presenter
Authors

Abstract

Background

PCVs have been recommended for U.S. children since 2000 and for adults aged ≥65 years since August 2014. We evaluated PCV impact on IPD.

Methods

IPD cases (isolation of pneumococcus from sterile sites) were identified through CDC’s Active Bacterial Core surveillance during 1998-2018. Isolates were serotyped by Quellung or whole genome sequencing and classified as PCV13-type and non-vaccine-type (NVT). Incidence rates (cases/100,000) were calculated using U.S. Census Bureau population denominators.

Results

During 1998-2018, overall and PCV13-type IPD rates declined significantly among children and adults aged ≥65 years (Figures); serotypes 3, 19A, and 19F caused most of the remaining PCV13-type IPD. NVT IPD rates did not change. The most common NVTs in 2018 were 22F (10% of all IPD), 9N (7%) and 15A (5%). Among children, the proportion of cases with meningitis increased from 5% to 14%(p<0.01), and the proportion with pneumonia/empyema increased from 17% to 31%(p<0.01). Among adults, the proportion of cases with meningitis did not change (3%), while the proportion with pneumonia/empyema increased from 72% to 76%(p=0.01).

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Conclusions

Overall IPD incidence among children and adults decreased following PCV introduction for children, driven primarily by reductions in PCV-type IPD. Increases in NVT IPD were minimal compared with PCV benefits.

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