Racial disparities in invasive Streptococcus pneumoniae infections, 1998-2009

Societal Cost of Racial Pneumococcal Disease Disparities in US Adults Aged 50 Years or Older

OBJECTIVE

This study aimed to estimate the societal cost of racial disparities in pneumococcal disease among US adults aged ≥  50 years.

METHODS

In a model-based analysis, societal costs of invasive pneumococcal disease (IPD) and hospitalized nonbacteremic pneumococcal pneumonia (NBP) were estimated using (1) direct medical costs plus indirect costs of acute illness; (2) indirect costs of pneumococcal mortality; and (3) direct and indirect costs of related disability. Disparities costs were calculated as differences in average per-person pneumococcal disease cost between Black and non-Black adults aged ≥  50 years multiplied by the Black population aged ≥  50 years. Costs were in 2019 US dollars (US$), with future costs discounted at 3% per year.

RESULTS

Total direct and indirect costs per IPD case were US$186,791 in Black populations and US$182,689 in non-Black populations; total hospitalized NBP costs per case were US$100,632 (Black) and US$96,781 (non-Black). The difference in population per-person total pneumococcal disease costs between Black and non-Black adults was US$47.85. Combined societal costs of disparities for IPD and hospitalized NBP totaled US$673.2 million for Black adults aged ≥  50 years. Disease and disability risks, life expectancy, and case-fatality rates were influential in one-way sensitivity analyses, but the lowest cost across all analyses was US$194 million. The 95% probability range of racial disparity costs were US$227.2-US$1156.9 million in a probabilistic sensitivity analysis.

CONCLUSIONS

US societal cost of racial pneumococcal disease disparities in persons aged ≥ 50 years is substantial. Successful pneumococcal vaccination policy and programmatic interventions to mitigate these disparities could decrease costs and improve health.

Impact of 13-Valent Pneumococcal Conjugate Vaccine on Invasive Pneumococcal Disease Among Adults With HIV-United States, 2008-2018

BACKGROUND

People with HIV (PWH) are at increased risk for invasive pneumococcal disease (IPD). Thirteen-valent pneumococcal conjugate vaccine (PCV13) was recommended for use in US children in 2010 and for PWH aged 19 years or older in 2012. We evaluated the population-level impact of PCV13 on IPD among PWH and non-PWH aged 19 years or older.

METHODS

We identified IPD cases from 2008 to 2018 through the Active Bacterial Core surveillance platform. We estimated IPD incidence using the National HIV Surveillance System and US Census Bureau data. We measured percent changes in IPD incidence from 2008 to 2009 to 2017-2018 by HIV status, age group, and vaccine serotype group, including serotypes in recently licensed 15-valent (PCV15) and 20-valent (PCV20) PCVs.

RESULTS

In 2008-2009 and 2017-2018, 8.4% (552/6548) and 8.0% (416/5169) of adult IPD cases were among PWH, respectively. Compared with non-PWH, a larger proportion of IPD cases among PWH were in adults aged 19-64 years (94.7%-97.4% vs. 56.0%-60.1%) and non-Hispanic Black people (62.5%-73.0% vs. 16.7%-19.2%). Overall and PCV13-type IPD incidence in PWH declined by 40.3% (95% confidence interval: -47.7 to -32.3) and 72.5% (95% confidence interval: -78.8 to -65.6), respectively. In 2017-2018, IPD incidence was 16.8 (overall) and 12.6 (PCV13 type) times higher in PWH compared with non-PWH; PCV13, PCV15/non-PCV13, and PCV20/non-PCV15 serotypes comprised 21.5%, 11.2%, and 16.5% of IPD in PWH, respectively.

CONCLUSIONS

Despite reductions post-PCV13 introduction, IPD incidence among PWH remained substantially higher than among non-PWH. Higher-valent PCVs provide opportunities to reduce remaining IPD burden in PWH.

Disease-Specific Health Disparities: A Targeted Review Focusing on Race and Ethnicity

Background: Wide disparities in health status exist in the United States across race and ethnicity, broadly driven by social determinants of health—most notably race and ethnic group differences in income, education, and occupational status. However, disparities in disease frequency or severity remain underappreciated for many individual diseases whose distribution in the population varies. Such information is not readily accessible, nor emphasized in treatment guidelines or reviews used by practitioners. Specifically, a summary on disease-specific evidence of disparities from population-based studies is lacking. Our goal was to summarize the published evidence for specific disease disparities in the United States so that this knowledge becomes more widely available “at the bedside”. We hope this summary stimulates health equity research at the disease level so that these disparities can be addressed effectively. Methods: A targeted literature review of disorders in Pfizer’s current pipeline was conducted. The 38 diseases included metabolic disorders, cancers, inflammatory conditions, dermatologic disorders, rare diseases, and infectious targets of vaccines under development. Online searches in Ovid and Google were performed to identify sources focused on differences in disease rates and severity between non-Hispanic Whites and Black/African Americans, and between non-Hispanic Whites and Hispanics. As a model for how this might be accomplished for all disorders, disparities in disease rates and disease severity were scored to make the results of our review most readily accessible. After primary review of each condition by one author, another undertook an independent review. Differences between reviewers were resolved through discussion. Results: For Black/African Americans, 29 of the 38 disorders revealed a robust excess in incidence, prevalence, or severity. After sickle cell anemia, the largest excesses in frequency were identified for multiple myeloma and hidradenitis suppurativa. For Hispanics, there was evidence of disparity in 19 diseases. Most notable were metabolic disorders, including non-alcoholic steatohepatitis (NASH). Conclusions: This review summarized recent disease-specific evidence of disparities based on race and ethnicity across multiple diseases, to inform clinicians and health equity research. Our findings may be well known to researchers and specialists in their respective fields but may not be common knowledge to health care providers or public health and policy institutions. Our hope is that this effort spurs research into the causes of the many disease disparities that exist in the United States.

Nasopharyngeal microbiome composition associated with Streptococcus pneumoniae colonization suggests a protective role of Corynebacterium in young children

Streptococcus pneumoniae (Spn) is a leading respiratory tract pathogen that colonizes the nasopharynx (NP) through adhesion to epithelial cells and immune evasion. Spn actively interacts with other microbiota in NP but the nature of these interactions are incompletely understood. Using 16S rRNA gene sequencing, we analyzed the microbiota composition in the NP of children with or without Spn colonization. 96 children were included in the study cohort. 74 NP samples were analyzed when children were 6 months old and 85 NP samples were analyzed when children were 12 months old. We found several genera that correlated negatively or positively with Spn colonization, and some of these correlations appeared to be influenced by daycare attendance or other confounding factors such as upper respiratory infection (URI) or Moraxella colonization. Among these genera, Corynebacterium showed a consistent inverse relationship with Spn colonization with little influence by daycare attendance or other factors. We isolated Corynebacterium propinquum and C. pseudodiphtheriticum and found that both inhibited the growth of Spn serotype 22F strain in vitro.

Racial Disparities in Incidence of Legionnaires' Disease and Social Determinants of Health: A Narrative Review

OBJECTIVES

Racial and socioeconomic disparities in the incidence of Legionnaires' disease have been documented for the past 2 decades; however, the social determinants of health (SDH) that contribute to these disparities are not well studied. The objective of this narrative review was to characterize SDH to inform efforts to reduce disparities in the incidence of Legionnaires' disease.

METHODS

We conducted a narrative review of articles published from January 1979 through October 2019 that focused on disparities in the incidence of Legionnaires' disease and pneumonia (inclusive of bacterial pneumonia and/or community-acquired pneumonia) among adults and children (excluding articles that were limited to people aged <18 years). We identified 220 articles, of which 19 met our criteria: original research, published in English, and examined Legionnaires' disease or pneumonia, health disparities, and SDH. We organized findings using the Healthy People 2030 SDH domains: economic stability, education access and quality, social and community context, health care access and quality, and neighborhood and built environment.

RESULTS

Of the 19 articles reviewed, multiple articles examined disparities in incidence of Legionnaires' disease and pneumonia related to economic stability/income (n = 13) and comorbidities (n = 10), and fewer articles incorporated SDH variables related to education (n = 3), social support (none), health care access (n = 1), and neighborhood and built environment (n = 6) in their analyses.

CONCLUSIONS

Neighborhood and built-environment factors such as housing, drinking water infrastructure, and pollutant exposures represent critical partnership and research opportunities. More research that incorporates SDH and multilevel, cross-sector interventions is needed to address disparities in Legionnaires' disease incidence.

Marked Reduction of Socioeconomic and Racial Disparities in Invasive Pneumococcal Disease Associated With Conjugate Pneumococcal Vaccines

BACKGROUND

It is not known whether reductions in socioeconomic and racial disparities in incidence of invasive pneumococcal disease (defined as the isolation of Streptococcus pneumoniae from a normally sterile body site) noted after pneumococcal conjugate vaccine (PCV) introduction have been sustained.

METHODS

Individual-level data collected from 20 Tennessee counties participating in Active Bacterial Core surveillance over 19 years were linked to neighborhood-level socioeconomic factors. Incidence rates were analyzed across 3 periods-pre-7-valent PCV (pre-PCV7; 1998-1999), pre-13-valent PCV (pre-PCV13; 2001-2009), and post-PCV13 (2011-2016)-by socioeconomic factors.

RESULTS

A total of 8491 cases of invasive pneumococcal disease were identified. Incidence for invasive pneumococcal disease decreased from 22.9 (1998-1999) to 17.9 (2001-2009) to 12.7 (2011-2016) cases per 100 000 person-years. Post-PCV13 incidence (95% confidence interval [CI]) of PCV13-serotype disease in high- and low-poverty neighborhoods was 3.1 (2.7-3.5) and 1.4 (1.0-1.8), respectively, compared with pre-PCV7 incidence of 17.8 (15.7-19.9) and 6.4 (4.9-7.9). Before PCV introduction, incidence (95% CI) of PCV13-serotype disease was higher in blacks than whites (17.3 [15.1-19.5] vs 11.8 [10.6-13.0], respectively); after introduction, PCV13-type disease incidence was greatly reduced in both groups (white: 2.7 [2.4-3.0]; black: 2.2 [1.8-2.6]).

CONCLUSIONS

Introduction of PCV13 was associated with substantial reductions in overall incidence and socioeconomic and racial disparities in PCV13-serotype incidence.

Racial Disparities in Adult Pneumococcal Vaccination Indications and Pneumococcal Hospitalizations in the U.S

BACKGROUND

Racial disparities in U.S. adult pneumococcal vaccination rates persist despite reduced barriers to access. Consequently, racial and ethnic minorities experience pneumococcal disease at higher rates than whites. This study examined prevalence of high-risk conditions and pneumococcal hospitalizations among U.S. black and non-black populations aged ≥50 years.

METHODS

National Health Interview Survey, National Center for Health Statistics and National Inpatient Sample data were used to create black and non-black population cohorts, determine risk factors for pneumococcal disease (pneumococcal vaccine indications) and assess the impact of pneumococcal hospitalization. Each racial cohort was segmented into groups based on the presence of immunocompromising or other pneumococcal high-risk conditions. Persons without those conditions were separated into smokers (also a pneumococcal vaccine indication) and nonsmokers. Mortality was estimated from NCHS life table data. NIS data provided length of stay and costs (calculated from cost to charge ratios) for admissions related to pneumococcal disease including bacteremia, meningitis and nonbacteremic pneumonia.

RESULTS

There were similar proportions of immunocompromised (<5%) and smokers (14%) in both racial cohorts. Likelihood of non-immunocompromising pneumococcal high-risk conditions was higher for blacks than non-blacks at age 65, but higher for non-blacks than blacks at age 80 years (P < 0.001). Age-specific relative likelihood of mortality was 1.1%-12% higher in blacks than non-blacks (P < 0.001). Length of stay was significantly longer for blacks than non-blacks in all age and discharge status groups for non-bacteremic pneumonia and for blacks discharged alive with invasive pneumococcal disease. Costs were higher for blacks 65 years or older with invasive pneumococcal disease.

CONCLUSION

Marked differences exist between U.S. black and non-black populations in likelihood of conditions conferring a high-risk of pneumococcal disease, and for length of stay and costs of pneumococcal disease hospitalizations. Further research is recommended to identify cost-effective policies or interventions to increase vaccine uptake in higher risk populations.

Pneumococcal serotype distribution: A snapshot of recent data in pediatric and adult populations around the world

S. pneumoniae infection remains a serious public health concern despite the availability of vaccines covering up to 23 of more than 94 known serotypes. The purpose of the present study was to monitor recent serotype distribution data. PubMed, EMBASE, Cochrane Reviews and Ingenta databases were searched. Serotype data covering invasive pneumococcal disease (IPD) and non-IPD were extracted from articles published from March 2014 to March 2015. Fifty-nine studies presented pneumococcal serotype prevalence by specific age categories. Most prevalent serotypes not covered by pneumococcal conjugate vaccines (PCV) were as follows: 15B, 22F, 15A, 23A among children under the age of 7 y with IPD; among adults with IPD: 22F, 11A, 10A, 38 in the 65 y and older age group; 12F, 9N, 8 in the 50-64 year-old age group and 12F, 8, 6C, 16F in the 15-59 age group. Geographic variations in serotype distribution highlight the importance of monitoring evolving pneumococcal serotype prevalence after pneumococcal vaccine implementation.

Bias with respect to socioeconomic status: A closer look at zip code matching in a pneumococcal vaccine effectiveness study

In 2010, 13-valent pneumococcal conjugate vaccine (PCV13) was introduced in the US for prevention of invasive pneumococcal disease in children. Individual-level socioeconomic status (SES) is a potential confounder of the estimated effectiveness of PCV13 and is often controlled for in observational studies using zip code as a proxy. We assessed the utility of zip code matching for control of SES in a post-licensure evaluation of the effectiveness of PCV13 (calculated as [1-matched odds ratio]*100). We used a directed acyclic graph to identify subsets of confounders and collected SES variables from birth certificates, geocoding, a parent interview, and follow-up with medical providers. Cases tended to be more affluent than eligible controls (for example, 48.3% of cases had private insurance vs. 44.6% of eligible controls), but less affluent than enrolled controls (52.9% of whom had private insurance). Control of confounding subsets, however, did not result in a meaningful change in estimated vaccine effectiveness (original estimate: 85.1%, 95% CI 74.8–91.9%; adjusted estimate: 82.5%, 95% CI 65.6–91.1%). In the context of a post-licensure vaccine effectiveness study, zip code appears to be an adequate, though not perfect, proxy for individual SES.

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Socioeconomic status (SES) may impact enrollment in vaccine effectiveness studies.

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We assessed zip code matching as a proxy for SES in a pneumococcal vaccine study.

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After zip code matching, we found differences in SES between cases and controls.

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Differences did not appear to substantially bias estimated vaccine effectiveness.

Disparities in PCV impact between different ethnic populations cohabiting in the same region: A systematic review of the literature

BACKGROUND

Invasive pneumococcal disease (IPD) and pneumonia are major causes of morbidity, especially in developing countries. While pneumococcal disease rates differences between various populations are well known, data are scarce regarding disparities in PCV impact on pneumococcal disease rates between populations living in the same country.

OBJECTIVE

The aim of this systematic literature review was to describe disparities in PCV impact between different populations.

METHODS

A systematic literature search was performed using the PubMed database. Studies evaluating pneumococcal disease rates at any age were included. The search was limited to articles written in English and published between 2000 and 2015. Independent extraction of articles was performed by two authors (NS, SB-S). Search terms included: pneumococcus, pneumococcal disease, IPD, pneumonia, PCV, pneumococcal vaccine, population, race, ethnicity, differences, and disparity. We defined resource-poor populations as African-Americans, Aboriginal, Alaska natives and Navajo native-Americans populations compared with the respective resource-rich populations, including White, non-Aboriginal, non-Alaska natives and general US population.

RESULTS

Eighteen articles meeting the selection criteria were identified; 17 regarding IPD and one regarding pneumonia. Nine articles compared IPD rates in African-Americans and Whites in the US, six compared Aboriginal and non-Aboriginal populations; two compared Alaska natives vs. non-native Alaskans in the US and one article compared Navajo native-Americans and general population in the US. Only minor difference where usually noted in the incidence rate ratios (IRRs) comparing pre- and post-PCV rates of IPD and pneumonia between resource rich and resource poor populations. In contrast, absolute rate reductions were higher in resource-poor compared with resource-rich populations.

CONCLUSION

While differences in IPD and pneumonia rates between resource-poor and resource-rich populations were decreased following PCV introduction, disparity is still apparent and is not fully eliminated in any of the studies. Younger (<2years) populations in resource-poor populations seem to benefit the most from PCV introduction.

Persistent Sex Disparities in Invasive Pneumococcal Diseases in the Conjugate Vaccine Era

BACKGROUND

Few studies have characterized the role of sex on the incidence of invasive pneumococcal disease (IPD). We examined sex differences in rates of IPD, and trends after the introduction of pneumococcal conjugate vaccines (PCVs).

METHODS

We used active population and laboratory-based IPD surveillance data from the Centers for Disease Control and Prevention Active Bacterial Core surveillance program (1998-2013) in Tennessee. Population-based rates of IPD by sex, race, age group, and PCV era were calculated. Rates were compared using incidence rate ratios.

RESULTS

Throughout the study years, rates of IPD were higher in male than in female subjects, particularly in children <2 years and adults 40-64 years of age, with male subjects having IPD rates 1.5-2 times higher than female subjects. The proportions of comorbid conditions were similar in male and female subjects . Sex rate differences persisted after stratification by race. Although the introductions of 7-valent PCV (PCV7) and 13-valent PCV (PCV13) were associated with declines in IPD rates in both sexes, rates of IPD after PCV13 were still significantly higher in male than in female subjects among children and adults 40-64 and >74 years of age.

CONCLUSIONS

Rates of IPD were generally higher in male than in female subjects. These sex differences were observed in different race groups and persisted after introduction of both PCVs.

Emerging Infections Program Efforts to Address Health Equity

The Emerging Infections Program (EIP), a collaboration between (currently) 10 state health departments, their academic center partners, and the Centers for Disease Control and Prevention, was established in 1995. The EIP performs active, population-based surveillance for important infectious diseases, addresses new problems as they arise, emphasizes projects that lead to prevention, and develops and evaluates public health practices. The EIP has increasingly addressed the health equity challenges posed by Healthy People 2020. These challenges include objectives to increase the proportion of Healthy People-specified conditions for which national data are available by race/ethnicity and socioeconomic status as a step toward first recognizing and subsequently eliminating health inequities. EIP has made substantial progress in moving from an initial focus on monitoring social determinants exclusively through collecting and analyzing data by race/ethnicity to identifying and piloting ways to conduct population-based surveillance by using area-based socioeconomic status measures.

Retrospective economic evaluation of childhood 7-valent pneumococcal conjugate vaccination in Australia: Uncertain herd impact on pneumonia critical

BACKGROUND

Retrospective cost-effectiveness analyses of vaccination programs using routinely collected post-implementation data are sparse by comparison with pre-program analyses. We performed a retrospective economic evaluation of the childhood 7-valent pneumococcal conjugate vaccine (PCV7) program in Australia.

METHODS

We developed a deterministic multi-compartment model that describes health states related to invasive and non-invasive pneumococcal disease. Costs (Australian dollars, A$) and health effects (quality-adjusted life years, QALYs) were attached to model states. The perspective for costs was that of the healthcare system and government. Where possible, we used observed changes in the disease rates from national surveillance and healthcare databases to estimate the impact of the PCV7 program (2005-2010). We stratified our cost-effectiveness results into alternative scenarios which differed by the outcome states included. Parameter uncertainty was explored using probabilistic sensitivity analysis.

RESULTS

The PCV7 program was estimated to have prevented ∼5900 hospitalisations and ∼160 deaths from invasive pneumococcal disease (IPD). Approximately half of these were prevented in adults via herd protection. The incremental cost-effectiveness ratio was ∼A$161,000 per QALY gained when including only IPD-related outcomes. The cost-effectiveness of PCV7 remained in the range A$88,000-$122,000 when changes in various non-invasive disease states were included. The inclusion of observed changes in adult non-invasive pneumonia deaths substantially improved cost-effectiveness (∼A$9000 per QALY gained).

CONCLUSION

Using the initial vaccine price negotiated for Australia, the PCV7 program was unlikely to have been cost-effective (at conventional thresholds) unless observed reductions in non-invasive pneumonia deaths in the elderly are attributed to it. Further analyses are required to explore this finding, which has significant implications for the incremental benefit achievable by adult PCV programs.

Racial and Regional Differences in Rates of Invasive Pneumococcal Disease

BACKGROUND AND OBJECTIVES

Invasive pneumococcal disease (IPD) remains an important cause of illness in US children. We assessed the impact of introduction of the 13-valent pneumococcal conjugate vaccine (PCV13) on pediatric IPD rates, as well as changes in racial and regional differences in IPD, in Tennessee.

METHODS

Data from active laboratory and population-based surveillance of IPD were used to compare IPD rates in the early-PCV7 (2001-2004), late-PCV7 (2005-2009), and post-PCV13 (2011-2012) eras. IPD rates were further stratified according to age, race, and region (east and middle-west TN).

RESULTS

Among children aged <2 years, IPD rates declined by 70% from 67 to 19 per 100 000 person-years in the early-PCV7 era and post-PCV13 era, respectively. Similar decreasing trends in IPD rates were observed in older children aged 2 to 4 years and 5 to 17 years. In the late-PCV7 era, IPD rates in children aged <2 years were higher in black children compared with white children (70 vs 43 per 100 000 person-years); however, these racial differences in IPD rates were no longer significant after PCV13 introduction. Before PCV13, IPD rates in children aged <2 years were also higher in east Tennessee compared with middle-west Tennessee (91 vs 45 per 100 000 person-years), but these differences were no longer significant in the post-PCV13 era.

CONCLUSIONS

PCV13 introduction led to substantial declines in childhood IPD rates and was associated with reduced regional and racial differences in IPD rates in Tennessee.

A current and historical perspective on disparities in US childhood pneumococcal conjugate vaccine adherence and in rates of invasive pneumococcal disease: Considerations for the routinely-recommended, pediatric PCV dosing schedule in the United States

Previous research has suggested that reducing the US 4-dose PCV13 schedule to a 3-dose schedule may provide cost savings, despite more childhood pneumococcal disease. The study also stressed that dose reduction should be coupled with improved PCV adherence, however, US PCV uptake has leveled-off since 2008. An estimated 24–36% of US children aged 5–19 months are already receiving a reduced PCV schedule (i.e., missing ≥1 dose). This raises a practical concern that, under a reduced, 3-dose schedule, a similar proportion of children may receive ≤2 doses. It is also unknown if a reduced, 3-dose PCV schedule in the United States will afford the same disease protection as 3-dose schedules used elsewhere, given lower US PCV adherence. Finally, more assurance is needed that, under a reduced schedule, racial, socioeconomic, and geographic disparities in PCV adherence will not correspond with disproportionately higher rates of pneumococcal disease among poor or minority children.