Socioeconomic and racial disparities of pediatric invasive pneumococcal disease after the introduction of the 7-valent pneumococcal conjugate vaccine

Impact of health disparity on pediatric infections

PURPOSE OF REVIEW

The COVID-19 pandemic highlighted the health disparities among minoritized children due to structural racism and socioeconomic inequalities. This review discusses how health disparities affect pediatric infections and how they can be addressed.

RECENT FINDINGS

In addition to disparities in healthcare access due to poverty, geography, and English-language proficiency, implicit and explicit bias affects the healthcare quality and subsequent outcomes in children and adolescents with infections. Disparities in clinical trial enrollment affect the generalizability of research findings. Physicians who understand their patients' languages and the contexts of culture and socioeconomic conditions are better equipped to address the needs of specific populations and the health disparities among them.

SUMMARY

Addressing disparities in pediatric infections requires prioritization of efforts to increase physician workforce diversity in Pediatric Infectious Diseases, as well as education in bias reduction and culturally sensitive clinical practice, in addition to socioeconomic interventions that improve healthcare access, delivery, and outcomes.

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.

Evidence for an Inherited Contribution to Sepsis Susceptibility Among a Cohort of U.S. Veterans

Analyze a unique clinical and genealogical resource for evidence of familial clustering of sepsis to test for an inherited contribution to sepsis predisposition.

Racial/Ethnic Disparities in the Incidences of Bronchiolitis Requiring Hospitalization

BACKGROUND

Race/ethnicity is currently not considered a risk factor for bronchiolitis, except for indigenous populations in Western countries. A better understanding of the potential impact of race/ethnicity can inform programs, policies, and practices related to bronchiolitis.

METHODS

We performed a population-based, longitudinal, observational study using the State Inpatient Database from New York State in the United States. Infants born between 2009 and 2013 at term without comorbidities were followed for the first 2 years of life, up to 2015. We calculated the cumulative incidences among different race/ethnicity groups, and evaluated the risks by developing logistic regression models.

RESULTS

Of 877 465 healthy, term infants, 10 356 infants were hospitalized with bronchiolitis. The overall cumulative incidence was 11.8 per 1000 births. The cumulative incidences in non-Hispanic White, non-Hispanic Black, Hispanic, and Asian infants were 8.6, 15.4, 19.1, and 6.5 per 1000 births, respectively. In a multivariable analysis adjusting for socioeconomic status, the risks remained substantially high among non-Hispanic Black (odds ratio, 1.42; 95% confidence interval [CI], 1.34-1.51) and Hispanic infants (odds ratio, 1.77; 95% CI, 1.67-1.87), whereas being of Asian race was protective (odds ratio, .62; 95% CI, .56-.69).

CONCLUSIONS

The risks of bronchiolitis hospitalization in the first 2 years of life were substantially different by race/ethnicity, with Hispanic and Black infants having the highest rates of hospitalization. Further research is needed to develop and implement culturally appropriate public health interventions to reduce racial and ethnic health disparities in bronchiolitis.

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.

Commentary: Why Has Uptake of Pneumococcal Vaccines for Children Been So Slow? The Perils of Undervaluation

Pediatric pneumococcal disease exacts a substantial burden on global health, much of which is vaccine-preventable. Despite this considerable burden and the demonstrably high efficacy of pneumococcal conjugate vaccines (PCVs), the overall level of PCV uptake remains concerningly low, especially compared with that of other childhood-recommended vaccines, such as tuberculosis and polio. A broad set of plausible explanations exists for this low uptake, including logistical challenges, psychosocial factors and affordability. One additional and systematic cause of low uptake, which is the focus of our discussion, is economists' and policymakers' tendency to undervalue vaccination in general by adopting a narrow health sector perspective when performing economic evaluations of vaccines. We present an alternative, societal framework for economic evaluations that encompasses a broader set of socioeconomic benefits in addition to health benefits. Quantifying a more comprehensive taxonomy of PCV's benefits will help to address potential undervaluation and may be sufficient not only to justify recommendation and reimbursement but also to stimulate efforts and investment toward closing coverage gaps.

Socioeconomic Status, Race/Ethnicity, and Health Disparities in Children and Adolescents in a Mixed Rural-Urban Community-Olmsted County, Minnesota

OBJECTIVE

To characterize disparities in childhood health outcomes by socioeconomic status (SES) and race/ethnicity in a mixed rural-urban US community.

METHODS

This was a retrospective population-based study of children 18 years and younger residing in Olmsted County, Minnesota, in 2009. The prevalence rates of childhood health outcomes were determined using International Classification of Diseases, Ninth Revision codes. Socioeconomic status was measured using the HOUsing-based SocioEconomic Status index (HOUSES), derived from real property data. Adjusting for age and sex, logistic regression models were used to examine the relationships among HOUSES, race/ethnicity, and prevalence of childhood health outcomes considering an interaction between HOUSES and race/ethnicity. Odds ratios were calculated using the lowest SES quartile and non-Hispanic white participants as the reference groups.

RESULTS

Of 31,523 eligible children, 51% were male and 86% were of non-Hispanic white race/ethnicity. Overall, lower SES was associated with higher prevalence of bronchiolitis, urinary tract infection, asthma, mood disorder, and accidents/adverse childhood experiences (physical and sexual abuse) in a dose-response manner (P<.04). Prevalence rates of all childhood conditions considered except for epilepsy were significantly different across races/ethnicities (P<.002). Racial/ethnic disparities for asthma and mood disorder were greater with higher SES.

CONCLUSION

Significant health disparities are present in a predominantly affluent, non-Hispanic white, mixed rural-urban community. Socioeconomic status modifies disparities by race/ethnicity in clinically less overt conditions. Interpretation of future health disparity research should account for the nature of disease.

Pneumococcal vaccination coverage among children with sickle cell anemia, sickle cell trait, and normal hemoglobin

BACKGROUND

Children with sickle cell anemia and sickle cell trait are at an increased risk of invasive pneumococcal disease compared to children with normal hemoglobin. We assessed and compared pneumococcal vaccination status among these three groups.

PROCEDURE

Children with sickle cell anemia and sickle cell trait were identified using Michigan newborn screening records (1997-2014); each child was matched to four children with normal hemoglobin based on age, Medicaid enrollment (at least 1 year from 2012-2014), race, and census tract. Vaccination records were obtained from the state's immunization system. Pneumococcal vaccine coverage (PCV7 or PCV13 depending on date of administration) was assessed at milestone ages of 3, 5, 7, and 16 months. The proportion of children with vaccine coverage at each milestone was calculated overall and compared among children with sickle cell anemia, sickle cell trait, and normal hemoglobin using chi-square tests.

RESULTS

The study population consisted of 355 children with sickle cell anemia, 17,319 with sickle cell trait, and 70,757 with normal hemoglobin. The proportion of children with age-appropriate pneumococcal vaccination coverage was low at each milestone and generally decreased over time. Children with sickle cell anemia were more likely to be covered compared to children with sickle cell trait or normal hemoglobin.

CONCLUSIONS

Despite higher pneumococcal vaccination coverage among children with sickle cell anemia, opportunities for improvement exist among all children. Targeted interventions will benefit from mechanisms to identify children with increased risks such as sickle cell anemia or trait to improve pneumococcal vaccination coverage among these groups.

Changes in Childhood Pneumonia Hospitalizations by Race and Sex Associated with Pneumococcal Conjugate Vaccines

Introduction of pneumococcal conjugate vaccines in the childhood immunization schedule was associated with decreases in all-cause pneumonia hospitalizations among black and white children in Tennessee, USA. Although racial disparities that existed before introduction of these vaccines have been substantially reduced, rates remain higher in boys than in girls among young children.

Risk factors for community-acquired bacterial meningitis

BACKGROUND

Bacterial meningitis is a significant burden of disease and mortality in all age groups worldwide despite the development of effective conjugated vaccines. The pathogenesis of bacterial meningitis is based on complex and incompletely understood host-pathogen interactions. Some of these are pathogen-specific, while some are shared between different bacteria.

METHODS

We searched the database PubMed to identify host risk factors for bacterial meningitis caused by the pathogens Streptococcus pneumoniae, Neisseria meningitidis and Haemophilus influenzae type b, because they are three most common causative bacteria beyond the neonatal period.

RESULTS

We describe a number of risk factors; including socioeconomic factors, age, genetic variation of the host and underlying medical conditions associated with increased susceptibility to invasive bacterial infections in both children and adults.

CONCLUSIONS

As conjugated vaccines are available for these infections, it is of utmost importance to identify high risk patients to be able to prevent invasive disease.

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.

Trends in Infectious Disease Hospitalizations in US Children, 2000 to 2012

BACKGROUND

Although infectious diseases (IDs) remain a major public health problem in US children, there have been no recent efforts to examine comprehensively the change in epidemiology of ID hospitalizations.

METHODS

A serial cross-sectional analysis using the Kids' Inpatient Database 2000, 2003, 2006, 2009, and 2012. We identified children ≤19 years of age with a primary diagnosis of IDs. Outcomes were national rate of ID hospitalizations, in-hospital mortality, length-of-stay and hospitalization-related direct costs. Negative binomial and multivariable logistic models were constructed to test the change in hospitalization rate and in-hospital mortality, respectively.

RESULTS

We identified 3,691,672 weighted hospitalizations for IDs, accounting for 24.5% of all pediatric hospitalizations. From 2000 to 2012, the rate of overall ID hospitalizations decreased from 91.0 to 75.8 per 10,000 US children (P < 0.001). The most frequently listed ID subgroup was lower respiratory infections (42.8% of all ID hospitalizations in 2012). Although the hospitalization rate for most ID subgroups decreased, the hospitalization rate for skin infections significantly increased (67.6% increase; P < 0.001). The multivariable model demonstrated a significant decline in in-hospital mortality (odds ratio for comparison of 2012 with 2000, 0.63; 95% confidence interval, 0.51-0.79). From 2000 to 2012, there was no significant change in the median length-of-stay (2 days in 2000 to 2 days in 2012; Ptrend = 0.33). The median direct cost for ID hospitalization increased from $3452 in 2003 to $3784 in 2012 (P = 0.007), with the nationwide direct cost of $4.4 billion in 2012.

CONCLUSIONS

We found a statistically significant decline in overall ID hospitalization rate among US children from 2000 to 2012, whereas skin infections statistically significantly increased. In addition, the median direct cost per ID hospitalization increased by 10% during the study period.

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.

Disparities of Shigellosis Rates among California Children by Race/Ethnicity and Census Tract Poverty Level, 2000-2010

BACKGROUND

We examined surveillance data for disparities in shigellosis rates among children by census tract (CT) poverty level and race/ethnicity in California.

METHODS

We geocoded addresses of 9740 children younger than 15 years of age from 2000-2010 California shigellosis surveillance data and calculated incidence rate (IR) per 100,000 population by age group and race/ethnicity. We linked geocoded cases to 2006-2010 American Community Survey CT-level poverty data and used IR ratios to compare children in the most impoverished CTs with those in the least impoverished CTs. The contribution of socioeconomic inequalities to age-standardized racial and ethnic disparities was explored using Poisson regression.

RESULTS

Per 100,000 population, shigellosis IR was highest among California children less than 5 years old (16.4) and of Hispanic ethnicity (15.2). The age-standardized IR was 22.3 per 100,000 person-years in CTs with more than 40% of the population below the poverty line and 4.1 per 100,000 person-years in CTs with less than 5% of the population below the poverty line, an IR ratio of 5.8 (95% confidence interval: 5.2, 6.5).

CONCLUSIONS

Shigellosis rates among California children were highest among Hispanics and increased with CT poverty.