Disparities between black and white children in hospitalizations associated with acute respiratory illness and laboratory-confirmed influenza and respiratory syncytial virus in 3 US counties--2002-2009

A Review of Respiratory Syncytial Virus Epidemiology Among Children: Linking Effective Prevention to Vulnerable Populations

Respiratory syncytial virus (RSV) is the greatest contributor to lower respiratory tract infections (LRTI) in children less than 5 years of age and the leading cause for infant hospitalizations in the United States (US). The burden of severe disease disproportionately impacts racial and ethnic minority groups, highlighting the need for interventions that promote health equity. Recent advancements in effective prophylactic agents have the potential to drastically alter the landscape of RSV disease among all young children. The effectiveness of prophylaxis, however, will rely on a clear understanding of RSV epidemiology. The purpose of this review is to discuss key aspects of RSV epidemiology while focusing on efforts to support equitable distribution of prophylactic agents to mitigate existing health disparities.

Respiratory Syncytial Virus Hospitalizations Associated With Social Vulnerability by Census Tract: An Opportunity for Intervention?

Background

Respiratory syncytial virus (RSV) can cause hospitalization in young children and older adults. With vaccines and monoclonal antibody prophylaxis increasingly available, identifying social factors associated with severe illnesses can guide mitigation efforts.

Methods

Using data collected by the RSV Hospitalization Surveillance Network from 2016 to 2023, we identified RSV hospitalizations in Tennessee. We linked hospitalization information (eg, patient demographic characteristics and outcome) with population-level variables (eg, social vulnerability and health care insurance coverage) from publicly available data sets using census tract of residence. Hospitalization incidence was calculated and stratified by period (2016-2020 and 2020-2023). We modeled social vulnerability effect on hospitalization incidence using Poisson regression.

Results

Among 2687 RSV hospitalizations, there were 677 (25.2%) intensive care unit admissions and 38 (1.4%) deaths. The highest RSV hospitalization incidences occurred among children aged <5 years and adults aged ≥65 years: 272.8 per 100 000 person-years (95% CI, 258.6-287.0) and 60.6 (95% CI, 56.0-65.2), respectively. Having public health insurance was associated with higher hospitalization incidence as compared with not having public insurance: 60.5 per 100 000 person-years (95% CI, 57.6-63.4) vs 14.3 (95% CI, 13.4-15.2). Higher hospitalization incidence was associated with residing in a census tract in the most socially vulnerable quartile vs the least vulnerable quartile after adjusting for age, sex, and period (incidence rate ratio, 1.4; 95% CI, 1.3-1.6).

Conclusions

RSV hospitalization was associated with living in more socially vulnerable census tracts. Population measures of social vulnerability might help guide mitigation strategies, including vaccine and monoclonal antibody promotion and provision to reduce RSV hospitalization.

Racial and Ethnic Identity and Vulnerability to Upper Respiratory Viral Infections Among US Children

BACKGROUND

It is unclear whether there are racial/ethnic disparities in the risk of upper respiratory viral infection acquisition and/or lower respiratory manifestations.

METHODS

We studied all children and children with asthma aged 6 to 17 years in the National Health and Nutrition Examination Survey (2007-2012) to evaluate (1) the association between race/ethnicity and upper respiratory infection (URI) and (2) whether race/ethnicity is a risk factor for URI-associated pulmonary eosinophilic inflammation or decreased lung function.

RESULTS

Children who identified as Black (adjusted odds ratio [aOR], 1.38; 95% CI, 1.10-1.75) and Mexican American (aOR, 1.50; 95% CI, 1.16-1.94) were more likely to report a URI than those who identified as White. Among those with asthma, Black children were more than twice as likely to report a URI than White children (aOR, 2.28; 95% CI, 1.31-3.95). Associations between URI and pulmonary eosinophilic inflammation or lung function did not differ by race/ethnicity.

CONCLUSIONS

Findings suggest that there may be racial and ethnic disparities in acquiring a URI but not in the severity of infection. Given that upper respiratory viral infection is tightly linked to asthma exacerbations in children, differences in the risk of infection among children with asthma may contribute to disparities in asthma exacerbations.

Respiratory Syncytial Virus-Associated Hospitalizations Among Children <5 Years Old: 2016 to 2020

BACKGROUND

Respiratory syncytial virus (RSV) is the leading cause of hospitalization in US infants. Accurate estimates of severe RSV disease inform policy decisions for RSV prevention.

METHODS

We conducted prospective surveillance for children <5 years old with acute respiratory illness from 2016 to 2020 at 7 pediatric hospitals. We interviewed parents, reviewed medical records, and tested midturbinate nasal ± throat swabs by reverse transcription polymerase chain reaction for RSV and other respiratory viruses. We describe characteristics of children hospitalized with RSV, risk factors for ICU admission, and estimate RSV-associated hospitalization rates.

RESULTS

Among 13 524 acute respiratory illness inpatients <5 years old, 4243 (31.4%) were RSV-positive; 2751 (64.8%) of RSV-positive children had no underlying condition or history of prematurity. The average annual RSV-associated hospitalization rate was 4.0 (95% confidence interval [CI]: 3.8-4.1) per 1000 children <5 years, was highest among children 0 to 2 months old (23.8 [95% CI: 22.5-25.2] per 1000) and decreased with increasing age. Higher RSV-associated hospitalization rates were found in premature versus term children (rate ratio = 1.95 [95% CI: 1.76-2.11]). Risk factors for ICU admission among RSV-positive inpatients included: age 0 to 2 and 3 to 5 months (adjusted odds ratio [aOR] = 1.97 [95% CI: 1.54-2.52] and aOR = 1.56 [95% CI: 1.18-2.06], respectively, compared with 24-59 months), prematurity (aOR = 1.32 [95% CI: 1.08-1.60]) and comorbid conditions (aOR = 1.35 [95% CI: 1.10-1.66]).

CONCLUSIONS

Younger infants and premature children experienced the highest rates of RSV-associated hospitalization and had increased risk of ICU admission. RSV prevention products are needed to reduce RSV-associated morbidity in young infants.

Application of Global Lung Function Initiative Global Spirometry Reference Equations across a Large, Multicenter Pulmonary Function Lab Population

Rationale: Global Lung Function Initiative (GLI) Global spirometry reference equations were recently derived to offer a "race-neutral" interpretation option. The impact of transitioning from the race-specific GLI-2012 to the GLI Global reference equations is unknown. Objectives: Describe the direction and magnitude of changes in predicted lung function measurements in a population of diverse race and ethnicity using GLI Global in place of GLI-2012 reference equations. Methods: In this multicenter cross-sectional study using a large pulmonary function laboratory database, 109,447 spirometry tests were reanalyzed using GLI Global reference equations and compared with the existing GLI-2012 standard, stratified by self-reported race and ethnicity. Measurements and Main Results: Mean FEV1 and FVC percent predicted increased in the White and Northeast Asian groups and decreased in the Black, Southeast Asian, and mixed/other race groups. The prevalence of obstruction increased by 9.7% in the White group, and prevalences of possible restriction increased by 51.1% and 37.1% in the Black and Southeast Asian groups, respectively. Using GLI Global in a population with equal representation of all five race and ethnicity groups altered the interpretation category for 10.2% of spirometry tests. Subjects who self-identified as Black were the only group with a relative increase in the frequency of abnormal spirometry test results (32.9%). Conclusions: The use of GLI Global reference equations will significantly impact spirometry interpretation. Although GLI Global offers an innovative approach to transition from race-specific reference equations, it is important to recognize the continued need to place these data within an appropriate clinical context.

Effect Modification of Racial Differences in Pediatric COVID-19 Inpatient Admissions in a Large Healthcare Database

BACKGROUND

Coronavirus disease 2019 (COVID-19) has been more severe in racial and ethnic minorities relative to non-Hispanic White populations. Here, we investigate how these disparities vary across effect modifiers in a pediatric population.

METHODS

Using the TriNetX Dataworks Network from April 2020 to September 2021, we compared inpatient rates between non-Hispanic Black and non-Hispanic White patients among pediatric COVID-19 cases. Following propensity score matching, comparisons were performed within subgroups of 4 potential effect modifiers: age group (0-2, 3-5, 6-11 and 12-18 years), presence of complex comorbidities, quarter of the year (from 2020 Q2 to 2021 Q3) and geographic regions of the United States.

RESULTS

The cohort included 47,487 COVID-19 cases, of which 13,130 were Black patients. Among most subgroups of effect modifiers, inpatient rates were higher among the Black patients. The largest variation in disparities was observed across age groups and the presence of complex comorbidities. Twelve to 18 years old Black children had a 1.7% point [confidence interval (CI): 0.8-2.4] higher inpatient rate than the matched White children, whereas 0-2 years old Black children had a 2.5% point (CI: 0.9-4.1) lower rate than the matched White children. Among children with complex comorbidities, inpatient rates for Black children was 6.2 (CI: 3.4-8.9) percentage points higher than the White children; however, among kids without complex comorbidities, inpatient rates were comparable.

CONCLUSIONS

Among pediatric patients experiencing COVID-19, higher inpatient rates for Black compared with White patients were observed among older children and those with complex comorbidities. These findings can spur discussions of potential root causes of these disparities, including structural racism.

Trends and Economic Implications of Disparities in Postoperative Pneumonia

BACKGROUND

Postoperative pneumonia is the third most common surgical complication and can seriously impair surgical rehabilitation and lead to related morbidity and mortality. We evaluated the temporal trends in racial and ethnic disparities in postoperative pneumonia and quantified the economic burden resulting from these inequalities in the United States.

METHODS

This population-based study includes 195 028 children (weighted to 964 679) admitted for elective surgery across 5340 US hospitals reporting to the Nationwide Inpatient Sample between 2010 and 2018. We estimated the risk-adjusted incidence of postoperative pneumonia, comparing racial and ethnic groups. We also quantified the inflation-adjusted hospital costs attributable to racial and ethnic disparities in postoperative pneumonia.

RESULTS

The risk-adjusted rates of pneumonia declined across all racial and ethnic categories, with Black children having the lowest annual rate of decline (Black: 0.03 percentage points, Hispanic: 0.05 percentage points, white: 0.05 percentage points). The risk-adjusted rates of pneumonia trended consistently higher for Black and Hispanic children, relative to white children, throughout the study period (Black versus white: relative risk, 1.31 (95% confidence interval, 1.14-1.51), P < .01; Hispanic versus white: relative risk, 1.16 (95% confidence interval, 1.02-1.32), P = .02). These disparities did not narrow significantly over time. During the study period, the excess hospitalization cost attributable to racial and ethnic disparities in postoperative pneumonia was $24 533 458 for Black children and $26 200 783 for Hispanic children (total, $50 734 241).

CONCLUSIONS

Against the backdrop of decreasing postoperative pneumonia, Black and Hispanic children continue to experience higher rates compared with white children. These persistent disparities in postoperative pneumonia were associated with considerable excess cost of surgical care.

Do upper respiratory viruses contribute to racial and ethnic disparities in emergency department visits for asthma?

BACKGROUND

There are marked disparities in asthma-related emergency department (ED) visit rates among children by race and ethnicity. Following the implementation of coronavirus disease 2019 (COVID-19) prevention measures, asthma-related ED visits rates declined substantially. The decline has been attributed to the reduced circulation of upper respiratory viruses, a common trigger of asthma exacerbations in children.

OBJECTIVES

To better understand the contribution of respiratory viruses to racial and ethnic disparities in ED visit rates, we investigated whether the reduction in ED visit rates affected Black, Latinx, and White children with asthma equally.

METHODS

Asthma-related ED visits were extracted from electronic medical records at Dell Children's Medical Center in Travis County, Texas. ED visit rates among children with asthma were derived by race/ethnicity. Incidence rate ratios (IRRs) and 95% CIs were estimated by year (2019-2021) and season.

RESULTS

In spring 2019, the ED visit IRRs comparing Black children with White children and Latinx children with White children were 6.67 (95% CI = 4.92-9.05) and 2.10 (95% CI = 1.57-2.80), respectively. In spring 2020, when infection prevention measures were implemented, the corresponding IRRs decreased to 1.73 (95% CI = 0.90-3.32) and 0.68 (95% CI = 0.38-1.23), respectively.

CONCLUSIONS

The striking reduction of disparities in ED visits suggests that during nonpandemic periods, respiratory viruses contribute to the excess burden of asthma-related ED visits among Black and Latinx children with asthma. Although further investigation is needed to test this hypothesis, our findings raise the question of whether Black and Latinx children with asthma are more vulnerable to upper respiratory viral infections.

Comparing Racial Differences in Emphysema Prevalence Among Adults With Normal Spirometry: A Secondary Data Analysis of the CARDIA Lung Study

BACKGROUND

Computed tomography (CT) imaging complements spirometry and may provide insight into racial disparities in respiratory health.

OBJECTIVE

To determine the difference in emphysema prevalence between Black and White adults with different measures of normal spirometry results.

DESIGN

Observational study using clinical data and spirometry from the CARDIA (Coronary Artery Risk Development in Young Adults) study obtained in 2015 to 2016 and CT scans done in 2010 to 2011.

SETTING

4 U.S. centers.

PARTICIPANTS

Population-based sample of Black and White adults.

MEASUREMENTS

Self-identified race and visually identified emphysema on CT in participants with different measures of "normal" spirometry results, calculated using standard race-specific and race-neutral reference equations.

RESULTS

A total of 2674 participants (485 Black men, 762 Black women, 659 White men, and 768 White women) had both a CT scan and spirometry available for analysis. Among participants with a race-specific FEV1 between 80% and 99% of predicted, 6.5% had emphysema. In this group, emphysema prevalence was 3.9-fold (95% CI, 2.1- to 7.1-fold; 15.5% vs. 4.0%) higher among Black men than White men and 1.9-fold (CI, 1.0- to 3.8-fold; 6.6% vs. 3.4%) higher among Black women than White women. Among participants with a race-specific FEV1 between 100% and 120% of predicted, 4.0% had emphysema. In this category, Black men had a 6.4-fold (CI, 2.2- to 18.7-fold; 13.9% vs. 2.2%) higher prevalence of emphysema than White men, whereas Black and White women had a similar prevalence of emphysema (2.6% and 2.0%, respectively). The use of race-neutral equations to identify participants with an FEV1 percent predicted between 80% and 120% attenuated racial differences in emphysema prevalence among men and eliminated racial differences among women.

LIMITATION

No CT scans were obtained during the most recent study visit (2015 to 2016) when spirometry was done.

CONCLUSION

Emphysema is often present before spirometry findings become abnormal, particularly among Black men. Reliance on spirometry alone to differentiate lung health from lung disease may result in the underrecognition of impaired respiratory health and exacerbate racial disparities.

PRIMARY FUNDING SOURCE

National Institutes of Health.

Racial and Ethnic Differences of Influenza-Associated Pediatric Hospitalizations and Deaths, 2008-2017

Background: Influenza is one of the most common causes of acute respiratory infections in children; its complications are a leading cause of morbidity and mortality. There is a paucity of pediatric data on influenza disparities among racial/ethnic minorities. Our study assesses if there are racial/ethnic differences in hospitalizations and mortality in children infected with influenza. Methods: This was a retrospective cohort study using the National Inpatient Sample (NIS) from January 1, 2008 to December 31, 2017. We included children 18 years and younger hospitalized with a primary or secondary diagnosis of influenza or its subtypes. We generated adjusted odds ratios (aORs) and 95% confidence intervals (CIs) to evaluate the associations between patient characteristics and influenza hospitalizations and influenza-related mortality. Results: There were 226,535 (0.04%) influenza-associated hospitalizations. When compared with non-Hispanic (NH) White children, minority children were more likely to be hospitalized with an influenza diagnosis [Hispanics (aOR = 1.25; 95% CI, 1.17 to 1.33), NH-Blacks (aOR = 1.21, 95% CI, 1.17 to 1.33) and NH-Others group (aOR = 1.11; 95% CI, 1.04 to 1.19)]. There was no racial/ethnic difference in mortality. Conclusions: Minority children experienced a higher likelihood of influenza-associated hospitalizations but not mortality. Further research is needed to reduce the racial/ethnic disparities of influenza's impact.

Enterovirus D68-Associated Acute Respiratory Illness ─ New Vaccine Surveillance Network, United States, July-November 2018-2020

Enterovirus D68 (EV-D68) is associated with a broad spectrum of illnesses, including mild to severe acute respiratory illness (ARI) and acute flaccid myelitis (AFM). Enteroviruses, including EV-D68, are typically detected in the United States during late summer through fall, with year-to-year fluctuations. Before 2014, EV-D68 was infrequently reported to CDC (1). However, numbers of EV-D68 detection have increased in recent years, with a biennial pattern observed during 2014-2018 in the United States, after the expansion of surveillance and wider availability of molecular testing. In 2014, a national outbreak of EV-D68 was detected (2). EV-D68 was also reported in 2016 via local (3) and passive national (4) surveillance. EV-D68 detections were limited in 2017, but substantial circulation was observed in 2018 (5). To assess recent levels of circulation, EV-D68 detections in respiratory specimens collected from patients aged <18 years* with ARI evaluated in emergency departments (EDs) or admitted to one of seven U.S. medical centers^† within the New Vaccine Surveillance Network (NVSN) were summarized. This report provides a provisional description of EV-D68 detections during July-November in 2018, 2019 and 2020, and describes the demographic and clinical characteristics of these patients. In 2018, a total of 382 EV-D68 detections in respiratory specimens obtained from patients aged <18 years with ARI were reported by NVSN; the number decreased to six detections in 2019 and 30 in 2020. Among patients aged <18 years with EV-D68 in 2020, 22 (73%) were non-Hispanic Black (Black) persons. EV-D68 detections in 2020 were lower than anticipated based on the biennial circulation pattern observed since 2014. The circulation of EV-D68 in 2020 might have been limited by widespread COVID-19 mitigation measures; how these changes in behavior might influence the timing and levels of circulation in future years is unknown. Ongoing monitoring of EV-D68 detections is warranted for preparedness for EV-D68-associated ARI and AFM.

Predicting Flow Rate Escalation for Pediatric Patients on High Flow Nasal Cannula Using Machine Learning

Background: High flow nasal cannula (HFNC) is commonly used as non-invasive respiratory support in critically ill children. There are limited data to inform consensus on optimal device parameters, determinants of successful patient response, and indications for escalation of support. Clinical scores, such as the respiratory rate-oxygenation (ROX) index, have been described as a means to predict HFNC non-response, but are limited to evaluating for escalations to invasive mechanical ventilation (MV). In the presence of apparent HFNC non-response, a clinician may choose to increase the HFNC flow rate to hypothetically prevent further respiratory deterioration, transition to an alternative non-invasive interface, or intubation for MV. To date, no models have been assessed to predict subsequent escalations of HFNC flow rates after HFNC initiation. Objective: To evaluate the abilities of tree-based machine learning algorithms to predict HFNC flow rate escalations. Methods: We performed a retrospective, cohort study assessing children admitted for acute respiratory failure under 24 months of age placed on HFNC in the Johns Hopkins Children's Center pediatric intensive care unit from January 2019 through January 2020. We excluded encounters with gaps in recorded clinical data, encounters in which MV treatment occurred prior to HFNC, and cases electively intubated in the operating room. The primary study outcome was discriminatory capacity of generated machine learning algorithms to predict HFNC flow rate escalations as compared to each other and ROX indices using area under the receiver operating characteristic (AUROC) analyses. In an exploratory fashion, model feature importance rankings were assessed by comparing Shapley values. Results: Our gradient boosting model with a time window of 8 h and lead time of 1 h before HFNC flow rate escalation achieved an AUROC with a 95% confidence interval of 0.810 ± 0.003. In comparison, the ROX index achieved an AUROC of 0.525 ± 0.000. Conclusion: In this single-center, retrospective cohort study assessing children under 24 months of age receiving HFNC for acute respiratory failure, tree-based machine learning models outperformed the ROX index in predicting subsequent flow rate escalations. Further validation studies are needed to ensure generalizability for bedside application.

Parental Vaccine Hesitancy and Risk of Pediatric Influenza Under-Vaccination in a Safety-Net Health Care System

OBJECTIVE

To measure the risk of influenza under-vaccination in children of vaccine-hesitant parents, referent to children of nonhesitant parents, in a sample of disadvantaged families in one influenza season.

STUDY DESIGN

A prospective observational cohort study of English- and Spanish-speaking parents of 2-year-olds presenting at random for well, sick, or specialty visit care from August 1, 2019 to February 28, 2020. Parents answered demographic questions and the Parent Attitudes about Childhood Vaccines survey. We followed children until season's end, extracting vaccination data on April 30, 2020. We dichotomized vaccination status as unvaccinated or partially/fully vaccinated, analyzing data with multivariable Poisson regression; in secondary analyses, we conducted adjusted time-to-event analyses.

RESULTS

Overall, 263 parents consented (response rate: 90%); our final sample included 255 dyads. Thirty-three (13%) parents were vaccine hesitant. In adjusted analyses, children of hesitant parents (n = 33) had a 195% increased risk (adjusted Risk Ratio 2.95; 95% confidence interval 1.91, 4.56) of being unvaccinated at season's end, referent to children of nonhesitant parents (n = 222). In time-to-event analyses, children of vaccine-hesitant parents were also more likely to be unvaccinated before influenza activity peaked (P = .02).

CONCLUSIONS

Parental vaccine hesitancy tripled the risk of pediatric influenza nonvaccination in a sample of poor and minority families during the 2019 to 2020 influenza season. As parental vaccine hesitancy appears to exacerbate pediatric influenza vaccination disparities, future work should explore parental hesitancy with poor and minority stakeholders and tailor evidence-based interventions to benefit children from these communities who receive care at all practice sites.

Rates of Influenza-Associated Hospitalization, Intensive Care Unit Admission, and In-Hospital Death by Race and Ethnicity in the United States From 2009 to 2019

IMPORTANCE

Racial and ethnic minority groups, such as Black, Hispanic, American Indian or Alaska Native, and Asian or Pacific Islander persons, often experience higher rates of severe influenza disease.

OBJECTIVE

To describe rates of influenza-associated hospitalization, intensive care unit (ICU) admission, and in-hospital death by race and ethnicity over 10 influenza seasons.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study used data from the Influenza-Associated Hospitalization Surveillance Network (FluSurv-NET), which conducts population-based surveillance for laboratory-confirmed influenza-associated hospitalizations in selected counties, representing approximately 9% of the US population. Influenza hospitalizations from the 2009 to 2010 season to the 2018 to 2019 season were analyzed. Data were analyzed from October 2020 to July 2021.

MAIN OUTCOMES AND MEASURES

The main outcomes were age-adjusted and age-stratified rates of influenza-associated hospitalization, ICU admission, and in-hospital death by race and ethnicity overall and by influenza season.

RESULTS

Among 113 352 persons with an influenza-associated hospitalization (34 436 persons [32.0%] aged ≥75 years; 61 009 [53.8%] women), 70 225 persons (62.3%) were non-Hispanic White (White), 24 850 persons (21.6%) were non-Hispanic Black (Black), 11 903 persons (10.3%) were Hispanic, 5517 persons (5.1%) were non-Hispanic Asian or Pacific Islander, and 857 persons (0.7%) were non-Hispanic American Indian or Alaska Native. Among persons aged younger than 75 years and compared with White persons of the same ages, Black persons were more likely to be hospitalized (eg, age 50-64 years: rate ratio [RR], 2.50 95% CI, 2.43-2.57) and to be admitted to an ICU (eg, age 50-64 years: RR, 2.09; 95% CI, 1.96-2.23). Among persons aged younger than 50 years and compared with White persons of the same ages, American Indian or Alaska Native persons were more likely to be hospitalized (eg, age 18-49 years: RR, 1.72; 95% CI, 1.51-1.96) and to be admitted to an ICU (eg, age 18-49 years: RR, 1.84; 95% CI, 1.40-2.42). Among children aged 4 years or younger and compared with White children, hospitalization rates were higher in Black children (RR, 2.21; 95% CI, 2.10-2.33), Hispanic children (RR, 1.87; 95% CI, 1.77-1.97), American Indian or Alaska Native children (RR, 3.00; 95% CI, 2.55-3.53), and Asian or Pacific Islander children (RR, 1.26; 95% CI, 1.16-1.38), as were rates of ICU admission (Black children: RR, 2.74; 95% CI, 2.43-3.09; Hispanic children: RR, 1.96; 95% CI, 1.73-2.23; American Indian and Alaska Native children: RR, 3.51; 95% CI, 2.45-5.05). In this age group and compared with White children, in-hospital death rates were higher among Hispanic children (RR, 2.98; 95% CI, 1.23-7.19), Black children (RR, 3.39; 95% CI, 1.40-8.18), and Asian or Pacific Islander children (RR, 4.35; 95% CI, 1.55-12.22). Few differences were observed in rates of severe influenza-associated outcomes by race and ethnicity among adults aged 75 years or older. For example, in this age group, compared with White adults, hospitalization rates were slightly higher only among Black adults (RR, 1.05; 95% CI 1.02-1.09). Overall, Black persons had the highest age-adjusted hospitalization rate (68.8 [95% CI, 68.0-69.7] hospitalizations per 100 000 population) and ICU admission rate (11.6 [95% CI, 11.2-11.9] admissions per 100 000 population).

CONCLUSIONS AND RELEVANCE

This cross-sectional study found racial and ethnic disparities in rates of severe influenza-associated disease. These data identified subgroups for whom improvements in influenza prevention efforts could be targeted.

Racial disparities in influenza immunization during pregnancy in the United States: A narrative review of the evidence for disparities and potential interventions

OBJECTIVE

The objectives of this review were to summarize existing data on racial disparities in maternal immunization for influenza in the U.S. and to review the literature on interventions to improve the uptake of the influenza vaccine among Black pregnant women.

DATA SOURCES

U.S. survey data on maternal influenza immunization by racial and ethnic group were summarized in narrative form. To review intervention studies, PubMed, CINAHL, EMBASE, and the Cochrane Library databases were searched for English language articles published 2017 to 2021, in addition to studies identified by a previous systematic review.

STUDY ELIGIBILITY CRITERIA

Peer-reviewed studies conducted in the U.S. and reporting interventions designed to increase the uptake of the influenza vaccine in pregnancy with study populations including at least 20% of participants identifying as Black were included.

STUDY APPRAISAL AND SYNTHESIS METHODS

Studies were grouped and reviewed in a narrative manner according to whether they were conducted in predominantly Black populations or in more racially diverse populations, and whether they tested multicomponent or single-component interventions.

RESULTS

A decade of survey data show that Black women in the U.S. consistently have the lowest rate of influenza immunization in pregnancy. Black women report a lower rate of being recommended or offered the vaccine, and provider recommendation is associated with greater vaccine uptake. Intervention studies to increase influenza immunization among Black pregnant women have reported mixed results. Successful interventions include multicomponent practice-based interventions, group prenatal care, and culturally competent patient educational messages.

CONCLUSIONS

Racial disparities in maternal uptake of the influenza vaccine are long-standing, but not intractable. More research is needed to test interventions to address this disparity, with a focus on increasing provider recommendation and offer of the vaccine, addressing patients' concerns about vaccine safety and efficacy, improving providers' cultural competence, and building trust between providers and patients.

Racial and ethnic disparities in viral acute respiratory infections in the United States: protocol of a systematic review

BACKGROUND

The COVID-19 pandemic caused by SARS-CoV-2 has highlighted consistent inequities in incidence, disease severity, and mortality across racial and ethnic minority populations in the United States (US) and beyond. While similar patterns have been observed with previous viral respiratory pathogens, to date, no systematic review has comprehensively documented these disparities or potential contributing factors. In response, this review aims to synthesize data on racial and ethnic disparities in morbidity and mortality due to viral acute respiratory infections (ARI) other than SARS-CoV-2. This review will focus on understanding structural health and social factors to contextualize race and ethnicity driving these disparities in the US.

METHODS

We will conduct a systematic review of studies published from January 1, 2002, onward. Our search will include PubMed/MEDLINE, EBSCO Host-CINAHL Plus, PsycInfo, EMBASE, and Cochrane Library databases to identify relevant articles. We will include studies of any design that describe racial/ethnic disparities associated with viral ARI conducted in the US. Primary outcomes include incidence, disease severity or complication, hospitalization, or death attributed to ARI. Secondary outcomes include uptake of preventive interventions including vaccination, handwashing, social distancing, and wearing masks. Two reviewers will independently screen all citations, full-text articles, and abstract relevant data. Data characterizing individual-, community-, and structural-level factors associated with these disparities will be abstracted to better understand the underlying structural inequities contributing to racial disparities in ARI. We will assess the methodological quality of all studies and will conduct meta-analyses using random effects models if appropriate.

DISCUSSION

Findings from this systematic review will shed light on patterns of racial and ethnic disparities in viral ARI in the United States to support mathematical modeling of epidemic trajectories, intervention impact, and structural drivers of transmission, including structural racism. Moreover, data emerging from this review may reignite pandemic preparedness focused on communities with specific vulnerabilities related to living and working conditions given prevailing structural inequities, thus facilitating improved future pandemic responses to novel or endemic viral respiratory pathogens.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42020219771.

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.

Epidemiological and virological characteristics of respiratory tract infections in children during COVID-19 outbreak

Background

To investigate the impact of protective measures and isolation on respiratory tract infections in children during the COVID-19 outbreak.

Methods

We extracted data on outpatient visits and respiratory infection visits, and tests of respiratory viruses (adenovirus (ADV), influenza A (FluA), influenza B (FluB) and respiratory syncytial virus (RSV)) from electronic healthcare records in Children’s Hospital, Zhejiang University School of Medicine during the COVID-19 outbreak (January–April, 2020), compared with those in 2018 and 2019 during the same periods.

Results

We found that outpatient visits in January, 2020 was comparable with those in 2018 and 2019, but decreased by 59.9% (288,003 vs. 717,983) and 57.4% (288,003 vs. 676,704), respectively during the period of February-April, 2020, as compared with the same periods in 2018 and 2019. The total number of respiratory tract infections from January to April 2020 decreased by 65.7% (119,532 vs.348,762) and 59.0% (119,532 vs.291,557), respectively compared with the same periods in 2018 and 2019. The proportion of respiratory tract infections during the outbreak also dropped compared with the same periods in 2018 and 2019 (P<0.001). We also found significantly decreased number of completed tests for respiratory viruses and positive cases of ADV, FluA, FluB, and RSV during February-April, 2020.

Conclusions

In this study, we found that outpatient visits and respiratory tract infections in children significantly decreased during COVID-19 outbreak. Adequate protective measures and isolation in children may help to prevent respiratory virus infections in children.

Relationship between neighborhood census-tract level socioeconomic status and respiratory syncytial virus-associated hospitalizations in U.S. adults, 2015-2017

Background

Respiratory syncytial virus (RSV) infection causes substantial morbidity and mortality in children and adults. Socioeconomic status (SES) is known to influence many health outcomes, but there have been few studies of the relationship between RSV-associated illness and SES, particularly in adults. Understanding this association is important in order to identify and address disparities and to prioritize resources for prevention.

Methods

Adults hospitalized with a laboratory-confirmed RSV infection were identified through population-based surveillance at multiple sites in the U.S. The incidence of RSV-associated hospitalizations was calculated by census-tract (CT) poverty and crowding, adjusted for age. Log binomial regression was used to evaluate the association between Intensive Care Unit (ICU) admission or death and CT poverty and crowding.

Results

Among the 1713 cases, RSV-associated hospitalization correlated with increased CT level poverty and crowding. The incidence rate of RSV-associated hospitalization was 2.58 (CI 2.23, 2.98) times higher in CTs with the highest as compared to the lowest percentages of individuals living below the poverty level (≥ 20 and < 5%, respectively). The incidence rate of RSV-associated hospitalization was 1.52 (CI 1.33, 1.73) times higher in CTs with the highest as compared to the lowest levels of crowding (≥5 and < 1% of households with > 1 occupant/room, respectively). Neither CT level poverty nor crowding had a correlation with ICU admission or death.

Conclusions

Poverty and crowding at CT level were associated with increased incidence of RSV-associated hospitalization, but not with more severe RSV disease. Efforts to reduce the incidence of RSV disease should consider SES.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-05989-w.

Racial and Ethnic Disparities in Viral Acute Respiratory Infections in the United States: Protocol of a Systematic Review

Background:

The COVID-19 pandemic caused by SARS-CoV-2 has highlighted consistent inequities in the risk of infection, severity of disease, or mortality across racial and ethnic minority populations in the United States and beyond. Although novel, SARS-CoV-2 shares commonalities in transmission dynamics with other viral respiratory pathogens where similar disparities in morbidity and mortality have been documented. However, to date, there has not been a systematic review of disparities in viral respiratory pathogens. In response, this review aims to synthesize data on racial and ethnic disparities in morbidity and mortality due to viral acute respiratory infections (ARI) other than SARS-CoV-2. In particular, this review will focus on understanding structural health and social factors outside of race and ethnicity driving these disparities in the United States.

Methods:

We will conduct a systematic review of studies published between January 1, 2002 and September 30, 2020 that capture data on racial and ethnic disparities associated with increased incidence, disease severity, risk of hospitalization and/or death in viral ARI in the United States. Data characterizing individual-, community-, and structural-level factors associated with these disparities will be abstracted to better understand the underlying structural inequities contributing to racial disparities in ARI. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines will be used with reviewers employing COVIDENCE to conduct two independent rounds of title/abstract and full text reviews for all articles. A built-in tool in COVIDENCE will be used for data abstraction.

Discussion:

Findings from this systematic review will shed light on patterns of racial and ethnic disparities in viral ARI in the United States. Leveraging these data can support predictive studies of the differential impacts of COVID-19 across the United States as well as adaptive intervention strategies mitigating structural inequities, including structural racism, driving both incidence and disparities in marginalized communities. Moreover, data emerging from this review may reignite pandemic preparedness focused on vulnerable communities given structural inequities, facilitating improved future pandemic responses to novel or endemic viral respiratory pathogens in the United States.

Systematic review registration:

PROSPERO CRD42020219771

Current State and Challenges in Developing Respiratory Syncytial Virus Vaccines

Respiratory syncytial virus (RSV) is the main cause of acute respiratory tract infections in infants and it also induces significant disease in the elderly. The clinical course may be severe, especially in high-risk populations (infants and elderly), with a large number of deaths in developing countries and of intensive care hospitalizations worldwide. To date, prevention strategies against RSV infection is based on hygienic measures and passive immunization with humanized monoclonal antibodies, limited to selected high-risk children due to their high costs. The development of a safe and effective vaccine is a global health need and an important objective of research in this field. A growing number of RSV vaccine candidates in different formats (particle-based vaccines, vector-based vaccines, subunit vaccines and live-attenuated vaccines) are being developed and are now at different stages, many of them already being in the clinical stage. While waiting for commercially available safe and effective vaccines, immune prophylaxis in selected groups of high-risk populations is still mandatory. This review summarizes the state-of-the-art of the RSV vaccine research and its implications for clinical practice, focusing on the characteristics of the vaccines that reached the clinical stage of development.

Intravenous peramivir vs oral oseltamivir in high-risk emergency department patients with influenza: Results from a pilot randomized controlled study

Background

Peramivir offers a single‐dose intravenous (IV) treatment option for influenza (vs 5‐day oral dosing for oseltamivir). We sought to compare outcomes of emergency department (ED) patients at high risk for influenza complications treated with IV peramivir vs oral oseltamivir.

Methods

During the 2015‐16 and 2016‐17 influenza seasons, adult patients in two US EDs were randomized to either oral oseltamivir or IV peramivir treatment group. Eligibility included positive molecular influenza test; met CDC criteria for antiviral treatment; able to provide informed consent and agree to follow‐up assessment. Outcomes were measured by clinical end‐point indicators, including FLU‐PRO Score, Ordinal Scale, Patient Global Impression on Severity Score, and Karnofsky Performance Scale for 14 days. Non‐inferior t test was performed to assess comparative outcomes between the two groups.

Results

Five hundred and seventy‐five (68%) of 847 influenza‐positive patients were approached. Two hundred and eighty‐four met enrollment criteria and 179 were enrolled; of these 95 (53%) were randomized to peramivir, and 84 to oseltamivir. Average FLU‐PRO score at baseline was similar (peramivir: 2.67 vs oseltamivir: 2.52); the score decreased over time for both groups (day 5: peramivir: 1.71 vs oseltamivir: 1.62; day 10: peramivir: 1.48 vs oseltamivir: 1.37; day 14: peramivir: 1.40 vs oseltamivir: 1.33; all P < .05 for significantly non‐inferior). Influenza‐related complications were similar between two groups (All: peramivir: 31% vs oseltamivir: 21%, P > .05; pneumonia: peramivir: 11% vs oseltamivir: 14%, P > .05).

Conclusions

Clinical outcomes of influenza‐infected patients treated with single‐dose IV peramivir were comparable to those treated with oral oseltamivir, suggesting potential utility of peramivir for influenza‐infected patients in the ED.

Aryl Hydrocarbon Receptor Role in Co-Ordinating SARS-CoV-2 Entry and Symptomatology: Linking Cytotoxicity Changes in COVID-19 and Cancers; Modulation by Racial Discrimination Stress

There is an under-recognized role of the aryl hydrocarbon receptor (AhR) in co-ordinating the entry and pathophysiology of the severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) that underpins the COVID-19 pandemic. The rise in pro-inflammatory cytokines during the 'cytokine storm' induce indoleamine 2,3-dioxygenase (IDO), leading to an increase in kynurenine that activates the AhR, thereby heightening the initial pro-inflammatory cytokine phase and suppressing the endogenous anti-viral response. Such AhR-driven changes underpin the heightened severity and fatality associated with pre-existent high-risk medical conditions, such as type II diabetes, as well as to how racial discrimination stress contributes to the raised severity/fatality in people from the Black Asian and Minority Ethnic (BAME) communities. The AhR is pivotal in modulating mitochondrial metabolism and co-ordinating specialized, pro-resolving mediators (SPMs), the melatonergic pathways, acetyl-coenzyme A, and the cyclooxygenase (COX) 2-prostaglandin (PG) E2 pathway that underpin 'exhaustion' in the endogenous anti-viral cells, paralleling similar metabolic suppression in cytolytic immune cells that is evident across all cancers. The pro-inflammatory cytokine induced gut permeability/dysbiosis and suppression of pineal melatonin are aspects of the wider pathophysiological underpinnings regulated by the AhR. This has a number of prophylactic and treatment implications for SARS-CoV-2 infection and cancers and future research directions that better investigate the biological underpinnings of social processes and how these may drive health disparities.

Respiratory Virus-related Emergency Department Visits and Hospitalizations Among Infants in New Zealand

BACKGROUND

Estimates of the contribution of respiratory viruses to emergency department (ED) utilization remain limited.

METHODS

We conducted surveillance of infants with acute respiratory infection (ARI) associated ED visits, which then resulted in either hospital admission or discharge home. Seasonal rates of specific viruses stratified by age, ethnicity, and socioeconomic status were estimated for both visits discharged directly from ED and hospitalizations using rates of positivity for each virus.

RESULTS

During the 2014-2016 winter seasons, 3585 (66%) of the 5412 ARI ED visits were discharged home directly and 1827 (34%) were admitted to hospital. Among visits tested for all respiratory viruses, 601/1111 (54.1%) of ED-only and 639/870 (73.4%) of the hospital-admission groups were positive for at least one respiratory virus. Overall, respiratory virus-associated ED visit rates were almost twice as high as hospitalizations. Respiratory syncytial virus was associated with the highest ED (34.4 per 1000) and hospitalization rates (24.6 per 1000) among infants. ED visit and hospitalization rates varied significantly by age and virus. Māori and Pacific children had significantly higher ED visit and hospitalization rates for all viruses compared with children of other ethnicities.

CONCLUSIONS

Many infants with acute respiratory virus infections are managed in the ED rather than admitted to the hospital. Higher rates of ED-only versus admitted acute respiratory virus infections occur among infants living in lower socioeconomic households, older infants and infants of Māori or Pacific versus European ethnicity. Respiratory virus infections resulting in ED visits should be included in measurements of ARI disease burden.

Respiratory Syncytial Virus-Associated Hospitalizations Among Young Children: 2015-2016

BACKGROUND

Respiratory syncytial virus (RSV) is a major cause of hospitalized acute respiratory illness (ARI) among young children. With RSV vaccines and immunoprophylaxis agents in clinical development, we sought to update estimates of US pediatric RSV hospitalization burden.

METHODS

Children <5 years old hospitalized for ARI were enrolled through active, prospective, population-based surveillance from November 1, 2015, to June 30, 2016, at 7 US pediatric hospital sites. Clinical information was obtained from parent interviews and medical records. Midturbinate nasal and throat flocked swabs were collected and tested for RSV by using molecular diagnostic assays at each site. We conducted descriptive analyses and calculated population-based rates of RSV-associated hospitalizations.

RESULTS

Among 2969 hospitalized children included in analyses, 1043 (35%) tested RSV-positive; 903 (87%) children who were RSV-positive were <2 years old, and 526 (50%) were <6 months old. RSV-associated hospitalization rates were 2.9 per 1000 children <5 years old and 14.7 per 1000 children <6 months old; the highest age-specific rate was observed in 1-month-old infants (25.1 per 1000). Most children who were infected with RSV (67%) had no underlying comorbid conditions and no history of preterm birth.

CONCLUSIONS

During the 2015-2016 season, RSV infection was associated with one-third of ARI hospitalizations in our study population of young children. Hospitalization rates were highest in infants <6 months. Most children who were RSV-positive had no history of prematurity or underlying medical conditions, suggesting that all young children could benefit from targeted interventions against RSV.

The impact of ethnicity on clinical outcomes in COVID-19: A systematic review

BACKGROUND

The relationship between ethnicity and COVID-19 is uncertain. We performed a systematic review to assess whether ethnicity has been reported in patients with COVID-19 and its relation to clinical outcomes.

METHODS

We searched EMBASE, MEDLINE, Cochrane Library and PROSPERO for English-language citations on ethnicity and COVID-19 (1st December 2019-15th May 2020). We also reviewed: COVID-19 articles in NEJM, Lancet, BMJ, JAMA, clinical trial protocols, grey literature, surveillance data and preprint articles on COVID-19 in MedRxiv to evaluate if the association between ethnicity and clinical outcomes were reported and what they showed. PROSPERO:180654.

FINDINGS

Of 207 articles in the database search, five reported ethnicity; two reported no association between ethnicity and mortality. Of 690 articles identified from medical journals, 12 reported ethnicity; three reported no association between ethnicity and mortality. Of 209 preprints, 34 reported ethnicity - 13 found Black, Asian and Minority Ethnic (BAME) individuals had an increased risk of infection with SARS-CoV-2 and 12 reported worse clinical outcomes, including ITU admission and mortality, in BAME patients compared to White patients. Of 12 grey literature reports, seven with original data reported poorer clinical outcomes in BAME groups compared to White groups.

INTERPRETATION

Data on ethnicity in patients with COVID-19 in the published medical literature remains limited. However, emerging data from the grey literature and preprint articles suggest BAME individuals are at an increased risk of acquiring SARS-CoV-2 infection compared to White individuals and also worse clinical outcomes from COVID-19. Further work on the role of ethnicity in the current pandemic is of urgent public health importance.

FUNDING

NIHR.

Disparities in Human Papillomavirus Vaccine Series Completion by Adolescent Males: A Retrospective Cohort Study

OBJECTIVE

Human papillomavirus (HPV) vaccine has been recommended for male patients for the prevention of genital warts and precancerous anal lesions since 2009. Our objective was to characterize race and insurance-based disparities in HPV vaccine completion among male patients who initiated the HPV vaccine series.

METHODS

This was a retrospective cohort study of adolescent male patients in a primary care network who initiated the HPV vaccine series from October 2009 to December 2013. We measured vaccine series completion as the primary outcome. We evaluated associations between outcomes and race and insurance status, controlling for potential confounders and effect modification with multivariable logistic regression. Analyses were stratified by vaccine recommendation era (permissive vs routine).

RESULTS

In total, 42% of males in the cohort (16,691) completed the vaccine series. In the permissive vaccine era (2009-2011), non-black patients (53%) were more likely to complete than black patients (32%) and non-Medicaid patients (49%) were more likely to complete than Medicaid patients (33%). These differences persisted in the routine recommendation era (2012-2013). In both the permissive and routine eras, Medicaid insurance was associated with a larger reduction in the predicted probability of vaccine series completion for non-black patients. Adherence to the recommended vaccination schedule was low, with a median time to completion of 8.9 months. Using the updated completion schedule (2016), we found that completion rates were greater (54.1%) with continued differences based on race (60% vs 45.7% for non-black vs black patients) and insurance (57.4% vs 46.4% completion for non-Medicaid vs Medicaid patients).

CONCLUSIONS

We found significant disparities in HPV vaccine series completion rates among male patients based on race and insurance, unchanged based on era of initiation or visit frequency.

Estimated Burden of Community-Onset Respiratory Syncytial Virus-Associated Hospitalizations Among Children Aged <2 Years in the United States, 2014-15

BACKGROUND

Respiratory syncytial virus (RSV) is a major cause of hospitalizations in young children. We estimated the burden of community-onset RSV-associated hospitalizations among US children aged <2 years by extrapolating rates of RSV-confirmed hospitalizations in 4 surveillance states and using probabilistic multipliers to adjust for ascertainment biases.

METHODS

From October 2014 through April 2015, clinician-ordered RSV tests identified laboratory-confirmed RSV hospitalizations among children aged <2 years at 4 influenza hospitalization surveillance network sites. Surveillance populations were used to estimate age-specific rates of RSV-associated hospitalization, after adjusting for detection probabilities. We extrapolated these rates using US census data.

RESULTS

We identified 1554 RSV-associated hospitalizations in children aged <2 years. Of these, 27% were admitted to an intensive care unit, 6% needed mechanical ventilation, and 5 died. Most cases (1047/1554; 67%) had no underlying condition. Adjusted age-specific RSV hospitalization rates per 100 000 population were 1970 (95% confidence interval [CI],1787 to 2177), 897 (95% CI, 761 to 1073), 531 (95% CI, 459 to 624), and 358 (95% CI, 317 to 405) for ages 0-2, 3-5, 6-11, and 12-23 months, respectively. Extrapolating to the US population, an estimated 49 509-59 867 community-onset RSV-associated hospitalizations among children aged <2 years occurred during the 2014-2015 season.

CONCLUSIONS

Our findings highlight the importance of RSV as a cause of hospitalization, especially among children aged <2 months. Our approach to estimating RSV-related hospitalizations could be used to provide a US baseline for assessing the impact of future interventions.

Evaluation of a New Clinical Endpoint for Moderate to Severe Influenza Disease in Children: A Prospective Cohort Study

BACKGROUND

A moderate to severe (M/S) influenza clinical endpoint has been proposed in children, defined as fever >39°C, otitis media, lower respiratory tract infection, or serious extrapulmonary manifestations. The objective of the study was to evaluate the M/S measure against clinically relevant outcomes including hospitalization, emergency room visits, antimicrobial use, and child/parental absenteeism.

METHODS

We conducted a prospective observational study of children aged 6 months-8 years at the Children's Hospital Colorado emergency department (ED) and urgent care site during 2016-2017 and 2017-2018. Children with influenza-like illness (ILI) underwent influenza testing by polymerase chain reaction (PCR); children who tested positive and a subset of matched test-negative controls underwent follow-up at 2 weeks. The primary outcome was the proportion of children who were hospitalized. Secondary outcomes included recurrent ED visits, antimicrobial use, hospital charges, and child/parental absenteeism within 14 days.

RESULTS

Among 1478 children enrolled with ILI, 411 (28%) tested positive for influenza by PCR. Of children with influenza illness, 313 (76%) met the M/S definition. Children with M/S influenza were younger (3.8 years vs 4.8 years), infected with influenza A (59% vs 44%), and more frequently hospitalized (unadjusted risk difference [RD], 6.3%; 95% confidence interval [CI], 2.1-10.4; P = .03) and treated with antibiotics (unadjusted RD, 13.3%; 95% CI, 4.3-22.4; P < .01) compared to those with mild disease.

CONCLUSIONS

Children with M/S influenza have a higher risk of hospitalization and antibiotic use compared with mild disease. This proposed definition may be a useful clinical endpoint to study the public health and clinical impact of influenza interventions in children.

CLINICAL TRIALS REGISTRATION

NCT02979626.

Comparisons between ethnic groups in hospitalizations for respiratory syncytial virus bronchiolitis in Israel

BACKGROUND

Ethnic disparities have been shown in respiratory syncytial virus (RSV) bronchiolitis. However, it is unclear whether such differences are related to access to care. We compared demographic and clinical characteristics of Arab and Jewish children hospitalized for RSV bronchiolitis in Israel, a country with universal health insurance.

METHODS

We reviewed the medical records of all children (n = 309) aged less than 24 months who were hospitalized with RSV between 2008 and 2011 in one medical center in Israel. Demographic, clinical, laboratory and radiological data were collected. The RSV antigen was identified using immunochromatography.

RESULTS

The annual incidence of RSV hospitalization was 5.4/1000 and 6.8/1000 among Arab and Jewish children, respectively. Arab patients were significantly younger and had significantly younger parents; most lived in low socioeconomic status towns (93.7% vs. 13.3%; p<0.001) and had more siblings (median 2 vs. 1; p = 0.01) compared to Jewish patients. Disease severity did not differ between the two ethnic groups (p = 0.3). The main predictors of severe illness were having pneumonia (adjusted odds ratio [OR] 3.86; 95% confidence intervals [CI] 1.87-7.97) and history of respiratory diseases (adjusted OR 3.89; 95% CI 1.22-12.38).

CONCLUSIONS

The incidence of hospitalizations for RSV bronchiolitis tended to be higher among Jewish than Arab children, possibly due to differences in health care utilization patterns. Differences between the Jewish and Arab patients in demographic factors likely mirror differences between the groups in the general population. Pneumonia, and not ethnicity, affected the severity of RSV bronchiolitis.

Inpatient burden of juvenile dermatomyositis among children in the United States

BACKGROUND

Juvenile dermatomyositis (JDM) is a rare autoimmune disease that causes significant morbidity and quality of life impairment. Little is known about the inpatient burden of JDM in the US. Our goal was to determine the prevalence and risk factors for hospitalization with juvenile dermatomyositis and assess inpatient burden of JDM.

METHODS

Data on 14,401,668 pediatric hospitalizations from the 2002-2012 Nationwide Inpatient Sample (NIS) was analyzed. ICD-9-CM coding was used to identify hospitalizations with a diagnosis of JDM.

RESULTS

There were 909 and 495 weighted admissions with a primary or secondary diagnosis of JDM, respectively. In multivariable logistic regression models with stepwise selection, female sex (logistic regression; adjusted odds ratio [95% confidence interval]) (2.22 [2.05-2.42]), non-winter season (fall: 1.18[1.06-1.33]; spring (1.13 [1.01-1.27]; summer (1.53 [1.37-1.71]), non-Medicaid administered government insurance coverage (2.59 [2.26-2.97]), and multiple chronic conditions (2-5: 1.41[1.30-1.54]; 6+: 1.24[1.00-1.52]) were all associated with higher rates of hospitalization for JDM. The weighted total length of stay (LOS) and inflation-adjusted cost of care for patients with a primary inpatient diagnosis of JDM was 19,159 days and $49,339,995 with geometric means [95% CI] of 2.50 [2.27-2.76] days and $7350 [$6228-$8674], respectively. Costs of hospitalization in primary JDM and length of stay and cost in secondary JDM were significantly higher compared to those without JDM. Notably, race/ethnicity was associated with increased LOS (log-linear regression; adjusted beta [95% confidence interval]) (Hispanic: 0.28 [0.14-0.41]; other non-white: 0.59 [0.31-0.86]) and cost of care (Hispanic: 0.30 [0.05-0.55]).

CONCLUSION

JDM contributes to both increased length of hospitalization and inpatient cost of care. Non-Medicaid government insurance was associated with higher rates of hospitalization for JDM while Hispanic and other non-white racial/ethnic groups demonstrated increased LOS and cost of care.

Epidemiology of bronchiolitis: a description of emergency department visits and hospitalizations in Puerto Rico, 2010-2014

BACKGROUND

Little is known about the epidemiology of bronchiolitis as a clinical diagnosis and its impact on emergency department visits and hospitalizations in tropical and semitropical regions. We described the epidemiology of bronchiolitis emergency visits and hospitalizations, its temporal trend and geographic distribution in Puerto Rico between 2010 and 2014.

METHODS

We performed a retrospective descriptive analysis of a representative sample of privately insured children with bronchiolitis from January 2010 to December 2014. Data was provided by the largest private health insurer in Puerto Rico and identified children < 24 months of age with bronchiolitis by International Classification of Diseases, Ninth Revision code 466, 466.11, and 466.19. Chi-square and one-way ANOVA compared sex, age, diagnosis, and severity across the years. Joinpoint Poisson regression analysis evaluated the temporal trend distribution of bronchiolitis hospitalizations per calendar year. A P value less than 0.05 was statistically significant.

RESULTS

During the study period, the annual proportion of emergency department visits and hospitalizations due to bronchiolitis increased from 3 to 5%, and 26 to 38%, respectively. The annual incidence rate of hospitalizations was 3.2 per 1000 privately insured children < 24 months. Non-RSV bronchiolitis was the most frequent diagnosis (51%). Hospitalizations occurred year-round, but increased significantly from August through December. Most children hospitalized resided in the metropolitan San Juan (35%) and surrounding urban areas. Total hospital charges decreased from $3.78 to $3.74 million, with an average cost per hospitalization of $4320.12 (11.3% increase; P = 0.0015).

CONCLUSIONS

This is the first study that evaluates the epidemiological characteristics of bronchiolitis in a primarily Hispanic population, living in a tropical country, and using data from a privately insured population. We found a small but significant increase in proportion of emergency visits and hospitalizations. Temporal trend shows year-round hospitalizations with an earlier seasonal peak and longer duration, consistent with Puerto Rico's seasonal rainfall throughout the study period. Further studies are needed to elucidate whether this epidemiologic pattern can also be seen in publicly insured children and whether Hispanic ethnicity is a risk factor for increased hospitalizations or is related to health disparities in the US healthcare system.

Predictors of Hospitalization, Length of Stay, and Cost of Care Among Adults With Dermatomyositis in the United States

OBJECTIVE

To determine the prevalence and risk factors for hospitalization with dermatomyositis and assess inpatient burden of dermatomyositis.

METHODS

Data on 72,651,487 hospitalizations from the 2002-2012 Nationwide Inpatient Sample, a 20% stratified sample of all acute-care hospitalizations in the US, were analyzed. International Classification of Diseases, Ninth Revision, Clinical Modification coding was used to identify hospitalizations with a diagnosis of dermatomyositis.

RESULTS

There were 9,687 and 43,188 weighted admissions with a primary or secondary diagnosis of dermatomyositis, respectively. In multivariable logistic regression models with stepwise selection, female sex (logistic regression: adjusted odds ratio 2.05 [95% confidence interval (95% CI) 1.80, 2.34]), nonwhite race (African American: 1.68 [1.57, 1.79]; Hispanic: 2.38 [2.22, 2.55]; Asian: 1.54 [1.32, 1.81]; and multiracial/other: 1.65 [1.45, 1.88]), and multiple chronic conditions (2-5: 2.39 [2.20, 2.60] and ≥6: 2.80 [2.56, 3.07]) were all associated with higher rates of hospitalization for dermatomyositis. The weighted total length of stay (LOS) and inflation-adjusted cost of care for patients with a primary inpatient diagnosis of dermatomyositis was 80,686 days and $168,076,970, with geometric means of 5.38 (95% CI 5.08, 5.71) and $11,682 (95% CI $11,013, $12,392), respectively. LOS and costs of hospitalization were significantly higher in patients with dermatomyositis compared to those without. Notably, race/ethnicity was associated with increased LOS (log-linear regression: adjusted β [95% CI] for African American: 0.14 [0.04, 0.25] and Asian: 0.38 [0.22, 0.55]) and cost of care (Asian: 0.51 [0.36, 0.67]).

CONCLUSION

There is a significant and increasing inpatient burden for dermatomyositis in the US. There appear to be racial differences, as nonwhites have higher prevalence of admission, increased LOS, and cost of care.

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.

•

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

•

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

•

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

•

Differences did not appear to substantially bias estimated vaccine effectiveness.

Defining the Epidemiology and Burden of Severe Respiratory Syncytial Virus Infection Among Infants and Children in Western Countries

INTRODUCTION

The REGAL (RSV [respiratory syncytial virus] Evidence-a Geographical Archive of the Literature) series provides a comprehensive review of the published evidence in the field of RSV in Western countries over the last 20 years. This first of seven publications covers the epidemiology and burden of RSV infection.

METHODS

A systematic review was undertaken for articles published between Jan 1, 1995 and Dec 31, 2015 across PubMed, Embase, The Cochrane Library, and Clinicaltrials.gov. Studies reporting data for hospital visits/admissions for RSV infection among children (≤18 years of age), as well as studies reporting RSV-associated morbidity, mortality, and risk factors were included. Study quality and strength of evidence (SOE) were graded using recognized criteria.

RESULT

2315 studies were identified of which 98 were included. RSV was associated with 12-63% of all acute respiratory infections (ARIs) and 19-81% of all viral ARIs causing hospitalizations in children (high SOE). Annual RSV hospitalization (RSVH) rates increased with decreasing age and varied by a factor of 2-3 across seasons (high SOE). Studies were conflicting on whether the incidence of RSVH has increased, decreased, or remained stable over the last 20 years (moderate SOE). Length of hospital stay ranged from 2 to 11 days, with 2-12% of cases requiring intensive care unit admission (moderate SOE). Case-fatality rates were <0.5% (moderate SOE). Risk factors associated with RSVH included: male sex; age <6 months; birth during the first half of the RSV season; crowding/siblings; and day-care exposure (high SOE).

CONCLUSION

RSV infection remains a major burden on Western healthcare systems and has been associated with significant morbidity. Further studies focusing on the epidemiology of RSV infection (particularly in the outpatient setting), the impact of co-infection, better estimates of case-fatality rates and associated risk factors (all currently moderate/low SOE) are needed to determine the true burden of disease.

FUNDING

Abbvie.

Respiratory Syncytial Virus Preterm (32-36 Completed Weeks of Gestation) Risk Estimation Measure for RSV Hospitalization in Ireland: A Prospective Study

BACKGROUND

In several countries, respiratory syncytial virus prophylaxis is offered to late preterm infants who are at escalated risk of respiratory syncytial virus hospitalization (RSVH). However, targeted prophylaxis should be informed by country-specific data. This study, which uniquely includes 36 weeks of gestational age (GA) infants, aims to establish the risk factors for RSVH in 32-36 weeks of GA infants in Ireland.

METHODS

A prospective observational study at 13 hospitals of laboratory-confirmed RSVH in nonprophylaxed 32-36 weeks of GA infants was conducted from July 2011 to February 2014. Baseline and first-year clinical data were analyzed by using SPSS software Version 22 (IBM Corp, Armonk, NY). Significant (P < 0.05) variables were entered into multiple logistic regression to determine the independent risk factors for RSVH.

RESULTS

Sixty-three percent of eligible infants (1825 of 2877) were recruited. The RSVH rate was 3.6% (65 of 1807 analyzed infant records). There was no RSV-attributable mortality. Twelve infants required intensive care. Of the 15 variables correlating to RSVH, 5 independent risk factors were identified: older siblings [odds ratio (OR): 3.8; 95% confidence interval (CI): 1.97-7.41], being Caucasian (OR: 2.3; 95% CI: 1.04-5.29), neonatal respiratory morbidity (OR: 2.2; 95% CI: 1.28-3.94); birth July 15 to December 15 (OR: 2.1; 95% CI: 1.09-3.92) and family history of asthma (OR: 1.9; 95% CI: 1.01-3.39). Birth from 36 weeks to 36 + 6 days mitigated RSVH risk (relative risk: 0.58; 95% CI: 0.34-0.99); however, risk factors were similar to the 32-35 weeks of GA cohort.

CONCLUSION

Neonatal respiratory morbidity or being Caucasian were the population-specific independent risk factors for RSVH in 32-36 weeks of GA in Ireland, whereas the other identified independent risk factors mirrored those established in previous studies.

Impacting delayed pediatric influenza vaccination: a randomized controlled trial of text message reminders

BACKGROUND

Influenza vaccination coverage is low, especially among low-income populations. Most doses are generally administered early in the influenza season, yet sustained vaccination efforts are crucial for achieving optimal coverage. The impact of text message influenza vaccination reminders was recently demonstrated in a low-income population. Little is known about their effect on children with delayed influenza vaccination or the most effective message type.

PURPOSE

To determine the impact of educational plus interactive text message reminders on influenza vaccination of urban low-income children unvaccinated by late fall.

DESIGN

Randomized controlled trial.

SETTING/PARTICIPANTS

Parents of 5,462 children aged 6 months-17 years from four academically affiliated pediatric clinics who were unvaccinated by mid-November 2011.

INTERVENTION

Eligible parents were stratified by their child's age and pediatric clinic site and randomized using a 1:1:1 allocation to educational plus interactive text message reminders, educational-only text message reminders, or usual care. Using an immunization registry-linked text messaging system, parents of intervention children received up to seven weekly text message reminders. One of the messages sent to parents in the educational plus interactive text message arm allowed selection of more information about influenza and influenza vaccination.

MAIN OUTCOME MEASURES

Influenza vaccination by March 31, 2012. Data were collected and analyzed between 2012 and 2014.

RESULTS

Most children were publicly insured and Spanish speaking. Baseline demographics were similar between groups. More children of parents in the educational plus interactive text message arm were vaccinated (38.5%) versus those in the educational-only text message (35.3%; difference=3.3%, 95% CI=0.02%, 6.5%; relative risk ratio (RRR)=1.09, 95% CI=1.002, 1.19) and usual care (34.8%; difference=3.8%, 95% CI=0.6%, 7.0%; RRR=1.11, 95% CI=1.02-1.21) arms.

CONCLUSIONS

Text message reminders with embedded educational information and options for interactivity have a small positive effect on influenza vaccination of urban, low-income, minority children who remain unvaccinated by late fall.

Evaluation of Diverse Community Asthma Interventions: Balancing Health Outcomes with Developing Community Capacity for Evidence-Based Program Measurement

The challenge of evaluating community asthma management programs is complicated by balancing the emphasis on health outcomes with the need to build community process capacity for conducting and monitoring evidence-based programs. The evaluation of a Georgia Childhood Asthma Management Program, a Healthcare Georgia Foundation-supported initiative for multiple diverse programs and settings, provides an example of an approach and the results that address this challenge. A "developmental evaluation" approach was applied, using mixed methods of quantitative and qualitative data collection and analysis, to assess the progress of community asthma prevention programs in building community within the context of: where the community is starting, community-level systems changes, and the community's progress toward becoming more outcome measurement oriented and evidence based. Initial evaluation efforts revealed extensive mobilization of community assets to manage childhood asthma. However, there were minimal planned efforts to assess health outcomes and systems changes, and the lack of a logic model-based program design linking evidence-based practices to outcomes. Following developmental technical assistance within evaluation efforts, all programs developed logic models, linking practices to outcomes with data collection processes to assess progress toward achieving the selected outcomes. This developmental approach across diverse projects and communities, along with a quality improvement benchmarking approach to outcomes, created a focus on health status outcome improvement. Specifically, this approach complemented an emphasis on an improved community process capacity to identify, implement, and monitor evidence-based asthma practices that could be used within each community setting.

Hospitalizations for severe lower respiratory tract infections

BACKGROUND

Hospitalization for lower respiratory tract infections (LRTIs) among children have been well characterized. We characterized hospitalizations for severe LRTI among children.

METHODS

We analyzed claims data from commercial and Medicaid insurance enrollees (MarketScan) ages 0 to 18 years from 2007 to 2011. LRTI hospitalizations were identified by the first 2 listed International Classification of Diseases, Ninth Revision discharge codes; those with ICU admission and/or receiving mechanical ventilation were defined as severe LRTI. Underlying conditions were determined from out- and inpatient discharge codes in the preceding year. We report insurance specific and combined rates that used both commercial and Medicaid rates and adjusted for age and insurance status.

RESULTS

During 2007-2011, we identified 16797 and 12053 severe LRTI hospitalizations among commercial and Medicaid enrollees, respectively. The rates of severe LRTI hospitalizations per 100000 person-years were highest in children aged <1 year (commercial: 244; Medicaid: 372, respectively), and decreased with age. Among commercial enrollees, ≥ 1 condition increased the risk for severe LRTI (1 condition: adjusted relative risk, 2.68; 95% confidence interval, 2.58-2.78; 3 conditions: adjusted relative risk, 4.85; 95% confidence interval, 4.65-5.07) compared with children with no medical conditions. Using commercial/Medicaid combined rates, an estimated 31289 hospitalizations for severe LRTI occurred each year in children in the United States.

CONCLUSIONS

Among children, the burden of hospitalization for severe LRTI is greatest among children aged <1 year. Children with underlying medical conditions are at greatest risk for severe LRTI hospitalization.

Updated guidance for palivizumab prophylaxis among infants and young children at increased risk of hospitalization for respiratory syncytial virus infection

Guidance from the American Academy of Pediatrics (AAP) for the use of palivizumab prophylaxis against respiratory syncytial virus (RSV) was first published in a policy statement in 1998. Guidance initially was based on the result from a single randomized, placebo-controlled clinical trial conducted in 1996-1997 describing an overall reduction in RSV hospitalization rate from 10.6% among placebo recipients to 4.8% among children who received prophylaxis. The results of a second randomized, placebo-controlled trial of children with hemodynamically significant heart disease were published in 2003 and revealed a reduction in RSV hospitalization rate from 9.7% in control subjects to 5.3% among prophylaxis recipients. Because no additional controlled trials regarding efficacy were published, AAP guidance has been updated periodically to reflect the most recent literature regarding children at greatest risk of severe disease. Since the last update in 2012, new data have become available regarding the seasonality of RSV circulation, palivizumab pharmacokinetics, the changing incidence of bronchiolitis hospitalizations, the effects of gestational age and other risk factors on RSV hospitalization rates, the mortality of children hospitalized with RSV infection, and the effect of prophylaxis on wheezing and palivizumab-resistant RSV isolates. These data enable further refinement of AAP guidance to most clearly focus on those children at greatest risk.

Child, household, and caregiver characteristics associated with hospitalization for influenza among children 6-59 months of age: an emerging infections program study

BACKGROUND

Young children are at increased risk of severe outcomes from influenza illness, including hospitalization. We conducted a case-control study to identify risk factors for influenza-associated hospitalizations among children in US Emerging Infections Program sites.

METHODS

Cases were children 6-59 months of age hospitalized for laboratory-confirmed influenza infections during 2005-2008. Age- and zip-code-matched controls were enrolled. Data on child, caregiver and household characteristics were collected from parents and medical records. Conditional logistic regression was used to identify independent risk factors for hospitalization.

RESULTS

We enrolled 290 (64%) of 454 eligible cases and 1089 (49%) of 2204 eligible controls. Risk for influenza hospitalization increased with maternal age <26 years [odds ratio (OR): 1.8, 95% confidence interval (CI): 1.1-2.9]; household income below the poverty threshold (OR: 2.2, 95% CI: 1.4-3.6); smoking by >50% of household members (OR: 2.9, 95% CI: 1.4-6.6); lack of household influenza vaccination (OR: 1.8, 95% CI: 1.2-2.5) and presence of chronic illnesses, including hematologic/oncologic (OR: 11.8, 95% CI: 4.5-31.0), pulmonary (OR: 2.9, 95% CI: 1.9-4.4) and neurologic (OR: 3.8, 95% CI: 1.6-9.2) conditions. Full influenza immunization decreased the risk among children 6-23 months of age (OR: 0.5, 95% CI: 0.3-0.9) but not among those 24-59 months of age (OR: 1.5, 95% CI: 0.8-3.0; P value for difference = 0.01).

CONCLUSIONS

Chronic illnesses, young maternal age, poverty, household smoking and lack of household influenza vaccination increased the risk of influenza hospitalization. These characteristics may help providers to identify young children who are at greatest risk for severe outcomes from influenza illness.

School-located influenza vaccination decreases laboratory-confirmed influenza and improves school attendance

BACKGROUND

School-located influenza vaccination (SLV) programs can efficiently immunize large numbers of school-aged children. We evaluated the impact of SLV on laboratory-confirmed influenza and absenteeism.

METHODS

Active surveillance for influenza-like illness (ILI) was conducted on 4455 children in 4 SLV intervention and 4 control elementary schools (grades K-6) matched for sociodemographic characteristics during the 2010-2011 influenza season in Los Angeles County, California. Combined nose/throat swabs were collected from febrile children with ILI at presentation to the school nurse or during absenteeism.

RESULTS

In SLV schools, 26.9%-46.6% of enrolled students received at least 1 dose of either inactivated or live attenuated influenza vaccine compared with 0.8%-4.3% in control schools. Polymerase chain reaction for respiratory viruses (PCR) was performed on 1021 specimens obtained from 898 children. Specimens were positive for influenza in 217 (21.3%), including 2009 H1N1 (30.9%), H3 (9.2%), and B (59.9%). Children attending SLV schools, regardless of vaccination status, were 30.8% (95% confidence interval, 10.1%-46.8%) less likely to acquire influenza compared with children at control schools. Unvaccinated children were indirectly protected in the school with nearly 50% vaccination coverage compared with control schools (influenza rate, 27.1 vs 60.0 per 1000 children; P = .023). Unvaccinated children missed more school days than vaccinated children (4.3 vs 2.8 days per 100 school days; P < .001).

CONCLUSIONS

Vaccination of at least a quarter of the school population resulted in decreased influenza rates and improved school attendance. Herd immunity for unvaccinated children may occur in schools with vaccination coverage approaching 50%.

Effectiveness of influenza vaccine against life-threatening RT-PCR-confirmed influenza illness in US children, 2010-2012

BACKGROUND

No studies have examined the effectiveness of influenza vaccine against intensive care unit (ICU) admission associated with influenza virus infection among children.

METHODS

In 2010-2011 and 2011-2012, children aged 6 months to 17 years admitted to 21 US pediatric intensive care units (PICUs) with acute severe respiratory illness and testing positive for influenza were enrolled as cases; children who tested negative were PICU controls. Community controls were children without an influenza-related hospitalization, matched to cases by comorbidities and geographic region. Vaccine effectiveness was estimated with logistic regression models.

RESULTS

We analyzed data from 44 cases, 172 PICU controls, and 93 community controls. Eighteen percent of cases, 31% of PICU controls, and 51% of community controls were fully vaccinated. Compared to unvaccinated children, children who were fully vaccinated were 74% (95% CI, 19% to 91%) or 82% (95% CI, 23% to 96%) less likely to be admitted to a PICU for influenza compared to PICU controls or community controls, respectively. Receipt of 1 dose of vaccine among children for whom 2 doses were recommended was not protective.

CONCLUSIONS

During the 2010-2011 and 2011-2012 US influenza seasons, influenza vaccination was associated with a three-quarters reduction in the risk of life-threatening influenza illness in children.

Recent advances in diagnosis, prevention, and treatment of human respiratory syncytial virus

Human respiratory syncytial virus (RSV) is a common cause of respiratory infection in infants and the elderly, leading to significant morbidity and mortality. The interdisciplinary fields, especially biotechnology and nanotechnology, have facilitated the development of modern detection systems for RSV. Many anti-RSV compounds like fusion inhibitors and RNAi molecules have been successful in laboratory and clinical trials. But, currently, there are no effective drugs for RSV infection even after decades of research. Effective diagnosis can result in effective treatment, but the progress in both of these facets must be concurrent. The development in prevention and treatment measures for RSV is at appreciable pace, but the implementation into clinical practice still seems a challenge. This review attempts to present the promising diverse research approaches and advancements in the area of diagnosis, prevention, and treatment that contribute to RSV management.

Respiratory syncytial virus-associated hospitalizations among children less than 24 months of age

BACKGROUND

Respiratory syncytial virus (RSV) infection is a leading cause of hospitalization among infants. However, estimates of the RSV hospitalization burden have varied, and precision has been limited by the use of age strata grouped in blocks of 6 to ≥ 12 months.

METHODS

We analyzed data from a 5-year, prospective, population-based surveillance for young children who were hospitalized with laboratory-confirmed (reverse-transcriptase polymerase chain reaction) RSV acute respiratory illness (ARI) during October through March 2000-2005. The total population at risk was stratified by month of age by birth certificate information to yield hospitalization rates.

RESULTS

There were 559 (26%) RSV-infected children among the 2149 enrolled children hospitalized with ARI (85% of all eligible children with ARI). The average RSV hospitalization rate was 5.2 per 1000 children <24 months old. The highest age-specific rate was in infants 1 month old (25.9 per 1000 children). Infants ≤ 2 months of age, who comprised 44% of RSV-hospitalized children, had a hospitalization rate of 17.9 per 1000 children. Most children (79%) were previously healthy. Very preterm infants (<30 weeks' gestation) accounted for only 3% of RSV cases but had RSV hospitalization rates 3 times that of term infants.

CONCLUSIONS

Young infants, especially those who were 1 month old, were at greatest risk of RSV hospitalization. Four-fifths of RSV-hospitalized infants were previously healthy. To substantially reduce the burden of RSV hospitalizations, effective general preventive strategies will be required for all young infants, not just those with risk factors.