Cell-free DNA blood test for the diagnosis of pediatric tuberculous meningitis

Pediatric tuberculous meningitis (TBM) is a severe form of tuberculosis that may present in children. The current diagnostic methods may have a limited impact on initial clinical decision-making. We present three children with tuberculous meningitis who had Mycobacterium tuberculosis complex cell-free DNA (cfDNA) detected in their blood within three days of sampling. Our cases described here illustrate for the first time the potential role of cfDNA blood tests in the rapid diagnosis of TBM.

Increasing Rates of RSV Hospitalization among Preterm Infants: A Decade of Data

OBJECTIVE

In 2014, the American Academy of Pediatrics (AAP) changed its policy on the use of respiratory syncytial virus immunoprophylaxis (RSV-IP) so that RSV-IP was no longer recommended for use among infants without other medical conditions born >29 weeks of gestational age (wGA). This study examines 10-year trends in RSV-IP and RSV hospitalizations among term infants and preterm infants born at 29 to 34 wGA, including the 5 RSV seasons before and 5 RSV seasons after the AAP guidance change.

STUDY DESIGN

A retrospective observational cohort study of a convenience sample of infants less than 6 months of age during RSV season (November-March) born between July 1, 2008, and June 30, 2019, who were born at 29 to 34 wGA (preterm) or >37 wGA (term) in the IBM MarketScan Commercial and Multi-State Medicaid databases. We excluded infants with medical conditions that would independently qualify them for RSV-IP. We identified RSV-IP utilization along with RSV and all-cause bronchiolitis hospitalizations during each RSV season. A difference-in-difference model was used to determine if there was a significant change in the relative rate of RSV hospitalizations following the 2014 policy change.

RESULTS

There were 53,535 commercially insured and 85,099 Medicaid-insured qualifying preterm infants and 1,111,670 commercially insured and 1,492,943 Medicaid-insured qualifying term infants. Following the 2014 policy change, RSV-IP utilization decreased for all infants, while hospitalization rates tended to increase for preterm infants. Rate ratios comparing preterm to term infants also increased. The relative rate for RSV hospitalization for infants born at 29 to 34 wGA increased significantly for both commercially and Medicaid-insured infants (1.95, 95% CI: 1.67-2.27, p <0.001; 1.70, 95% CI: 1.55-1.86, p <0.001, respectively). Findings were similar for all-cause bronchiolitis hospitalizations.

CONCLUSION

We found that the previously identified increase in RSV hospitalization rates among infants born at 29 to 34 wGA persisted for at least 5 years following the policy change.

KEY POINTS

· Immunoprophylaxis rates decreased after the 2014 American Academy of Pediatrics guidelines update.. · Rate of RSV hospitalization increased among preterm infants after the 2014 AAP guidelines update.. · Increase in RSV hospitalization persisted for at least 5 years after AAP guidelines update..

COVID-19 Epidemiology, Immunity, and Vaccine Development in Children: A Review

Although pediatric populations experienced lower COVID-19 severity and mortality than adults, the epidemiology of this disease continues to evolve. COVID-19 clinical manifestations in pediatrics commonly include fever and cough, but may differ from adults and by variant. Serious complications, including MIS-C, rarely occur. Although early data showed a decreased likelihood of COVID-19 transmission from children versus adults, outbreaks and viral shedding studies support pediatric transmission potential. Children may mount more robust initial immune responses to SARS-CoV-2 versus adults. COVID-19 vaccines with available pediatric data include BNT162b2, mRNA-1273, CoronaVac, and BBIBP-CorV. Depending on age group and jurisdiction, BNT162b2 and mRNA-1273 have received full approval or emergency/conditional authorization in the United States and European Union from 6 months of age. Clinical trials have shown BNT162b2 and mRNA-1273 safety and high efficacy in pediatric populations, with demonstrably noninferior immune responses versus young adults. Real-world studies further support BNT162b2 safety and effectiveness against the Delta variant. mRNA vaccination benefits are considered to outweigh risks, including myocarditis; however, pediatric vaccination rates remain relatively low. Given a growing body of clinical trial and real-world data showing vaccine safety and effectiveness, pediatric vaccination should be prioritized as an important strategy to control the pandemic.

Relative efficacy of varicella vaccines: network meta-analysis of randomized controlled trials

OBJECTIVE

Although varicella vaccination is highly effective, no head-to-head randomized controlled trials (RCTs) have compared the efficacy of different vaccine formulations. This study assessed the relative efficacy of different varicella vaccines using network meta-analysis (NMA).

METHODS

We estimated the relative efficacies of varicella vaccines and dosing regimens from RCTs using Bayesian NMA. Modeling-based time-series NMA (MBNMA) was performed, accounting for differences in time since vaccination, to extrapolate long-term vaccine efficacy (VE).

RESULTS

Eight RCTs were included based on systematic review of biomedical databases. Efficacy data were reported for four varicella-containing vaccines: Varivax (V-MSD, one and two dose), Varilrix (V-GSK, one dose), Priorix-Tetra (MMRV-GSK, one dose), and Sinovac (V-Sinovac, one dose). All varicella vaccines were effective versus no vaccination. Two-dose V-MSD (98.29%, 95% credible interval [CrI] 96.08-99.23) showed significantly higher VE versus all one-dose varicella-containing vaccines, but no significant difference versus two-dose MMRV-GSK (95.19%, 95% CrI 90.3-97.63). Two-dose MMRV-GSK showed higher VE than one-dose V-GSK (66.47%; 95% CrI 43.02-79.43), but no significant differences in VE versus one-dose V-MSD or one-dose V-Sinovac. In one-dose comparisons, V-MSD showed significantly higher VE (93.09%, 95% CrI 89.13-95.96) than V-GSK, but no significant difference versus V-Sinovac (89.22%; 95% CrI 67.1-96.5). MBNMA indicated that protection against varicella was sustained without waning over the 10 year follow-up.

CONCLUSIONS

Our study reported higher VE for two-dose V-MSD and MMRV-GSK. Among one-dose formulations, one-dose V-MSD was more efficacious than one-dose V-GSK. Policymakers should take into consideration differences in VE when implementing one- versus two-dose strategies in universal vaccination programs.

Recognition & management of varicella infections and accuracy of antimicrobial recommendations: Case vignettes study in the US

Background

In 1995, the CDC recommended one-dose routine varicella immunization for children <12 years of age, expanding its recommendation to two doses in 2006. Today, with widespread varicella vaccination coverage, an estimated 3.5 million cases of varicella, 9,000 hospitalizations, and 100 deaths are prevented annually in the United States. Since varicella infections are now uncommon, health care providers (HCPs) may not recognize varicella infections and may prescribe inappropriate treatment.

Methods

An online survey of HCPs was conducted to assess recognition and management of varicella infections. Responses to eight varicella vignettes describing patients with varying varicella symptoms were analyzed and descriptive analyses performed. Stratified analysis comparing responses of those licensed before and in/after 1996 was also performed.

Results

153 HCPs (50 nurse practitioners, 103 doctors) completed the survey. Mean age of respondents was 44 years. 62% were female, and 82% were licensed before 1996. Varicella infection was correctly diagnosed 79% of the time. HCPs correctly recognized uncomplicated varicella vignettes 85% of the time versus 61% of the time for complicated varicella vignettes. Antibiotics were recommended 17% of the time and antivirals 18% of the time, of which 25% and 69% (respectively) were not appropriate per guidelines. HCPs licensed before 1996 were better able to recognize varicella compared to those licensed later, but prescribed more antimicrobials medications to treat varicella.

Conclusions

Although most HCPs recognized varicella infection, a sizable proportion could not recognize cases with complications, and some of the varicella cases were inappropriately treated with antibiotics and/or antivirals. Additional HCP training and high vaccination coverage are important strategies to avoid inaccurate diagnoses and minimize unnecessary exposure to antimicrobial/antiviral therapies.

Impact of universal varicella vaccination on the use and cost of antibiotics and antivirals for varicella management in the United States

Background

Our objective was to estimate the impact of universal varicella vaccination (UVV) on the use and costs of antibiotics and antivirals for the management of varicella among children in the United States (US).

Methods

A decision tree model of varicella vaccination, infections and treatment decisions was developed. Results were extrapolated to the 2017 population of 73.5 million US children. Model parameters were populated from published sources. Treatment decisions were derived from a survey of health care professionals’ recommendations. The base case modelled current vaccination coverage rates in the US with additional scenarios analyses conducted for 0%, 20%, and 80% coverage and did not account for herd immunity benefits.

Results

Our model estimated that 551,434 varicella cases occurred annually among children ≤ 18 years in 2017. Antivirals or antibiotics were prescribed in 23.9% of cases, with unvaccinated children receiving the majority for base case. The annual cost for varicella antiviral and antibiotic treatment was approximately $14 million ($26 per case), with cases with no complications accounting for $12 million. Compared with the no vaccination scenario, the current vaccination rates resulted in savings of $181 million (94.7%) for antivirals and $78 million (95.0%) for antibiotics annually. Scenario analyses showed that higher vaccination coverage (from 0% to 80%) resulted in reduced annual expenditures for antivirals (from $191 million to $41 million), and antibiotics ($82 million to $17 million).

Conclusions

UVV was associated with significant reductions in the use of antibiotics and antivirals and their associated costs in the US. Higher vaccination coverage was associated with lower use and costs of antibiotics and antivirals for varicella management.

Congenital Syphilis and the Prozone Phenomenon: Case Report

Congenital syphilis represents an important public health challenge in the United States, and its prevalence has been increasing for the past 10 years because of many factors. The diagnosis can be difficult given its various and nonspecific clinical manifestations in newborns, and the possibility of false negative results during prenatal care. The prozone phenomenon, caused by an excess of antibody, which interferes with the regular screening tests, is a cause of false negative tests. This could delay the diagnosis and increase morbidity and mortality in the newborn. We present a case of congenital syphilis in a 3-month-old infant whose mother had prenatal care and negative tests for syphilis, which contributed to the late diagnosis. In the face of clinical findings suggestive of congenital syphilis and negative maternal syphilis tests healthcare providers should consider the possibility of maternal false negative test caused by the prozone phenomenon.

Rationale for the Development of a Pentavalent Meningococcal Vaccine: A US-Focused Review

While invasive meningococcal disease (IMD) is uncommon, it can result in serious sequelae and even death. In 2018 in the United States, the incidence of IMD per 100,000 people was 0.03 among adolescents 11−15 years of age, 0.10 among persons 16−23 years of age, and 0.83 among infants < 1 year of age. Serogroup B accounted for 86%, 62%, and 66% of cases, respectively, in those age groups. Currently, routine meningococcal vaccination covering serogroups ACWY (MenACWY) is recommended in the United States for all adolescents at 11−12 years of age, with a booster dose at 16 years of age, whereas a meningococcal serogroup B (MenB) vaccine series is recommended for persons 16−23 years of age under the shared clinical decision-making paradigm. The MenACWY vaccination program in adolescents has been successful in reducing disease burden, but does not prevent disease caused by serogroup B, which accounts for more than half of IMD cases. There are currently no approved vaccines that cover all of the most common disease-causing meningococcal serogroups, which are A, B, C, W, and Y. A pentavalent MenABCWY vaccine that is constituted from 2 licensed meningococcal vaccines—MenB-FHbp and MenACWY-TT—is being investigated in healthy persons ≥ 10–25 years of age. The addition of a MenABCWY vaccine is the next natural step in the incremental meningococcal immunization program in the United States to improve protection against the most common serogroup causing IMD, with no increase in the number of immunizations needed. With high uptake, routine use of MenABCWY could reduce IMD cases and associated mortality, the rate of long-term physical and psychosocial sequelae in survivors, and costs associated with controlling outbreaks, particularly on college campuses. A MenABCWY vaccine would also reduce the number of injections required for adolescents, potentially improving compliance.

1021. Utility of Cell-Free DNA Sequencing in Diagnosing Murine typhus in Children

Background

Murine typhus is a zoonotic infection caused by Rickettsia typhi and transmitted through infected fleas. Geographic distribution within the United States is limited primarily to South Texas and Southern California. Infection is typically associated with a triad of fever, headache, and rash, although is only present in one-third of cases. Immunofluorescence assay (IFA) is currently the gold standard for diagnosis, but it has its limitations as it is dependent on the time to seroconversion and has low specificity due to cross-reactivity among other rickettsial species. Cell-free DNA (cfDNA) sequencing for broad-range pathogen detection may offer higher sensitivity at the early stages of the disease.

Methods

We performed a retrospective electronic medical record search of children with cfDNA sequencing detection of Murine typhus hospitalized at Driscoll Children’s Hospital, Corpus Christi, Texas, between June 2020 and May 2021.

Results

We found 4 children (range 9-15 year-old) positive for R. typhi by cfDNA sequencing. All patients presented with fever of unknown origin and rash. Also, 2 patients were diagnosed with pneumonia. One patient exhibited severe illness with acute kidney injury, elevation of transaminases and encephalitis that warranted admission to the pediatric intensive care unit. All patients defervesced and improved within 48 hours of doxycycline initiation; average length of stay 6 days (range 3-12 days). In one patient, M. typhus was detected by Karius® test only, in the other three was concordant with serology.

Conclusion

We highlight next-generation cfDNA sequencing as a useful tool in identifying the etiologic agent of patients with fever of known origin, where murine typhus is one of the possible etiologies. Preventing extensive laboratory workup and subsequent delay of assessment and management. The rapid turnaround time of cfDNA test allows for de-escalation of therapy and initiation of appropriate treatment.

Disclosures

Jaime Fergie, MD, AstraZeneca (Scientific Research Study Investigator)Explify (Speaker’s Bureau)Karius (Speaker’s Bureau)Pfizer, Merck, AstraZeneca, and Sanofi (Speaker’s Bureau)Pfizer, Merck, Sanofi, and Moderna (Consultant, Advisor or Review Panel member)

Prevention of measles, mumps and rubella: 40 years of global experience with M-M-RII

Measles, mumps, and rubella are highly contagious diseases that caused significant global mortality and morbidity in the pre-vaccine era. Since its first approval in the United States over 40 years ago, M-M-R_II has been used in >75 countries for prevention of these diseases. The vaccine has been part of immunization programs that have achieved dramatic global reductions in case numbers and mortality rates, as well as the elimination of measles and rubella in several countries and regions. This report summarizes over four decades of global safety, immunogenicity, efficacy, and effectiveness data for the vaccine. We include studies on the use of M-M-R_II in different age groups, concomitant use with other routine childhood vaccines, administration via different routes, persistence of immunity, and vaccine effectiveness during outbreaks of measles and mumps. We conclude that M-M-R_II is well tolerated and has shown consistently high performance during routine use in multiple countries, in randomized controlled trials with diverse designs, and in outbreak settings, including use as measles postexposure prophylaxis. Physicians, parents, and the public can continue to have a high degree of confidence in the use of M-M-R_II as a vital part of global public health programs.

Unintended Consequences Following the 2014 American Academy of Pediatrics Policy Change for Palivizumab Prophylaxis among Infants Born at Less than 29 Weeks' Gestation

OBJECTIVE

The aim of this study is to compare outpatient respiratory syncytial virus (RSV) immunoprophylaxis (IP) use and relative RSV hospitalization (RSVH) rates for infants <29 weeks' gestational age (wGA) versus term infants before and after the 2014 American Academy of Pediatrics (AAP) policy change.

STUDY DESIGN

Infants were identified in the MarketScan Commercial and Multi-State Medicaid databases. Outpatient RSV IP receipt and relative <29 wGA/term hospitalization risks in 2012 to 2014 and 2014 to 2016 were assessed using rate ratios and a difference-in-difference model.

RESULTS

Outpatient RSV IP receipt by infants <29 wGA and aged <3 months in the Commercial and Medicaid populations and those aged 3 to <6 months in the Medicaid population declined after 2014. Relative RSVH risks for infants <29 wGA were numerically greater after 2014, with infants aged <3 months and Medicaid infants experiencing the greatest increases. Difference-in-difference results indicated a significantly increased relative risk of RSVH for infants <29 wGA versus term (both cohorts aged 0 to <6 months) in the Medicaid-insured population (1.68, p = 0.0054). A nonsignificant increase of similar magnitude occurred in the commercially insured population (1.57, p = 0.2867).

CONCLUSION

The 2014 policy change was associated with a decrease in RSV IP use and an increase in RSVH risk among otherwise healthy infants <29 wGA.

Use of M-M-R II outside of the routinely recommended age range - a systematic literature review

M-M-R®_II (M-M-R II) is routinely used in many countries at 12–15 months with a second dose at 4 to 6 years of age. However, the vaccine may need to be administered at other ages due to delays in the immunization schedule or in certain situations such as outbreaks or international travel. A systematic literature review was conducted to evaluate efficacy, immunogenicity and safety of M-M-R II among 6- to 11-month-olds and persons ≥7 years of age. A search for randomized controlled trials (RCTs) was conducted in 2019 including Medline, Embase and Cochrane CENTRAL. Only one study reported seroconversion rates after one dose in infants at 9 months of age: 87.4% (measles), 92.3% (mumps), and 91.2% (rubella); no safety data were reported. Seven studies reported immunogenicity and safety data for M-M-R II at ≥7 years of age. Seroconversion rates ranged from 96%-100% (measles), 65%-100% (mumps), and 91%-100% (rubella). Rates of selected adverse events ranged from 5.2%-8.7% for fever (≥38°C or ≥38.1°C), 2%-33.3% for injection site reactions, and 0.4% for measles/rubella-like rash (one study). No efficacy studies were found. This literature review identified RCTs with evidence to support that M-M-R II is immunogenic and well tolerated in individuals ≥7 years of age.

Immunity to SARS-CoV-2: Lessons Learned

In the year since the emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and with understanding of the etiology of the coronavirus disease 2019 (COVID-19) pandemic, it has become clear that most infected individuals achieve some form of immunity against the virus with relatively few reported reinfections. A number of vaccines have already achieved emergency use authorization based on data from large phase 3 field efficacy clinical trials. However, our knowledge about the extent and durability of this immunity, and the breadth of vaccine coverage against SARS-CoV-2 variants is still evolving. In this narrative review, we summarize the latest and rapidly developing understanding of immunity to SARS-CoV-2 infection, including what we have learned about the key antigens of SARS-CoV-2 (i.e., the spike protein and its receptor-binding domain), their importance in vaccine development, the immediate immune response to SARS-CoV-2, breadth of coverage of emerging SARS-CoV-2 variants, contributions of preexisting immunity to related coronaviruses, and duration of immunity. We also discuss lessons from newer approaches, such as systems serology, that provide insights into molecular and cellular immune responses elicited and how they relate to the trajectory of infection, and potentially inform immune correlates of protection. We also briefly examine the limited research literature on immune responses in special populations, such as pregnant women and children.

Implementation Experience With Meningococcal Serogroup B Vaccines in the United States: Impact of a Nonroutine Recommendation

BACKGROUND

Meningococcal serogroup B (MenB) is the leading cause of invasive meningococcal disease among US adolescents and young adults, accounting for 62% of cases in 16-23-year-olds in 2018. Since 2015, the Advisory Committee on Immunization Practices (ACIP) has recommended vaccination of healthy adolescents against MenB based on shared clinical decision-making (previously called "Category B" or individual clinical decision-making). However, MenB vaccine coverage and series completion rates remain low. Herein we examine implementation experience of adolescent MenB vaccination in the United States under this nonroutine ACIP recommendation.

METHODS

PubMed was searched for English-language articles published after 2015 examining MenB vaccination implementation in the United States. Studies reporting MenB vaccination awareness, coverage, knowledge of recommendations and implementation barriers or access disparities were included.

RESULTS

Identified studies provided evidence that ACIP's MenB vaccination recommendation is poorly understood and prone to misinterpretation by US healthcare providers. Parental awareness of MenB vaccines is low, and racial and socioeconomic disparities exist regarding vaccine receipt. Parents rely on providers to learn about MenB disease risk and benefits of vaccination, with provider recommendations carrying substantial weight in vaccination decisions.

CONCLUSIONS

Five years of evidence regarding the MenB vaccination implementation experience suggest that the nonstandard recommendation for MenB vaccines is partly responsible for low vaccine coverage. Further, inconsistent implementation of ACIP recommendations could be limiting access to MenB vaccines. Providers need additional support and guidance to implement the shared clinical decision-making recommendation, in turn ensuring equitable access for vaccine-eligible adolescents to enable comprehensive protection against meningococcal disease.

Next-generation sequencing-based clinical metagenomics identifies Prevotella pleuritidis in a diabetic adolescent with large parapneumonic effusion and negative growth of pleural fluid culture: a case report

We report a 12-year-old diabetic boy with a right-sided parapneumonic effusion and pneumonia who failed initial empirical antibiotics. Prevotella pleuritidis was identified from the pleural fluid using next-generation sequencing-based clinical metagenomics with cultures of pleural fluid and blood resulting negative. The patient responded well to intravenous meropenem followed by oral metronidazole.

1513. Medically Attended Respiratory Syncytial Virus Hospitalizations (RSVH) and All-Cause Bronchiolitis Hospitalizations (BH) Among Children Aged ≤ 24 Months at RSV Season Start With Higher-Risk Congenital Heart Disease (CHD) Before and After the 2014 American Academy of Pediatrics (AAP) Policy

Background

In 2014, the AAP stopped recommending palivizumab for use in children with hemodynamically significant CHD (hs-CHD) aged 12 to 24 months at the RSV season start. This analysis investigates the impact of the 2014 AAP policy on the contemporary burden of RSVH and BH in children with CHD for whom palivizumab immunoprophylaxis is no longer recommended.

Methods

All children with CHD aged ≤ 24 months at the start of the RSV season and hospitalized for RSV or BH during the 2010-2017 RSV seasons (November-March) were studied. RSVH and BH were defined by International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) and ICD-10-CM codes. As there are no ICD codes for hs-CHD, we evaluated the effect of the guidance on higher-risk CHD as defined by ICD codes.¹ Frequency and characteristics of RSVH and BH and disease severity (including intensive care unit [ICU] admission and mechincal ventilation) for these children before and after the 2014 AAP guidance using the Children’s Hospital Association’s Pediatric Health Information System^® (PHIS) data set were described. SAS version 9.4 was used for statistical analysis of this data, with z-tests method used to determine statistical significance.

Results

RSVH significantly increased after 2014 for all higher-risk CHD children aged ≤ 24 months (3.4% [1992 RSVH CHD/59,217 RSVH] before the 2014 guidance and 4.0% [1798 RSVH CHD/45,470 RSVH] after; P< 0.0001) and for the subgroup of children aged 12 to 24 months at the start of the RSV season (0.5% before the guidance and 0.8% after; P< 0.0001). Disease severity as measured by ICU admissions in the 12 to 24 months subgroup also significantly increased after the 2014 guidance (0.2% before the guidance and 0.3% after; P< 0.0001). Mechanical ventilation usage was not statistically significantly increased after the 2014 guidance (P=0.188). A similar pattern of results was found for BH.

Conclusion

RSVH, BH, and associated disease severity significantly increased among higher-risk CHD children aged 12 to 24 months, within the PHIS health system, after the 3 RSV seasons following the 2014 AAP RSV immunoprophylaxis recommendations.

Disclosures

Jaime Fergie, MD, AstraZeneca (Speaker’s Bureau)Sobi, Inc. (Speaker’s Bureau) Tara Gonzales, MD, Sobi, Inc. (Employee) Mina Suh, MPH, International Health, EpidStrategies (Employee) Xiaohui Jiang, MS, EpidStrategies (Employee) Jon Fryzek, PhD, MPH, EpidStrategies (Employee) Adam Bloomfield, MD, FAAP, Sobi, Inc. (Employee)

1387. Current practices in the diagnosis and treatment of varicella infections in the United States

Background

The Advisory Committee on Immunization Practices recommended a 1 dose varicella immunization program in 1996, expanding this to include 2 doses in 2006. As a result, more than 3.5 million cases of varicella, 9,000 hospitalizations, and 100 deaths are prevented annually in the United States. Since varicella infections have become uncommon, the response of health care providers (HCPs) to patients presenting with varicella symptoms may result in misdiagnosis and/ mistreatment. This study investigated the diagnostic and treatment strategies used by HCPs for managing varicella infections in US children.

Methods

An online cross-sectional survey of licensed HCPs was conducted, after an Institution review board approval and HCP consent. 8 clinical vignettes with information on patients with varying varicella symptoms (representing uncomplicated and complicated cases) were presented. For each vignette, HCPs selected a diagnosis and appropriate intervention(s) from pre-determined lists. Descriptive analyses were performed.

Results

A total of 153 HCPs (50 nurses, 103 doctors) completed the survey. Mean age was 44 years, 62% were female, and 82% were licensed after 1995. Varicella infection was correctly diagnosed 79% of the time. HCPs were able to recognize uncomplicated cases of varicella 85% of the time and complicated cases 61% of the time. HCPs recommended the correct intervention 43% of the time for uncomplicated cases and 25% of the time for complicated cases. For example, HCPs recommended antibiotics 17% of the time and/or antivirals 18% of the time (Table 1), of which 25% and 69% (respectively) were not appropriate per the American Academy of Pediatrics guidelines respectively. Antibiotics were incorrectly recommended 6% of the time for uncomplicated cases of varicella.

Table 1. Additional Diagnosis & Treatment Results

Conclusion

Given the low incidence of varicella infections in the US, complicated cases of varicella may be under-recognized or inappropriately treated by some HCPs. Additional training may help HCPs better recognize/ treat cases of varicella. Further, ensuring high rates of varicella vaccination is important to avoid vaccine preventable conditions and to minimize unnecessary exposure to antimicrobial and antiviral therapies.

Disclosures

Jaime Fergie, MD, AstraZeneca (Speaker’s Bureau)Sobi, Inc. (Speaker’s Bureau) Manjiri D. Pawaskar, PhD, Merck & Co., Inc (Employee, Shareholder) Phani Veerkani, MD, DrPH, Merck (Research Grant or Support) Salome Samant, MBBS, MPH, Merck & Co., Inc., Kenilworth, NJ, USA (Employee, Shareholder) Carolyn Harley, PhD, Merck (Consultant) Joanna MacEwan, PhD, PRECISIONheor (Employee) Taylor T. Schwartz, MPH, Merck (Consultant, Grant/Research Support, Scientific Research Study Investigator, Research Grant or Support) Shikha Surati, MPH, Merck & Co., Inc. (Employee, Shareholder)

1520. Respiratory Syncytial Virus Hospitalizations (RSVH) and All-Cause Bronchiolitis Hospitalizations (BH) Among Children Aged ≤ 24 Months at the Start of RSV Season With Bronchopulmonary Dysplasia/Chronic Lung Disease of Prematurity (BPD/CLDP) Before and After the 2014 American Academy of Pediatrics (AAP) Policy

Background

The AAP, in 2014, stopped endorsing palivizumab for use in children with BPD/CLDP born at < 32 weeks’ gestational age (wGA) between the ages of 12 to 24 months not requiring medical support during the 6 months before the start of RSV season and all children with BPD/CLDP born at > 32 wGA. We sought to understand the impact of the guidance change on RSVH and BH in children no longer advised for RSV immunoprophylaxis with palivizumab.

Methods

Children with BPD/CLDP aged ≤ 24 months at the RSV season start and hospitalized for RSV or bronchiolitis during the 2010-2017 RSV seasons (November-March) were studied. RSVH, BH, and BPD/CLDP were defined by International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) and ICD-10-CM codes. ICD-9 codes for wGA combine 31 and 32 wGA into one code. Therefore, for BPD/CLDP, we classified group 1 as children aged 12 to 24 months who were born at < 31 wGA and group 2 as those born at ≥ 31 wGA. The Children’s Hospital Association’s Pediatric Health Information System^® (PHIS) data set was used to describe frequency and characteristics of RSVH and BH and disease severity (including intensive care unit [ICU] admission and mechanical ventilation [MV]) before and after the 2014 AAP policy. Statistical analyses were done using z-tests; SAS version 9.4.

Results

Among children with BPD/CLDP, RSVH rates were 1.7% (1035/59,217) before 2014 and 2.1% (973/45,470) after 2014 (P< 0.0001). RSVH rose after the policy change vs before among children with BPD/CLDP in both group 1 (0.40% vs 0.26%; P< 0.0001) and group 2 (0.22% vs 0.14%; P=0.002). Similarly, BH also increased for both group 1 (P< 0.0001) and group 2 (P=0.002) after the guidance change vs before. Although ICU admissions increased significantly for children with BPD/CLDP in both group 1 (P< 0.0001) and group 2 (P=0.0004), use of MV (P=0.002) increased after 2014 for children with BPD/CLDP in group 1 only. Similar results were observed for BH.

Conclusion

This analysis highlights the increase in RSVH, BH, and associated severity among BPD/CLDP subgroups within the PHIS health system after 2014. Further study of long-term complications associated with RSVH in these children is warranted.

Disclosures

Jaime Fergie, MD, AstraZeneca (Speaker’s Bureau)Sobi, Inc. (Speaker’s Bureau) Tara Gonzales, MD, Sobi, Inc. (Employee) Mina Suh, MPH, International Health, EpidStrategies (Employee) Xiaohui Jiang, MS, EpidStrategies (Employee) Jon Fryzek, PhD, MPH, EpidStrategies (Employee) Adam Bloomfield, MD, FAAP, Sobi, Inc. (Employee)

Update on respiratory syncytial virus hospitalizations among U.S. preterm and term infants before and after the 2014 American Academy of Pediatrics policy on immunoprophylaxis: 2011-2017

Palivizumab is the only licensed respiratory syncytial virus (RSV) immunoprophylaxis (IP) available to prevent severe RSV disease in high-risk pediatric populations, including infants born at 29-34 weeks' gestational age (wGA). In 2014, the American Academy of Pediatrics (AAP) stopped recommending RSV IP use for otherwise healthy 29-34 wGA infants and stated that 29-34 wGA infants and term infants have similar RSV hospitalization (RSVH) rates. This study aimed to compare RSV IP use and RSVH rates in 29-34 wGA infants and term infants during the 3 RSV seasons before and after the 2014 AAP policy change. RSV IP use in otherwise healthy infants 29-30, 31-32, and 33-34 wGA was estimated from pharmacy or outpatient medical claims for palivizumab. RSVH rates in the first 6 months of life were calculated per 100 infant-seasons. RSVH rate ratios were used to compare preterm infants and term infants before and after the policy change. Across infant cohorts (29-34 wGA) and chronologic age groups (<3 months and 3-<6 months), absolute decreases in RSV IP use between the combined 2011-2014 seasons and 2014-2017 seasons ranged from 7% to 38% and from 68% to 97%, respectively. Compared with 2011-2014, the RSVH risk increased 2.09-fold (P< .001) and 1.76-fold (P< .001) in 2014-2017 for infants born at 29-34 wGA and aged <6 months with commercial and Medicaid insurance, respectively. Overall, RSV IP use declined in the RSV seasons following the 2014 RSV IP policy change, and RSVH increased among 29-34 wGA infants aged <6 months.

Respiratory Syncytial Virus and All-Cause Bronchiolitis Hospitalizations Among Preterm Infants Using the Pediatric Health Information System (PHIS)

Background

In 2014, the American Academy of Pediatrics stopped recommending palivizumab to otherwise healthy 29–34 weeks’ gestational age (wGA) infants aged <12 months at respiratory syncytial virus (RSV) season start. Here, we compare the burden of RSV hospitalizations (RSVH) and all-cause bronchiolitis hospitalizations (BH) before and after 2014 among otherwise healthy 29–34 wGA infants hospitalized at ≤6 months of age.

Methods

A historical, observational cohort study was conducted to evaluate RSVH and BH in 29–34 wGA infants during the 2010–2017 RSV seasons using encounter data from 51 United States children’s hospitals that comprise the Pediatric Health Information System.

Results

The overall cohort included 67 570 RSVH out of 96 281 patients with BH. wGA was known for 22 937 RSVH and 33 289 BH. For 29–34 wGA infants, there were 8.7% and 14.2% RSVH before and after 2014, respectively (P < .0001). Intensive care unit admissions increased for RSVH (from 54.5% to 64.2%; P = .0002) and BH (from 46.7% to 54.5%; P = .0005) after controlling for sex, race, comorbidity, and cluster. The total cost of care increased for RSVH from $37 million to nearly $60 million.

Conclusions

RSVH, BH, and their severity increased among 29–34 wGA infants in the 3 RSV seasons following 2014.

Impact of the 2014 American Academy of Pediatrics Immunoprophylaxis Policy on the Rate, Severity, and Cost of Respiratory Syncytial Virus Hospitalizations among Preterm Infants

OBJECTIVE

This study examined the rate, severity, and cost of respiratory syncytial virus (RSV) hospitalizations among preterm infants 29 to 34 weeks gestational age (wGA) versus term infants before and after a 2014 change in the American Academy of Pediatrics policy for RSV immunoprophylaxis.

STUDY DESIGN

Preterm (29-34 wGA) and term infants born from July 2011 to March 2017 and aged < 6 months were identified in a U.S. commercial administrative claims database. RSV hospitalization (RSVH) rate ratios, severity, and costs were evaluated for the 2011 to 2014 and 2014 to 2017 RSV seasons. Postpolicy changes in RSVH risks for preterm versus term infants were assessed with difference-in-difference (DID) modeling to control for patient characteristics and temporal trends.

RESULTS

In the DID analysis, prematurity-associated RSVH risk was 55% greater in 2014 to 2017 versus 2011 to 2014 (relative risk = 1.55, 95% confidence interval: 1.10-2.17, p = 0.011). RSVH severity increased among preterm infants after 2014 and was highest among those aged < 3 months. Differences in mean RSVH costs for preterm infants in 2014 to 2017 versus 2011 to 2014 were not statistically significant.

CONCLUSION

RSVH risk for preterm versus term infants increased after the policy change, confirming previous national analyses. RSVHs after the policy change were more severe, particularly among younger preterm infants.

2638. Respiratory Syncitial Virus Hospitalizations (RSVH) and All-Cause Bronchiolitis Hospitalizations (BH) Among 29–34 Weeks Gestational Age (wGA) Preterm Infants Before and After the 2014 American Academy of Pediatrics (AAP) Immunoprophylaxis Policy Change Using the Children’s Hospital Association’s Pediatric Health Information System (PHIS)

Background

In 2014, the AAP stopped recommending RSV immunoprophylaxis for otherwise healthy 29–34 wGA preterm infants. This study examined the risk of RSVH and BH among 29–34 wGA infants before the AAP policy change (November 1, 2010–March 31, 2014) and after (November 1, 2014–March 31, 2017) using PHIS hospital-level encounter data from 51 US children’s hospitals.

Methods

The study population included the first November to March RSVH (ICD9 = 79.6, 480.1, 466.11, ICD10 = B97.4, J12.1, J21.0) or BH (RSVH or unspecified bronchiolitis [ICD9 = 466.19, ICD10 = J21.1, J21.8, J21.9]) among infants 6 months of age or younger admitted to a PHIS hospital between November 1, 2010 and March 31, 2017. The proportion of RSVH and BH by wGA categories (22–28 wGA, 29–34 wGA, 35–36 wGA, and term infants [37+ wGA]) were compared in the time period before and after 2014. Frequencies and proportions were calculated overall for all infants and by demographic and clinical factors for 29–34 wGA infants for RSVH and BH, separately. Statistically significant differences before and after the AAP policy were compared using χ 2 test or Wilcoxon rank-sum test, as appropriate.

Results

96,281 infants with BH, including 67,570 with RSVH, were studied. Among infants with known gestational age, the proportions of hospitalizations for RSVH and BH increased after the AAP policy change for all wGA categories, except for term infants (table). Infants 29–34 wGA represented 8.7% of all RSVH before the policy change and 14.2% of all RSVH after the policy change (P < 0.0001). No significant differences were found by gender or co-morbidity for infants 29–34 wGA. Among infants 29–34 wGA, the intensive care unit admission rate increased significantly for RSVH (from 54.5% to 64.2%, P < 0.0001) and BH (from 46.7% to 54.5%, P < 0.0001) after the policy change. The median RSVH length of stay (from 6 to 7 days, P = 0.047) and median adjusted estimated cost (from $14,077 to $16,058, P = 0.038) increased significantly after the policy change.

Conclusion

RSV and all-cause bronchiolitis hospitalizations and their severity increased among preterm infants 29–34 wGA in the 3-year period following the 2014 AAP policy change on RSV immunoprophylaxis.

Disclosures

All authors: No reported disclosures.

Respiratory Syncytial Virus Hospitalizations among U.S. Preterm Infants Compared with Term Infants Before and After the 2014 American Academy of Pediatrics Guidance on Immunoprophylaxis: 2012-2016

OBJECTIVE

The objective of this study was to compare risk for respiratory syncytial virus (RSV) hospitalizations (RSVH) for preterm infants 29 to 34 weeks gestational age (wGA) versus term infants before and after 2014 guidance changes for immunoprophylaxis (IP), using data from the 2012 to 2016 RSV seasons.

STUDY DESIGN

Using commercial and Medicaid claims databases, infants born between July 1, 2011 and June 30, 2016 were categorized as preterm or term. RSVH during the RSV season (November-March) were identified for infants aged <6 months and rate ratios (RRs) for hospitalization comparing preterm and term infants were calculated. Difference-in-difference models were fit to evaluate the changes in hospitalization risks in preterm versus term infants from 2012 to 2014 seasons to 2014 to 2016 seasons.

RESULTS

In all seasons, preterm infants had higher RSVH rates than term infants. Seasonal RRs prior to the guidance change for preterm wGA categories versus term infants ranged from 1.6 to 3.4. After the guidance change, the seasonal RRs ranged from 2.6 to 5.6. In 2014 to 2016, the risk associated with prematurity of 29 to 34 wGA versus term was significantly higher than in 2012 to 2014 (P<0.0001 for commercial and Medicaid samples).

CONCLUSION

In infants aged <6 months, the risk for RSVH for infants 29 to 34 wGA compared with term infants increased significantly after the RSV IP recommendations became more restrictive.

740. Impact of the 2014 American Academy of Pediatrics Guidance on Respiratory Syncytial Virus Hospitalization Rates for Preterm Infants &lt;29 Weeks Gestational Age at Birth: 2012–2016

Background

In 2014, the American Academy of Pediatrics stopped recommending RSV immunoprophylaxis (RSV IP) for otherwise healthy infants 29–34 weeks gestational age (wGA), while continuing to recommend RSV IP for infants born at &lt;29 wGA. The decline in RSV IP and associated increase in RSV hospitalizations (RSVH) among infants 29–34 wGA have been described previously, but potential effects of the 2014 guidance change on preterm infants &lt;29 wGA are unknown. This study compared 2012–2014 and 2014–2016 outpatient RSV IP use as well as RSVH rates relative to term infants among otherwise healthy &lt;29 wGA infants.

Methods

Infants born from July 1, 2011 to June 30, 2016 were followed from birth hospitalization discharge through their first year of life in the MarketScan Commercial (COM) and Multistate Medicaid (MED) databases. DRG and ICD codes identified term and &lt;29 wGA infants at birth. RSV IP receipt was derived from pharmacy and outpatient medical claims (inpatient RSV IP data were unavailable). RSVH were derived from inpatient medical claims. RSVH IP use and RSVH were assessed across three chronologic age (CA) groups: &lt;3 months, 3–&lt;6 months, and 6–&lt;12 months. RSVH rate ratios for 2012–2014 and 2014–2016 were calculated for &lt;29 wGA infants using healthy term infants 0–&lt;12 months of age as a reference category.

Results

Outpatient RSV IP receipt fell after 2014 for &lt;29 wGA infants across all CA categories, with the greatest decline observed among infants &lt;3 months CA (Table 1). Greater RSVH rates for &lt;29 wGA infants relative to term infants were observed after 2014 (Figures 1 and 2), with infants &lt;3 months CA experiencing the greatest percentage increases in relative RSVH risks.

Conclusion

Outpatient RSV IP decreased and RSVH relative to term infants increased among otherwise healthy &lt;29 wGA infants following the 2014 policy change, even though RSV IP continued to be recommended. The effects were greatest for infants &lt;3 months CA and those insured by Medicaid.

Funded by AstraZeneca

Disclosures

M. Goldstein, AstraZeneca/MedImmune: Consultant, Research grant and Research support. L. R. Krilov, AstraZeneca/MedImmune: Consultant, Research grant and Research support. J. Fergie, AstraZeneca/MedImmune: Consultant and Speaker’s Bureau, Research grant and Research support. L. Brannman, AstraZeneca: Employee, Salary and Stocks. C. S. Ambrose, AstraZeneca: Employee, Salary and Stocks. S. Wade, Wade Outcomes Research and Consulting contracted by Truven: Consultant, Consulting fee. A. Kong, Truven Health Analytics, an IBM Company: Employee, Salary.

735. Severity and Healthcare Costs of Respiratory Syncytial Virus Hospitalizations in US Preterm Infants Born at 29–34 Weeks Gestation: 2014–2016

Background

In 2014, the American Academy of Pediatrics recommended against the use of respiratory syncytial virus (RSV) immunoprophylaxis in infants 29–34 weeks gestational age (wGA) at birth without chronic lung disease/bronchopulmonary dysplasia (CLD/BPD) or congenital heart disease (CHD). To inform discussions of the clinical and economic value of RSV immunoprophylaxis in these infants, we compared RSV hospitalization (RSVH) severity and costs incurred by infants hospitalized from 2014–2016 at <6 months chronologic age (CA) for two groups: 29–34 wGA infants without CLD/BPD or CHD and term infants (≥37 wGA) without major health problems.

Methods

Births were identified in the MarketScan Commercial (COM) and Multistate Medicaid (MED) databases. Term and 29–34 wGA infants without CLD/BPD or CHD were selected using DRG and ICD-9/10-CM diagnosis codes. RSVH occurring from Julu 1, 2014 to June 30, 2016 while infants were <6 months CA (the period of highest RSVH incidence) were identified by ICD-9/10-CM diagnosis codes. Severity measures were length of stay (LOS) in days, intensive care unit (ICU) admissions, and healthcare costs (paid amounts on reimbursed hospital claims in 2016 US$). Comparisons between term and 29–34 wGA infants were made with t-tests and chi-squared tests.

Results

There were 1,114 RSVH in the COM data and 3,167 RSVH in the MED data during the study period. Mean LOS was longer for 29–34 wGA infants than term infants for each age category (P < 0.05) and tended to be longer for MED infants vs. COM infants (Figure 1). Thirty-eight percent of COM 29–34 wGA infants and 52% of MED 29–34 wGA infants hospitalized for RSV at <3 months CA were admitted to the ICU (Figure 2). RSVH costs for 29–34 wGA infants were greater than term RSVH costs for each age category (P < 0.05) and were greatest among 29–34 wGA infants hospitalized at <3 months CA: $41,104 for 29–34 wGA COM infants and $24,049 for 29–34 wGA MED infants (Figure 3).

Conclusion

RSVH severity and costs were significantly higher for 29–34 wGA infants without CLD/BPD or CHD relative to term infants. Infants hospitalized at <3 months CA experienced the most severe hospitalizations and incurred the highest costs.

This study was funded by AstraZeneca.

Disclosures

M. Goldstein, AstraZeneca/MedImmune: Consultant, Research grant and Research support. L. R. Krilov, AstraZeneca/MedImmune: Consultant, Research grant and Research support. J. Fergie, AstraZeneca/MedImmune: Consultant and Speaker’s Bureau, Research grant and Research support. C. S. Ambrose, AstraZeneca: Employee, Salary and Stocks. S. Wade, Wade Outcomes Research and Consulting: Employee, Salary. A. Kong, Truven Health Analytics, an IBM Company: Employee, Salary. L. Brannman, AstraZeneca: Employee, Salary and Stocks.

743. Severity and Costs of Respiratory Syncytial Virus and Bronchiolitis Hospitalization in Commercially Insured Preterm and Term Infants Before and After the 2014 American Academy of Pediatrics Guidance Change on Immunoprophylaxis

Background

Methods

Results

Conclusion

Disclosures

Influenza-Associated Acute Necrotizing Encephalopathy in Siblings

Encephalopathy is an important complication associated with influenza, most frequently observed in young children, with a wide range of severity. The most severe category of influenza-associated encephalopathy (IAE) is acute necrotizing encephalopathy (ANE), characterized by high frequency of neurologic sequelae and fatal outcomes. We report two young siblings who developed fever and seizures with altered mental status. Influenza A(H1N1)pdm09 virus infection was identified in upper respiratory tract specimens from both patients, and neuroimaging revealed bilateral inflammatory lesions, consistent with acute necrotizing encephalopathy. Neither child had received influenza vaccination. Both children progressed to critical illness and required invasive mechanical ventilation. In addition to critical care management, both patients received high-dose corticosteroids, mannitol, anticonvulsants, and antiviral treatment of influenza. The older child recovered fully and was discharged 2 weeks after illness onset, but the younger sibling developed severe brainstem edema and cerebellar tonsillar herniation, and died on illness day 11. Both children tested positive for Ran Binding Protein 2 (RANBP2) gene mutations. RANBP2 is a genetic polymorphism associated with recurrent episodes of necrotizing encephalitis with respiratory viral infections. Annual influenza vaccination is especially important for ANE survivors, with or without RANBP2 mutations, their household contacts, and caregivers. During influenza season, close monitoring of any child with a history of neurological complications associated with respiratory illness is indicated, with prompt initiation of antiviral treatment with onset of acute respiratory illness, and influenza testing performed by molecular assay.

Two Infants with Presumed Congenital Zika Syndrome, Brownsville, Texas, USA, 2016-2017

Since 2007, Zika virus has spread through the Pacific Islands and the Americas. Beginning in 2016, women in Brownsville, Texas, USA, were identified as possibly being exposed to Zika virus during pregnancy. We identified 18 pregnant women during 2016-2017 who had supportive serologic or molecular test results indicating Zika virus or flavivirus infection. Two infants were evaluated for congenital Zika syndrome after identification of prenatal microcephaly. Despite standard of care testing of mothers and neonates, comparative results were unreliable for mothers and infants, which highlights the need for clinical and epidemiologic evidence for an accurate diagnosis. A high index of suspicion for congenital Zika syndrome for at-risk populations is useful because of current limitations of testing.

Palivizumab Prophylaxis for Respiratory Syncytial Virus: Examining the Evidence Around Value

Respiratory syncytial virus (RSV) infection is the most common cause of lower respiratory tract infection and the leading cause of hospitalization among young children, incurring high annual costs among US children under the age of 5 years. Palivizumab has been found to be effective in reducing hospitalization and preventing serious lower respiratory tract infections in high-risk infants. This paper presents a systematic review of the cost-effectiveness studies of palivizumab and describes the main highlights of a round table discussion with clinical, payer, economic, research method, and other experts. The objectives of the discussion were to (1) review the current state of clinical, epidemiology, and economic data related to severe RSV disease; (2) review new cost-effectiveness estimates of RSV immunoprophylaxis in US preterm infants, including a review of the field’s areas of agreement and disagreement; and (3) identify needs for further research.

The 2014-2015 National Impact of the 2014 American Academy of Pediatrics Guidance for Respiratory Syncytial Virus Immunoprophylaxis on Preterm Infants Born in the United States

OBJECTIVE

This article aims to compare respiratory syncytial virus (RSV) immunoprophylaxis (IP) use and RSV hospitalization rates (RSVH) in preterm and full-term infants without chronic lung disease of prematurity or congenital heart disease before and after the recommendation against RSV IP use in preterm infants born at 29 to 34 weeks' gestational age (wGA).

STUDY DESIGN

Infants in commercial and Medicaid claims databases were followed from birth through first year to assess RSV IP and RSVH, as a function of infant's age and wGA. RSV IP was based on pharmacy or outpatient medical claims for palivizumab. RSVH was based on inpatient medical claims with a diagnosis of RSV.

RESULTS

Commercial and Medicaid infants 29 to 34 wGA represented 2.9 to 3.5% of all births. RSV IP use in infants 29 to 34 wGA decreased 62 to 95% (p < 0.01) in the 2014-2015 season relative to the 2013-2014 season. Compared with the 2013-2014 season, RSVH increased by 2.7-fold (p = 0.02) and 1.4-fold (p = 0.03) for infants aged <3 months and 29 to 34 wGA in the 2014-2015 season with commercial and Medicaid insurance, respectively. In the 2014-2015 season, RSVH for infants 29 to 34 wGA were two to seven times higher than full-term infants without high-risk conditions.

CONCLUSION

Following the 2014 RSV IP guidance change, RSV IP use declined and RSVH increased among infants born at 29 to 34 wGA and aged <3 months.

The 2014-2015 National Impact of the 2014 American Academy of Pediatrics Guidance for Respiratory Syncytial Virus Immunoprophylaxis on Preterm Infants Born in the United States

OBJECTIVE

This article aims to compare respiratory syncytial virus (RSV) immunoprophylaxis (IP) use and RSV hospitalization rates (RSVH) in preterm and full-term infants without chronic lung disease of prematurity or congenital heart disease before and after the recommendation against RSV IP use in preterm infants born at 29 to 34 weeks' gestational age (wGA).

STUDY DESIGN

Infants in commercial and Medicaid claims databases were followed from birth through first year to assess RSV IP and RSVH, as a function of infant's age and wGA. RSV IP was based on pharmacy or outpatient medical claims for palivizumab. RSVH was based on inpatient medical claims with a diagnosis of RSV.

RESULTS

Commercial and Medicaid infants 29 to 34 wGA represented 2.9 to 3.5% of all births. RSV IP use in infants 29 to 34 wGA decreased 62 to 95% (p < 0.01) in the 2014-2015 season relative to the 2013-2014 season. Compared with the 2013-2014 season, RSVH increased by 2.7-fold (p = 0.02) and 1.4-fold (p = 0.03) for infants aged <3 months and 29 to 34 wGA in the 2014-2015 season with commercial and Medicaid insurance, respectively. In the 2014-2015 season, RSVH for infants 29 to 34 wGA were two to seven times higher than full-term infants without high-risk conditions.

CONCLUSION

Following the 2014 RSV IP guidance change, RSV IP use declined and RSVH increased among infants born at 29 to 34 wGA and aged <3 months.

Septic Arthritis and Hemarthroses Caused by Haemophilus influenzae Serotype A in Children

Invasive disease caused by Haemophilus influenzae serotype A (Hia) is rare in children. Clinical syndromes caused by Hia include meningitis, sepsis and respiratory tract infections. Septic arthritis is rare in children with invasive Hia infection and hemarthrosis has not been described in the published literature. We report a case of septic arthritis and hemarthrosis caused by Hia infection in a 2.5 year-old-boy and review invasive Hia infection in children.

Myositis in a child with murine typhus

A 12-year-old boy presented with fever, lower extremity pain and weakness. Examination revealed paraparesis, thigh and calf tenderness. Labs showed high creatinine phosphokinase and Rickettsia typhi titers. This case illustrates endemic typhus should be considered in the differential diagnosis of myositis especially in areas with high prevalence of the disease. To our knowledge, this is the first reported case of myositis and paraparesis associated with a case of murine typhus.

Murine typhus in children, South Texas

Children from South Texas were evaluated for immunoglobulin G to Rickettsia typhi, the causative agent of murine typhus. Of 513 children, 8.6% of those 1-5 years of age, 13.3% of those 6-11 years of age, and 13.8% of those 12-17 years of age had positive results.

Lack of usefulness of an abnormal white blood cell count for predicting a concurrent serious bacterial infection in infants and young children hospitalized with respiratory syncytial virus lower respiratory tract infection

BACKGROUND

There continues to be controversy on the most appropriate way to manage infants and young children with fever and documented RSV lower respiratory tract infection (LRTI). The objective of this study was to determine the usefulness of an abnormal white blood cell (WBC) count for predicting a concurrent serious bacterial infection in patients admitted with RSV LRTI.

METHODS

The medical records were reviewed of patients discharged with RSV LRTI during the 5 RSV seasons from July 1, 2000 through June 30, 2005. Data were collected on age and gender as well as temperature, complete blood count with manual differential and bacterial cultures obtained at admission.

RESULTS

The inclusion criteria was met by 1920 patients. There were 672 febrile patients who had a complete blood count and a bacterial culture. One (5.0%) of 20 patients with a WBC <5000 had a positive culture, 23 (4.7%) of 492 patients with a WBC 5000-14,999 had a positive culture, 5 (4.8%) of 105 patients with a WBC 15,000-19,999 had a positive culture, 2 (5.7%) of 35 patients with a WBC 20,000-24,999 had a positive culture, none of 11 patients with a WBC 25,000-29,999 had a positive culture and 3 (33%) of 9 patients with a WBC >30,000 had a positive culture. Overall, cultures were positive in 34 (5.1%; 95% CI: 3.4-6.8%) of the febrile patients tested and almost all (32; 94%) showed positive urine cultures.

CONCLUSION

The probability of an abnormal WBC count <5000 and 15,000-30,000 being associated with a concurrent serious bacterial infection was very low and no different from that of a normal WBC count in febrile patients admitted with RSV LRTI.

Prevalence of methicillin-resistant Staphylococcus aureus nasal carriage in patients admitted to Driscoll Children's Hospital

A nasal swab specimen was collected for culture within 48 hours of admission and a questionnaire was completed using a convenience sample of 350 patients admitted to Driscoll Children's Hospital between February 15 and March 15, 2005. Of the 350 patients enrolled, 125 (36%) patients were colonized with Staphylococcus. aureus and 76 (61%) of the 125 S. aureus isolates were methicillin-resistant.

Economic impact of the community-acquired methicillin-resistant Staphylococcus aureus epidemic on the Driscoll Children's Health Plan

Cellulitis and abscess accounted for increasing percentages of inpatient (4.6-11.1%), outpatient (0.6-1.2%) and total (1.7-3.3%) expenses from 2001 through 2004. The per member per month expenses attributed to cellulitis and abscess increased from $0.74 in 2001 to $1.19 in 2004. The epidemic of community-acquired methicillin-resistant Staphylococcus aureus infections in children has had a significant economic impact on the Driscoll Children's Health Plan.

Epidemic of Community-Acquired Methicillin-Resistant Staphylococcus aureus Infections

BACKGROUND

Previously we reported the rapid emergence and exponential increase of community-acquired (CA) methicillin-resistant Staphylococcus aureus (MRSA) infections in South Texas children.

OBJECTIVE

To assess whether changes have occurred in the frequency, types, susceptibility, and treatment of CAMRSA infections at Driscoll Children's Hospital.

METHODS

Data from 1990 through 2001 were collected during 2 previous studies. Data from 2002 through 2003 were collected and compared with data from 1990 through 2001. All S aureus isolates were identified by a computer-assisted search of culture results, and the medical records were reviewed for all patients with MRSA infections.

RESULTS

A total of 1002 MRSA cases were identified from 1990 through 2003 of which 928 (93%) were community-acquired. The number of CAMRSA cases ranged from 0 to 9 per year from 1990 through 1999 and then increased exponentially from 36 in 2000 to 459 in 2003. The most common type of CAMRSA infection in children without (94%) and with (72%) risk factors was cellulitis and abscess. A higher percentage of children with risk factors had invasive CAMRSA infections (26% vs 3%; P<.001). From 2002 through 2003, there was a significant difference in clindamycin susceptibility between CAMRSA isolates from children without and with risk factors and nosocomial isolates (97% and 86% vs 62%; P<.005). A higher percentage of patients admitted for treatment of CAMRSA infections received an empirical intravenous antibiotic to which the organism was susceptible when comparing 2002-2003 with 1990-2000 (96% vs 15%; P<.001). During this 14-year study, all patients recovered, including those with life-threatening CAMRSA infections.

CONCLUSION

The rapid emergence of CAMRSA as a cause of noninvasive and invasive infections in children, which started occurring in the 1990s, has reached epidemic proportions.

Emergence of community-acquired methicillin-resistant Staphylococcus aureus in complicated parapneumonic effusions

A retrospective study was conducted of all patients with complicated parapneumonic effusion discharged between January 1, 1994 and March 31, 2004. We identified 54 patients. The number of patients with complicated parapneumonic effusion per 10,000 admissions increased from 4.4 in 1994 to 18.4 in 2000 (P = 0.03) and then decreased to 13.9 in 2003 (not statistically significant). Community-acquired methicillin-resistant Staphylococcus aureus accounted for none of the 36 cases from 1994 through 2001 and 4 of the 18 cases from 2002 through 2004.

Spontaneous splenic rupture in a child with murine typhus

A 10-year-old boy hospitalized with murine typhus infection had splenic rupture as a complication. Surgical intervention was not required. He recovered and was discharged a week after admission. This is the first reported case of spontaneous splenic rupture in a child with murine typhus.

Driscoll Children's Hospital respiratory syncytial virus database: risk factors, treatment and hospital course in 3308 infants and young children, 1991 to 2002

BACKGROUND

Treatment of respiratory syncytial virus (RSV) lower respiratory tract infection has historically been one of the most frequent reasons for admission to Driscoll Children's Hospital.

OBJECTIVE

The objective of this study was to examine the relationship of risk factors for a severe and complicated disease course to the treatment and hospital length of stay.

METHODS

Subjects were identified through a retrospective review of the medical records of all patients discharged with a diagnosis of RSV lower respiratory tract infection during 9 of the 11 RSV seasons between July 1, 1991 and June 30, 2002. The RSV seasons from 1991-1992 to 1994-1995 were compared with the RSV seasons from 1995-1996 to 2001-2002 with regard to treatment and hospital course.

RESULTS

There were a total of 3308 admissions. Compared with patients with no risk factors, higher percentages of patients with age <6 weeks, history of prematurity, congenital heart disease and neurologic disease were admitted to the pediatric intensive care unit (PICU) and required mechanical ventilation (P < 0.001). Also the hospital length of stay was longer for patients with each of these individual risk factors (P < 0.001). The hospital length of stay and the percentages of patients admitted to the PICU and requiring on mechanical ventilation increased as the number of risk factors increased from zero to 3 or more (P < 0.001). Of patients with 3 or more risk factors, the average hospital length of stay was 13.5 days; 67% were admitted to the PICU, and 47% required mechanical ventilation. Ribavirin use decreased in patients with each of the individual risk factors (P < 0.001) as well as in patients with one or more risk factors (P < 0.001). At the same time the PICU admission rate increased from 6.1% to 11.2% (P < 0.001).

CONCLUSIONS

Patients with three or more risk factors were at very high risk for having a severe or complicated disease course associated with admission to the PICU, placement on mechanical ventilation and a longer hospital length of stay.

Concurrent serious bacterial infections in 912 infants and children hospitalized for treatment of respiratory syncytial virus lower respiratory tract infection

The objective of this study was to report the frequency of concurrent serious bacterial infections in infants and young children hospitalized for treatment of respiratory syncytial virus (RSV) lower respiratory tract infection. Data were collected through a retrospective review of the medical records of all 912 patients with a discharge diagnosis of RSV bronchiolitis or pneumonia between July 1, 2000 and June 30, 2002. Two (0.43%) of 470 patients tested had a positive blood culture; both patients were >90 days of age. None of 101 patients tested had a positive cerebrospinal fluid culture, and 28 of 234 (12.0%) patients tested had a positive urine culture. Routine sepsis and meningitis workups are not necessary in non-toxic-appearing infants and young children with RSV lower respiratory tract infection.

Effect of an educational program on the treatment of RSV lower-respiratory-tract infection

The effectiveness and outcomes of an educational program to decrease ribavirin and antimicrobial prescribing rates and associated costs for patients with respiratory syncytial virus (RSV) lower-respiratory-tract infection are described. An educational program on the appropriate treatment for RSV infections was conducted for attending physicians and medical residents with multiple methods and forums during the 1994-95 RSV season. A retrospective chart review of 2396 patients admitted to a pediatric teaching hospital from July 1, 1991, through June 30, 1998, was conducted to measure the frequencies of ribavirin and antimicrobial prescribing in infants and young children hospitalized with RSV lower-respiratory-tract infection. The results before and after the educational program were compared. Ribavirin was prescribed for 37.9% of patients before the program, and only 9.0% received it afterward (p < 0.001). Before the program, 24.8% of patients with no risk factors received ribavirin compared with 1.6% of patients after the program (p < 0.001). However, more patients with three or more risk factors for morbidity and mortality received ribavirin before the program than afterward (97.8% versus 39.2%, respectively). A broad-spectrum i.v. antimicrobial was prescribed for 85.6% of patients before the program while 60.6% received one afterward (p < 0.001). The cost savings for ribavirin and antimicrobials during the three-year period after the program were $1,235,484 and $34,839, respectively. Hospital length of stay decreased from 5.6 to 5.1 days (p < 0.001). No readmissions occurred during the study period. A multifaceted educational intervention program may have been somewhat effective in modifying physician's prescribing habits for the treatment of RSV lower-respiratory-tract infection.

Concurrent serious bacterial infections in 2396 infants and children hospitalized with respiratory syncytial virus lower respiratory tract infections

BACKGROUND

At Driscoll Children's Hospital (Corpus Christi, Tex), we observed that most infants and children hospitalized for treatment of respiratory syncytial virus (RSV) bronchiolitis and/or pneumonia received broad-spectrum intravenous antibiotics despite having typical RSV signs and symptoms and positive RSV-rapid-antigen tests on admission. Physicians were concerned about the possibility of concurrent serious bacterial infections, especially in infants younger than 3 months and in those with infiltrates present on the chest x-ray films.

OBJECTIVE

To report the frequency of concurrent serious bacterial infections in infants and children hospitalized for treatment of RSV lower respiratory tract infections.

METHODS

The medical records of 2396 infants and children admitted to Driscoll Children's Hospital with RSV bronchiolitis and/or pneumonia during 7 RSV seasons from July 1, 1991, through June 30, 1998, were reviewed.

RESULTS

There were positive cultures obtained from initial sepsis/meningitis workups on admission in 39 infants and children (1.6%). Of these, 12 (31%) were positive blood cultures and 27 (69%) were positive urine cultures. There were no positive cerebrospinal fluid cultures. All of the positive blood cultures contained either Staphylococcus epidermidis, Staphylococcus warneri, or Bacillus species, which are common contaminants. None of the patients received a standard 10-day course of intravenous antibiotic therapy. All of the positive urine cultures were typical urinary tract pathogens. All of the patients were treated.

CONCLUSIONS

Concurrent serious bacterial infections are rare in infants and children hospitalized with RSV lower respiratory tract infections and the empiric use of broad-spectrum intravenous antibiotics is unnecessary in children with typical signs and symptoms of RSV bronchiolitis.