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.

2328. Human Respiratory Syncytial Virus Subgroups among Hospitalized Infants in the United States, 2015–2016

Background

Respiratory syncytial virus (RSV) is a major cause of severe acute respiratory illnesses (ARI) in young children. Circulation of RSV subgroups A and B can vary by season and geographic location, and may have implications for disease susceptibility, outcomes, and prevention measures. We investigated RSV subgroup distribution among samples collected in the New Vaccine Surveillance Network.

Methods

Prospective active surveillance for hospitalized ARI was conducted from November 1, 2015 to June 30, 2016 among children < 12 months of age at seven pediatric hospital sites. Mid-turbinate nasal and throat flocked swabs (combined when both available) and/or tracheal aspirates were collected and tested for RSV at each site using real-time reverse transcription polymerase chain reaction (rRT–PCR) assays; RSV A/B subgroup results were available from four sites that did their own subgroup testing (Cincinnati, Kansas City, Houston, and Oakland). At three sites (Rochester, Nashville, Seattle), approximately 50 RSV-positive specimens were sampled based on the monthly distribution for each site and 1:1 distribution by gender, and then assayed for subgroup at CDC. Patient information was obtained from medical records; chi-square tests were used to compare the distribution of A and B subgroups by site.

Results

Of 704 RSV-positive hospitalized infants, subgroup data from 586 were analyzed; 340 (58%) were RSV A and 246 (42%) were RSV B. The median age for both RSV A and RSV B patients was 2 months. Subgroup distribution varied by geographic location, with the overall proportion of RSV A ranging from 18–83% across sites (P < 0.01). Peak RSV A and B detections by month varied by site, occurring from November–February (figure).

Conclusion

During the 2015–2016 season, RSV A and B subgroups co-circulated among hospitalized infants enrolled at seven US sites. The predominance of RSV subgroup varied by geographic location. Continued surveillance and additional subgroup testing over multiple seasons should improve understanding of the epidemiologic significance of RSV infections by subgroup.

Disclosures

All authors: No reported disclosures.

751. Acute Respiratory Illness Hospitalizations Among Young Children: Multi-Center Viral Surveillance Network, United States, 2015–2016

Background

Viral infections are a significant cause of severe acute respiratory illnesses (ARI) in young children. Understanding the current epidemiology of these viruses is important for informing treatment and prevention measures. We describe the New Vaccine Surveillance Network (NVSN) and report preliminary results from 2015 to 2016.

Methods

Prospective active surveillance for hospitalized ARI was conducted from November 1, 2015 to June 30, 2016 among children <5 years of age at seven pediatric hospital sites (figure) using a broad case definition based on admission diagnoses. Parent interviews and medical chart reviews were performed, and mid-turbinate nasal and throat flocked swabs and/or tracheal aspirates were tested for adenovirus, human metapneumovirus (HMPV), influenza, parainfluenza viruses (PIV) 1–3, respiratory syncytial virus (RSV), and rhinovirus/enterovirus using molecular diagnostic assays at each site. Asymptomatic controls <5 years of age were also enrolled.

Results

Among 2,974 hospitalized children with ARI whose specimens were tested for viruses, 2,228 (75%) were <2 years old, with 745 (25%) 0–2 months, and 309 (10%) 3–5 months old. The majority were male (58%; n = 1,732) and 63% (n = 1,093) had no documented comorbid conditions. The median length of stay was 2 days; 1,683 (57%) received supplemental oxygen, 435 (15%) were admitted to intensive care, 95 (3%) required mechanical ventilation, and 1 (<1%) died. Viruses were detected in 2,242 (75%) children with ARI, with >1 virus detected in 234 (8%). RSV was detected in 1,039 (35%) children with ARI, HMPV in 245 (8%), influenza in 104 (4%), and PIV-1, PIV-2, and PIV-3 in 49 (2%), 2 (<1%), and 78 (3%), respectively. Rhinovirus/enterovirus was detected in 849 (29%) and adenovirus in 118 (4%) children with ARI, but were also detected in 18% (n = 227) and 5% (n = 60), respectively, of the 1,243 controls tested; the other viruses were more rarely detected in controls.

Conclusion

During the 2015–2016 season, viral detections were common in young children hospitalized for ARI at seven US sites. NVSN combines clinical data with current molecular laboratory techniques to describe respiratory virus epidemiology in cases of hospitalized pediatric ARI in order to inform current and future prevention, treatment, and healthcare utilization measures.

Disclosures

N. Halasa, Sanofi Pasteur: Investigator, Research support. GSK: Consultant, Consulting fee. Moderna: Consultant, Consulting fee. J. Englund, Gilead: Consultant and Investigator, Consulting fee and Research support. Novavax: Investigator, Research support. GlaxoSmithKline: Investigator, Research support. Alios: Investigator, Research support. MedImmune: Investigator, Research support. J. V. Williams, Quidel: Board Member, Consulting fee. GlaxoSmithKline: Consultant, Consulting fee.

721. Clinical Respiratory Syndromes and Association with Influenza Clinical Diagnostic Testing and Antiviral Treatment among Children Hospitalized with Acute Respiratory Illness, 2015–2016

Background

We investigated clinical influenza testing and treatment in children hospitalized with acute respiratory illness (ARI) who had distinct respiratory syndromes.

Methods

Children <18 years old with ARI were enrolled at seven hospitals in the New Vaccine Surveillance Network (NVSN) between November 1, 2015–June 30, 2016. ICD10 admission diagnosis codes were grouped to define syndromes of bronchiolitis, asthma, pneumonia, and croup. At clinician discretion, influenza testing with a rapid influenza diagnostic test or molecular assay was performed on respiratory samples. As part of the study, each site performed influenza testing using molecular assays on mid-turbinate nasal and throat swabs from all enrolled children. Analysis was restricted to influenza season; children who received antivirals before hospitalization were excluded.

Results

Among 2,134 children with available ICD10 codes, on preliminary analysis 1,119 (52%) had influenza testing ordered by a clinician: 111 (10%) were positive, and 57 (51%) of 111 received antiviral treatment. Of the 2,134, 858 (40%) had one of the four mutually exclusive syndromes (table). Hospital clinical testing per clinician discretion was influenza positive in 16 of the 858 children (percent positivity per syndrome ranged from <1% to 38%; table). Research study testing of children not undergoing clinical influenza testing identified 11 additional positives. Antiviral treatment was highest for pneumonia patients.

Conclusion

Understanding testing and treatment practices by clinical syndrome may help to identify missed opportunities for influenza diagnosis and treatment.

Table:

Disclosures

J. Englund, Gilead: Consultant and Investigator, Consulting fee and Research support. Novavax: Investigator, Research support. GlaxoSmithKline: Investigator, Research support. Alios: Investigator, Research support. MedImmune: Investigator, Research support. N. B. Halasa, sanofi pasteur: Investigator, Research support. GSK: Consultant, Consulting fee. Moderna: Consultant, Consulting fee.

Factors influencing HPV vaccine delivery by healthcare professionals at public health posts in São Paulo, Brazil

OBJECTIVE

To assess the association between Brazilian healthcare providers' characteristics and their knowledge, perceptions, and practices regarding the HPV vaccine.

METHODS

An observational cross-sectional study was conducted at five public health posts in São Paulo between July 28 and August 8, 2014. Healthcare professionals directly involved in patient care were asked to complete a written survey. Factors associated with routine verification of HPV vaccination status were evaluated using Poisson regression.

RESULTS

Among 200 participants included, 74 (38.5%) reported never and 70 (36.5%) reported always asking about HPV immunization status. Doctors were significantly less likely to report always asking than were community health agents (5/39 [12.8%] vs 32/60 [53.3%]; adjusted prevalence ratio [aPR] 0.25 [95% confidence interval (CI) 0.07-0.91]). Knowledge about the correct dosing schedule was associated with always rather than never verifying vaccination status (aPR 2.46 [95% CI 1.06-5.70]).

CONCLUSION

Knowledge and attitude played secondary roles in influencing HPV vaccine verification. Community health agents were crucial for vaccine promotion; continued education and support of this group is essential for the sustained success of HPV immunization efforts in Brazil.

Paving pathways: Brazil's implementation of a national human papillomavirus immunization campaign

In 2014, Brazil introduced an HPV immunization program for girls 9-13 years of age as part of the Unified Health System's (SUS) National Immunization Program. The first doses were administered in March 2014; the second ones, in September 2014. In less than 3 months more than 3 million girls received the first dose of quadrivalent HPV vaccine, surpassing the target rate of 80%. This paper examines three elements that may influence the program's long-term success in Brazil: sustaining effective outreach, managing a large technology-transfer collaboration, and developing an electronic immunization registry, with a focus on the State of São Paulo. If these three factors are managed, the Government of Brazil is primed to serve as a model of success for other countries interested in implementing a national HPV vaccination program to decrease HPV-related morbidity and mortality.