Kent Korgenski

Impact of the pneumococcal conjugate vaccine on pneumococcal parapneumonic empyema.

Background: Pediatric pneumococcal parapneumonic empyema (PPE) has become increasingly common. In the last decade, Utah has had one of the highest rates of PPE in the United States, 14/100,000 children, attributed primarily to Streptococcus pneumoniae serotype 1. Our objective was to describe the temporal trends in PPE in Utah before and after the availability of the 7-valent pneumococcal conjugate vaccine (PCV-7). Methods: The Intermountain Health Care (IHC) data warehouse was queried for all cases of empyema in children younger than 18 years, defined as International Classification of Diseases, 9th revision, Clinical Modification code 510.9, for the study period March 1996–June 2005. We also retrieved and serotyped all blood and pleural fluid isolates of S. pneumoniae from children younger than 18 years with a diagnosis of PPE at Primary Childrens Medical Center (PCMC) between March 1996 and June 2005. The pre-PCV-7 period (PRE) included 57 months (March 1996–December 2000) and the post-PCV-7 period (POST) included 54 months (January 2001–June 2005). Results: We identified 776 cases of pediatric empyema in the IHC system, and 478 (62%) were managed at PCMC. In the years 1996–2000, we managed a mean of 38 cases of empyema per year compared with 71.5 cases per year between 2001 and 2004 (P = 0.006). At PCMC, there were 295 cases of invasive pneumococcal disease (IPD), and 74 (25%) were PPE. During the PRE period, PPE represented 24 of 137 (17.5%) cases of IPD compared with 50 of 158 (32%) in the POST period (P = 0.008). One-half of the children with PPE required intensive care and 4 died. During the PRE and POST periods, PPE was most often caused by serotype 1 (46 and 34%, respectively), but in the POST period serogroups 3 (20%), and 19A (14%) were also prevalent. PPE in PCV-7-immunized children was caused exclusively by nonvaccine serotypes. Conclusions: PPE in the post-PCV-7 era is more common, representing one-third of the IPD in children in UT. PPE is associated with significant morbidity and mortality. Serotype 1 remains the most common cause of PPE, but serotypes 3 and 19A are emerging.

Temporal trends of invasive disease due to Streptococcus pneumoniae among children in the intermountain west : Emergence of nonvaccine serogroups

BACKGROUND Use of the heptavalent pneumococcal conjugate vaccine (PCV-7 [Prevnar]) has been associated with decreased a incidence of invasive pneumococcal disease (IPD) among children in the United States. METHODS Cases of IPD in children < 18 years of age insured by or receiving health care from Intermountain Health Care during 1996-2003 were identified. Isolates of S. pneumoniae from children with IPD treated at Primary Childrens Medical Center (PCMC; Salt Lake City, UT) during 1997-2003 were serogrouped. Temporal trends of IPD, serogroup distribution of pneumococci, and antibiotic resistance among pneumococci were analyzed. RESULTS A total of 1535 cases of IPD were identified. The rate of IPD decreased 27% after the introduction of PCV7. Among children with IPD who were cared for at PCMC, disease in 73% was caused by PCV7 serogroups in 1997-2000, compared with 50% in 2001-2003 (P < .001), and the percentage of isolates resistant to penicillin decreased from 34% in 1997-2000 to 22% in 2001-2003 (P = .04). The percentage of IPD cases that were empyema increased from 16% to 30% (P = .015), and the percentage of severe cases of IPD increased from 57% to 71% (P = .026). Children with IPD due to non-PCV7 serogroups were older, were more likely to have parapneumonic empyema, and had longer hospital stays. CONCLUSIONS The incidence of IPD in the IMW decreased by 27% after the introduction of the PCV7 vaccine. During the postvaccine period (2001-2003), there were significant decreases in the proportion of cases of IPD caused by PCV7 and antibiotic-resistant serogroups. These benefits were accompanied by a significant increase in the proportion of IPD cases due to non-PCV7 serogroups, with increases in the incidence of empyema and severe IPD.

Seasonal Invasive Pneumococcal Disease in Children: Role of Preceding Respiratory Viral Infection

OBJECTIVE. Our objective was to demonstrate correlations between invasive pneumococcal disease in children and circulating respiratory viruses. METHODS. This retrospective study included 6 winter respiratory viral seasons (2001–2007) in Intermountain Healthcare, an integrated health system in the Intermountain West, including Primary Childrens Medical Center in Salt Lake City, Utah. Children <18 years of age who were hospitalized with either invasive pneumococcal disease in any Intermountain Healthcare facility or culture-confirmed invasive pneumococcal disease at Primary Childrens Medical Center were included. We analyzed the correlation between invasive pneumococcal disease and circulating respiratory viruses. RESULTS. A total of 435 children with invasive pneumococcal disease and 203 with culture-confirmed invasive pneumococcal disease were hospitalized in an Intermountain Healthcare facility or Primary Childrens Medical Center during the study period. During the same period, 6963 children with respiratory syncytial virus, 1860 with influenza virus, 1459 with parainfluenza virus, and 818 with adenoviruses were evaluated at Primary Childrens Medical Center. A total of 253 children with human metapneumovirus were identified during the last 5 months of the study. There were correlations between invasive pneumococcal disease and seasonal respiratory syncytial virus, influenza virus, and human metapneumovirus activity. The correlation with invasive pneumococcal disease was strong up to 4 weeks after respiratory syncytial virus activity. For influenza virus and human metapneumovirus, the correlations were strong at 2 weeks after activity of these viruses. Pneumonia was the most common clinical disease associated with culture-confirmed invasive pneumococcal disease, mostly attributable to serotypes 1, 19A, 3, and 7F. CONCLUSIONS. In the post–pneumococcal conjugate vaccine era, seasonal increases in respiratory syncytial virus, influenza virus, and human metapneumovirus infections in children were associated with increased pediatric admissions with invasive pneumococcal disease, especially pneumonia caused by nonvaccine serotypes.

Pneumococcal Necrotizing Pneumonia in Utah: Does Serotype Matter?

BACKGROUND Streptococcus pneumoniae is the most common cause of bacterial pneumonia in children. Despite the use of the 7-valent pneumococcal conjugate vaccine, the incidence of pneumococcal necrotizing pneumonia (PNP) has been increasing. Our objectives were to describe temporal trends in PNP and to evaluate pneumococcal serotypes associated with PNP in Utah. METHODS We performed a retrospective review of all children <18 years of age who were cared for at a tertiary care childrens hospital and who had blood, lung tissue, broncheoalveolar lavage, or pleural fluid cultures that grew S. pneumoniae, as well as radiographic evidence of pneumonia, from January 1997 through March 2006. All S. pneumoniae isolates were typed. RESULTS A total of 124 children with pneumococcal pneumonia were identified, and 33 (27%) of these children had radiographic evidence of PNP. During the period 1997-2000, 5 (13%) of 39 cases of culture-confirmed pneumococcal pneumonia were associated with PNP. In contrast, during the period 2001-2006, 28 (33%) of 85 pneumococcal pneumonia cases were complicated by PNP (odds ratio, 3.34; 95% confidence interval, 1.11-12.03). Non-7-valent pneumococcal conjugate vaccine serotypes comprised 49% of the isolates during 1997-2000 and 88% of isolates during 2001-2006 (odds ratio, 7.89; 95% confidence interval, 2.91-21.90). Pneumonia due to serotype 3 was most often associated with PNP. Eleven (79%) of 14 cases of serotype 3-associated pneumonia were associated with PNP. When compared with all other serotypes, serotype 3 was strongly associated with necrosis (odds ratio, 14.67; 95% confidence interval, 3.39-86.25). CONCLUSIONS PNP is a serious and increasingly common complication of S. pneumoniae pneumonia in Utah. Infection with serotype 3 is associated with an increased risk of developing PNP. The increase in the incidence of infection due to nonvaccine serotypes reported worldwide and the changing epidemiology of invasive pneumococcal disease should be considered when developing vaccine strategies.

Molecular Epidemiology of Pediatric Pneumococcal Empyema from 2001 to 2007 in Utah

ABSTRACT Utah had a high rate of pediatric pneumococcal empyema (PPE) prior to licensure of the pneumococcal conjugate vaccine (PCV-7) in 2000. The majority (62%) of PPE cases was due to nonvaccine serotypes, primarily Streptococcus pneumoniae serotype 1, multilocus sequence type (MLST) 227. PPE in Utah children has increased over the last decade. It is unclear whether the increase was due to serotype replacement or switch. In this study, we describe the incidence and molecular epidemiology of PPE by MLST in Utah children after the licensure of PCV-7. Empyema rates increased from 8.5/100,000 children in the state of Utah in 2001 to 12.5/100,000 children in 2007 (P = 0.006). Ninety-eight percent was due to nonvaccine serotypes (P < 0.001 when compared to the pre-PCV-7 period). PPE was primarily due to serotypes 1, 3, 19A, and 7F, with MLST demonstrating sequence types (ST) that were commonly present in the United States prior to licensure of PCV-7. Serotype switch was not documented. Replacement disease with common ST of serotypes 1,3, 7F, and 19A rather than serotype switch was responsible for the increase in PPE in Utah children.

Costs and Infant Outcomes After Implementation of a Care Process Model for Febrile Infants

OBJECTIVE: Febrile infants in the first 90 days may have life-threatening serious bacterial infection (SBI). Well-appearing febrile infants with SBI cannot be distinguished from those without by examination alone. Variation in care resulting in both undertreatment and overtreatment is common. METHODS: We developed and implemented an evidence-based care process model (EB-CPM) for the management of well-appearing febrile infants in the Intermountain Healthcare System. We report an observational study describing changes in (1) care delivery, (2) outcomes of febrile infants, and (3) costs before and after implementation of the EB-CPM in a children’s hospital and in regional medical centers. RESULTS: From 2004 through 2009, 8044 infants had 8431 febrile episodes, resulting in medical evaluation. After implementation of the EB-CPM in 2008, infants in all facilities were more likely to receive evidence-based care including appropriate diagnostic testing, determination of risk for SBI, antibiotic selection, decreased antibiotic duration, and shorter hospital stays (P < .001 for all). In addition, more infants had a definitive diagnosis of urinary tract infection or viral illness (P < .001 for both). Infant outcomes improved with more admitted infants positive for SBI (P = .011), and infants at low risk for SBI were more often managed without antibiotics (P < .001). Although hospital admissions were shortened by 27%, there were no cases of missed SBI. Health Care costs were also reduced, with the mean cost per admitted infant decreasing from

Respiratory Syncytial Virus–Associated Mortality in Hospitalized Infants and Young Children

7178 in 2007 to

Gordonia Species: Emerging Pathogens in Pediatric Patients That Are Identified by 16S Ribosomal RNA Gene Sequencing

5979 in 2009 (−17%, P < .001). CONCLUSIONS: The EB-CPM increased evidence-based care in all facilities. Infant outcomes improved and costs were reduced, substantially improving value.

Association of 2009 Pandemic Influenza A (H1N1) Infection and Increased Hospitalization With Parapneumonic Empyema in Children in Utah

BACKGROUND AND OBJECTIVE: Respiratory syncytial virus (RSV) is a common cause of pediatric hospitalization, but the mortality rate and estimated annual deaths are based on decades-old data. Our objective was to describe contemporary RSV-associated mortality in hospitalized infants and children aged <2 years. METHODS: We queried the Healthcare Cost and Utilization Project Kids’ Inpatient Database (KID) for 2000, 2003, 2006, and 2009 and the Pediatric Health Information System (PHIS) administrative data from 2000 to 2011 for hospitalizations with International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis codes for RSV infection and mortality. RESULTS: The KID data sets identified 607 937 RSV-associated admissions and 550 deaths (9.0 deaths/10 000 admissions). The PHIS data set identified 264 721 RSV-associated admissions and 671 deaths (25.4 deaths/10 000 admissions) (P < .001 compared with the KID data set). The 2009 KID data set estimated 42.0 annual deaths (3.0 deaths/10 000 admissions) for those with a primary diagnosis of RSV. The PHIS data set identified 259 deaths with a primary diagnosis of RSV, with mortality rates peaking at 14.0/10 000 admissions in 2002 and 2003 and decreasing to 4.0/10 000 patients by 2011 (odds ratio: 0.27 [95% confidence interval: 0.14–0.52]). The majority of deaths in both the KID and PHIS data sets occurred in infants with complex chronic conditions and in those with other acute conditions such as sepsis that could have contributed to their deaths. CONCLUSIONS: Deaths associated with RSV are uncommon in the 21st century. Children with complex chronic conditions account for the majority of deaths, and the relative contribution of RSV infection to their deaths is unclear.

Tetanus, diphtheria, acellular pertussis vaccine during pregnancy: pregnancy and infant health outcomes.

Gordonia species are emerging pathogens that are often misidentified as Rhodococcus or Nocardia species but are reliably distinguished by 16S ribosomal RNA gene sequencing. We present a case series of 6 episodes of catheter-associated infection caused by Gordonia species in 5 patients seen at a tertiary care pediatric hospital and describe the management and outcomes of this infection in adults and children.