Edward O Mason

Texas Children's Hospital, Houston, Texas, United States

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Publications (212)857.59 Total impact

  • 2014 American Academy of Pediatrics National Conference and Exhibition; 10/2014
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    ABSTRACT: Background: Following routine use of the 13-valent pneumococcal conjugate vaccine (PCV13, contains PCV7 serotypes [STs] + STs 1, 3, 5, 6A, 7F , 19A), invasive pneumococcal infections (IPI) declined over 40% in 2011 compared to the average number of cases in 2007 to 2009 at 8 children's hospitals in the United States. The most common STs causing IPI in 2011 were 19A, 7F and 33F (Pediatr Infect Dis J 2013;32:203-7). We now report findings for 2012 and 2013. Methods: IPI have been prospectively identified by investigators at 8 children's hospitals in the US since 1993. Demographic and clinical data are collected on case report forms and isolates are sent to a central laboratory where serotyping and antibiotic susceptibilities are performed. Dichotomous variables were analyzed by chi-square. Results: The total number of IPI, most common STs and % of children under 60 months old for each year is shown in the table. The total number of IPI has continued to decrease each year primarily related to declines in ST 19A (P=0.003) and 7F (P=0.02) isolates. However, ST 3 isolates remained at pre-PCV13 numbers. 9 children with ST 19A isolates and 4 children with ST 3 isolates had received 2 or more doses of PCV13 prior to IPI. In 2013, 3 of 12 children had received 4 PCV13 doses prior to ST19A IPI. Only 3 ST 1, 7 ST 19F, and 0 ST 5 isolates were encountered over these 3 years. STs 33F, 22F, 35B, 10, and 15C were the most common non-PCV13 STs. In 2012 and 2013, almost 75% of isolates were non-PCV13 STs. The % of children with underlying conditions was 45-46% each year. The most common conditions were malignancies (n=41), cardiovascular (n=15), genetic (n=14), renal (n=13) and central nervous system (n=10). Non-PCV13 STs accounted for 78% (32/144) of IPI isolates from children with underlying conditions. Isolates 2011 2012 2013 Total 128 112 104 19A 34 (2)* 16 (2) 12 (5) 3 5 (1) 6 (1) 11 (2) 7F 11 3 2 6C 5 3 5 33F 8 10 10 22F 5 9 8 35B 6 4 8 10 3 9 4 15C 3 8 3 23B 2 5 6 23A 4 6 2 12F 3 5 4 % non PCV13 54 73 74 % < 60 mon. 60 63 55 *() number of children who received ≥ 2 doses of PCV13 Conclusion: IPIs among 8 children's hospital continued to decline 2 and 3 years after full implementation of PCV13. STs 19A and 7F cases declined markedly whereas ST3 cases remained unchanged compared with pre-PCV13 findings. The number of non-PCV13 ST isolates has remained steady with STs 33F and 22F being the most common non-PCV13 STs in 2011 to 2013.
    IDWeek 2014 Meeting of the Infectious Diseases Society of America; 10/2014
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    ABSTRACT: Background: After the introduction of PCV7 the incidence of pediatric pneumococcal meningitis (PM) decreased significantly. The impact of PCV13 on PM in children is unknown. We compared the serotype (ST) distribution, antibiotic susceptibility and outcomes of children with PM 3 yrs before and 3 yrs after the introduction of PCV13. Methods: We identified patients ≤18 years with PM at 8 children's hospitals in the US (1/1/2007 - 12/31/2013). Pneumococcal isolates were collected prospectively. Serotyping and antibiotic susceptibility were performed in a central laboratory. Clinical and laboratory data were collected retrospectively. Patients were divided into 3 subgroups: pre-PCV13 (2007-2009), transitional year (2010) and post-PCV13 (2011-2013). Dichotomous variables were analyzed by Χ2 test and continuous variables with parametric/non-parametric tests. Results: During the study period, 173 of 1158 (15%) children with invasive pneumococcal disease (IPD) had PM; 76 of 644 (12%) during 2007-2009 and 69 of 344 (20%) during 2011-2013 (+8%, p<0.001) (Figure). We obtained clinical data from 125 patients (72%), of those 7 pneumococcal isolates were not viable for serotyping. In 2010, 22 cases were identified. 2007-2009 2011-2013 p N=103 56 47 Age, mo median (IQR) 16.8 (5-81) 16.3 (6-84) 0.9 Underlying condition (%) 16(29) 17(36) 0.4 CSF WBC (x103/mm3), median (IQR) 1.1 (0.1-2.9) 0.9 (0.1-2.8) 0.9 PCV13 ST 26/54 (48) 12/45 (27) 0.03 ST 19A 10/54 (19) 10/45 (22) 0.7 Penicillin MIC ≥0.12g/ml 13/54 (24) 14/45 (31) 0.4 Ceftriaxone MIC ≥0.5g/ml* 9/54 (17) 9/45 (20) 0.7 Death 1 (1.8) 5 (10.6) 0.08 Intensive care 33 (59) 38(81) 0.02 Fever after admission, days 3.22.4 4.73.7 0.02 *All ST 19A and 35B ST 7F decreased by 13% (p=0.02). The most common non-PCV13 STs during 2011-2013 were 33F (n=5; increased by 11%, p=0.02), 22F and 35B (n=4 each). Other measures of severity were similar during 2007-2009 and 2011-2013. Of all survivors, 46% had neurologic sequelae and 24% had sensorineural hearing loss. Rates of sequelae were similar among PCV13 and non-PCV13 ST cases; and during 2007-2009 and 2011-2013. Conclusion: After the introduction of PCV13, the number of cases of PM per year in children has remained unchanged, but with an increasing proportion of PM among children with IPD. ST 19A continues to be the most common ST in 2011-2013. Rates of morbidity and mortality remain substantial.
    IDWeek 2014 Meeting of the Infectious Diseases Society of America; 10/2014
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    ABSTRACT: Staphylococcus aureus bacteremia without a localizing source in children is not well described. We identified patients with a positive blood culture for S. aureus from an 11-year surveillance study. Thirty-six cases of primary bacteremia were identified accounting for 5.7% of bacteremias. Most patients had comorbidities (86.1%), most commonly immunosuppression (33.3%).
    The Pediatric Infectious Disease Journal 05/2014; 33(5):e132-4. · 3.14 Impact Factor
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    ABSTRACT: The widespread use of the 7-valent pneumococcal conjugate vaccine has been associated with epidemiological changes of mucosal and invasive pneumococcal disease. No study describes the impact of 13-valent pneumococcal conjugate vaccine (PCV13) on chronic sinusitis in children. We describe changes in epidemiology of S. pneumoniae chronic sinusitis after the introduction of PCV13 at Texas Children's Hospital (TCH). We identified patients <18 years with positive sinus culture for S. pneumoniae who underwent endoscopic sinus surgery due to chronic sinusitis from August 2008 to December 2013 at TCH. Isolates were serotyped by the capsular swelling method. Demographic and clinical information was collected retrospectively. The χ2 test and Fisher's exact test were used to analyze dichotomous variables. We identified 91 cases of chronic sinusitis with positive sinus culture for S. pneumoniae. Sixty-one (67%) isolates were non-PCV13 serotypes. PCV13 cases decreased 31% in the post-PCV13 period (p=0.003). Serotype 19A decreased 27% in the post-PCV13 period (p=0.007), but accounted for all the isolates with penicillin MIC ≥ 4µg/ml and ceftriaxone MIC ≥2 µg/ml. Serotypes 19A (38%) and 15C (17%) were the most common in the pre- and post-PCV13 periods, respectively. The most common organism co-isolated was Haemophilus influenzae (52%). Isolation of Prevotella spp. increased in the post-PCV13 period (p=0.02). S. pneumoniae continues to represent an important pathogen in chronic sinusitis in children < 5 years. After the introduction of PCV13, S. pneumoniae isolation declined in children with chronic sinusitis at TCH. We also observed a substantial reduction of PCV13 serotypes, predominantly serotype 19A.
    The Pediatric Infectious Disease Journal 04/2014; · 3.14 Impact Factor
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    ABSTRACT: Background: Topical antimicrobial and antiseptic agents are commonly used in the management of minor skin and soft tissue infections (SSTI). Resistance to mupirocin has been documented in S. aureus isolates causing SSTIs. Data are limited, however, on the prevalence of retapamulin resistance or tolerance to antiseptics. We sought to determine the prevalence of decreased susceptibility to retapamulin and mupirocin as well as the potential for decreased chlorhexidine susceptibility of S. aureus isolates from SSTIs in children.Methods: Two-hundred isolates from patients with a single SSTI and 200 isolates from patients with ≥3 previous episodes from the years 2010-2012 were selected from a S. aureus surveillance study. Screening for retapamulin resistance was performed by the macrobroth dilution method; mupirocin MICs were determined by E-test. PCR was performed for the presence of the smr gene associated with elevated MIC/MBCs to chlorhexidine.Results: Among the isolates screened, 38 isolates (9.5%) exhibited retapamulin resistance of which 22(57.9%) were MRSA. Two isolates (0.5%) displayed cross-resistance to retapamulin and linezolid. Thirty-nine isolates (9.8%) were found to have mupirocin resistance. smr-positive S. aureus accounted for 14% of isolates. The proportion of smr-positive organisms increased during the study (p=0.005).Conclusions: The prevalence of in vitro resistance to topical antimicrobials among S. aureus causing SSTI in healthy children in our community is almost 10%. Retapamulin resistance was associated with cross resistance to linezolid in 0.5% of isolates. In addition, there was an increase in the proportion of smr-positive isolates. Further research including clinical correlations with these findings is warranted.
    Antimicrobial Agents and Chemotherapy 03/2014; · 4.57 Impact Factor
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    ABSTRACT: Children with probable CA-SA skin and soft (SSI) or invasive infections were randomized to routine daily hygienic measures with or without "bleach baths" twice a week (Bleach) for 3 months. Within 12 months a medically attended recurrence occurred in 84/495 (17%) of Bleach vs. 103/492 (21%) of Control enrollees (p=0.15).
    Clinical Infectious Diseases 11/2013; · 9.42 Impact Factor
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    ABSTRACT: Background: Several virulence genes encoding proteins have been suggested as potential vaccine candidates for protection against either pneumococcal carriage or invasive disease. The distribution of these genes across serotypes and genotypes has not been analyzed, following the introduction of the pneumococcal conjugate vaccines (PCV7 and 13). Our study sought virulence genes commonly found in isolates recovered from children in the post-PCV era. Methods: Fifteen pneumococcal genes were selected. Sixty clinical S. pneumoniae isolates from 2001-2012 were selected from our collection; 92% of isolates were obtained post 2007. 49 non-PCV13 and 11 PCV13 serotypes were chosen to maximize the genetic variation among strains and included internationally recognized clones and sequence types (STs) observed among several serotypes. DNA was extracted. Multilocus sequence typing (MLST) was performed. Presence of genes was detected by polymerase chain reaction using primers designed from published sequences. Results: Forty-nine non-PCV13 isolates included serotypes 7C, 8, 10, 11, 12F, 13, 15A, 15B, 15C, 16, 17, 18A, 21, 22F, 23A, 23B, 24, 31, 33A, 33F, 34, 35B, 38, and 4 nontypeable (NT) strains. Eleven PCV13 isolates included serotypes 3, 6A, 18C, 19A, 19F, and 23F. Six genes were present across all strains including the NT S. pneumoniae, while cbpA, lytA, pspA and rrgC were present in less than 25% of the isolates (Table). Genomic diversity was evident by MLST, by which 47 STs were identified. Gene target(n=15) PCR-positive (n=60) pcsB, potD, pppA,sp2108, sp0148, stkP 60 (100%) nanA, pia, plyA, psaA 56-59 (93-98%) phtA 36 (60%) cbpA, lytA 9-13 (15-22%) pspA, rrgC 4-6 (7-10%) Conclusion: This study identified 6 genes encoding potential vaccine candidates that were present in both classic and NT S. pneumoniae representing a wide variety of genotypes. Expanded studies on the prevalence of specific genetic components across a larger number of isolates and genotypes will provide knowledge necessary to select candidates that maximize coverage against pneumococcal isolates.
    IDWeek 2013 Meeting of the Infectious Diseases Society of America; 10/2013
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    ABSTRACT: Background: Recurrent infections in normal children caused by community associated S. aureus (CA-SA) occur in up to 50% of patients. Optimal methods for preventing recurrent infections are unknown. Methods: Children with probable CA-SA skin and soft (SSI) or invasive infections at Texas Children’s Hospital were randomized to routine daily hygienic measures plus "bleach baths" (5 ml household bleach per gallon of bath water) twice a week (Bleach) or routine daily hygienic measures alone (Control) for 3 mon. The nose, throat and groin were cultured for SA colonization. A research nurse blinded to treatment contacted families at 2 weeks and 3, 6, and 12 mon. to ask if the child had had a medically attended SSI (MA-SSI). The study was designed to detect a 50% reduction in first recurrent MA-SSI assuming a 14% recurrence rate, 85% rate of + SA clinical culture at enrollment and 20% loss to follow-up with 90% power. Analysis was based on intention to treat. Results: SA was isolated from the initial infection site for 890/987 children enrolled; 557/987 were colonized at ≥ 1 site at enrollment. The groin, nose and throat were colonized in 379, 215, and 167 children, respectively. Selected characteristics are shown in the table. Bleach (n=495) Control (n=492) Median Age years (range) 1.8 (.13-18) 1.9 (.26-19) Site of infection (SSI/Invasive) 466/29 457/35 Isolate MR/MS 347/104 313/121 Within 12 mon. of enrollment, a MA-SSI occurred in 84/495 (17%) of Bleach vs. 103/492 (20.9%) of Control enrollees (log-rank p=0.15). A multivariable Cox proportional hazards regression model was used to simultaneously estimate the risk of a recurrent MA-SSI by treatment and age groups. Bleach patients were about 0.79 times less likely to have a reinfection within 1 year; however, the point estimate was not significant at the 0.05 level (95% CI: 0.59, 1.06). Adjusted for treatment group, the risk of reinfection among patients ≤1.86 years was about 2.1 times> that for patients >1.86 years. The effect of age did not significantly depend on the treatment group (p=0.75). Reinfection was not different in those colonized. Conclusion: The groin was the most common site of colonization at initial infection. Younger children were more likely to have recurrent MA-SSI within 1 year of enrollment. The 20% decrease in MA-SSI recurrences with “Bleach baths” was not statistically significant.
    IDWeek 2013 Meeting of the Infectious Diseases Society of America; 10/2013
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    ABSTRACT: Background: Few studies describe age-specific reductions in the proportion of pediatric invasive pneumococcal disease (IPD) caused by serotype 19A and other 13-valent pneumococcal conjugate vaccine (PCV13) serotypes. Methods: Using ecological data, we determined age-specific proportions of IPD caused by serotype 19A and the other serotypes included in PCV13 before (2008-2009) and after (2010-2011) PCV13 introduction. IPD cases were identified from 8 children’s hospitals (US Pediatric Multicenter Pneumococcal Surveillance Group). We compared baseline rates (2008-2009) to the most recent data (2011) using Chi-square tests. Results: Among those aged 0-17 years, the proportion of IPD caused by serotype 19A in 2008-2009, 2010, and 2011 was 37%, 37%, and 28%. The proportion of IPD caused by the other 12 (non-19A) PCV13 serotypes for those same years was 66%, 62%, and 48%. However, reductions were not consistent across age group. Specifically, for those aged 0-1 year, there was a 44% (p<.01) relative reduction in the proportion of IPD caused by PCV13 serotypes, where as the percentage among those aged 2-17 was only 17% (p=.12) (p for interaction =.05). The difference in these two age groups was driven largely by the difference in reduction of the proportion of IPD caused by serotype 19A. While there was a 36% relative decrease (p<.01) in the proportion of IPD caused by serotype 19A among those aged 0-1, there was no change among those aged 2-17 (p=.87) (p for interaction =.04). For the other non-19A PCV13 serotypes, the relative percent reduction (32%, p=.04) did not depend on age group (p for interaction =.86). Only 2 children aged ≥11 had received PCV13. The proportion of children with IPD that had underlying comorbidities increased significantly with increasing age. For ages <1 year, 1-2, 3-5, and 6-17 years, respectively, 27%, 32%, 45%, and 60% of children with IPD had comorbid disease (p-trend<.001). Conclusion: Children aged 0-1 year had significant reductions in both 19A and in the other 12 (non-19A) PCV13 serotypes from 2008 through 2011. Children aged 2-17, however, had a reduction in non-19A PCV13 serotypes, but not 19A. Reasons for this could include lack of early indirect effect, virulence of 19A, and more comorbid disease and low PCV13 utilization in older children.
    IDWeek 2013 Meeting of the Infectious Diseases Society of America; 10/2013
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    ABSTRACT: Background: Weight has been implicated as a risk factor for symptomatic community-acquired methicillin resistant Staphylococcus aureus (CA-MRSA). Information from Texas Children’s Hospital (TCH) in Houston, TX was used to implement a case-control study to assess weight-for-age percentile (WFA), race and seasonal exposure as risk factors. Methods: A retrospective chart review to collect data from TCH was conducted covering the time period January 1st, 2008 to May 31st, 2011. Cases were confirmed and identified through the S. aureus surveillance study database at TCH and were matched on a 1:1 ratio to controls that were seen by the emergency department for non-infected fractures from June 1st, 2008 to May 31st, 2011. Data abstraction was performed using TCH’s electronic medical records (EMR) system (EPIC ®). Results: Of 702 CA-MRSA identified cases, ages 9 to 16.99, 564 (80.3%) had the variable ‘weight’ present in their EMR, were not duplicates and not determined to be outliers. Cases were randomly matched to a pool of available controls (n=1864) according to age and gender, yielding 539 1:1 matched pairs (95.5% case matching success) and a total study sample size, N=1078. Case median age was 13.38 years with the majority being White (66.05%) and male (59.4%). Adjusted conditional logistic regression analysis of the matched pairs identified the following risk factors to presenting with CA-MRSA infection among pediatric patients, ages 9 to 16.99 years: a) Individual weight in the highest (75th-99.9th) WFA quartile (OR=1.36; 95% confidence interval [CI]=1.06-1.74; P= 0.016), b) Infection during summer months (OR: 1.69; 95% CI=1.2-2.38; P= 0.003), c) patients of African American race/ethnicity (OR= 1.48; 95% CI=1.13-1.95; P= 0.004). Conclusion: Pediatric patients, 9 to 16.99 years of age, in the highest WFA quartile (75th-99.9th), or of African-American race had an associated increased risk of presenting with CA-MRSA infection. Furthermore, children in this population were at a higher risk of contracting CA-MRSA infection during the summer season.
    IDWeek 2013 Meeting of the Infectious Diseases Society of America; 10/2013
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    ABSTRACT: BACKGROUND:After licensure of the 7-valent pneumococcal conjugate vaccine (PCV7) in the United States in 2000, the incidence of pediatric pneumococcal meningitis decreased significantly. However, cases continue to occur. It is unknown whether meningitis due to PCV7 and non-PCV7 serotypes causes similar morbidity and mortality.METHODS:We performed a retrospective cohort study of laboratory-confirmed pneumococcal meningitis among Utah children from 1997 to 2010. We reviewed medical records and obtained clinical data during the acute illness and follow-up data on neurologic sequelae.RESULTS:Sixty-eight cases of meningitis were identified. PCV7 serotypes caused 64% of cases before and 25% of cases after licensure of PCV7 (P < .01). The age range was similar before and after PCV7 licensure (P = .5). The overall case fatality rate was 13% and was similar among cases caused by PCV7 and non-PCV7 serotypes (P = .7). Children with PCV7 serotypes were more likely to require mechanical ventilation (68% vs 34%; P < .01). Of all survivors, 63% had neurologic sequelae, and the proportion was similar after infection with PCV7 or non-PCV7 serotypes (P = .1). More than one-half (54%) of all children who developed pneumococcal meningitis in the PCV7 period were eligible for PCV7 and had not been immunized.CONCLUSIONS:Pneumococcal meningitis continues to be associated with high mortality and morbidity; death and neurologic sequelae are common with both PCV7 and non-PCV7 serotype meningitis. The substantial burden of this disease and continued cases among unimmunized children reinforce the need for more effective immunization strategies and continued surveillance in the era of PCV13.
    PEDIATRICS 08/2013; · 5.30 Impact Factor
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    ABSTRACT: CA-S. aureus (CA-MRSA in 57%) infections were reviewed in 179 infants (0-60 d) from June 2006-June 2011. CA-MSSA accounted for 16/44 (36%) in Year 1 up to 12/25 (48%) in Year 5 (P=0.08). Abscess/cellulitis infections were more likely (P=0.006) to be caused by CA-MRSA (67%) versus other manifestations of infections (46%). Among 160 isolates, 13% were clindamycin resistant and 63% were USA300.
    The Pediatric Infectious Disease Journal 08/2013; · 3.14 Impact Factor
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    ABSTRACT: There are limited data characterizing recurrent staphylococcal disease in children. We sought to define the clinical features and laboratory findings of children with recurrent community-associated (CA) S. aureus infections presenting to Texas Children's Hospital (TCH) in Houston, TX. Medical records of children with recurrent, culture-proven CA-S. aureus infections at TCH from 8/1/2001-7/29/2009 were reviewed, and antibiotic susceptibility patterns were obtained for all S. aureus isolates. 694 otherwise healthy patients presented to TCH with 2-7 episodes of CA-S. aureus infection, accounting for 1495 encounters, 823 hospitalizations, and 3337 inpatient days. In 90% of patients with ≤ 12 months separating their initial and recurrent infections, the methicillin susceptibility of the initial and recurrent isolates was the same, compared with 79% of patients with > 12 months separating their infections. The overall antibiotic susceptibility pattern did not change between isolates in 71% of otherwise healthy children compared with only 33% of children with eczema. 92% of otherwise healthy children had only recurrent SSTI; 8% had ≥ 1 non-SSTI. The location of SSTI's varied by age, with children ≤ 36 months of age being more likely to have ≥ 1 S. aureus infection located in the diaper area. Our study demonstrates that recurrent staphylococcal disease requiring emergency center or inpatient care is common, accounting for significant utilization of hospital resources. Children with recurrent staphylococcal infections are likely to have repeated infections from the same staphylococcal strain (by antibiotic susceptibility pattern), indicating that persistent colonization, frequent exposure to others who are chronically colonized, or environmental contamination is playing a role in recurrent disease. Finally, our study emphasizes the need for repeat cultures in children with recurrent disease, as 29% of healthy children and 67% of children with a predisposing risk factor (such as eczema) have a change in the antibiotic susceptibility pattern between S. aureus isolates.
    The Pediatric Infectious Disease Journal 07/2013; · 3.14 Impact Factor
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    ABSTRACT: BACKGROUND:Introduction of the heptavalent pneumococcal conjugate vaccine (PCV7) changed the epidemiology of invasive pneumococcal disease (IPD). We evaluated the changes that occurred after PCV7 introduction among Utah infants aged 1 to 90 days, too young to be fully immunized.METHODS:We identified children <18 years with culture-confirmed IPD from 1997-2010. We analyzed demographic, clinical, and serotype data for infants aged 1-90 days. The pre- and post-vaccine introduction periods spanned 1997-2000 and 2001-2010, respectively.RESULTS:Of 513 children with IPD, 36 were 1 to 90 days and accounted for 7% of IPD cases in both the pre- and post-vaccine introduction period. The pre-vaccine IPD incidence rate was 5.0 per 100 000 live births, and was unchanged in the post-vaccine introduction period. IPD caused by PCV7 serotypes decreased by 74% (from 2.2 to 0.58 per 100 000), whereas non-vaccine serotype IPD increased by 57% (from 2.8 to 4.4 per 100 000). Sixteen infants (44%) required intensive care, and 3 (8%) died. Bacteremia without focus (56%) and meningitis (44%) were the predominant syndromes in the pre- and post-vaccine introduction periods, respectively. In the post-vaccine introduction period, serotype 7F was the most common serotype among infants and was responsible for 50% of meningitis.CONCLUSIONS:The incidence of IPD in Utah infants aged 1 to 90 days caused by PCV7 serotypes decreased after PCV7 introduction, but overall incidence was unchanged. In the post-vaccine introduction period, serotype 7F predominated in this age group and was associated with meningitis.
    PEDIATRICS 06/2013; · 5.30 Impact Factor
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    ABSTRACT: BACKGROUND:: Invasive meningococcal infections can be devastating. Substantial endotoxemia releases mature and immature neutrophils. Endothelial margination of mature neutrophils may increase the immature to total neutrophil ratio. These changes have not been previously well-described in invasive meningococcal disease. METHODS:: Using 2001-2011 data from the US Multicenter Meningococcal Surveillance Study, the diagnostic sensitivity and clinical correlates of white blood cell count (WBC), absolute neutrophil count (ANC), immature neutrophil count (INC), and immature-to-total neutrophil ratio (ITR) were evaluated alone and in combination at the time of diagnosis of invasive meningococcal disease. RESULTS:: 216 patients were evaluated: meningococcemia (65), meningitis (145), and other foci (6). ANC ≤ 1000/mm or ≥ 10,000/mm was present in 137 (63%), INC ≥ 500/mm in 170 (79%), and ITR ≥0.20 in 139 (64%). One or more of these 3 criteria were met in 204/216 (94%). Results were similar for meningococcemia and meningitis subgroups. All 13 cases with mildest disease met one or more of the 3 criteria. Eight children presented with absolute neutrophil counts <1000/mm: three of them died and a fourth required partial amputation in all four limbs. CONCLUSIONS:: Invasive meningococcal disease is characterized by striking abnormalities in absolute neutrophil count, immature neutrophil count, and/or immature-to-total neutrophil ratio. Neutropenia was associated with a poor prognosis. Notably, without immature neutrophil counts, 37% of cases would have been missed. Automated methods not measuring immature WBCs should be avoided when assessing febrile children. Serious infection should be considered when counts meet any of the three criteria.
    The Pediatric Infectious Disease Journal 06/2013; · 3.14 Impact Factor
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    ABSTRACT: BACKGROUND:: The 13-valent pneumococcal conjugate vaccine (PCV13) was introduced for routine administration to infants and children in 2010 in the United States. We have monitored clinical and microbiologic features of invasive pneumococcal infections among children before and after PCV13 use. METHODS:: Infants and children cared for at 8 children hospitals in the United States with culture-proven invasive infections caused by S. pneumoniae were identified in an ongoing prospective surveillance study. Demographic and clinical data were recorded on a standard case report form. Serotype and antimicrobial susceptibilities of isolates were determined. RESULTS:: Since routine PCV13 immunization in 2010, invasive pneumococcal infections decreased 42% overall and 53% for children <24 months of age in 2011 compared with the average number of cases for 2007 to 2009. PCV13 serotype isolates decreased 57% during these same time periods; 19A, 7F and 3 decreased by 58%, 54% and 68%, respectively. The number of infections caused by serotypes 1 and 6C also decreased in 2011. The most common non-PCV13 serotypes encountered in 2010 and 2011 combined were 33F, 22F, 12, 15B, 15C, 23A and 11. Bacteremia, pneumonia and mastoiditis cases decreased more than meningitis cases. CONCLUSIONS:: After the introduction of PCV13, invasive pneumococcal infections decreased among 8 children hospitals compared with the 3 years before PCV13 use. Slight increases in some non-PCV13 serotype isolates were noted in 2011. Continued surveillance is necessary to determine the effectiveness of PCV13 including herd protection as well as any emerging invasive serotypes.
    The Pediatric Infectious Disease Journal 03/2013; 32(3):203-207. · 3.14 Impact Factor
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    ABSTRACT: Among 594 Streptococcus pneumoniae serotype 19A invasive pneumococcal disease (IPD) isolates from 1993-2011, we identified 85 sequence types (ST) by multilocus sequence typing (MLST). CC320 was associated with multidrug resistance and reduced susceptibility to penicillin and ceftriaxone and still predominated among declining serotype 19A IPD isolates following PCV13 introduction.
    Journal of clinical microbiology 02/2013; · 4.23 Impact Factor
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    ABSTRACT: Background: Congenital heart disease (CHD) is the most common risk factor for infective endocarditis (IE) in children. Staphylococcus aureus is among the most common organisms to causes IE yet there is little data describing the spectrum and risk factors for invasive S. aureus disease in children with CHD. We examined the clinical and molecular epidemiology of S. aureus infections in children with CHD. Methods: Patients with a history of CHD and culture proven S. aureus infection were identified from a surveillance study of S. aureus infections from 2001-2011. Selected clinical and laboratory data from medical records were collected on case report forms. Isolates were characterized by pulsed field gel electrophoresis and antimicrobial susceptibility data was compared. Dichotomous variables were compared with X2 and continuous variables with t-test wth two-tailed p values < 0.05 considered significant. Results: 249 S. aureus infections developed in 228 patients with CHD. The most common cardiac diagnosis was ventricular septal defects (47/228, 20.6%). 92/228 (40.4%) patients were under 1-year-old. Methicillin-resistance was seen in 134/249 (53.8%) isolates and was more often associated with the USA300 pulsotype (78.5% vs 26.5% of MSSA isolates, p < 0.0001). The most common infectious diagnosis was skin-and-soft-tissue-infection (39.4%), followed by bacteremia (17.6%) and surgical site infection (15.3%). Bacteremia was associated with IE in 10/44 (22.7%) episodes. IE was more often associated with older age (7.4 y vs. 0.4 y, p=0.02), thrombocytopenia (107,000 vs 251,000 /mm3, p=0.01) and a higher admission CRP (28.4 mg/dl vs 4.4 mg/dl, p=0.0002) compared to uncomplicated bacteremia. 182 infections followed CV surgery with 50% of invasive infections occurring within the first 30 days. Conclusion: S. aureus is an important cause of morbidity among children with CHD, particularly those under 1 year-old. IE was common with S. aureus bacteremia in this population and thrombocytopenia and extreme elevation of CRP may serve as useful predictive markers. In surgical patients, invasive staphylococcal disease was most common in the first month following corrective repair of CHD. Further research into prevention of these infections is warranted.
    IDWeek 2012 Meeting of the Infectious Diseases Society of America; 10/2012
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    ABSTRACT: Background: Isolation of pneumococcal serotype 19A from invasive pneumococcal disease (IPD) in children dramatically increased after the 7-valent pneumococcal conjugate vaccine (PCV7) was introduced in 2000. With the inclusion of serotype 19A in the 13-valent PCV, licensed in 2010, a decline in serotype 19A isolates is expected. We analyzed serotype 19A invasive isolates from 1993-2011 by multilocus sequence type (MLST) and antimicrobial susceptibility (AS). Methods: Invasive isolates prospectively collected from 1993-2011 and corresponding patient data were retrieved from a study database. Penicillin (PEN) and ceftriaxone (CEF) MICs by microbroth, and AS by Kirby-Bauer test for erythromycin (E), clindamycin (C) and trimethoprim-sulfamethoxazole (TS) were obtained (CLSI guidelines). MLST was performed as advised (www.mlst.net). Statistical analysis was performed using the Fisher’s exact test. Results: We identified 84 sequence types (ST) among 586 isolates. Serotype 19A isolates were isolated at a rate of <20 per year until 2005. In 2007, a peak was reached with 87 isolates after which the yearly numbers declined. Two main clusters were identified by eBURST analysis: ST199+22 single locus variants (SLV) and 320+7 SLV. ST199+ SLV encompassed 224 isolates and predominated until 2006, when ST320+SLV became predominant. Overall, ST320+ SLV included 231 (39.4%) isolates. In 2011, a total of 26 serotype 19A isolates were collected: 2 (8%) 199+SLV, 19 (73%) 320+SLV and 5 of other STs. Disease presentations included meningitis (n=56), bacteremia (n=196), pneumonia (n=212), bone and joint (n=24), mastoiditis (n=73), cellulitis/abscess (n=17), other (n=8). Compared to all other STs, ST320+SLV were associated with Caucasian ethnicity (58% vs 34%, p<0.001), mastoiditis (21% vs 7%, p<0.001), non-susceptibility to E (99% vs 29%, p<0.001), C (95% vs 51%, p<0.001) and TS (99% vs 58%, p<0.001). ST320+SLV median MIC was 2 ug/ml (range 0.25-8 ug/ml) for PEN and 1 ug/ml (range 0.125-8 ug/ml) for CEF. Conclusion: Serotype 19A IPD has declined among our 8 children’s hospitals post PCV13.ST320+SLV, associated with multidrug resistance and reduced susceptibility to PEN and CEF, predominates while ST199 has been almost completely eliminated.
    IDWeek 2012 Meeting of the Infectious Diseases Society of America; 10/2012

Publication Stats

6k Citations
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Institutions

  • 1988–2013
    • Texas Children's Hospital
      Houston, Texas, United States
  • 2005–2012
    • University of Utah
      • • Department of Pediatrics
      • • School of Medicine
      Salt Lake City, UT, United States
    • University of Pittsburgh
      • School of Medicine
      Pittsburgh, PA, United States
  • 1981–2012
    • Baylor College of Medicine
      • • Department of Pediatrics
      • • Section of Infectious Diseases
      Houston, TX, United States
  • 1996–2005
    • University of Texas Health Science Center at Houston
      • Department of Pathology and Laboratory Medicine
      Houston, Texas, United States
  • 2000–2004
    • Wake Forest School of Medicine
      • Department of Pediatrics
      Winston-Salem, NC, United States
  • 2003
    • University of Southern California
      • Department of Pediatrics
      Los Angeles, CA, United States
  • 2001–2003
    • Childrens Hospital of Pittsburgh
      • Division of Pediatric Infectious Diseases
      Pittsburgh, Pennsylvania, United States
  • 2002
    • Children's Memorial Hospital
      Chicago, Illinois, United States
  • 2001–2002
    • University of Arkansas at Little Rock
      Little Rock, Arkansas, United States
  • 1999
    • University of Illinois at Chicago
      • Pediatric Division of Infectious Diseases (Chicago)
      Chicago, IL, United States
    • Arkansas Children's Hospital
      Little Rock, Arkansas, United States
    • University of California, San Diego
      San Diego, California, United States
  • 1998
    • University of California, Los Angeles
      • Division of Infectious Diseases
      Los Angeles, CA, United States
  • 1991
    • The Ohio State University
      Columbus, Ohio, United States
  • 1988–1989
    • Washington University in St. Louis
      • Department of Pediatrics
      Saint Louis, MO, United States