Pneumococcal Pneumonia Requiring Hospitalization in US Children in the 13-Valent Pneumococcal Conjugate Vaccine Era.

BACKGROUND.: The impact of PCV13 on a number of clinical aspects of pneumococcal pneumonia (PP) in children has not been reported. We compared the serotype distribution, antibiotic susceptibility, and outcomes of children with PP 4 years before and 4 years after the introduction of PCV13. METHODS.: We identified patients ≤18 years with PP at 8 children's hospitals in the United States (2006-2014). Pneumococcal isolates were collected prospectively. Serotyping and antibiotic susceptibility were performed in a central laboratory. Clinical and laboratory data were collected retrospectively. Annual pneumococcal pneumonia hospitalization rates per 100 000 admissions with 95% confidence intervals were calculated. Dichotomous variables were analyzed by χ2 test and continuous variables with Mann-Whitney U test. RESULTS.: A total of 377 patients with PP requiring hospitalization were identified. Hospitalization rates of PP decreased from 53.6 to 23.3 per 100000 admissions post PCV13 (P < .0001). Complicated PP rates also decreased (P < .0001). Need for intensive care, mechanical ventilation, and invasive procedure remained unchanged after the introduction of PCV13. Comorbidities were more common among children with uncomplicated than complicated pneumonia (52.2% vs. 22.5%, P < .001). Overall, PCV13 serotypes 19A, 3, 7F, and 1 caused 80% of PP. Hospitalization rates of PCV13 serotype pneumonia decreased from 47.2 to 15.7 per 100000 admissions post PCV13. In 2014, the most common serotypes were 3, 19A and 35B. CONCLUSIONS.: PP requiring hospitalization significantly decreased in children after PCV13 introduction. Complicated PP rates decreased steadily in 2011-2014. PCV13 serotypes 19A and 3 were still responsible for half of the cases of PP in 2011-2014.

Emergence of Multidrug-Resistant Pneumococcal Serotype 35B among Children in the United States.

Streptococcus pneumoniae serotype 35B is a nonvaccine serotype associated with high rates of penicillin nonsusceptibility. An increase in the proportion of multidrug-resistant (MDR) 35B isolates has recently been reported. The genetic events contributing to the emergence of MDR serotype 35B are unknown. The sequence type (ST) composition of 78 serotype 35B isolates obtained from pediatric patients with invasive pneumococcal disease from 1994 to 2014 and 48 isolates from pediatric patients with otitis media (noninvasive) from 2011 to 2014 was characterized by multilocus sequence typing (MLST). The most common STs were ST558 (69.2%), ST156 (10.3%), and ST452 (3.8%). Two major clonal complexes (CC), CC558 and CC156, were identified by eBURST analysis. Overall, 91% (71/78) of isolates were penicillin nonsusceptible and 16.7% (13/78) were MDR. Among all invasive serotype 35B isolates, MDR isolates increased significantly, from 2.9% (1/35) to 27.9% (12/43) (P = 0.004), after the 13-valent pneumococcal conjugate vaccine (PCV13) was introduced. All CC156 isolates were identified after the introduction of PCV13 (0/35 [0%] before versus 9/43 [20.9%] after; P = 0.003) and were MDR. All CC156 isolates had similar antimicrobial susceptibility patterns; in contrast, high variability in antimicrobial susceptibility was observed among CC558 isolates. The distributions of CC558 and CC156 among invasive and noninvasive isolates were not different. The increased prevalence of MDR serotype 35B after the introduction of PCV13 was directly associated with the emergence of ST156. Genotyping suggests that capsular switching has occurred between MDR vaccine serotypes belonging to ST156 (e.g., 9V, 14, and 19A) and serotype 35B.

Invasive pneumococcal infections in children following transplantation in the pneumococcal conjugate vaccine era.

BACKGROUND: Pediatric recipients of hematopoietic stem cell and solid organ transplants are at increased risk of invasive pneumococcal infections (IPI). Data on IPI in this population are scarce. To our knowledge, this is the first study describing the epidemiology of IPI among pediatric transplant recipients in the pneumococcal conjugate vaccine (PCV) era. METHODS: We identified transplant recipients with IPI at 8 children's hospitals in the U.S. from our surveillance database (2000-2014). Pneumococcal isolates were collected prospectively. Serotyping and antibiotic susceptibility were performed in a central laboratory. Categorical variables were analyzed by Fisher's exact test and continuous variables with nonparametric tests. Indirect cohort study design was used to calculate vaccine effectiveness. RESULTS: We identified 65 episodes of IPI in transplant recipients. Recurrent IPI was observed in 10% of transplant recipients. The IPI crude incidence rate in solid organ transplant recipients was higher than in the general population. Most IPI episodes occurred >6 months after transplantation. Bacteremia and pneumonia were the most common presentations. Meningitis was unusual. No case fatalities were observed. Serotype 19A was the most common serotype (n=10), followed by 6C (n=7). In 2010-2014, 37% of IPI was caused by PCV13 serotypes. Four cases of vaccine breakthrough were identified. Most isolates were susceptible to penicillin and ceftriaxone. Pneumococcal conjugate and polysaccharide immunization rates were low. CONCLUSION: Pediatric transplant recipients remain at increased risk of IPI in the vaccine era. Most cases presented as a late post-transplant infection. The interval between transplantation and IPI may allow adequate time for pneumococcal immunization.

Impact of the 13-Valent Pneumococcal Conjugate Vaccine on Pneumococcal Meningitis in US Children.

BACKGROUND: The impact of 13-valent pneumococcal conjugate vaccine (PCV13) on pneumococcal meningitis (PM) in US children is unknown. We compared the serotype distribution, antibiotic susceptibility, hospital course, and outcomes of children with PM 3 years before and 3 years after the introduction of PCV13. METHODS: We identified patients ≤ 18 years of age with PM at 8 children's hospitals in the United States. Pneumococcal isolates were collected prospectively. Serotyping and antibiotic susceptibility were performed in a central laboratory. Clinical data were abstracted from medical records. Patients were divided into 3 subgroups: pre-PCV13 (2007-2009), transitional year (2010), and post-PCV13 (2011-2013). Categorical variables were analyzed by the χ(2) test and continuous variables by the Mann--Whitney U test. RESULTS: During the study period, 173 of 1207 episodes (14%) of invasive pneumococcal disease were identified as PM; 76 of 645 (12%) were during 2007-2009 and 69 of 394 (18%) during 2011-2013 (50% increase; P = .03). The proportion of PCV13 serotype cases decreased from 54% in 2007-2009 to 27% in 2011-2013 (P = .001). Non-PCV13 serotype cases represented 73% of the isolates in 2011-2013. Isolates with ceftriaxone minimum inhibitory concentration ≥ 1 µg/mL decreased (13% to 3%) from 2007-2009 to 2011-2013 (P = .03). No significant differences were identified for hospital course or outcome, with the exception that a greater proportion of patients had subdural empyema and hemiparesis in 2011-2013. CONCLUSIONS: After the introduction of PCV13, the number of cases of PM in children remained unchanged compared with 2007-2009, although the proportion of PCV13 serotypes decreased significantly. Serotype 19A continued to be the most common serotype in 2011-2013. Antibiotic resistance decreased significantly. Morbidity and case-fatality rate due to PM remain substantial.

Multicenter surveillance of Streptococcus pneumoniae isolates from middle ear and mastoid cultures in the 13-valent pneumococcal conjugate vaccine era.

BACKGROUND: Streptococcus pneumoniae is a common cause of otitis media (OM) in children; mastoiditis remains an important complication of OM. Limited data are available on the impact of the 13-valent pneumococcal conjugate vaccine (PCV13) on pneumococcal otitis. METHODS: Investigators from 8 children's hospitals in the United States prospectively collected pneumococcal isolates from middle ear or mastoid cultures from children from 2011 to 2013. Serotype and antibiotic susceptibilities were determined and PCV13 doses for children documented. RESULTS: Over the 3-year period, the proportion of isolates included in PCV13 (plus a related serotype) decreased significantly (P = .0006) among the middle ear/mastoid isolates (2011, 50% [74/149]; 2012, 40.5% [47/116]; 2013, 29% [34/118]). The number of serotype 19A isolates in 2013 (n = 12, 10.2% of total) decreased 76% compared with the number of 19A isolates in 2011 (n = 50, 33.6% of total). Of the children from whom serotype 19A was isolated (n = 93), 55% had previously received <3 doses of PCV13. The most common non-PCV13 serotypes for the combined years were 35B (n = 37), 21 (n = 20), 23B (n = 20), 15B (n = 18), 11 (n = 17), 23A (n = 14), 15A (n = 14), and 15C (n = 14). The proportion of isolates with a penicillin minimal inhibitory concentration >2 µg/mL decreased significantly over the 3 years (2011, 22% [35/154]; 2012, 20% [24/118]; 2013, 10% [12/120]; P < .02). CONCLUSIONS: The number of pneumococcal isolates and the percentage of isolates with high-level penicillin resistance from cultures taken from children with OM or mastoiditis for clinical indications have decreased following PCV13 use, largely related to decreases in serotype 19A isolates.

Changes in Streptococcus pneumoniae serotype 19A invasive infections in children from 1993 to 2011.

Among 594 Streptococcus pneumoniae serotype 19A invasive pneumococcal disease (IPD) isolates collected from 1993 to 2011, we identified 85 sequence types by multilocus sequence typing. 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.

Decrease in Pediatric Invasive Pneumococcal Disease During the COVID-19 Pandemic.

Measures to limit SARS-CoV-2 transmission in 2020 reduced other viral infections. Among 7 US children's hospitals, invasive pneumococcal disease cumulative incidence decreased by 46% in 2020 vs 2017-2019. Limited droplet transmission of pneumococci and preceding viral pathogens may be responsible.

Increase in prevalence of Streptococcus pneumoniae serotype 6C at Eight Children's Hospitals in the United States from 1993 to 2009.

Streptococcus pneumoniae serotype 6C, which was described in 2007, causes invasive disease in adults and children. We investigated the prevalence of 6C among pediatric isolates obtained from eight children's hospitals in the United States. S. pneumoniae isolates were identified from a prospective multicenter study (1993 to 2009). Fifty-seven serotype 6C isolates were identified by multiplex PCR and/or Quellung reaction. Five were isolated before 2000, and the prevalence increased over time (P < 0.000001). The median patient age was 2.1 years (range, 0.2 to 22.5 years). Clinical presentations included bacteremia (n = 24), meningitis (n = 7), pneumonia (n = 4), abscess/wound (n = 3), mastoiditis (n = 2), cellulitis (n = 2), peritonitis (n = 1), septic arthritis (n = 1), otitis media (n = 10), and sinusitis (n = 3). By broth microdilution, 43/44 invasive serotype 6C isolates were susceptible to penicillin (median MIC, 0.015 µg/ml; range, 0.008 to 2 µg/ml); all were susceptible to ceftriaxone (median MIC, 0.015 µg/ml; range, 0.008 to 1 µg/ml). By disk diffusion, 16/44 invasive isolates (36%) were nonsusceptible to erythromycin, 19 isolates (43%) were nonsusceptible to trimethoprim-sulfamethoxazole (TMP-SMX), and all isolates were clindamycin susceptible. Multilocus sequence typing (MLST) revealed 24 sequence types (STs); 9 were new to the MLST database. The two main clonal clusters (CCs) were ST473 and single-locus variants (SLVs) (n = 13) and ST1292 and SLVs (n = 23). ST1292 and SLVs had decreased antibiotic susceptibility. Serotype 6C causes disease in children in the United States. Emerging CC1292 expressed TMP-SMX resistance and decreased susceptibility to penicillin and ceftriaxone. Continued surveillance is needed to monitor changes in serotype prevalence and possible emergence of antibiotic resistance in pediatric pneumococcal disease.

Invasive Pneumococcal Disease in Children's Hospitals: 2014-2017.

BACKGROUND: The 13-valent pneumococcal conjugate vaccine (PCV13) was licensed in the United States in 2010. We describe invasive pneumococcal disease (IPD) in children at 8 children's hospitals in the US from 2014 to 2017. METHODS: Children with IPD occurring from 2014 to 2017 were identified from a prospective study. Demographic and clinical data, including results of any immune evaluation along with the number and dates of previous pneumococcal conjugate vaccines administered, were recorded on case report forms. Isolate serotypes were determined in a central laboratory. Pneumococcal conjugate vaccine doses were counted if IPD occurred ≥2 weeks after a dose. RESULTS: PCV13 serotypes accounted for 23.9% (115 out of 482) of IPD isolates from 2014 to 2017. Serotypes 3, 19A, and 19F accounted for 91% of PCV13 serotypes. The most common non-PCV13 serotypes were 35B, 23B, 33F, and 22F. An underlying condition was significantly (P < .0001) more common in children with IPD due to non-PCV13 serotypes (200 out of 367, 54.5%) than for children with PCV13 serotypes (27 out of 115, 23.5%). An immune evaluation was undertaken in 28 children who received ≥2 PCV13 doses before IPD caused by a PCV13 serotype. Only 1 was found to have an immunodeficiency. CONCLUSIONS: PCV13 serotypes (especially serotypes 3, 19A, and 19F) continue to account for nearly a quarter of IPD in US children 4 to 7 years after PCV13 was introduced. Underlying conditions are more common in children with non-PCV13 serotype IPD. Immune evaluations in otherwise healthy children with PCV13 serotype IPD despite receiving ≥2 PCV13 doses did not identify an immunodeficiency.

Serious neurologic sequelae in cases of meningitis arising from infection by conjugate vaccine-related and nonvaccine-related serogroups of Streptococcus pneumoniae.

BACKGROUND: Introduction of the heptavalent conjugate vaccine for Streptococcus pneumoniae (PCV7) has led to a dramatic decline in meningitis by PCV7 serotypes, raising the possibility of similar trends by PCV7-related serogroups through cross-protection. A present concern, however, is of serotype replacement by pneumococci not related to PCV7 serogroups. If this occurs, there are currently few data to predict whether clinical outcomes will change substantially. METHODS: To address these questions, we analyzed medical records of 86 cases of pneumococcal meningitis treated at Nationwide Children's Hospital (1993-2004). Adverse neurologic sequelae and death were compared between cases with cerebrospinal fluid isolates characterized as vaccine-related serogroups-serotypes belonging to PCV7 or related to PCV7 serogroups, and those designated nonvaccine serogroups-serotypes neither belonging to PCV7 nor related to PCV7 serogroups. Serotype 19A, because of recent reports of increased incidence, was subanalyzed separately. RESULTS: Thirty-six of 86 (42%) subjects had serious complications, including 6 who died. All 6 deaths occurred in patients with vaccine-related serogroups. Deafness was the most common complication, occurring in 26 (32.5%) survivors. There was no difference in the frequency of total complications between PCV7-related and non-PCV7 groups: 5 of 12 (42%) for non-PCV7 serogroups versus 31 of 74 (42%) for PCV-related serogroups (OR: 1.0; 95% CI: 0.2-4.0). Serious outcomes occurred in 3 of 4 cases due to serogroup 19A. Non-PCV7 serogroups increased slightly at the end of the study period. CONCLUSIONS: In children with pneumococcal meningitis, infections with non-PCV7 serogroups seem less likely to result in death. Among survivors, there is preliminary evidence of parity in neurologic sequelae between PCV7 and non-PCV7 serogroups.

Pneumococcal colonization among tracheostomy tube dependent children.

Streptococcus pneumoniae colonization is a precursor to pneumococcal disease. Although children with a tracheostomy have an increased risk of pneumococcal pneumonia, the pneumococci colonizing their lower airways remain largely uncharacterized. We sought to compare lower respiratory tract isolates colonizing tracheostomy patients and a convenience sample of isolates from individuals intubated for acute conditions. We collected pneumococcal isolates from the lower respiratory tract of 27 patients with a tracheostomy and 42 patients intubated for acute conditions. We compared the penicillin susceptibility, rates of co-colonization, genetic background, and serotype of isolates colonizing these patient populations. Isolates from both groups showed high genetic diversity. Forty multi-locus sequence types and 20 serotypes were identified. There was no significant difference in serotype distribution, co-colonization rates, vaccine coverage, or non-susceptibility to penicillin among pneumococcal isolates from the two groups. Colonization of the lower airways with non-vaccine serotypes 15B/C, 23B and 35B was noted for the first time in patients with tracheostomies and supports recently observed increases in nasopharyngeal colonization and disease due to these serotypes.

Invasive Pneumococcal Disease in Infants Aged 0-60 Days in the United States in the 13-Valent Pneumococcal Conjugate Vaccine Era.

We identified 53 infants aged 0-60 days with invasive pneumococcal disease (IPD) at 8 children's hospitals in the United States (2005-2015). After the introduction of 13-valent pneumococcal conjugate vaccine (PCV13), IPD caused by PCV13 serotypes decreased ~30% providing some evidence of indirect protection. However, approximately 60% of IPD was still caused by PCV13 serotypes.

Recurrent systemic pneumococcal disease in children.

BACKGROUND: Recurrent systemic pneumococcal infection usually occurs in immunocompromised patients and patients with underlying conditions. METHODS: Between 1993 and 2006, investigators at 8 pediatric hospitals prospectively identified cases of invasive pneumococcal disease (IPD) and retrospectively documented demographics and clinical information. Antibiotic susceptibility was determined for penicillin and ceftriaxone by microbroth dilution. Isolates were serotyped and molecular relatedness determined using pulse field gel electrophoresis (PFGE). RESULTS: Four thousand sixty-seven children were diagnosed with IPD over 12.3 years. One hundred and 8 episodes of recurrent disease were seen in 90 children (2.6%); 75 experienced 2 infections, 12 experienced 3 infections and 3 experienced 4 infections. Fourteen of the 15 children with >2 episodes of infection had underlying conditions. The mean duration between 1st and 2nd infection was 22.9 weeks for children with no known underlying condition and 43.0 weeks for children with an underlying condition (P = 0.001). Seventy episodes of IPD among the 90 patients were caused by a different serotype or a different genotype as demonstrated by the PFGE. Sixteen children had intervals <30 days between infections; 7 were caused by different strains. CONCLUSIONS: Approximately 80% of the children with recurrent invasive pneumococcal disease had underlying conditions. Seven of 16 children with recurrent infection <30 days apart were caused by acquisition of a new strain. Relapse of infection requires documentation that the pneumococcal isolates are not only the same serotype but also have the same PFGE patterns.

Pneumococcal endocarditis in children.

Endocarditis due to Streptococcus pneumoniae is unusual in children, accounting for 3%-7% of all cases of childhood endocarditis. The US Pediatric Multicenter Pneumococcal Surveillance Group has prospectively identified patients with invasive disease at 8 children's hospitals. During the period of 1 September 1993 through 28 February 2003, a total of 11 children with pneumococcal endocarditis were seen. Seven (64%) were 3-36 months old; 8 (73%) were boys. Ten (91%) had preexisting structural heart disease; 5 had undergone previous heart surgery. Concomitant sites of infection were noted in 6 patients (55%), including 3 patients with meningitis. One patient (9%) died during hospitalization, and 5 others (45%) experienced serious complications. Only 2 patients remained hospitalized for their entire course of parenteral antibiotic therapy. Eight of 10 pneumococcal isolates tested were vaccine or vaccine-related serotypes included in the currently licensed 7-valent conjugated pneumococcal vaccine. Pneumococcal endocarditis in children is unusual but often has serious complications.

Macrolide resistance among middle ear isolates of Streptococcus pneumoniae observed at eight United States pediatric centers: prevalence of M and MLSB phenotypes.

BACKGROUND: Increasing macrolide resistance among middle ear isolates complicates treatment of otitis media in children. When macrolide resistance is mediated via an efflux pump (M phenotype), the MICs of erythromycin, clarithromycin and azithromycin are usually below 32 microg/ml, and the pneumococcus remains susceptible to clindamycin. The association of prior specific macrolide therapy with the isolation of a macrolide resistant strain has not been reported. OBJECTIVES: To determine the mechanism of macrolide resistance in Streptococcus pneumoniae recovered from the middle ears of children with otitis media and their association, if any, with ethnicity, age, serogroup/serotype and prior antibiotic therapy. METHODS: Middle ear isolates collected by members of the United States Pediatric Multicenter Pneumococcal Surveillance Group during a 6-year period from September 1994 through August 2000 were studied. Antibiotic susceptibility to penicillin and ceftriaxone was determined by microbroth dilution. Disc diffusion susceptibility to erythromycin and clindamycin was performed to categorize macrolide resistance mechanisms. The medical record was reviewed to determine demographics and history of previous antibiotic therapy. Isolates were serogrouped or serotyped by the capsular swelling method. RESULTS: Of the 1088 isolates available for testing, 51% were nonsusceptible to penicillin and 37% were nonsusceptible to erythromycin. Erythromycin resistance increased form 15% in 1994 through 1995 to 56% in 1999 through 2000. Seventy-five percent of macrolide-resistant strains were M phenotype. Macrolide resistance was less likely in isolates recovered from African-Americans and more likely in isolates obtained from children <3 years of age and from isolates obtained at time of tympanostomy tube placement. Neither erythromycin, nor clarithromycin nor azithromycin prescribed in the 30 days before infection was more likely than another to be associated with increased macrolide resistance. However, any macrolide alone or in combination with another antimicrobial taken before infection was associated with increased macrolide resistance among the S. pneumoniae organisms isolated from the middle ear. CONCLUSIONS: Macrolide resistance among middle ear isolates of S. pneumoniae increased during the 6-year study. The proportion of M phenotype remained constant at 75%, meaning that these isolates remain susceptible to clindamycin. Continued surveillance to document potential changes is essential.

Invasive pneumococcal infections in children with asplenia.

BACKGROUND: Asplenia is associated with an increased risk of infections caused by Streptococcus pneumoniae. Overwhelming infection can be fulminate and lead to a fatal outcome. OBJECTIVE: To review the epidemiology and clinical course of invasive S. pneumoniae infections in children with asplenia before the release of the conjugate pneumococcal vaccine. METHODS: Children with S. pneumoniae infections from eight children's hospitals in the US were identified prospectively from September, 1993, to August, 1999. Further demographic, medical and microbiologic information was gathered retrospectively from the charts of patients with asplenia. RESULTS: Twenty-two asplenic patients with 26 episodes of invasive S. pneumoniae were identified. This represents 1% of the 2,581 episodes of invasive S. pneumoniae infections identified in our study. Twelve had congenital asplenia (CA), and 10 had undergone surgical splenectomy. Nine of the patients with CA had associated complex congenital heart disease. The median age at first infection was 12.5 months for CA patients as compared with 69 months in children with surgical splenectomy (P < 0.001). Seventy-five percent of those eligible had received the polysaccharide pneumococcal vaccine. The most common serotypes isolated were 6B (8), 23F (7), 18C (2) and 19A (2). Antimicrobial prophylaxis had been prescribed for 82% of the study cohort. Clinical presentations of the 26 episodes included fever (22), shock (7), petechiae or purpura (7), disseminated intravascular coagulation (5) and respiratory distress (5). Clinical illness included bacteremia alone (12), meningitis alone (8), bacteremia with otitis media-sinusitis (3), bacteremia with pneumonia (2) and meningitis with osteomyelitis (1). Five of the 6 patients who died had meningitis. Three of the survivors (19%) had significant morbidity, and all of them had meningitis. Two patients had 2 episodes each, and 1 patient had 3 episodes. All but 1 of the multiple episodes was with a different serotype. Forty-six percent of isolates were nonsusceptible to penicillin, and 19% were nonsusceptible to ceftriaxone. There was no association between antimicrobial resistance and mortality. CONCLUSIONS: Invasive pneumococcal disease in patients with asplenia has a high mortality, especially in those with meningitis. Even though the new conjugate vaccine might increase protection, 19% of patients had disease caused by serotypes not included in the current heptavalent vaccine. Clinicians should continue to be aggressive in evaluating asplenic patients with unexplained fevers.

Six year multicenter surveillance of invasive pneumococcal infections in children.

OBJECTIVE: Monitor clinical and microbiologic features including antimicrobial susceptibility of invasive pneumococcal infections among children. DESIGN: A 6-year (September, 1993, through August, 1999) prospective surveillance study of all invasive pneumococcal infections in children. PATIENTS: Infants and children cared for at eight children's hospitals in the United States with culture-proved invasive pneumococcal infection. RESULTS: During the 6-year period 2581 episodes of invasive pneumococcal infection occurred in 2498 children. Underlying conditions were present in 29% of the children. Of children without an underlying condition, 15% of the total infections occurred in those 25 to 60 months old. As the ages of the children advanced the proportion of cases classified as bacteremia declined, whereas the proportion classified as pneumonia increased. Also, as the ages of the children increased the proportion of isolates in serotypes/serogroups 1, 3 and 23 increased. whereas the proportion for serotype 14 diminished. During the 6 years of the study, there was a significant increase in the percentage of isolates intermediate or resistant to penicillin (P < 0.000001) or intermediate to ceftriaxone (P < 0.002). By the sixth year of the study, 37 and 11% of the isolates were nonsusceptible to penicillin or ceftriaxone, respectively. Antibiotic use in the 30 days before diagnosis of systemic pneumococcal infection occurred in 30 to 35% of the children for each of the 6 years. The overall case-fatality rate for children with systemic pneumococcal infection was 1.56%. Mortality was greatest in children >60 months old and in those with underlying conditions; mortality was not related to antibiotic susceptibility. CONCLUSIONS: The percentage of pneumococcal isolates recovered from children with systemic infection which were intermediate for penicillin or ceftriaxone or resistant to penicillin increased steadily during the 6-year period. There was also a trend toward increasing rates of resistance to ceftriaxone. The age and serogroup/serotype distributions of our patients support the recommendations to consider administration of the seven valent pneumococcal conjugate vaccine for all children 24 to 59 months old, with special consideration for selected groups.

Acute myopericarditis associated with cat scratch disease in an adolescent.

Cat scratch disease is generally characterized by a self-limited chronic regional lymphadenopathy, but numerous other clinical manifestations involving a variety of organ systems have been reported. Cardiac involvement is unusual and when reported, it has been associated with culture-negative endocarditis in adults. We present the case of an adolescent male with typical cat scratch disease and associated myopericarditis.

Early trends for invasive pneumococcal infections in children after the introduction of the 13-valent pneumococcal conjugate vaccine.

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.