Impact of heptavalent pneumococcal conjugate vaccine on nasopharyngeal carriage of penicillin-resistant Streptococcus pneumoniae among day-care center attendees in central Greece

BACKGROUND: In Greece, the heptavalent pneumococcal conjugate vaccine (PCV7) became available in October 2004 and it was incorporated into the national immunization schedule in January 2006. METHODS: In February 2005, a yearly surveillance of the nasopharyngeal colonization with Streptococcus pneumoniae in children attending day-care centers in Central Greece began. RESULTS: Between February 2005 and May 2007, nasopharyngeal cultures were obtained from 1829 children aged 13-76 months (median age, 47 months). The proportion of attendees vaccinated with > or =1 doses of PCV7 increased from 13% (2005) to 33% (2006) and to 70% (2007); 98% had been immunized on toddler catch-up schedules. Among vaccinated carriers, the proportion of PCV7 serotypes decreased from 33% (2005) to 29% (2006) and to 8.6% (2007) (chi for trend, P < 0.001), the proportion of PCV7-related serotypes increased from 13% (2005) to 26% (2006) and to 28% (2007) (P = 0.16), whereas the proportion of non-PCV7 serotypes was 48% in 2005, 31% in 2006, and 55% in 2007 (P = 0.17). The proportion of PCV7 serotypes declined also among unvaccinated carriers. The carriage of serotype 19A did not increase. Among vaccinated carriers, the rate of highly penicillin-resistant isolates decreased from year 1 to year 3, respectively, 11%, 7.7%, and 0.6% (P = 0.001), whereas the proportion of penicillin-intermediate pneumococci was 13% in 2005, 23% in 2006, and 26% in 2007 (P = 0.22). CONCLUSIONS: In Central Greece, widespread PCV vaccination was followed by a significant reduction of carriage of highly penicillin-resistant pneumococci. The frequency of penicillin-intermediate isolates did not change significantly among vaccinated carriers.     

Prevalence of Pneumococcal Bacteremia in Children with Sickle Cell Disease

We performed a retrospective chart review of children with sickle cell disease hospitalized for fever at our local institution. We reviewed 456 hospitalizations in 133 patients between January 2006 and June 2012. The prevalence of true bacteremia was 4%. The mean C-reactive protein values and temperatures were nonsignificantly higher in patients with positive blood cultures. The mean time to detection was 22.5 hours in bacteremia compared to 32.6 hours in blood cultures that grew contaminants (p = .034). Only two (0.4%) cases of pneumococcal bacteremia were reported and both occurred before May 2010, which marks the introduction of 13-valent pneumococcal vaccine (PCV13). Both patients with pneumococcal bacteremia had discontinued penicillin prophylaxis after the age of 5 years. The first patient was immunized but contracted a nonvaccine serotype (23B). The second patient was partially vaccinated and acquired a vaccine-preventable serotype (23F). Both serotypes were sensitive to ceftriaxone and vancomycin; one was resistant to penicillin. This is the first study reporting the prevalence of pneumococcal bacteremia since the introduction of PCV13.     

Eradication of Invasive Pneumococcal Disease due to the Seven-valent Pneumococcal Conjugate Vaccine Serotypes in Calgary, Alberta

BACKGROUND:: The seven-valent pneumococcal conjugate vaccine (PCV7) was licensed in Canada in 2001. Routine infant vaccination programs in Alberta began in 2002. Several years after PCV7 introduction, the routine use of PCV7 in infants and high-risk children has led to near elimination of invasive pneumococcal disease (IPD) caused by vaccine serotypes. METHODS:: Prospective, population-based surveillance of all IPD cases was conducted from January 1998 to December 2010. Demographic, clinical and microbiologic data were collected. RESULTS:: There were 1462 IPD cases over 13 years. Comparing PCV7 serotype IPD incidence in the prevaccine period (1998-2001) to the late postvaccine period (2007-2010), there were declines in children 0-5 months (100%), 6-23 months (98%), 2-4 years (97%), 5-15 years (100%) as well as in adults 16-64 years (73%), 65-84 years (90%) and ≥85 years of age (100%). From 2008 to 2010, there were no cases of PCV7 serotype IPD in children under 2 years of age. There have been increases in non-PCV7 serotype IPD; notably, serotypes 5 and 19A have increased significantly in adults and 19A in children. CONCLUSIONS:: PCV7 serotype IPD has been eliminated in vaccine-eligible young children and nearly eliminated in all other age groups. Serotype 19A increased significantly at all ages before the introduction of an expanded valency pneumococcal conjugate vaccine.     

Impact of conjugate vaccine on transmission of antimicrobial-resistant Streptococcus pneumoniae among Alaskan children

BACKGROUND: The impact of heptavalent pneumococcal conjugate vaccine (PCV7) on transmission of antimicrobial-resistant Streptococcus pneumoniae is an important concern for countries considering PCV7 introduction. METHODS: Every winter from 2000 to 2004, as PCV7 was routinely introduced, we obtained nasopharyngeal swabs for pneumococcal culture, serotyping, and susceptibility testing from 150 children aged 3-59 months at each of 3 Anchorage, Alaska clinics. We assessed risk factors for pneumococcal carriage, including vaccination status and antimicrobial use. RESULTS: Between 2000 and 2004, 2250 nasopharyngeal swabs from 2061 infants and children were collected. The proportion of children receiving > or = 1 PCV7 vaccination increased from 0 to 89%, whereas overall pneumococcal carriage remained stable (38% versus 41%, respectively). Among S. pneumoniae carriers, we observed declines in carriage of PCV7 serotypes (from 54% to 10%, P < 0.01) and trimethoprim-sulfamethoxazole nonsusceptible strains (44% to 16%, P < 0.01), but not in PCN-nonsusceptible strains (36% versus 37%). Among PCN-nonsusceptible types, the proportion of serotype 19A strains increased from 10% to 32% (P = 0.0002). Recent beta-lactam use was stable throughout the period (29% overall), whereas trimethoprim-sulfamethoxazole use declined from 6% to 2% (P = 0.02). CONCLUSIONS: PCV7 vaccination in the first 5 years did not affect overall pneumococcal carriage, but was associated with a shift in serotype distribution from PCV7 types to non-PCV7 types. With persistent pressure of some antimicrobials, reductions in carriage of antimicrobial nonsusceptible PCV7 types may be offset by increases in carriage of nonsusceptible non-PCV7 types.     

Increased antimicrobial resistance among nonvaccine serotypes of Streptococcus pneumoniae in the pediatric population after the introduction of 7-valent pneumococcal vaccine in the United States

BACKGROUND: The 7-valent pneumococcal conjugate vaccine (PCV7) was introduced in the United States in February 2000. The PROTEKT US study evaluated serotype distribution, PCV7 coverage and antimicrobial susceptibility among Streptococcus pneumoniae isolates collected from children aged 0 to 14 years in 2000 through 2001 (year 1; n = 2033), 2002 through 2003 (year 3; n = 1740) and 2003 through 2004 (year 4; n = 1591). METHODS: Serotyping was performed by Neufeld Quellung reaction. Antimicrobial susceptibilities were determined centrally according to Clinical Laboratory Standards Institute methodology and interpretive breakpoints. RESULTS: The proportion of isolates covered by PCV7 (vaccine serotypes) decreased from 65.5% (year 1) to 34.7% (year 3) and to 27.0% (year 4) (P < 0.0001) with similar changes seen at regional and state levels. The most common serotypes in year 4 were nonvaccine serotypes (NVS) 19A (19.0% of all isolates), 6A (7.8%), 3 (7.6%), 15 (6.3%) and 35B (5.8%) and vaccine serotype 19F (12.7%). NVS 19A increased relative to vaccine serotype 19F among isolates expressing the erm(B) + mef(A) macrolide-resistant genotype (P < 0.0001) between year 1 (7.8% [19A] versus 86.7% [19F]) and year 4 (45.5% [19A] versus 51.7% [19F]). Antimicrobial resistance rates (year 1 versus year 4) among NVS from nonblood (respiratory tract) sources increased for penicillin (resistant: 12.7-16.1% [P = 0.0857]; intermediate susceptibility: 20.1-31.5% [P < 0.0001]), erythromycin (21.2-31.6% [P < 0.0001]), amoxicillin-clavulanate (1.4-5.8% [P < 0.0001]) and multidrug resistance (resistance to > or =2 antimicrobial classes) (24.6-31.6% [P = 0.0034]). CONCLUSIONS: The proportion of S. pneumoniae isolates from U.S. pediatric patients covered by PCV7 decreased substantially in the 4 years after vaccine introduction. However, resistance to commonly used antimicrobials, including beta-lactams and macrolides, as well as multidrug-resistant strains increased significantly among respiratory tract isolates of NVS.     

Impact of pneumococcal conjugate vaccine and of reduction of antibiotic use on nasopharyngeal carriage of nonsusceptible pneumococci in children with acute otitis media

BACKGROUND: Penicillin resistance among pneumococci has increased in the past 15 years. The implementation of widespread vaccination with the heptavalent pneumococcal conjugate vaccine (PCV7) and the reduction of inappropriate antibiotic use could help reduce antibiotic resistance. METHODS: Between September 2001 and June 2004, 89 pediatricians distributed throughout France took part in this prospective study. We obtained 1906 nasopharyngeal swabs for culture from children aged 6 to 24 months with acute otitis media (AOM). At the same time as PCV7 was introduced into the routine immunization schedule, a plan to promote judicious antibiotic use was established. We recorded the frequency of antibiotic use, as well as the dates of immunization with PCV7. RESULTS: The proportion of PCV7-vaccinated children (> or =1 dose) increased from 8.2% (year 1) to 61.4% (year 3). The proportion of children who received antibiotics within 3 months before enrollment decreased from 51.8% in year 1 to 40.9% in year 3 (P < 0.001). Overall pneumococcal carriage and carriage of PCV7 serotypes decreased during the 3-year period by 16% (P < 0.001) and 35% (P < 0.001), respectively. Rates of highly penicillin resistant strains (PRP) decreased yearly: 15.4%, 10.6%, 6.7% (P < 0.001), respectively. Risks for PRP carriage were 4.2% for immunized children who had not received antibiotics, 8.6% for those vaccinated who also had received antibiotics, 10.3% for unimmunized children who had not received antibiotics, and 16.2% for unimmunized children who had received antibiotics (P < 0.001). CONCLUSION: Implementation of PCV7, combined with a reduction in antibiotic use, in a country with a high prevalence of antibiotic-resistant pneumococci appears to have a strong impact on the carriage of penicillin nonsusceptible pneumococci in children with AOM.     

Invasive pneumococcal disease after implementation of a reduced three-dose pneumococcal conjugate vaccine program: a pediatric tertiary care center experience

Following the implementation of a government-sponsored reduced three-dose (2 + 1) heptavalent conjugate pneumococcal vaccine (PCV7) program, we report a 61.4% decrease in the number of cases of invasive pneumococcal diseases (IPD) treated at our institution. Four years after the implementation of the three-dose reduced vaccine program, only 7.4% of IPD were caused by PCV7 serotypes, and there was an increase in the proportion of IPD caused by nonPCV7 serotypes; serotype 19A represented 40.7% of the strains isolated during the last year of the study. These results, similar to those previously observed with a regular four-dose (3 + 1) PCV7 schedule, are reassuring as to the effectiveness of a reduced three-dose (2 + 1) PCV7 program. Increasing numbers of IPD caused by nonPCV7 serotypes warrant the use of a new conjugate pneumococcal vaccine that contains serotype 19A.     

Pediatric complicated pneumonia and pneumococcal serotype replacement: trends in hospitalized children pre and post introduction of routine vaccination with Pneumococcal Conjugate Vaccine (PCV7)

Recent studies have described an increase in the incidence of complicated pneumonia in children, primarily caused by Streptococcus pneumoniae. The objective of this study was to determine if the incidence of complicated pneumonias in total and due to different pneumococcal serotypes has changed following the introduction of routine immunization with heptavalent pneumococcal conjugate vaccine (PCV7). A retrospective review of patients admitted to the Stollery Children’s Hospital in Edmonton, Alberta with complicated pneumonia between July 1, 1997 and June 30, 2007 (5 years before and after the introduction of PCV7) was completed. There were 34 children in the pre- and 68 in the post-PCV7 era (14.31 and 19.91 per 10,000 discharges, respectively, p = 0.114). Patient characteristics were not significantly different, and pneumococcus was the most common organism isolated (pre: 21% (7/34); post: 26% (18/68), p = 0.515). In patients where serotype data was available, non-vaccine pneumococcal serotypes accounted for 67% (12/18) cases in the post-PVC7 era versus 14% (1/7) in the pre-PCV7 era (p = 0.031). The incidence of non-vaccine serotypes was 0.42 and 3.51 per 10,000 discharges in the pre- and post-PCV7 eras, respectively (p = 0.020). There has been a non-significant trend towards an increase in the incidence of complicated pneumonia following the introduction of PCV7. S. pneumoniae remains the predominant organism identified with non-vaccine serotypes now accounting for almost all cases. Although it is not clear if this increase is attributable to the use of PCV7, expanding pneumococcal serotype coverage has the potential to prevent complicated pneumonia.     

Nasopharyngeal carriage of Streptococcus pneumoniae in healthy Turkish children after the addition of PCV7 to the national vaccine schedule

The aim of this study was to determine serotype distribution and investigate antimicrobial resistance patterns of Streptococcus pneumoniae in healthy Turkish children in the era of community-wide pneumococcal conjugate vaccine (PCV7). The study was conducted on 1,101 healthy children less than 18 years of age. Specimens were collected with nasopharyngeal swabs between April 2011 and June 2011. Penicillin and ceftriaxone susceptibilities were determined by E-test according to the 2008 Clinical Laboratory Standards Institute, and serotypes of the isolates were determined by Quellung reaction. The nasopharyngeal pneumococcal carriage rate was 21.9 % (241/1,101). Using the meningitis criteria of minimum inhibitory concentration values, 73 % of the isolates were resistant to penicillin and 47.7 % of them were resistant to ceftriaxone. Half of all pneumococcal isolates were serotyped as 19F (15.2 %), 6A (15.2 %), 23F (10.3 %), and 6B (9.3 %) and surprisingly, no serotype 19A was isolated. Serotype coverage rates of PCV7 and non-PCV7 were 46.2 and 53.8 %, respectively. The most common penicillin- and ceftriaxone-resistant serotypes were 6A, 6B, 14, 19F, and 23F. Penicillin- and ceftriaxone-resistant isolates were more prevalent in serotypes covered by PCV7 than the non-PCV7 serotypes. Conclusion: After the community-wide PCV7 vaccination, more non-PCV7 serotypes were isolated from the carriers compared to the time before PCV7 was used especially the serotype 6A, and the antimicrobial resistance of pneumococci was significantly increased.     

Invasive Infektion durch Streptococcus pneumoniae Serotyp 8 im Säuglingsalter

Background

Despite the (now) extended spectrum of pneumococcal vaccination by PCV13 (PCV: pneumococcal conjugate vaccine), invasive pneumococcal disease continues to occur.

Case

We report on a 4-month-old female infant who was admitted to the pediatric hospital because of high fever and decreased oral intake of 2 day’s duration prior to admission.

Diagnosis

After extensive diagnostics (blood work, catheter urinalysis, cerebrospinal fluid analysis and culture, blood culture, catheter urine culture, throat swab, stool test, sonography of the brain), a diagnosis of invasive infection by Streptococcus pneumoniae serotype 8 (meningitis, sepsis) was made. The hospital course was complicated by cerebral empyema.

Conclusion

Consideration should be given to adding more serotypes to the conjugate vaccine, especially those which are known for invasive infections, as in our case, serotype 8.     

Streptococcus pneumoniae carriage among febrile children at the time of PCV-10 immunization in pediatric emergencies at Mohammed VI University Hospital Centre in Marrakesh (Morocco)

ObjectivesIn Morocco, 13-valent pneumococcal conjugated vaccine (PCV) was introduced in the childhood immunization program in October 2010 and changed to PCV-10 in July 2012. The purpose of this study was firstly to determine the prevalence of pneumococcus carriage in a population of febrile infants in Marrakesh and secondly, to investigate the risk factors for carriage and the distribution of circulating serotypes.Material and methodsThis prospective study was conducted from February to June 2017, in the pediatric emergency department of the Mother and Child Hospital of Mohammed VI University Hospital Centre (UHC) in Marrakesh. At total of 183 febrile infants, aged 2–18 months, were enrolled in this study and were swabbed for nasopharyngeal carriage. Pneumococci were cultured, identified, serotyped, and tested for penicillin susceptibility. Demographic data and risk factors for carriage were collected. The statistical analyses performed were the following: the analysis of the risk factors using logistic regression, the estimation of serotype diversity with the Simpson index, and the Chi² test to compare serotype distribution in the prevaccination (a cohort of 660 healthy children, less than 2 years old, in the Marrakesh region, in 2008–2009) and postvaccination periods.ResultsThe prevalence of Streptococcus pneumoniae carriage was 68.3%. Of the 183 infants enrolled in this study, 111 had received at least one dose of PCV-10. Colonization by vaccine serotype among febrile children was related to incomplete vaccination status. In total, vaccine serotypes accounted for 6.4% (n = 8): 19F (n = 2), 1 (n = 2) and one strain for each of the following serotypes: 14, 23F, 6B, and 9 V. Non-vaccine and nontypeable strains presented 63.2% and 23.2%, respectively, with dominance of serotypes 6A (6.4%), 15A/15F (5.6%), 20, 22F/22A, 23B, and 11A/11D with a prevalence of 3.2%. The rate of pneumococcus strains with reduced susceptibility to penicillin was 33.6%, of which 90.2% were non-vaccine serotypes and nontypeable strains. Serotype diversity increased in the postvaccination period and the effectiveness of PCV-10 against vaccine serotypes was estimated at 89.6%.ConclusionAn important change in the distribution of vaccine and non-vaccine serotypes was observed after the introduction of the PCVs. In fact, the prevalence of vaccine serotypes decreased significantly while non-vaccine serotypes emerged. These results underscore the importance of maintaining close and prolonged surveillance of serotype distribution to monitor the dynamics of nasopharyngeal pneumococcal carriage.     

Increase in invasive nonvaccine pneumococcal serotypes at two hospitals in Barcelona: was replacement disease to blame?

Aim: To describe an increase in the incidence of invasive pneumococcal disease (IPD) caused by serotypes not contained in the heptavalent pneumococcal conjugate vaccine (PCV7) in children in two hospitals in Barcelona with different vaccine uptake. Methods: Cumulative incidences of IPD, vaccine and nonvaccine serotypes (NVSTs), and main clinical presentations before (1998–2001) and after vaccine introduction (2005–2008) were compared. Results: The incidence of IPD in children aged <2 years at Hospital Germans Trias i Pujol covering a population in which PCV7 was not widely used showed a nonsignificant increase from 29.9 to 58.8 per 100 000 child‐years between both periods. Following vaccine introduction, there was a 2.5‐fold increase in IPD caused by NVSTs in children aged <5 years. Analysis of trends in the almost fully vaccinated population of Hospital de Barcelona revealed a nonsignificant reduction in IPD incidence in children aged <2 years from 63.1 to 26.0 per 100 000 child‐years. NVSTs in children aged <5 years showed a nonsignificant 1.7‐fold increase in the vaccine period at this centre. Conclusions: The paradoxical increase in invasive infections caused by NVSTs in these populations with different vaccine use suggests that these changes were not driven only by PCV7.     

Program Szczepień Ochronnych w 2017 roku − powszechne szczepienia przeciwko pneumokokom u dzieci

In Poland, starting from 2017, mandatory vaccination against pneumococcus in children will be financed. There are two conjugate vaccines: PCV10 and PCV13 for children from 2 months of age. PCV10 vaccine was purchased for mandatory vaccination programme. In 2011?2015, PCV13 vaccine in children provided more than 20% broader serotypes coverage than the PCV10 vaccine (www.koroun.edu.pl). PCV13 is the only vaccine that demonstrated protection against invasive and non-invasive diseases caused by serotype 19A, which is the most common multi-drug resistant serotype in the population (approximately 80% of the isolates of 19A are MDR). Serotype 19A was the third most common serotype after 6B and 14, responsible for invasive pneumococcal disease (IPD) in children up to 2 years of age. The vaccine PCV10 does not include antigen of serotype 19A.In Kielce, over the last 10 years of the universal immunization programme, PCV7 / PCV13 in children showed reduction in carriage of penicillin-resistant serotypes of Streptococcus pneumoniae. Indirect effect as a decrease in pneumonia in non-vaccinated elderly population has been observed.Pediatric Group of Experts on the Immunization Programme by the Ministry of Health, based on the Polish data KOROUN, recommended vaccine PCV13 for the implementation as universal immunization for children. The arguments for the recommendation take into account the broadest serotype coverage, reducing the carriage of antibiotic-resistant serotypes and the impact of PCV13 vaccine to reduce pneumonia in non-vaccinated population.Vaccination in high-risk groups, including preterm newborns, remains unchanged. For this group, PCV13 is recommended.In the assessment of the effective prevention of pneumococcal disease, serotype coverage, real-world effectiveness of vaccines and health benefits for the entire population should be taken into account.     

Résistance aux antibiotiques des pneumocoques et H. influenzae isolés de la flore rhinopharyngée d’enfants présentant une otite moyenne aiguë entre 2006 et 2010

Objectives

The choice of antibiotics (ATB) to treat acute otitis media (AOM) has to take into account the level of resistance of bacteria species implicated. The aim of this study was to evaluate in France, ATB resistance of pneumococci and H. influenzae isolated from the nasopharyngeal flora, in children with AOM, vaccinated with 7 valent pneumococcal conjugate vaccine (PCV7).

Methods

From 2006 to 2010, 66 pediatricians performed nasopharyngeal specimens of children 6 to 24 months with AOM. Demographic characteristics, history, vaccination status and symptoms were reported on a case report form transmitted to ACTIV.

Results

Of the 3501 children included (mean age 13.5 ± 5 months), over 98% were PCV7 vaccinated and 41.1% were cared in day care center. A total of 47.3% of children had received ATB within 3 months before inclusion (cephalosporins, 22.6% and amoxicillin clavulanate, 19.2%). Pneumococcus and H. influenzae carriage was respectively 57.9% and 48.2%. Pneumococcal strains with reduced susceptibility to penicillin represented 46.3% of cases (3.9% highly resistant strains and 42.4% intermediate resistant strains). Factors that increased the risk of carrying these strains were: day care center (OR: 1.5, 95% CI: [1.2, 1.9]) and two courses or more of ATB before inclusion (OR: 2.6 (95% CI: [2.0, 3.4]). For H. influenzae strains the proportion of ßlactamases+ producing strains was 17.1% and those with reduced susceptibility due to penicillin binding protein changes (BLNAR+ strains+) accounted for 7.7% of cases. Three factors increased the risk of carriage BLNAR+ ßlactamase+ producing strains: age equal or greater than 12 months (OR: 3.5, 95% CI: [1.2, 10.3]), cephalosporin use (OR: 2.5, 95% CI: [1.0, 6.1]) and two courses or more of ATB before inclusion (OR: 3.1, 95% CI: [1.2, 8.0]).

Conclusion

The data in this study (reduction of ßlactamase producing H. influenzae strains and increase of intermediate penicillin pneumococcal strains) should help to change the choice of antibiotics for AOM in children in France, by reducing the role of oral cephalosporins and secondly, by giving frontline amoxicillin ± clavulanic acid.     

Effects of routine infant vaccination with the 7-valent pneumococcal conjugate vaccine on nasopharyngeal colonization with streptococcus pneumoniae in children in Calgary, Canada

BACKGROUND: All Streptococcus pneumoniae disease is preceded by nasopharyngeal (NP) colonization. We studied the impact of 7-valent pneumococcal conjugate vaccine (PCV7) on colonization in healthy children. METHODS: Routine PCV7 vaccination began in Alberta in 2002. Six point prevalence surveys were conducted from 2003 to 2005, in 7 community health centers in Calgary where children had their routine vaccinations. A questionnaire was administered and a single NP swab was obtained for culture. Serotyping was performed on all S. pneumoniae isolates. RESULTS: There were 3398 children with complete data, 1307, 1225, and 866 in 12-month, 18-month, and 4-6 year groups, respectively. None had received PCV7 in survey 1. From survey 2 onwards, 92-98% of 12-month-olds had 3 or more doses of PCV7, and from survey 3 onwards, 95-99% of 18-month-olds had 3 or more doses. By survey 6, only 4% of 4-6 year olds had 3 or more doses. The overall S. pneumoniae colonization rate was 20%. In all age groups, including unvaccinated 4-6 year olds, there were significant declines in PCV7 serotypes, and increases in non-PCV7 serotypes. The largest increases were serotypes 6A, 15C, and 11A. Multivariate analysis found that factors including age, siblings, daycare attendance, episodes of otitis media, and antibiotic use affected S. pneumoniae colonization but only PCV7 vaccination was associated with decreased PCV7 serotype colonization and increased non-PCV7 colonization. CONCLUSIONS: Routine PCV7 vaccination has led to significant changes in the predominant S. pneumoniae serotypes found in NP colonization in both vaccinated and unvaccinated children, indicating both a direct and herd effect.     

Étude du portage rhinopharyngé de Streptococcus pneumoniae et de sa sensibilité aux antibiotiques chez les enfants en bonne santé âgés de moins de 2 ans dans la région de Marrakech (Maroc)

The healthy carrier of Streptococcus pneumoniae (S. pneumoniae) has been studied very little at the national level. With the emergence of antibiotic-resistant strains worldwide, and the emergence of new serotypes, an epidemiological survey is needed before the vaccine can be introduced in Morocco.

Objectives

This study's objective was to determine the prevalence and risk factors of pneumococcal nasopharyngeal carriage in children less than 2 years of age in the Marrakech region and to assess the antibiotic susceptibility of the isolates and the serotypes present prior to the introduction of the conjugate pneumococcal vaccine.

Patients and methods

From 2008 to 2009, 660 nasopharyngeal samples were collected on children under 2 years of age during scheduled visits to dispensaries for routine immunization in the Marrakech region.

Results

S. pneumoniae carriage was found in 45.8% of children. Of the 660 samples, 302 strains were isolated. The percentage of pneumococcal strains with reduced susceptibility to penicillin (PRSP) was 34.7%. Among these strains, 87.1% showed low-level resistance and 12.9% high-level resistance. Resistance to amoxicillin was found in 3.3% of the strains and no strains were resistant to cefotaxime. Several risk factors for pneumococcal carriage were identified, the main ones being breastfeeding less than 2 months, the presence of more than one sibling, passive smoking, and low socioeconomic level. The most frequent serotypes were 19F, 6, 14, 23, 18, and 9. The study of the vaccine serotype distribution showed that the theoretical vaccine coverage of the 7 valent vaccines was at 57% for all the isolates.

Conclusion

These data show the frequency and the risk factors on nasopharyngeal carriage, and report the status of penicillin resistance of strains carrying children less than 2 years of age in the Marrakech region. The fluctuation of circulating serotypes at the national level underscores the importance of epidemiological surveillance carried out before the introduction of the heptavalent vaccine in Morocco.     

北京上海广州深圳4家儿童医院肺炎住院患儿肺炎链球菌分离株的血清型分布

目的了解目前从中国住院治疗肺炎患儿分离到的肺炎链球菌的血清型分布，及几种蛋白多糖结合疫苗的覆盖率，评估应用蛋白多糖结合疫苗预防肺炎链球菌感染的价值。方法选择2006年2月16日至2007年2月16日在首都医科大学附属北京儿童医院、复旦大学附属儿科医院、广州市儿童医院和深圳市儿童医院呼吸科住院治疗的肺炎患儿为研究对象，采用一次性吸痰管收集全部病例的呼吸道分泌物标本分离肺炎链球菌，部分患儿进行脑脊液、血液和胸腔积液中肺炎链球菌的分离。采用荚膜肿胀实验进行血清型分析。对4家儿童医院肺炎链球菌分离率和血清型进行分析，率的比较采用χ2检验或Fisher精确概率法。结果 研究期间共纳入2 865例肺炎患儿，2 865例呼吸道吸取物标本中分离到肺炎链球菌279株，其中有2株不同血清型菌株分离自同一病例，分离阳性率为9.7％（278/2 865）。3/8例胸腔积液中分离到肺炎链球菌，其中2例同时从呼吸道分泌物分离到肺炎链球菌，取其一进行血清分型，另1株从胸腔积液中分离的肺炎链球菌复苏失败，未进行血清分型。脑脊液和血液标本中未分离到肺炎链球菌。共有279株肺炎链球菌进行了血清型分析，以19F型最常见（60.6％，169/279），其次为19A（9.7％，27/279）、23F（9.3％，26/279）和6B（5.4％，15/279），上述4种血清型占全部菌株的84.9％（237/279）。肺炎链球菌7价结合疫苗（PCV7）覆盖率为81.0％，但在北京仅为46.0％，明显低于上海（80.0%）、广州(98.4%)和深圳（94.4%）。9价、10价和11价疫苗的覆盖率与PCV7相比并没有明显增加。13价疫苗的覆盖率（92.8％）较PCV7明显升高。结论4家儿童医院肺炎住院患儿分离的肺炎链球菌以19F、19A、23F和6B型常见。PCV7覆盖率为87％     

Pneumococcal vaccination in children at risk of developing recurrent acute otitis media - a randomized study

Aim: Acute otitis media (AOM) is a common childhood disease, which often becomes recurrent (rAOM). A small reduction in AOM episodes has been noted in unselected child cohorts after vaccination with heptavalent conjugate pneumococcal vaccine (PCV7). The purpose of this study was to investigate how vaccination affects young children at risk of developing rAOM. Methods: Ninety‐six children with an AOM onset before 6 months of age, implying a high risk for rAOM, were closely monitored until the age of 2 years. Forty‐six were vaccinated with PCV7 and 50 were not. All episodes of AOM, emergency visits and ventilation tube insertions were registered. Results: A total of 363 AOM episodes were diagnosed. The incidence was reduced by 26% (p = 0.03), the number of emergency visits because of suspected AOM by 36% (p = 0.01) and the proportion of children who received ventilation tubes was halved in the vaccine group (p = 0.02). Conclusions: During the first 2 years of life, PCV7 significantly reduced AOM episodes, emergency visits and ventilation tube insertions in children with rAOM. Pneumococcal vaccine may be a future route to reduce antibiotic use and health care consumption in otitis‐prone children.     

Aetiology of neonatal conjunctivitis evaluated in a population‐based setting

Aim

Our aim was to study prospectively the aetiology of neonatal conjunctivitis in a population‐based setting.

Methods

Altogether 173 neonates with clinical conjunctivitis aged on average 20 (SD 10) days were recruited from child welfare clinics in Oulu, Finland, in 2010–2015. Conjunctival specimens were collected from 167 neonates for multiplex polymerase chain reaction to detect 16 respiratory viruses, from 163 for polymerase chain reaction to detect Chlamydia trachomatis and Neisseria gonorrhoeae and from 160 for bacterial culture studies. The cases were followed up until the age of 18 months.

Results

Viral conjunctivitis was diagnosed in 8/167 (4.8%; 95% CI 2.1–9.2%), chlamydial or gonococcal conjunctivitis in 0/163 cases (0%; 95% CI 0–2.2%) and other bacterial conjunctivitis in 58/160 (36%; 95% CI 29–44%). Rhinovirus was found at the ocular site in 4/167 (2.4%) neonates, adenovirus in 3/167 (1.8%) and bocavirus in 1/167 (0.6%). The most commonly isolated bacteria included Staphylococcus aureus (16%), Moraxella catarrhalis (9.4%) and Streptococcus pneumoniae (3.1%). None of these pathogens was associated with the 4/173 (2.3%) cases later operated on for persistent nasolacrimal duct obstruction.

Conclusion

Chlamydia trachomatis was a rare pathogen in neonatal conjunctivitis in a population‐based setting, but respiratory viruses were detected more frequently than indicated earlier.

     

Management of the febrile child without a focus of infection in the era of universal pneumococcal immunization

Should strategies of management of invasive disease in the febrile child without focus of infection (occult bacteremia) be reconsidered in communities with universal immunization of infants with the conjugate vaccines for Haemophilus influenzae type b and Streptococcus pneumoniae (PCV7)? The incidence of occult bacteremia is likely to decrease with the virtual elimination of H. influenzae type b and vaccine serotype pneumococcal invasive diseases. The number of children with fever coming to physicians' offices, however, is unlikely to change. The challenge of distinguishing the febrile child with invasive bacterial disease who requires aggressive therapy from the febrile child who has a viral infection and requires only symptomatic therapy will persist. The bacteriology of invasive disease in infants and young children in 2002 will include pneumococcal serotypes not in PCV7; serotypes in PCV7 that occur in the unimmunized, partially immunized or fully immunized child (vaccine failures); Neisseria meningitidis; Salmonella spp., group A Streptococcus, Staphylococcus aureus and gram-negative enteric bacilli. Management plans published in the 1990s suggested an aggressive diagnostic approach to the febrile child 3 to 36 months old who was toxic or had a temperature of >39 degrees C. Diagnostic tests included white blood cell counts, cultures of blood and urine and chest radiograph and lumbar puncture as indicated by clinical signs and administration of parenteral ceftriaxone. Although PCV7 was extraordinarily effective in prevention of serotype-specific invasive pneumococcal disease in clinical trials, pediatricians need to know whether the results based on 38,000 enrollees will be maintained as millions of children are immunized. In addition questions about change in serotype of pneumococci causing invasive disease (serotype switching), herd immunity and durability of protection after immunization need to be answered. Until more experience is available to answer these questions, the febrile child without focus of infection should be managed without consideration of immunization with PCV7. Evaluation of the organism (serotype) and the host (acute and convalescent sera) should be undertaken for each case of invasive pneumococcal disease in this era of universal pneumococcal immunization.