Impact of the pneumococcal conjugate vaccine on serotype distribution and antimicrobial resistance of invasive Streptococcus pneumoniae isolates in Dallas, TX, children from 1999 through 2005

BACKGROUND: Because the heptavalent pneumococcal conjugate vaccine has reduced vaccine-type invasive pneumococcal disease (IPD) in children, a greater proportion of IPD is now caused by nonvaccine (NVT) serotypes. We analyzed the serotypes, antimicrobial resistance profiles and genetic relatedness of Streptococcus pneumoniae responsible for IPD at Children's Medical Center of Dallas. METHODS: S. pneumoniae isolates were collected from January 1, 1999 through December 31, 2005. Incidence of IPD was calculated using inpatient and emergency center admissions to Children's Medical Center of Dallas as the denominator. Isolates were serotyped, and their penicillin and cefotaxime susceptibility determined. The 19A isolates were further characterized by pulsed-field gel electrophoresis, multilocus sequence typing and determination of penicillin-binding proteins and mef and erm genes. RESULTS: The incidence of IPD decreased from 93.6 cases/100,000 patients in 1999 to a nadir of 41 cases/100,000 patients in 2003 (P < 0.001). The number of IPD cases caused by serotype 19A increased, accounting for 40% of the cases of IPD in 2005. Penicillin and cefotaxime susceptibility of IPD isolates did not change from 1999 through 2005 (P = 0.687). There was a decrease in penicillin (P < 0.001) and cefotaxime (P = 0.034) susceptibility in NVT serotypes from 1999 to 2005. Molecular characterization of 19A isolates revealed a predominance of ST-199 (62%). Several highly penicillin-resistant and intermediately cefotaxime-resistant strains emerged in 2004 and 2005. CONCLUSIONS: In Dallas, heptavalent pneumococcal conjugate vaccine reduced the incidence of IPD from 1999 to 2005 by reducing the incidence of vaccine-type disease. NVT serotypes, particularly 19A, were prevalent and more resistant to antimicrobials in 2004 and 2005.     

Site-specific disease potential of individual Streptococcus pneumoniae serotypes in pediatric invasive disease, acute otitis media and acute conjunctivitis

BACKGROUND: Recent studies have shown that some Streptococcus pneumoniae serotypes possess a higher potential to cause invasive disease than others. However, it is unknown whether disease potential for specific serotypes is similar for mucosal disease. Our objective was to assess the disease potential of individual S. pneumoniae serotypes causing invasive pneumococcal disease (IPD), acute otitis media (AOM) and acute conjunctivitis (AC) in children. METHODS: Serotypes of pneumococcal isolates from children with IPD, AOM and AC were compared with those carried by healthy children aged <3 years. All children resided in the same area and were studied during the same period. Odds ratios for disease were calculated for each diagnosis following multivariate analysis, including gender, age, ethnic group, previous antibiotic treatment and year variability. RESULTS: A total of 5,500 isolates were collected: 189 from blood or cerebrospinal fluid, 3,200 from middle ear fluid, 348 from conjunctiva and 1,763 from nasopharynx of healthy children. A significant positive association with IPD was demonstrated for serotypes 1, 5 and 12F; with AOM for serotypes 1, 3, 5, 12F, 19A and 19F; and with AC for serotype 3 and nontypeable S. pneumoniae. A significant negative association with IPD was demonstrated for nontypeable S. pneumoniae and with AOM for serotypes 6A, 6B, 15A and nontypeable S. pneumoniae. CONCLUSIONS: Our results reflect the importance of the polysaccharide capsule in site-specific disease potential and provide useful information regarding disease potential of nonvaccine serotypes shown to be involved in carriage replacement after vaccination with the 7-valent conjugate vaccine.     

Pneumococcal serotypes from acute otitis media in rural Kentucky

OBJECTIVE: Acute otitis media (AOM) accounts for most infections caused by, but few data are available regarding the incidence of pneumococcal serotypes recovered from children with AOM in the United States. METHODS: Between January 1992 and March 1998, 777 middle ear pathogens from AOM were obtained from 701 patients by tympanocentesis (84.6%) or by culture of otorrhea (15.4%) from spontaneous perforation or draining tubes. The ambulatory patient population was mostly white and cared for by a sole private pediatric practice in rural Kentucky. RESULTS: Penicillin-nonsusceptible (penicillin MIC > or = 0.1 microg/ml) (PNSP) isolates accounted for 18% [6% resistant PNSP (rPNSP) and 12% intermediate resistant PNSP], and penicillin-susceptible strains accounted for 35% of the pathogens recovered from children with culture-proved AOM. Comparing the frequency of isolates between 1992 and 1993 with those between 1994 and 1998, overall rates of PNSP strains remained remarkably stable (32.2% 37.3%), but intermediate resistant PNSP strains doubled from 14% to 27% ( < 0.01), whereas rPNSP strains fell by one-third. Serotypes 19F (34%), 23F (30%), 6B (26%) and 14 (8%) accounted for nearly all rPNSP isolates. Two cross-reactive serotypes (6A and 19A) not included in the available pneumococcal conjugate vaccine comprised 8.4 and 15% of all serotypes and PNSP serotypes, respectively. Nearly all PNSP strains recovered in children < or =24 months are included in the vaccine serogroups. CONCLUSION: Depending on rates of efficacy and serotype cross-protection, the current pneumococcal conjugate vaccine could potentially protect against most PNSP strains in all ages, particularly in those < or =24 months.     

Multinational study of pneumococcal serotypes causing acute otitis media in children

BACKGROUND: Streptococcus pneumoniae is a major cause of acute otitis media (AOM) in young children. More than 90 immunologically distinct pneumococcal serotypes have been identified, but limited information is available regarding their relative importance in AOM. METHODS: We analyzed nine existing datasets comprising pneumococcal isolates from middle ear fluid samples collected from 1994 through 2000 from 3,232 children with AOM from Finland, France, Greece, Israel, several East European countries, the US and Argentina. We examined the distribution of pneumococcal serotypes in relation to several demographic and epidemiologic variables, including gender, age, antibiotic resistance and source of culture material. RESULTS: The major serotypes identified included 19F and 23F, each comprising 13 to 25% of pneumococcal middle ear fluid isolates in most datasets; 14 and 6B, comprising 6 to 18%; whereas 6A, 19A and 9V each comprised 5 to 10%. Despite differences in location, study design and antibiotic susceptibility, each major serotype was prominent in most age groups of each dataset. Serotypes represented in the 7-valent pneumococcal conjugate vaccine (PCV-7, 4, 6B, 9V, 14, 18C, 19F, 23F) accounted for 60 to 70% of all pneumococcal isolates in the 6- to 59-month age range, but only 40 to 50% of isolates in children <6 or >/=60 months old. Serotype 3 and, in certain datasets, serotypes 1 and 5, were more important in the <6- and >/=60-month age groups. In each age group vaccine-related serotypes (mainly 6A and 19A) comprised an additional 10 to 15% of all pneumococcal isolates. Four serotypes (23F, 19F, 14 and 6B) accounted for 83% of all penicillin-resistant observations. CONCLUSIONS: This analysis of several geographically diverse datasets indicates that a limited number of serotypes, largely represented in PCV-7, accounted for the majority of episodes of pneumococcal AOM in children between 6 and 59 months of age. Certain serotypes appeared to be relatively more significant in children <6 months or >59 months of age.     

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.     

Antibiotic susceptibility of acute otitis media pathogens in otitis-prone Belgian children

A regional surveillance study was carried out in children with recurrent acute otitis media (AOM) to determine the antimicrobial susceptibility of three common AOM pathogens. Susceptibility to relevant antimicrobial agents was determined on 149 Streptococcus pneumoniae, 246 Haemophilus influenzae and 119 Moraxella catarrhalis strains isolated between January 1999 and January 2002, either from the nasopharynx or middle ear of 74 children with recurrent AOM, the majority (77%) being otitis-prone. Overall pneumococcal resistance to penicillin was 9.4% (6.7% penicillin-intermediate resistant, 2.7% penicillin-resistant), whereas cotrimoxazole and erythromycin resistance accounted for 25.5% and 38.9% respectively. The prevalence of antimicrobial-non-susceptible S. pneumoniae was the highest in middle ear isolates (P<0.05) and in otitis-prone children (P<0.01). Moreover, otitis-prone children harboured significantly more pneumococci resistant to at least two antimicrobial agents (24.3% versus 7.4%; P<0.01). No patient age related variation was observed. Five serogoups (6, 19, 23, 14 and 9) covered by the 7-valent pneumococcal conjugate vaccine, constituted most of the antibiotic resistant pneumococci. Among nasopharyngeal and middle ear H. influenzae isolates, 17.1% were resistant to ampicillin and 16.3% to cotrimoxazole. For M. catarrhalis, 92.4% of all isolates was ampicillin-resistant. Conclusion: this study confirms international and national differences in antimicrobial susceptibility profiles of three acute otitis media pathogens with relatively favourable antibiotic resistance rates in Belgian children with frequent acute otitis media. This at risk population of otitis-prone children is shown to harbour more antimicrobial resistant and multidrug resistant pneumococci. If antimicrobial therapy in this group of children is indicated, high dose amoxicillin is recommended whereas the use of macrolides is obsolete.Abbreviations AOM acute otitis media - MEF middle ear fluid - MIC minimal inhibitory concentration     

Epidemiology of acute otitis media caused by Streptococcus pneumoniae: emergence of serotype 19A

In this study, the authors report the distribution of serogroups/serotypes and their susceptibility profiles of Streptococcus pneumoniae causing recurrent and difficulties to treat acute otitis media (AOM) in children obtained at the ENT outpatient clinic of Robert Debré Hospital in Paris, between 2002-2008 after the implementation of the 7-valent pneumococcal conjugate vaccine. In this retrospective study, 126 S. pneumoniae isolates were obtained by tympanocentesis from 126 children with AOM during three different periods: 2002-2003 (period 1), 2004-2005 (period 2), and 2006-2008 (period 3). In period 1, the most common serotype was 19F. Between period 1 and period 3, the proportion of serotype 19F decreased from 39 to 13% (P=0.03). In contrast, the proportion of serotype 19A increased from 25 to 60% (P=0.03). So, they observed that vaccine-related serotype 19A became dominant among young children with AOM in 2006-2008. Overall, 15.1% of the isolates were penicillin susceptible, 73.8% intermediate and 11.1% were resistant. Most (94%) of the S. pneumoniae serotype 19A were penicillin intermediate.     

Nonvaccine Streptococcus pneumoniae serotypes causing acute bacterial meningitis

The pneumococcal heptavalent conjugate vaccine protects children aged less than 2 years old from invasive pneumococcal disease (IPD). Efficacy is 89-93% in the US population and 71-86% in European studies. The vaccine confers active immunization against the main serotypes causing IPD (4, 6B, 9V, 14, 18C, 19F y 23F). We describe 2 children who presented with pneumococcal meningitis caused by nonvaccine serotypes. As a result of the widespread use of the heptavalent vaccine, there may be a shift in the serotypes causing IPD.     

Epidemiology of pneumococcal infections in French children

Since 1977, resistance to beta-lactams and other families of antibiotics among isolates of Streptococcus pneumoniae has increased alarmingly worldwide. France is particularly affected by this phenomenon; in 1997 the French National Reference Centre for Pneumococci reported that 44% of S. pneumoniae strains were penicillin non-susceptible (PNSS). Furthermore, resistance to macrolides (53%) and sulphonamides (37%) was comparable; in addition, >50% of PNSS had a high level of resistance to penicillin and were multiresistant. The highest frequency of resistance is observed in children, particularly those with acute otitis media (AOM). CONCLUSION: The clinical consequences of increasing antibiotic resistance are evident for meningitis and AOM, prompting clinicians to consider alternative agents such as high-dose cefotaxime (300 mg/ kg/d) or ceftriaxone (100mg/kg/d) plus vancomycin (60 mg/kg/d) for meningitis, and high-dose amoxicillin (> 80 mg/kg/d) or ceftriaxone (50 mg/kg/d) for AOM.     

Epidemiology of pneumococcal infections in French children

Since 1977, resistance to ß-lactams and other families of antibiotics among isolates of Streptococcus pneumoniae has increased alarmingly worldwide. France is particularly affected by this phenomenon; in 1997 the French National Reference Centre for Pneumococci reported that 44% of S. pneumoniae strains were penicillin non-susceptible (PNSS). Furthermore, resistance to macrolides (53%) and sulphonamides (37%) was comparable; in addition, >50% of PNSS had a high level of resistance to penicillin and were multiresistant. The highest frequency of resistance is observed in children, particularly those with acute otitis media (AOM).
Conclusion : The clinical consequences of increasing antibiotic resistance are evident for meningitis and AOM, prompting clinicians to consider alternative agents such as high-dose cefotaxime (300 mg/ kg/d) or ceftriaxone (100mg/kg/d) plus vancomycin (60 mg/kg/d) for meningitis, and high-dose amoxicillin (>80 mg/kg/d) or ceftriaxone (50 mg/kg/d) for AOM.     

Epidemiology of meningitis and bacteraemia due to Streptococcus pneumoniae in The Netherlands

In The Netherlands, accurate data on the epidemiology of pneumococcal meningitis are available through a clinical microbiology laboratory-based national surveillance of cerebrospinal fluid isolates. The Netherlands Reference Laboratory for Bacterial Meningitis receives isolates of about 80% of all meningitis cases and about 40% of bacteraemic cases. The incidence of pneumococcal meningitis has increased slowly from 1.0/100000 in 1990 to 1.5/100000 since 1996. The highest age-specific incidence of meningitis was observed in children <5y of age (8.2/100000 in 1999). Of all isolates, 35% were from children <5 y of age. The number of isolates from non-meningitis patients with bacteraemia increased considerably since the early 1990s, especially among the elderly. The highest incidence was found in 1996, probably owing to a relatively severe winter. During 1995–1999, pneumococcal meningitis in The Netherlands was caused mainly by serotypes 3, 6B, 7F, 9V, 14, 18C, 19F, and 23F. Of the cases in children <15y, almost half were caused by serotypes 6B, 14, 18C, and 19F. The serotypes present in the 23-valent polysaccharide and 7-valent conjugate vaccines accounted for 87% and 47% of all meningitis cases, respectively. Pneumococcal resistance to penicillin in The Netherlands is still low, at about 1%. Genotypically, resistant strains belong to many clones. Horizontal transfer of capsular genes occurs among these isolates. In The Netherlands, 45% of cases of pneumococcal meningitis have severe predisposing factors. The case-fatality rate was significantly higher among patients with impaired immunity than among those with a break in the integrity of the dura.     

Epidemiology of meningitis and bacteraemia due to Streptococcus pneumoniae in The Netherlands

In The Netherlands, accurate data on the epidemiology of pneumococcal meningitis are available through a clinical microbiology laboratory-based national surveillance of cerebrospinal fluid isolates. The Netherlands Reference Laboratory for Bacterial Meningitis receives isolates of about 80% of all meningitis cases and about 40% of bacteraemic cases. The incidence of pneumococcal meningitis has increased slowly from 1.0/100,000 in 1990 to 1.5/100,000 since 1996. The highest age-specific incidence of meningitis was observed in children < 5 y of age (8.2/100,000 in 1999). Of all isolates, 35% were from children < 5 y of age. The number of isolates from non-meningitis patients with bacteraemia increased considerably since the early 1990s, especially among the elderly. The highest incidence was found in 1996, probably owing to a relatively severe winter. During 1995-1999, pneumococcal meningitis in The Netherlands was caused mainly by serotypes 3, 6B, 7F, 9V, 14, 18C, 19F, and 23F. Of the cases in children < 15 y, almost half were caused by serotypes 6B, 14, 18C, and 19F. The serotypes present in the 23-valent polysaccharide and 7-valent conjugate vaccines accounted for 87% and 47% of all meningitis cases, respectively. Pneumococcal resistance to penicillin in The Netherlands is still low, at about 1%. Genotypically, resistant strains belong to many clones. Horizontal transfer of capsular genes occurs among these isolates. In The Netherlands, 45% of cases of pneumococcal meningitis have severe predisposing factors. The case-fatality rate was significantly higher among patients with impaired immunity than among those with a break in the integrity of the dura.     

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 pneumococcal disease in Danish children, 1996-2007, prior to the introduction of heptavalent pneumococcal conjugate vaccine

Aim: The aim of this study was to document the epidemiology, microbiology and outcome of invasive pneumococcal disease (IPD) among children <16 years with quality surveillance data, just prior to the introduction of the heptavalent pneumococcal conjugate vaccine (PCV7) into the Danish routine immunization programme October 2007.
Methods: Clinical and microbiological records on cases of IPD in children <16 years admitted to Hvidovre Hospital, Denmark 1996–2007, were retrospectively reviewed.
Results: We identified 106 cases of IPD. The annual incidence of IPD was 11 per 100 000 in children <16 years, but considerably higher, 62 per 100 000, in children <2 years. Additionally, of the children with pneumococcal meningitis 86% were <2 years. We observed no fatalities. A total of 10% developed sequelae, but of the patients with pneumococcal meningitis 27% developed sequelae. Nine patients had known risk factors. The Streptococcus pneumoniae serotype was available for 81 cases. Seventy-five percent of the IPD cases in children aged <2 years were caused by one of the serotypes contained within PCV7, compared to only 24% in children ≥2 years.
Conclusion: Our data indicate that an estimated 75% of all IPD cases among children <2 years are caused by PCV7 serotypes and might therefore be prevented by PCV7 vaccination.     

Epidemiology of Streptococcus pneumoniae in Italian children

In Italy, data regarding the aetiological role, antibiotic resistance, and serotype distribution of isolates of Streptococcus pneumoniae are scarce and based on very small population samples. We found that S. pneumoniae caused about 30% of lower respiratory tract infections and 15% of acute otitis media infections in Italian children. The incidence of S. pneumoniae meningitis in subjects aged 0–4y was 1.1 ± 100000. In children <5y of age with meningitis, the most common S. pneumoniae serotypes were, in rank order, 14, 6, 23, 1 and 4; among 53 nasopharyngeal carriers the most frequent serotypes were 6 and 19. The actual percentage of resistance of S. pneumoniae to penicillin is 10.2%, while for macrolides it reaches 25.5%. More data on the distribution of serotypes in Italian children are urgently needed in order to obtain a better understanding of the impact of the new pneumococcal vaccines.     

Epidemiology of Streptococcus pneumoniae in Italian children

In Italy, data regarding the aetiological role, antibiotic resistance, and serotype distribution of isolates of Streptococcus pneumoniae are scarce and based on very small population samples. We found that S. pneumoniae caused about 30% of lower respiratory tract infections and 15% of acute otitis media infections in Italian children. The incidence of S. pneumoniae meningitis in subjects aged 0-4y was 1.1 x 100,000. In children <5 y of age with meningitis, the most common S. pneumoniae serotypes were, in rank order, 14, 6, 23, 1 and 4; among 53 nasopharyngeal carriers the most frequent serotypes were 6 and 19. The actual percentage of resistance of S. pneumoniae to penicillin is 10.2%, while for macrolides it reaches 25.5%. More data on the distribution of serotypes in Italian children are urgently needed in order to obtain a better understanding of the impact of the new pneumococcal vaccines.     

Epidemiology of pneumococcal infections in Swedish children

Objective: This paper provides an overview of pneumococcal infections in Swedish children.
Method: Data supplied by the Swedish Institute for Infectious Disease Control (SMI) provided information on invasive pneumococcal isolates and on isolates with reduced susceptibility to penicillin. Disease burden was estimated from data collected in northern Stockholm and Malmöhus County. Results: Only 3–6% of the total number of invasive pneumococcal isolates came from children 0–15 years of age. Predominant serotypes in descending frequency were 7, 6, 14, and 23. Strains from all sources with reduced sensitivity to penicillin (MIC 0.5 mg/l) were found in 3% of children and varied between 0.2% and 11%, with the highest value found in Southern Sweden (predominating strains were 9, 19, 15, 6, and 23). A 10-year review of all cases of meningitis in Northern Stockholm reflected an incidence of 10/100000 (0–2 years) or 5.8/100000 (0–5 years), with severe sequelae occurring in 20% of children. This information can be used to predict an annual incidence of 30 cases of meningitis in Sweden.
Conclusion: The large proportion of serotype 7 among invasive isolates is distressing since this serotype is not represented in the present 7- and 9-valent protein-conjugated vaccines under development. However, the heptavalent vaccine, including serotypes 4, 6B, 9V, 14, 18C, 19F, and 23F would (at a serotype level) provide coverage against 83% of the resistant isolates in Southern Sweden.     

Increase in invasive Streptococcus pneumoniae infections in children with sickle cell disease since pneumococcal conjugate vaccine licensure

Invasive pneumococcal disease (IPD) in children with sickle cell disease has decreased with prophylactic penicillin, pneumococcal polysaccharide vaccine, and pneumococcal protein-conjugate vaccine usage. We report 10 IPD cases since pneumococcal protein-conjugate vaccine licensure, including a recent surge of non-vaccine serotypes. IPD continues to be a serious risk in sickle cell disease.     

Characteristics of invasive pneumococcal disease in hospitalized children in Austria

In a prospective surveillance study covering all pediatric wards in Austria, 308 cases of invasive pneumococcal disease (IPD) were reported in hospitalized children <5 years of age between 2002 and 2012. Incidence was 7.1 per 100,000 per year for IPD with a case fatality rate of 3 %, and 1.9 per 100,000 per year for pneumococcal meningitis with a case fatality rate of 9 %. At hospital discharge, 17 % of the children were not fully recovered and suffered from problems such as hearing or motor deficits. Persistent sequelae 6 months after hospital discharge were present in 13 % of the children, a finding that emphasizes the seriousness of IPD. From 2007 onwards, we observed a shift of pneumococcal serotypes from those covered by the heptavalent vaccine to serotypes consequently added to 10- and 13-valent vaccines, particularly regarding serotype 19A. Among antimicrobial resistances detected, macrolide resistance was predominant; however, between 2002 and 2012, we saw an overall decrease of resistance rates. Conclusion: Considering this change of serotypes and the high rate of permanent sequelae after IPD, our data show the importance of pediatric pneumococcal vaccination and the relevance of continuous monitoring of circulating serotypes. By the end of 2012, which was the first year of universal mass vaccination against pneumococcal disease in Austria, no change in the incidence of invasive pneumococcal disease was observed yet.     

Nasopharyngeal carriage of <Emphasis Type="Italic">Streptococcus pneumoniae</Emphasis>

Objective To determine nasopharyngeal carriage rate and prevalent serogroups/ types (SGT) of S. pneumoniae in healthy children, assess their antimicrobial susceptibility and its implications over the heptavalent pneumococcal conjugate vaccine. Methods 200 healthy children aged between 3 months and 3 years attending Pediatric OPD at Sir Ganga Ram Hospital, New Delhi were studied. A nasopharyngeal swab was collected from each child which was processed to isolate Streptococcus pneumoniae. Serotyping was performed by the Quellung reaction. Antimicrobial susceptibility patterns were determined by disk diffusion and E test methods. Results S. pneumoniae carriage rate was 6.5%. Isolates belonged to serotypes 1, 6, 14 and 19, of which serotype 19 was the most common. None of the strains were totally resistant to penicillin though 2 (15.4%) were intermediately resistant. Overall, 84.6% of the isolates belonged to the strains covered by the heptavalent pneumococcal vaccine. Conclusion The heptavalent conjugate vaccine covers most isolated strains, but since the number of strains is very small, it is suggested that there is need for further studies in different regions to assess the usefulness of this vaccine.