Increase In Serotypes Research Articles

A multicenter study on the epidemiology of complicated parapneumonic effusion in the era of currently available pneumococcal conjugate vaccines

BackgroundParapneumonic effusion (PPE) is a common complication of pneumonia. Streptococcus pneumoniae is the most common cause of bacterial pneumonia. A reduction in pneumonia hospitalizations has been observed since the introduction of the 7-valent pneumococcal conjugate vaccine (PCV7). Despite this apparent benefit, an increase in the incidence of PPE was recorded in some countries following PCV7 implementation. As the 13-valent pneumococcal conjugate vaccine (PCV13) was expected to provide a wider protection against PPE, the aim of the present study was to evaluate the impact of PCV13 introduction on the epidemiology of complicated parapneumonic effusion (c-PPE) among children in the Athens greater area. MethodsAll cases of community-acquired pneumonia (CAP) with PPE requiring chest tube insertion (complicated PPE, c-PPE) hospitalized in the 3 public Children’s hospitals in Athens between 01/01/2004 and 31/12/2019 were included in the study. ResultsA total of 426 cases of c-PPE associated with pneumonia were recorded of which 198 were admitted during 2004–2010 (period A, prePCV13/PCV −7 introduction period) and 228 during 2011–2018 (period B, post - PCV13 period). A definite bacterial etiology was established in 44.4 % of all cases and of those 25.4 % were caused by S. pneumoniae. An increasing trend in c-PPE incidence was observed during period A; although, a significant decrease on c-PPE annual rates was observed during the period B (p = 0.011), a remarkable increase in serotype 3 cases was recorded. ConclusionA decreasing time trend in c-PPE cases among children was shown after the introduction of PCV13 in our area. However, serotype 3 is nowadays a common cause of PPE. Hence, continuous surveillance is imperative in order to follow c-PPE epidemiology over time.

Changes in the incidence of acute bacterial meningitis caused by Streptococcus pneumoniae and the implications of serotype replacement in children in Colombia after mass vaccination with PCV10.

IntroductionAcute bacterial meningitis (ABM) is a public health problem. The disease has reemerged after the introduction of pneumococcal conjugate vaccines (PCVs) due to an increase in serotypes that are not covered. The objective was to determine the changes in the disease incidence before and after the introduction of the 10-valent vaccine (PCV10) in Colombia.MethodsThis multicenter study was conducted in 17 hospitals in Colombia. Data were collected from January 2008 to December 2019 in 10 hospitals in Bogotá and from January 2017 to December 2019 in seven hospitals in Cali, Medellín and Cartagena. The data were grouped into three periods: 2008–2011, 2012–2015, and 2016-2019.ResultsOf the 706 cases of invasive pneumococcal disease, 81 (11.4%) corresponded to meningitis. The relative incidence in Bogotá in the first period was 0.6 per 100,000 patients ≤ 5 years, decreased to 0.4 per 100,000 patients ≤ 5 years in the second period and increased in the third period to 0.7 per 100,000 patients ≤ 5 years. Serotypes covered by PCV10 decreased from 75 to 9.1%, with Spn19A (31.8%) and Spn34 (13.6%) emerging in the third period. Increased resistance to penicillin (13 to 37%) and to ceftriaxone (5.9 to 16%) was due to the emergence of multidrug-resistant Spn19A. The total mortality rate was 23.5% and increased from 12 to 33%.ConclusionsABM due to pneumococcus has high morbidity and mortality rates. Reemergence of the disease has been observed due to the inclusion of polymerase chain reaction (PCR) for diagnosis and replacement of circulating serotypes after the introduction of PCV10, with an increase in Spn19A, which causes death and exhibits antimicrobial resistance. Continued surveillance is needed.

Pneumococcal Conjugate Vaccine Impact on Serotype 3: A Review of Surveillance Data.

IntroductionLimited changes in serotype 3 invasive pneumococcal disease (IPD) incidence rates after a decade of 13-valent pneumococcal conjugate vaccine (PCV13) introduction into several national immunization programs (NIP) have raised questions about PCV13's effectiveness against this serotype.MethodsWe analyzed the impact of pediatric PCV programs on serotype 3 IPD with two approaches. First, we reviewed the publicly available surveillance data from countries identified in two recently published reviews to describe the population impact of pediatric PCV13 or PCV10 vaccination programs on serotype 3 IPD. We then compared the observed trends in PCV10 and PCV13 countries to a previously described dynamic transmission model that simulates the spread of pneumococcal carriage and development of IPD in a population over time.ResultsWhen serotype 3 disease rates are compared from countries that have introduced either a 10-valent (PCV10) vaccine that does not contain serotype 3 in its formulation or PCV13 in their pediatric NIP, over time, serotype 3 incidence rate trends are markedly different. Countries with a PCV10 NIP showed a substantial linear increase in serotype 3 pneumococcal disease among all age groups since the time of PCV10 introduction, whereas countries with a PCV13 NIP experienced a modest decline during the 3–4 years after vaccine introduction followed by an inflection upward in subsequent years.ConclusionThese data suggest that PCV13 provides a certain degree of direct and indirect protection against serotype 3 at the population level and direct adult vaccination with a serotype 3-containing vaccine is likely to provide substantial benefit in the context of a pediatric PCV NIP. Further research around serotype 3 transmission patterns and epidemiology is nonetheless warranted.Supplementary InformationThe online version contains supplementary material available at 10.1007/s40121-021-00406-w.

Nationwide Trends of Invasive Pneumococcal Disease in Spain From 2009 Through 2019 in Children and Adults During the Pneumococcal Conjugate Vaccine Era.

Introduction of pneumococcal conjugate vaccines (PCVs) has reduced the disease caused by vaccine serotypes in children, providing herd protection to adults. However, the emergence of nonvaccine serotypes is of great concern worldwide. This study includes national laboratory data from invasive pneumococcal disease (IPD) cases that affected pediatric and adult populations during 2009-2019. The impact of implementing different vaccine strategies for immunocompetent adults by comparing Spanish regions that used the 13-valent PCV (PCV13) vs regions that used the 23-valent pneumococcal polysaccharide vaccine (PPV23) was also analyzed for 2017-2019. The overall reductions in IPD cases by PCV13 serotypes in children and adults were 88% and 59%, respectively, during 2009-2019, with a constant increase in serotype 8 in adults since 2015. IPD cases by additional serotypes covered by PPV23 increased from 20% in 2009 to 52% in 2019. In children, serotype 24F was the most frequent in 2019, whereas serotypes 3 and 8 accounted for 36% of IPD cases in adults. Introduction of PCV13 or PPV23 in the adult calendar of certain Spanish regions reduced the IPD cases by PCV13 serotypes by up to 25% and 11%, respectively, showing a decrease of serotype 3 when PCV13 was used. Use of PCV13 in children has affected the epidemiology, reducing the burden of IPD in children but also in adults by herd protection; however, the increase in serotype 8 in adults is worrisome. Vaccination with PCV13 in adults seems to control IPD cases by PCV13 serotypes including serotype 3.

Increase of serotype 8, ST53 clone, as the prevalent strain of Streptococcus pneumoniae causing invasive disease in Madrid, Spain (2012–2015)

IntroductionIn recent years, Streptococcus pneumoniae serotype 8 has become the most prevalent cause of invasive pneumococcal disease (IPD) in Madrid, Spain. The objective of this study was to characterize the invasive clones of S. pneumoniae serotype 8 in Madrid over the 2012–2015 period. MethodsFrom January 2012 to December 2015, a total of 1543 invasive isolates were studied. Serotyping was carried out by Pneumotest-Latex agglutination and Quellung reaction. Susceptibilities to penicillin, erythromycin and levofloxacin were determined by the Etest®. All serotype 8 strains were typed by multilocus sequence typing (MLST) and by pulsed-field gel electrophoresis (PFGE). ResultsTwo hundred and forty-eight (248) serotype 8 strains were detected (16.1%) and 243 of them were available for molecular typing. Nine sequence types (STs) by MLST (8-ST53, 8-ST63, 8-ST404, 8-ST1107, 8-ST989, 8-ST1110, 8-ST2231, 8-ST3544 and 8-ST4301), and nine PFGE profiles were identified (one corresponding to each ST). The 8-ST53 clone was the most widespread, and increased from 53.8% among all serotype 8 isolates in 2012, to 90.1% in 2015. In contrast, the 8-ST63 clone, resistant to levofloxacin and erythromycin, decreased from 30.8%, among all serotype 8 strains in 2012, to 5.0% in 2015. ConclusionsThe increase in our region of S. pneumoniae serotype 8, not included in conjugated vaccines, occurred at the expense of the 8-ST53 clone. On the contrary, the 8-ST63 clone decreased. Since clone 8-ST63 has the theoretical advantage of its levofloxacin-erythromycin resistance in comparison to 8-ST53, the predominance of 8-ST53 over 8-ST63 is striking.

Increase of serotype 8, ST53 clone, as the prevalent strain of Streptococcus pneumoniae causing invasive disease in Madrid, Spain (2012–2015)

IntroductionIn recent years, Streptococcus pneumoniae serotype 8 has become the most prevalent cause of invasive pneumococcal disease (IPD) in Madrid, Spain. The objective of this study was to characterize the invasive clones of S. pneumoniae serotype 8 in Madrid over the 2012–2015 period. MethodsFrom January 2012 to December 2015, a total of 1543 invasive isolates were studied. Serotyping was carried out by Pneumotest-Latex agglutination and Quellung reaction. Susceptibilities to penicillin, erythromycin and levofloxacin were determined by the Etest®. All serotype 8 strains were typed by multilocus sequence typing (MLST) and by pulsed-field gel electrophoresis (PFGE). ResultsTwo hundred and forty-eight (248) serotype 8 strains were detected (16.1%) and 243 of them were available for molecular typing. Nine sequence types (STs) by MLST (8-ST53, 8-ST63, 8-ST404, 8-ST1107, 8-ST989, 8-ST1110, 8-ST2231, 8-ST3544 and 8-ST4301), and nine PFGE profiles were identified (one corresponding to each ST). The 8-ST53 clone was the most widespread, and increased from 53.8% among all serotype 8 isolates in 2012, to 90.1% in 2015. In contrast, the 8-ST63 clone, resistant to levofloxacin and erythromycin, decreased from 30.8%, among all serotype 8 strains in 2012, to 5.0% in 2015. ConclusionsThe increase in our region of S. pneumoniae serotype 8, not included in conjugated vaccines, occurred at the expense of the 8-ST53 clone. On the contrary, the 8-ST63 clone decreased. Since clone 8-ST63 has the theoretical advantage of its levofloxacin-erythromycin resistance in comparison to 8-ST53, the predominance of 8-ST53 over 8-ST63 is striking.

Distribution of Streptococcus pneumoniae serotypes in the northeast macro-region of S\xe3o Paulo state/Brazil after the introduction of conjugate vaccine

BackgroundInfections caused by Streptococcus pneumoniae (Spn) still challenge health systems around the world, even with advances in vaccination programs. The present study evaluated the frequency of various Spn serotypes isolated in Regional Health Care Network 13 (RRAS 13), which includes the regional health departments (RHDs) of Araraquara, Barretos, Franca and Ribeirão Preto, especially after the introduction of 10-valent pneumococcal conjugate vaccine (PCV10) in 2010.MethodsThe analyzed Spn strains were isolated from patients with invasive pneumococcal diseases (IPDs) and then sent to Adolfo Lutz Institute (ALI) for further confirmative identification tests during the period from 1998 to 2013. The samples were from the cities in RRAS13, which is located in the Northeast region of São Paulo State, and totals 90 municipalities.ResultsWe analyzed strains isolated from 796 patients. They were predominantly: men (58.9%); 20 to 60 years old (32.2%); evaluated from 2003 to 2010 (60.2%); and diagnosed with meningitis (45.7%) and pneumonia (45.0%), the most common invasive pneumococcal diseases. In 2010, serotypes 3, 19F, 1, 23F, 6A and 6B were among the most frequent, while serotypes 3, 12F, 14, 6A, 18C, 8 and 6B were more common after the introduction of PCV10. Serotypes 14, 19F and 3 were more frequent in meningitis, while serotypes 14, 3 and 1 prevailed in pneumonia. After 2010, there was a decrease in serotypes 14, 1, 23F and 5 and an increase in serotypes 3, 12F, 11A and 8, which were not present in the vaccine.ConclusionsThe present study noted the increase in serotypes 3, 12F, 11A and 8 after vaccination. None of those serotypes are included in the available conjugate vaccines, which highlights the importance of continued monitoring of IPDs in order to measure the disease burden in the population in the long term and provide new epidemiological information to determine the impact of PCV10 in Brazil.

Impact of pneumococcal vaccination in children on serotype distribution in adult community-acquired pneumonia using the serotype-specific multiplex urinary antigen detection assay

The aim of the study was to compare the distribution of the vaccine-serotypes covered by pneumococcal conjugate vaccines (PCV7 and PCV13) in adult patients with pneumococcal community-acquired pneumonia in Germany between the periods 2002–2006 and 2007–2011 using a novel serotype-specific multiplex urinary antigen detection assay (SSUA). Vaccination of children started with PCV7 in 2007, which was replaced by PCV13 in 2010. Following confirmation of the accuracy of SSUA in long-term stored urine samples from 112 patients with confirmed pneumonia and known pneumococcal serotype, urine samples of 391 CAPNETZ patients with documented pneumococcal pneumonia (i.e. positive BinaxNOW® Streptococcus pneumoniae urine antigen test) but unknown serotype were tested for the 13 vaccine-serotypes using SSUA. The proportion of PCV7-serotypes significantly decreased in adult patients with pneumonia from 30.6% (2002–6) to 13.3% (2007–11, p<0.001); in bacteremic pneumonia, PCV7-serotypes completely disappeared (3/14 versus 0/19, p=0.058). Conversely, pneumococcal serotypes included by PCV13 remained stable during study period with a coverage of 61.5% (2002–06) and 59.7% (2007–11) in non-bacteremic pneumonia and 79% (for both periods) in bacteremic pneumonia, mainly due to an increase in pneumococcal serotypes 1, 3 and 7F during the second period. Thus, implementation of PCV7 in children in Germany in 2007 was associated with a significant decrease in vaccine-serotypes covered by PCV7 in adult patients with non-bacteremic pneumococcal pneumonia and with an elimination of PCV7 vaccine-serotypes in bacteremic pneumococcal pneumonia. PCV13 coverage remained high up to 2011, mainly due to an increase in serotypes 1, 3 and 7F.German Clinical Trials Register: DRKS00005274.

Surveillance of invasive in Streptococcus pneumoniae in Argentina 1994–2007: Changes in serotype distribution, serotype coverage of pneumococcal conjugate vaccines and antibiotic resistance

Streptococcus pneumoniaeis a prevalent cause of invasive diseases in children, justifying continuous surveillance programs such as by the SIREVA group (Pan American Health Organization). The aim of this study was to determine the serotype distribution of S. pneumoniae causing invasive disease in children < 6 years old, the serotype coverage of the pneumococcal conjugate vaccine 7-valent (PCV7), 10-valent (PCV10) and 13-valent (PCV13), and antibiotic resistance, from 1994 to 2007. During this period, 2205 invasive S. pneumoniaewere included in the study. Although 49 different capsular types were identified, 12 serotypes accounted for 86% of all isolates. These were prevalent throughout the study period with serotype 14 predominating. Penicillin non-susceptible S. pneumoniaewas detected in 33.2% of all isolates. The coverage of PCV7, PCV10 and PCV13 from 2004 to 2007 for children < 2 years old was 51.7%, 72.4% and 84.5%, respectively. The data demonstrates a decline in serotype 14, and an increase in serotypes 1 and 19A in the study period. Resistance to penicillin and trimethoprim-sulfamethoxazole decreased, while resistance to erythromycin increased. These results demonstrate the need for the introduction of a conjugate pneumococcal vaccine and continuing surveillance to monitor changes in serotypes distribution and antimicrobial resistance.

Genetically diverse serotypes III and VI substitute major clonal disseminated serotypes Ib and V as prevalent serotypes of Streptococcus agalactiae from 2007 to 2012.

Streptococcus agalactiae [group B Streptococcus (GBS)] has become more prevalent in nonpregnant women, the elderly, and people who are immunocompromised. We investigated the serotype and genomic changes of GBS human isolates from different hospitals from 2007 to 2012. The serotype and genotype of 658 GBS human isolates were determined with multiplex polymerase chain reaction and pulsed field gel electrophoresis analysis. Multilocus sequence typing analysis determined the sequence type (ST) of the major clones of serotypes Ib, V, and VI. Most of the isolates were collected from urine samples (60.5%) with a reduction in the rate from 74.6% in 2007 to 34.5% in 2012 and from infected patients older than 30 years (72.6%). The female/male ratio differed depending on the source: 3.52 in the urine group, 0.48 in the wound group, and 0.43 in pus. Serotypes Ib (16.5%), III (16.9%), V (27.2%), and VI (17.6%) were the most predominant among the nine serotypes identified and were separated into two prevalence patterns: a decrease in serotypes Ib and V and an increase in serotypes III and VI from 2007 to 2012. The prevalence change was associated with the urine group. Additionally, serotype VI become more prevalent in blood samples in four hospitals. The pulsed field gel electrophoresis analysis demonstrated three genetic patterns: limited pulsotypes and a major clonal dissemination for serotypes Ib and V, diverse pulsotypes for serotypes III, and diverse pulsotypes with a major clonal dissemination for serotype VI. Multilocus sequence typing analysis of the major clones identified ST12 for serotype Ib and ST1 for serotypes V and VI. Rapid genomic variations with different evolutionary patterns have led to the establishment of serotypes III and VI as the predominant GBS serotypes.

Erratum: Enhanced surveillance of invasive listeriosis in the Lombardy region, Italy, in the years 2006–2010 reveals major clones and an increase in serotype 1/2a

Background: Invasive listeriosis is a rare, life-threatening foodborne disease. Lombardy, an Italian region accounting for 16% of the total population, reported 55% of all listeriosis cases in the years 2006-2010. The aim of our study was to provide a snapshot of listeriosis epidemiology in this region after the implementation of a voluntary laboratory-based surveillance system. Methods: We characterized by serotyping, pulsed-field gel electrophoresis, multilocus sequence typing and detection of epidemic clone markers, 134 isolates from 132 listeriosis cases, including 15 pregnancy-related cases, occurring in the years 2006-2010 in Lombardy. Demographic and clinical characteristics of cases have also been described. Results: The mean age of non pregnancy-associated cases was 64.7 years, with 55.9% of cases being older than 65 years. Cases having no underlying medical conditions accounted for 11.6%. The all-cause fatality rate of 83 cases with a known survival outcome was 25.3%. Serotypes 1/2a and 4b comprised 52.2% and 38.8% of isolates, respectively. Seventy-three AscI pulsotypes and 25 sequence types assigned to 23 clonal complexes were recognized. Moreover, 53 (39.5%) isolates tested positive for the epidemic clone markers. Twelve molecular subtype clusters including at least three isolates were detected, with cluster 11 (1/2a/ST38) including 31 isolates identified during the entire study period. No outbreaks were notified to public health authorities during this period. Conclusions: The findings of our study proved that epidemiology of listeriosis in Lombardy is characterized by a high prevalence of major clones and the increasing role of serotype 1/2a. Molecular subtyping is an essential tool in the epidemiology and surveillance of listeriosis. Rapid molecular cluster detection could alert about putative outbreaks, thus increasing the chance of detecting and inactivating routes of transmission.

Impact of the pneumococcal conjugate vaccine on serotype distribution and susceptibility trends of pediatric non-invasive Streptococcus pneumoniae isolates in Tokai, Japan over a 5-year period

Introduction of the 7-valent pneumococcal conjugate vaccine (PCV7) in February 2010 markedly reduced the burden of invasive pneumococcal disease (IPD) and changed serotype distribution in Japan. We investigated the serotype distribution and susceptibility trends of non-invasive Streptococcus pneumoniae isolates collected from pediatric patients. A total of 564 pneumococcal isolates were collected over a 5-year period between 2008 and 2012. The coverage of PCV7 significantly decreased throughout the study period, from 49.3% in period 1 (between June 2008 and April 2009) to 23.4% in period 4 (between October 2011 and March 2012). This change was mainly due to a large decrease in the frequency of 19F (from 20.6% to 9.9%) and 6B (from 10.3% to 2.7%) and an increase in serotype 3 (from 5.1% to 13.5%) and serogroup 15 (from 4.4% to 9.0%). According to serotype replacement, the susceptible ratios of S.pneumoniae to β-lactams increased slightly while macrolide resistance remained high. The high frequency of macrolide-resistant pneumococcal isolates may continue because of the high frequency of erm(B) in replace serotypes such as serotype 3 and serogroup 15. The continuous surveillance study is essential following the introduction of a second generation 13-valent pneumococcal conjugate vaccine (PCV13).

Changes in serotype prevalence and antimicrobial resistance among invasive Streptococcus pneumoniae isolates in Korea, 1996–2008

We investigated changes in serotypes and antimicrobial susceptibilities among 386 isolates of invasive Streptococcus pneumoniae collected from numerous hospitals in Korea from 1996 to 2008. Serotypes 19F (9.8 %), 23F (8.3 %), 19A (7.8 %), 6A (7.5 %), 3 (7.3 %), 9V (6.5 %), 6B (6.2 %), 14 (4.9 %), 1 (3.9 %), 11A (3.9 %) and 4 (3.1 %) represented 69.2 % of all isolates. While the overall proportion of PCV7 serotypes was stable over time, we observed modest decreases in children <5 years old and in adults ≥65 years old between 1996-1999 and 2007-2008. An increased prevalence of non-PCV7 serotypes in these age groups was primarily attributable to an increase in serotypes 3, 6A and 19A. Most invasive S. pneumoniae isolates showed high resistance rates to erythromycin (74.9 %), tetracycline (71.1 %) and clindamycin (61.7 %). Between 1996-2003 and 2004-2008, non-susceptibility rates to cefotaxime and multi-drugs (three or more classes) in PCV7 serotypes showed a declining trend, while in non-PCV7 serotypes there was an increasing trend. Non-PCV7 serotypes 6A and 19A, which mostly exhibited multidrug-resistant phenotypes (69.0 % and 76.7 % respectively), increased between 1996-2003 and 2004-2008. Although PCV7 was introduced in Korea in November 2003, pneumococcal vaccination has not been included in the national child vaccination programme. Our results provide details of serotype occurrence that will be useful when adoption of universal pneumococcal vaccination in Korea is being considered.

Enhanced surveillance of invasive listeriosis in the Lombardy region, Italy, in the years 2006-2010 reveals major clones and an increase in serotype 1/2a.

BackgroundInvasive listeriosis is a rare, life-threatening foodborne disease. Lombardy, an Italian region accounting for 16% of the total population, reported 55% of all listeriosis cases in the years 2006-2010. The aim of our study was to provide a snapshot of listeriosis epidemiology in this region after the implementation of a voluntary laboratory-based surveillance system.MethodsWe characterized by serotyping, pulsed-field gel electrophoresis, multilocus sequence typing and detection of epidemic clone markers, 134 isolates from 132 listeriosis cases, including 15 pregnancy-related cases, occurring in the years 2006-2010 in Lombardy. Demographic and clinical characteristics of cases have also been described.ResultsThe mean age of non pregnancy-associated cases was 64.7 years, with 55.9% of cases being older than 65 years. Cases having no underlying medical conditions accounted for 11.6%. The all-cause fatality rate of 83 cases with a known survival outcome was 25.3%.Serotypes 1/2a and 4b comprised 52.2% and 38.8% of isolates, respectively. Seventy-three AscI pulsotypes and 25 sequence types assigned to 23 clonal complexes were recognized. Moreover, 53 (39.5%) isolates tested positive for the epidemic clone markers. Twelve molecular subtype clusters including at least three isolates were detected, with cluster 11 (1/2a/ST38) including 31 isolates identified during the entire study period. No outbreaks were notified to public health authorities during this period.ConclusionsThe findings of our study proved that epidemiology of listeriosis in Lombardy is characterized by a high prevalence of major clones and the increasing role of serotype 1/2a. Molecular subtyping is an essential tool in the epidemiology and surveillance of listeriosis. Rapid molecular cluster detection could alert about putative outbreaks, thus increasing the chance of detecting and inactivating routes of transmission.

Community-based outbreaks in vulnerable populations of invasive infections caused by Streptococcus pneumoniae serotypes 5 and 8 in Calgary, Canada.

BackgroundOutbreaks of invasive pneumococcal disease (IPD) typically occur within institutions. Beginning in 2005, we detected an increase in serotype (ST) 5 and ST8 IPD cases, predominantly in homeless persons living in an open community.Methodology/Principal FindingsCASPER (Calgary Area S. pneumoniae Epidemiology Research) surveillance study of all IPD (sterile site isolates) in our region (pop ∼1,100,000). Interviews and chart reviews of all cases and all isolates phenotypically analyzed and selected isolated tested by multi-locus sequence typing (MLST).Conclusions/SignificanceDuring 2005–2007, 162 cases of ST5 IPD and 45 cases of ST8 IPD were identified. The isolates demonstrated phenotypic and genotypic clonality. The ST5 isolates were sequence type (ST) 289 and demonstrated intermediate susceptibility to TMP-SMX. The ST8 isolates were predominantly ST1268, with a susceptible antimicrobial susceptibility profile. Individuals with ST5 IPD were more likely to be middle aged (OR 2.6), homeless (OR 4.4), using illicit drugs(OR 4.8), and asthmatic(OR 2.6). Those with ST8 were more likely to be male (OR 4.4), homeless (OR 2.6), aboriginal (OR7.3), and a current smoker (OR 2.5). Overlapping outbreaks of ST5 and ST8 IPD occurred in an open community in Calgary, Canada and homelessness was a predominant risk factor. Homelessness represents a unique community in which pneumococcal outbreaks can occur.

Particular Characteristics of Encapsulated Bacteria

The referenced article (1) also applies to hematological and oncological patients. The administration of dead vaccines is safe three to six months after the end of chemotherapy, although vaccine effectiveness may be reduced. Administration of attenuated live vaccines, however, has to be pondered very carefully. The Infectious Diseases Working Party of the German Society of Hematology and Oncology has published appropriate methods (www.dgho-infektionen.de). A warning to accompany the unequivocal indication for prophylactic vaccination against encapsulated bacteria: such vaccines do not guarantee protection from infection. Meta-analyses have shown that polysaccharide vaccines in chronically ill patients do not reduce the lethality of invasive pneumococcal disease (2). Evaluating surrogate markers rather than clinical end points in studies partially explain this association. The licensed pneumococcal polysaccharide vaccine has thus far not been adequately studied in hematology/oncology patients. Differences between vaccines also deserve attention: Pneumococcal polysaccharide vaccines—in contrast to conjugated vaccines—provoke T-cell independent, IgM dominant immune responses and lead to immunological short term memory. Because of the improved response to vaccination with conjugated vaccines in vaccine-naive immune systems, children receive conjugated vaccines. Successful studies of sequential polysaccharide vaccines and conjugated vaccines have been conducted in people who received stem cell transplants (3), accordingly, vaccination in this clientele is now being promoted. Expanding the license approval of the 13-valent conjugate vaccine from children younger than 5 years to adults older than 50 years is being investigated (www.pfizer.com). The vaccination might counterbalance the increasing antibiotic resistance of pneumococci. In reverse, increase in serotypes that are not captured by licensed vaccines might become a clinical problem. Other vaccine-preventable encapsulated bacteria may have vaccination gaps. The incidence of Haemophilus influenzae type B seems to be lower in adults than the incidence of non-encapsulated Haemophilus strains, which moreover are associated with higher letality (4). 50% of meningococci in Germany are of serotype B, and no vaccine exists for that serotype. For this reason, anti-infective prophylaxis should be considered after exposure, even in individuals who have been vaccinated. It seems obvious that clinical research into vaccination in at-risk adult patients needs to be intensified.

Incidence of invasive pneumococcal disease among elderly people in Southern Catalonia, Spain, 2002–2009: An increase in serotypes not contained in the heptavalent conjugate vaccine

Population-based surveillance study conducted among persons ≥ 65 years old in Southern Catalonia, Spain during 2002-2009. All cases with isolation of pneumococcus from normally sterile bodily fluids were included. Incidence rates of invasive pneumococcal disease (IPD) as well as rates of infections caused by serotypes included in the heptavalent pneumococcal conjugate vaccine (PCV7) and the 23-valent polysaccharide pneumococcal vaccine (PPV23) were compared for early (2002-2005) and contemporary (2006-2009) periods. Mean incidence rate (per 100,000 population-year) of IPD across study period was 48.0 [95% CI (confidence interval): 30.1-72.5]. Incidence rates for PCV7 serotypes slightly decreased by 21% between 2002-2005 and 2006-2009 (from 9.2 to 7.3; p = 0.511) whereas rates of IPD due to nonPCV7 serotypes largely increased by 172% (from 15.6 to 42.4; p < 0.001) during the same period. For PPV23 but nonPCV7 types, incidence rates increased by 146% (from 10.9 to 26.9; p < 0.001) whereas rates for nonPPV23 serotypes increased by 237% (from 4.6 to 15.5; p = 0.001). As an overall effect of these changes, the incidence of all IPD increased by a significant 69% (95% CI: 29%-110%). Specific incidence rates of serotypes 6A (from 1.7 to 4.1; p = 0.182), 7F (from 1.7 to 5.7; p = 0.052) and 19A (from 0.6 to 6.2; p = 0.004) substantially increased between both periods. According to these findings, Southern Catalonia region can be classified as a mesoendemic area of pneumococcal infections among elderly people, with a recent increase incidence of some nonPCV7 serotypes (especially 19A).

Age-Specific Cluster of Cases of Serotype 1 Streptococcus pneumoniae Carriage in Remote Indigenous Communities in Australia

Seven-valent pneumococcal conjugate vaccination commenced in 2001 for Australian indigenous infants. Pneumococcal carriage surveillance detected substantial replacement with nonvaccine serotypes and a cluster of serotype 1 carriage. Our aim was to review Streptococcus pneumoniae serotype 1 carriage and invasive pneumococcal disease (IPD) data for this population and to analyze serotype 1 isolates. Carriage data were collected between 1992 and 2004 in the Darwin region, one of the five regions in the Northern Territory. Carriage data were also collected in 2003 and 2005 from four regions in the Northern Territory. Twenty-six cases of serotype 1 IPD were reported from 1994 to 2007 in the Northern Territory. Forty-four isolates were analyzed by BOX typing and 11 by multilocus sequence typing. In the Darwin region, 26 children were reported carrying serotype 1 (ST227) in 2002 but not during later surveillance. Scattered cases of serotype 1 carriage were noted in two other regions. Cocolonization of serotype 1 with other pneumococcal serotypes was common (34% serotype 1-positive swabs). In conclusion, pneumococcal carriage studies detected intermittent serotype 1 carriage and an ST227 cluster in children in indigenous communities in the Northern Territory of Australia. There was no apparent increase in serotype 1 IPD during this time. The rate of serotype 1 cocolonization with other pneumococcal serotypes suggests that carriage of this serotype may be underestimated.

Temporal trends in circulating Bordetella pertussis strains in Australia.

Australia experienced a resurgence of pertussis in the 1990s despite improved vaccine coverage. Although much of the increase was attributable to increased detection of cases in older persons with waning immunity by serology, vaccine changes or alterations in circulating Bordetella pertussis strains may also have contributed. We determined the frequency of variants of B. pertussis pertactin (prn), and pertussis toxin subunit 1 (ptxS1) genes, restriction fragment length polymorphism (RFLP) types and fimbrial serotypes prevalent in Australia prior to, and during the 1990s. Ampoules of the whole-cell vaccine in use prior to 1999 and 84 B. pertussis isolates stored between 1967 and 1998 by laboratories around Australia were analysed. One pertactin allele, Prn3, not detected before 1985, was found in 24 out of 57 (42%) isolates between 1989 and 1998 (P<0.0001). PtxS1A was found in all isolates. IS1002 type 29, found in 17 out of 31 (55%) isolates tested, was the predominant RFLP type. The only difference in fimbrial serotype distribution between the time-periods was an increase in serotype 3 (P=0.054). The whole-cell vaccine contained only the alleles prn1 and ptxS1A. Antigenic shift in B. pertussis may have contributed to the re-emergence of pertussis in Australia. Monitoring these trends will be important as acellular vaccines are introduced and changes are made to pertussis vaccine schedules.

Prevalence and characteristics of pharyngeal group A beta-hemolytic streptococci in US Navy recruits receiving benzathine penicillin prophylaxis.

US military recruits receive benzathine penicillin prophylaxis because of endemicity of group A beta-hemolytic streptococcal (GABHS) infections. GABHS prevalence in Navy recruits receiving single-dose benzathine penicillin prophylaxis was assessed during spring and fall 1989 by culturing throat specimens from randomly selected groups of approximately 230 men before and 2, 4, and 7 weeks after prophylaxis and from men with pharyngitis diagnosed at sick call. Of 60 GABHS isolates, 75% were serotype M-3. The pharyngitis rate increased from 0.18% in the spring to 1.55% in the fall with a concurrent increase in serotype M-3 prevalence from 35% to 91%. The GABHS prevalence rate was three- to fourfold lower after prophylaxis. There were no cases of acute rheumatic fever (ARF) despite predominance of M-3, a rheumatogenic serotype. It was concluded that penicillin prophylaxis continues to be effective for control of GABHS infections and prevention of ARF in Navy recruits.