Large community outbreak of Streptococcus pneumoniae serotype 5 invasive infection in an impoverished, urban population

Indirect impact of childhood 13-valent pneumococcal conjugate vaccine (PCV13) in Canadian older adults: a Canadian Immunization Research Network (CIRN) retrospective observational study

BACKGROUND

13-valent pneumococcal conjugate vaccine (PCV13) has been part of publicly funded childhood immunisation programmes in Ontario and British Columbia (BC) since 2010. We assessed the indirect impact of infant PCV13 programmes on invasive pneumococcal disease (IPD) and all-cause pneumonia hospitalisation in older adults (aged ≥65 years) using a retrospective observational study.

METHODS

We extracted monthly IPD and all-cause pneumonia cases from laboratory and health administrative databases between January 2005 and December 2018. Using a quasi-experimental difference-in-differences design, we calculated the ratio of risk ratios (RRRs) using incidence rates of IPD or all-cause pneumonia cases before (pre-PCV13 period) and after (PCV13 period) 2010 with rates of fractures as controls.

RESULTS

The rates of all IPD or PCV serotype-specific IPD for older adults in both Ontario and BC did not change in 8 years after childhood PCV13 programme implementation. All-cause pneumonia increased in Ontario (RRR 1.38, 95% CI 1.11 to 1.71) but remained unchanged in BC.

CONCLUSIONS

Indirect community protection of older adults from hospitalisation with pneumococcal disease stalled despite maturation of childhood PCV13 vaccination programmes in two Canadian provinces.

Population-based incidence of invasive pneumococcal disease in children and adults in Ontario and British Columbia, 2002-2018: A Canadian Immunization Research Network (CIRN) study

BACKGROUND

Invasive pneumococcal disease (IPD) burden, evaluated in Canada using reported confirmed cases in surveillance systems, is likely underestimated due to underreporting. We estimated the burden of IPD in Ontario and British Columbia (BC) by combining surveillance data with health administrative databases.

METHODS

We established a cohort of 27,525 individuals in Ontario and BC. Laboratory-confirmed IPD cases were identified from Ontario's integrated Public Health Information System and the BC Centre for Disease Control Public Health Laboratory. Possible IPD cases were identified from hospitalization data in both provinces, and from emergency department visit data in Ontario. We estimated the age and sex adjusted annual incidence of IPD and pneumococcal conjugate/polysaccharide vaccine (PCV/PPV) serotype-specific IPD using Poisson regression models.

RESULTS

In Ontario, 20,205 overall IPD cases, including 15,299 laboratory-confirmed cases, were identified with relatively stable age- and sex-adjusted annual incidence rates ranging from 13.7/100,000 (2005) to 13.6/100,000 (2018). In BC, 7,320 overall IPD cases, including 5,932 laboratory-confirmed cases were identified; annual incidence rates increased from 10.9/100,000 (2002) to 13.2/100,000 (2018). Older adults aged ≥ 85 years had the highest incidence rates. During 2007-2018 the incidence of PCV7 serotypes and additional PCV13 serotypes decreased while the incidence of unique PPV23 and non-vaccine serotypes increased in both provinces.

CONCLUSIONS

IPD continues to cause a substantial public health burden in Canada despite publicly funded pneumococcal vaccination programs, resulting in part from an increase in unique PPV23 and non-vaccine serotypes.

The impact of childhood 13-valent pneumococcal conjugate vaccination on overall invasive pneumococcal disease, including the oldest old

Objectives: Our aim was to compare serotype distribution in invasive pneumococcal disease (IPD) in the Belgian population before and after introduction of the 13-valent conjugte vaccine (PCV13) in the national childhood vaccination schedule.Methods: Serotyping was performed on 12,534 pleural fluid and bacteraemic Streptococcus pneumoniae isolates sent to the National Reference Centre. We compared the distribution of serotypes (ST)/serogroups (SG) between the periods before (2007-2010) and after (2012-2015) the introduction of PCV13, in children and adults of different age groups, including older individuals (65-84 and ≥85 years).Results: The introduction of PCV13 in the childhood immunization program resulted in a reduction of 16% of all IPD-isolates. The prevalence of PCV13-SG decreased in all age groups: from 81% to 53% (p < 0.0001) in children <18 years, and from 69% to 53% (p < 0.0001) in individuals aged 18-64. This effect was also observed in age groups 65-84 (64% to 50%, p < 0.0001) and ≥85 years (63% to 47%; p < 0.0001). The proportion of IPD cases caused by non-PCV13 SG increased from 31% to 49% between the two periods, indicating replacement with non-vaccine SG. The coverage rate for the 23-valent polysaccharide vaccine (PPV23) in all age groups remains as high as 89% for the total group.Conclusion: After introduction of PCV13, a reduction of PCV13-serotypes occurred in IPD in all age groups. This supports the rationale to combine the effect of PCV13 with the broader coverage of PPV23 as a vaccination strategy for adults.

Pneumococcal Disease Outbreak at a State Prison, Alabama, USA, September 1-October 10, 20181

A pneumococcal disease outbreak caused by Streptococcus pneumoniae serotype 12F occurred in a state prison in Alabama, USA. Among 1,276 inmates, 40 cases were identified (3 confirmed, 2 probable, 35 suspected). Close living quarters, substance use, and underlying conditions likely contributed to disease risk. Prophylaxis for close contacts included azithromycin and 23-valent pneumococcal polysaccharide vaccine.

Serotypes of Streptococcus pneumoniae in Children Aged <5 Years Hospitalized With or Without Pneumonia in Developing and Emerging Countries: A Descriptive, Multicenter Study

BACKGROUND

Improving knowledge regarding Streptococcus pneumoniae distribution in pneumonia cases is important to better target preventive and curative measures. The objective was to describe S. pneumoniae serotypes in children with or without pneumonia.

METHODS

It was a case-control study carried out in 8 developing and emerging countries between 2010 and 2014. Cases were children aged <5 years admitted to the hospital for pneumonia. Controls were children admitted for surgery or routine outpatient care.

RESULTS

In nasopharyngeal samples, S. pneumoniae were detected in 68.2% of the cases and 47.5% of the controls (P < .001). Nasopharyngeal carriage was associated with a higher risk of being a case in 6/8 study sites (adjusted odds ratio ranged from 0.71 [95% confidence interval [CI], .39-1.29; P = .26] in India [Pune/Vadu] to 11.86 [95% CI, 5.77-24.41; P < .001] in Mongolia). The 13-valent pneumococcal conjugate vaccine (PCV13) serotypes were more frequently detected in cases with nasopharyngeal carriage (67.1%) than in controls with nasopharyngeal carriage (54.6%), P < .001. Streptococcus pneumoniae was detected in blood by polymerase chain reaction in 8.3% of the cases. Of 34 cases with an S. pneumoniae serotype detected in blood, 27 (79%) had the same serotype in the nasopharyngeal sample.

CONCLUSIONS

The results confirm the assumption that the isolate carrying or causing disease in an individual is of the same serotype. Most serotypes independently associated with nasopharyngeal carriage or pneumonia are covered by PCV13, suggesting that increased PCV coverage would reduce the burden of S. pneumoniae-related pneumonia.

Invasive pneumococcal disease confirmed in five different sites including Austrian syndrome in a male patient with methamphetamine abuse

A 60-year-old man with no significant medical history was found unresponsive by his neighbour; he had neck stiffness on physical examination in the emergency department. He later developed acute hypoxic respiratory failure requiring endotracheal intubation. He is a binge drinker on weekends, and methamphetamine was detected in his urine. Contrast-enhanced CT of the chest, abdomen and pelvis revealed multifocal pneumonia, bilateral psoas abscesses and right infraspinatus muscle abscess. Blood, sputum and cerebrospinal fluid cultures grew Streptococcus pneumoniae Transthoracic echocardiography (TTE) revealed tricuspid endocarditis with mild valve insufficiency. He was initially treated with intravenous antibiotics and underwent incision and drainage of right psoas abscess. However, he still had recurrent fever and confusion. Repeat TTE showed larger vegetation, and he also developed septic emboli at the posterior basal right lower lobe pulmonary artery. The patient underwent tricuspid valve debridement and was finally discharged after completing 6 weeks of intravenous antibiotic treatment.

Effectiveness of the 23-valent pneumococcal polysaccharide vaccine against vaccine serotype pneumococcal pneumonia in adults: A case-control test-negative design study

BACKGROUND

Vaccination with the 23-valent pneumococcal polysaccharide vaccine (PPV23) is available in the United Kingdom to adults aged 65 years or older and those in defined clinical risk groups. We evaluated the vaccine effectiveness (VE) of PPV23 against vaccine-type pneumococcal pneumonia in a cohort of adults hospitalised with community-acquired pneumonia (CAP).

METHODS AND FINDINGS

Using a case-control test-negative design, a secondary analysis of data was conducted from a prospective cohort study of adults (aged ≥16 years) with CAP hospitalised at 2 university teaching hospitals in Nottingham, England, from September 2013 to August 2018. The exposure of interest was PPV23 vaccination at any time point prior to the index admission. A case was defined as PPV23 serotype-specific pneumococcal pneumonia and a control as non-PPV23 serotype pneumococcal pneumonia or nonpneumococcal pneumonia. Pneumococcal serotypes were identified from urine samples using a multiplex immunoassay or from positive blood cultures. Multivariable logistic regression was used to derive adjusted odds of case status between vaccinated and unvaccinated individuals; VE estimates were calculated as (1 - odds ratio) × 100%. Of 2,357 patients, there were 717 PPV23 cases (48% vaccinated) and 1,640 controls (54.5% vaccinated). The adjusted VE (aVE) estimate against PPV23 serotype disease was 24% (95% CI 5%-40%, p = 0.02). Estimates were similar in analyses restricted to vaccine-eligible patients (n = 1,768, aVE 23%, 95% CI 1%-40%) and patients aged ≥65 years (n = 1,407, aVE 20%, 95% CI -5% to 40%), but not in patients aged ≥75 years (n = 905, aVE 5%, 95% CI -37% to 35%). The aVE estimate in relation to PPV23/non-13-valent pneumococcal conjugate vaccine (PCV13) serotype pneumonia (n = 417 cases, 43.7% vaccinated) was 29% (95% CI 6%-46%). Key limitations of this study are that, due to high vaccination rates, there was a lack of power to reject the null hypothesis of no vaccine effect, and that the study was not large enough to allow robust subgroup analysis in the older age groups.

CONCLUSIONS

In the setting of an established national childhood PCV13 vaccination programme, PPV23 vaccination of clinical at-risk patient groups and adults aged ≥65 years provided moderate long-term protection against hospitalisation with PPV23 serotype pneumonia. These findings suggest that PPV23 vaccination may continue to have an important role in adult pneumococcal vaccine policy, including the possibility of revaccination of older adults.

The association between regular cocaine use, with and without tobacco co-use, and adverse cardiovascular and respiratory outcomes

BACKGROUND

Understanding the potential impact of cocaine use on health is increasingly important as cocaine use rises in the U.S.

OBJECTIVES

This study evaluated the associations of regular cocaine use, with and without tobacco co-use, with cardiovascular and respiratory outcomes.

METHODS

Analysis of a limited dataset obtained through IBM Watson Health Explorys, a platform integrating electronic health record data. Matched controls were defined for: 1) cocaine-using patients (n = 8244; 44 % female); and subgroups of cocaine-using patients: 2) with an encounter diagnosis for tobacco use disorder (TUD; n = 4706); and 3) without a TUD diagnosis (non-TUD; n = 3538). Patients had at least one documented medical evaluation in the MetroHealth System (Cleveland, Ohio). Cocaine-using patients had an encounter diagnosis of cocaine abuse/dependence and/or ≥2 cocaine-positive drug screens. Control patients, with no documented cocaine-use, were matched to the cocaine-using patients on demographics, residential zip code median income, body mass index, and, for the total sample, TUD-status. Outcomes were encounter diagnosis (yes/no) of cerebrovascular accident, heart arrhythmia, myocardial infarction, subarachnoid hemorrhage, asthma, chronic obstructive pulmonary disease (COPD), pneumonia, and all-cause mortality.

RESULTS

TUD-patients had the greatest prevalence of cardiovascular and respiratory disease, regardless of cocaine-use indication. In the total sample, TUD, and non-TUD subgroups, regular cocaine use was significantly associated with greater risk for cerebrovascular accident, arrhythmia, myocardial infarction, asthma, COPD, pneumonia and mortality.

CONCLUSIONS

Cocaine use is associated with significantly greater risk of adverse cardiovascular and respiratory diagnoses and all-cause mortality.

Homelessness in Adults with Invasive Pneumococcal Disease (IPD) in Calgary, Canada

Background

Homelessness is uncommon but is frequently a characteristic in adults with invasive pneumococcal disease (IPD). In Calgary, homeless persons comprise approximately 0.2% of the population. We evaluated the relationship of homelessness and IPD in Calgary.

Methods

Demographic, clinical, and microbiologic data were collected by the Calgary Streptococcus pneumoniae Epidemiology Research (CASPER) team through prospective, population-based surveillance of all IPD cases. Here, we report on cases in adults (≥18 years) from 2000 to 2016.

Results

Of 1729 IPD cases, 321 (18.8%) occurred in homeless persons. Compared with nonhomeless persons, homeless persons were younger, more often male, smokers, alcohol abusers, illegal drug users, and had a primary diagnosis of pneumonia. In multivariable models of outcomes, homeless persons had lower odds of being admitted to the ICU (odds ratio [OR], 0.7; P = .02) and lower odds of death (OR, 0.6; P = .146). IPD caused by serotypes 4, 5, or 8, which have caused outbreaks in Calgary, was more common in homeless persons (54.4% vs 21.0%; P < .001). In addition, regardless of homeless status, persons with IPD caused by serotypes 4, 5, or 8 had lower odds of ICU admission and mortality (OR, 0.7; P = .017; and OR, 0.4; P = .004; respectively).

Conclusions

Homelessness is overrepresented in IPD cases in Calgary, despite most homeless persons having fewer risk factors than the overall population of persons with IPD. Most cases are caused by serotypes in both the 23-valent polysaccharide vaccine and the 13-valent conjugate vaccine. Thus, enhanced efforts are needed to deliver both vaccines to this vulnerable population.

Emergence of Streptococcus pneumoniae Serotype 12F after Sequential Introduction of 7- and 13-Valent Vaccines, Israel

Israel implemented use of 7- and 13-valent pneumococcal vaccine in 2009 and 2010, respectively. We describe results of prospective, population-based, nationwide active surveillance of Streptococcus pneumoniae serotype 12F (Sp12F) invasive pneumococcal disease (IPD) dynamics in the 7 years after vaccine introduction. Of 4,573 IPD episodes during July 2009-June 2016, a total of 434 (9.5%) were caused by Sp12F. Sp12F IPD rates (cases/100,000 population) increased in children <5 years of age, from 1.44 in 2009-2010 to >3.9 since 2011-2012, followed by an increase in all ages. During 2011-2016, Sp12F was the most prevalent IPD serotype. Sp12F isolates were mostly penicillin nonsusceptible (MIC >0.06 µg/mL; MIC₅₀ = 0.12) and predominantly of sequence type 3774), a clone exclusively found in Israel (constituting ≈90% of isolates in 2000-2009). The sharp increase, long duration, and predominance of Sp12F IPD after vaccine implementation reflect a single clone expansion and may represent more than a transient outbreak.

Streptococcus infantis, Streptococcus mitis, and Streptococcus oralis Strains With Highly Similar cps5 Loci and Antigenic Relatedness to Serotype 5 Pneumococci

Streptococcus pneumoniae is a highly impactful bacterial pathogen on a global scale. The principal pneumococcal virulence factor and target of effective vaccines is its polysaccharide capsule, of which there are many structurally distinct forms. Here, we describe four distinct strains of three Mitis group commensal species (Streptococcus infantis, Streptococcus mitis, and Streptococcus oralis) recovered from upper respiratory tract specimens from adults in Kenya and the United States that were PCR-positive for the pneumococcal serotype 5 specific gene, wzy5. For each of the four strains, the 15 genes comprising the capsular polysaccharide biosynthetic gene cluster (cps5) shared the same order found in serotype 5 pneumococci, and each of the serotype 5-specific genes from the serotype 5 pneumococcal reference strain shared 76-99% sequence identity with the non-pneumococcal counterparts. Double-diffusion experiments demonstrated specific reactivity of the non-pneumococcal strains with pneumococcal serotype 5 typing sera. Antiserum raised against S. mitis strain KE67013 specifically reacted with serotype 5 pneumococci for a positive Quellung reaction and stimulated serotype 5 specific opsonophagocytic killing of pneumococci. Four additional commensal strains, identified using PCR serotyping assays on pharyngeal specimens, revealed loci highly homologous to those of pneumococci of serotypes 12F, 15A, 18C, and 33F. These data, in particular the species and strain diversity shown for serotype 5, highlight the existence of a broad non-pneumococcal species reservoir in the upper respiratory tract for the expression of capsular polysaccharides that are structurally related or identical to those corresponding to epidemiologically significant serotypes. Very little is known about the genetic and antigenic capsular diversity among the vast array of commensal streptococcal strains that represent multiple diverse species. The discovery of serotype 5 strains within three different commensal species suggests that extensive capsular serologic overlap exists between pneumococci and other members of the diverse Mitis group. These findings may have implications for our current understanding of naturally acquired immunity to S. pneumoniae and pneumococcal serotype distributions in different global regions. Further characterization of commensal strains carrying homologs of serotype-specific genes previously thought to be specific for pneumococci of known serotypes may shed light on the evolution of these important loci.

Outbreak of invasive Streptococcus pneumoniae among an inner-city population in Victoria, British Columbia, 2016-2017

Background

Invasive pneumococcal disease (IPD) is a significant cause of morbidity and mortality; however, outbreaks of IPD are relatively rare. Homelessness and substance use are known risk factors for IPD and have been associated with several outbreaks in Canada, despite national recommendations for routine childhood and targeted adult pneumococcal vaccination.

Objectives

To describe the epidemiology and public health challenges related to an outbreak of novel serotype 4 IPD in a homeless and unstably housed population in Victoria, British Columbia during the autumn and winter of 2016-2017.

Results

Prospective, enhanced surveillance was initiated for laboratory confirmed cases reported to public health, including variables recording housing status and substance use. Thirty-three cases of serotype 4 IPD within the Victoria area were reported to public health between August 1, 2016 and September 1, 2017. Compared with other serotypes, these cases were more likely to be middle-aged, homeless or unstably housed, and to have a recent history of substance use. A targeted pneumococcal vaccination campaign was initiated in collaboration with external community organizations; however, these initiatives were challenged by incomplete data and staffing constraints.

Conclusion

This report illustrates an outbreak of serotype 4 IPD among an inner-city population with multiple risk factors, including homelessness, unstable housing and substance use. Given the challenges controlling the outbreak, outreach capacity and pneumococcal vaccination coverage is needed among this marginalized population.

Streptococcus pneumoniae outbreaks and implications for transmission and control: a systematic review

BACKGROUND

Streptococcus pneumoniae is capable of causing multiple infectious syndromes and occasionally causes outbreaks. The objective of this review is to update prior outbreak reviews, identify control measures, and comment on transmission.

METHODS

We conducted a review of published S. pneumoniae outbreaks, defined as at least two linked cases of S. pneumoniae.

RESULTS

A total of 98 articles (86 respiratory; 8 conjunctivitis; 2 otitis media; 1 surgical site; 1 multiple), detailing 94 unique outbreaks occurring between 1916 to 2017 were identified. Reported serotypes included 1, 2, 3, 4, 5, 7F, 8, 12F, 14, 20, and 23F, and serogroups 6, 9, 15, 19, 22. The median attack rate for pneumococcal outbreaks was 7.0% (Interquartile range: 2.4%, 13%). The median case-fatality ratio was 12.9% (interquartile range: 0%, 29.2%). Age groups most affected by outbreaks were older adults (60.3%) and young adults (34.2%). Outbreaks occurred in crowded settings, such as universities/schools/daycares, military barracks, hospital wards, and long-term care facilities. Of outbreaks that assessed vaccination coverage, low initial vaccination or revaccination coverage was common. Most (73.1%) of reported outbreaks reported non-susceptibility to at least one antibiotic, with non-susceptibility to penicillin (56.0%) and erythromycin (52.6%) being common. Evidence suggests transmission in outbreaks can occur through multiple modes, including carriers, infected individuals, or medical devices. Several cases developed disease shortly after exposure (< 72 h). Respiratory outbreaks used infection prevention (55.6%), prophylactic vaccination (63.5%), and prophylactic antibiotics (50.5%) to prevent future cases. PPSV23 covered all reported outbreak serotypes. PCV13 covered 10 of 16 serotypes. For conjunctival outbreaks, only infection prevention strategies were used.

CONCLUSIONS

To prevent the initial occurrence of respiratory outbreaks, vaccination and revaccination is likely the best preventive measure. Once an outbreak occurs, vaccination and infection-prevention strategies should be utilized. Antibiotic prophylaxis may be considered for high-risk exposed individuals, but development of antibiotic resistance during outbreaks has been reported. The short period between initial exposure and development of disease indicates that pneumococcal colonization is not a prerequisite for pneumococcal respiratory infection.

Willingness to use an in-hospital supervised inhalation room among people who smoke crack cocaine in Vancouver, Canada

INTRODUCTION AND AIMS

People who use illicit drugs (PWUD) often engage in drug use during hospitalisation. Adverse outcomes may arise from efforts to conceal inpatient drug use, especially in hospital settings that rely on abstinence-based policies. Harm reduction interventions, including supervised drug consumption services, have not been well studied in hospital settings. This study examines factors associated with willingness to use an in-hospital supervised inhalation room (SIR) among people who smoke crack cocaine in Vancouver, Canada.

DESIGN AND METHODS

Cross-sectional data from two open prospective cohorts of PWUD involving people who smoke crack cocaine were collected between June 2013 and May 2014. Multivariable logistic regression analyses were used to identify factors associated with willingness to use an in-hospital SIR.

RESULTS

Among 539 participants, 320 (59.4%) reported willingness to use an in-hospital SIR. Independent factors positively associated with willingness included: ever used drugs in hospital [adjusted odds ratio (AOR) = 1.89], and daily non-injection crack use (AOR = 1.63). Difficulty accessing new crack pipes (AOR = 0.51) was negatively associated with willingness (all P < 0.05). The most commonly reported reasons for willingness were to: remain in hospital (50.6%), reduce drug-related risks (25.6%) and reduce the stress of hospital discharge for using drugs (24.7%).

DISCUSSION AND CONCLUSIONS

A high proportion of people who smoke crack cocaine reported willingness to use an in-hospital SIR, and those willing were more likely to report heavy drug use and previous in-hospital use. These findings highlight the potential utility of SIRs to complement existing in-hospital services for PWUD.

Health outcomes associated with crack-cocaine use: Systematic review and meta-analyses

BACKGROUND

Crack-cocaine use is prevalent largely in socio-economically marginalized populations in the Americas. Its use has been associated with diverse health outcomes, yet no recent or systematic reviews of these exist.

METHODS

A systematic review of health outcomes associated with crack-cocaine use was performed, using MEDLINE, Scopus, Web of Science, CINAHL, PsycINFO, and LILACS up to October 2016. Search terms included crack-cocaine and health outcome-related keywords, targeting peer-reviewed studies on quantified health outcomes associated with crack-cocaine use. Random effects meta-analyses produced pooled odds ratios. Levels of evidence for major results were assessed using the GRADE approach. A review protocol was registered with PROSPERO (CRD42016035486).

RESULTS

Of 4700 articles returned, 302 met eligibility criteria, reporting on health outcomes for 14 of 22 ICD-10 chapters. Conclusive evidence and meta-analyses showed positive associations between crack-cocaine use and blood/sexually transmitted diseases (HIV and hepatitis C virus, others); moderate evidence and meta-analyses supported associations with neonatal health, and violence. There were mixed associations for mental and other health outcomes, yet insufficient evidence to perform meta-analyses for many categories (e.g., mortality). Most underlying research was of limited or poor quality, with crack-cocaine commonly assessed as a secondary covariate.

CONCLUSIONS

Crack-cocaine use was associated with a range of health outcomes, although it was unclear if there was direct causal impact, interactions between risk factors, or external drivers of both crack-cocaine use and outcomes. Rigorous epidemiological studies are needed to systematically assess health outcomes of crack-cocaine use and underlying pathways, also to inform evidence-based interventions.

Outcomes of Critically Ill Patients Who Have Serotype 5 Invasive Pneumococcal Disease

PURPOSE

To determine whether invasive pneumococcal disease (IPD) due to serotype 5, which occurred as a local outbreak in 2006 to 2007, is associated with intensive care unit (ICU) admission, hospital mortality, or organ supports in those who are critically ill.

MATERIALS AND METHODS

Retrospective review of patients who presented with IPD to 2 tertiary hospitals in Vancouver, Canada, from July 2004 to June 2007. We compared patient characteristics, interventions, and outcomes between patients who had serotype 5 and other serotypes using bivariate and multivariate analyses.

RESULTS

A total of 149 patients had serotype 5 and 106 had nonserotype 5. Patients with serotype 5 were younger, had lower prevalence of comorbid diseases, and had higher rates of substance use than patients with nonserotype 5. There were no differences in chest tube placement for complications of pneumonia or in ICU admission. Frequency of necrotizing pneumonia and hospital mortality were lower in the serotype 5 group. For the 71 patients with IPD who were admitted to ICU, there was no difference in severity of illness, ICU length of stay, or ICU mortality between the groups. There was also no difference in organ supports except that the serotype 5 group was more likely to receive vasopressors.

CONCLUSION

Serotype 5 in patients who have IPD is associated with no difference in ICU admission but with increased use of vasopressors and lower hospital mortality.

Burden of Culture-Confirmed Pediatric Pneumococcal Pneumonia in Latin America and the Caribbean: A Systematic Review and Meta-Analysis

BACKGROUND

Pneumococcal pneumonia (PP) causes almost one in five deaths in children younger than 5 years worldwide. In Latin America and the Caribbean (LAC), pneumonia causes 14% of all deaths. Although pneumococcal disease is a vaccine-preventable disease that accounts for a significant proportion of this burden, the decision-making process to introduce pneumococcal conjugate vaccines in official schedules is still complex in LAC. Confirmed PP cases and epidemiology are the basis for broader projections.

OBJECTIVE

To gather all the information available in the LAC region to assist decision makers.

METHODS

We performed a systematic review of studies of consolidating and culture-confirmed pediatric PP in LAC (2000-2016) using a generic academic Internet search and search engines without language restrictions. Pairs of reviewers independently selected and assessed the studies' methodological quality. We analyzed meta-information on pneumococcal serotypes available from the SIREVA laboratory-based surveillance system.

RESULTS

A total of 35 out of 750 initially identified studies were included. In the age group between 0 and 59 years, the incidence of culture-confirmed PP ranged from 10.2 to 43.0/100,000 children, with a pooled incidence of 20.4/100,000 children (95% confidence interval 0.0-123.2). Mortality ranged from 0.4 to 5.7/100,000 children, and the pooled mortality was 2.9/100,000 children (95% confidence interval 0.3-8.2). The pooled serotype distribution from surveillance data showed that serotypes 14, 1, and 6B were the most frequent serotypes in LAC, all included in licensed vaccines.

CONCLUSIONS

Studies on confirmed pediatric PP were scarce in LAC in 2000 to 2016. Epidemiology indicators and health resource use are still poorly defined.

Childhood pneumococcal disease in Africa - A systematic review and meta-analysis of incidence, serotype distribution, and antimicrobial susceptibility

BACKGROUND

Determining the incidence, disease-associated serotypes and antimicrobial susceptibility of invasive pneumococcal disease (IPD) among children in Africa is essential in order to monitor the impact of these infections prior to widespread introduction of the pneumococcal conjugate vaccine (PCV).

METHODS

To provide updated estimates of the incidence, serotype distribution, and antimicrobial susceptibility profile of Streptococcus pneumoniae causing disease in Africa, we performed a systematic review of articles published from 2000 to 2015 using Ovid Medline and Embase. We included prospective and surveillance studies that applied predefined diagnostic criteria. Meta-analysis for all pooled analyses was based on random-effects models.

RESULTS

We included 38 studies consisting of 386,880 participants in 21 countries over a total of 350,613 person-years. The pooled incidence of IPD was 62.6 (95% CI 16.9, 226.5) per 100,000 person-years, including meningitis which had a pooled incidence of 24.7 (95% CI 11.9, 51.6) per 100,000 person-years. The pooled prevalence of penicillin susceptibility was 78.1% (95% CI 61.9, 89.2). Cumulatively, PCV10 and PCV13 included 66.9% (95% CI 55.9, 76.7) and 80.6% (95% CI 66.3, 90.5) of IPD serotypes, respectively.

CONCLUSIONS

Our study provides an integrated and robust summary of incidence data, serotype distribution and antimicrobial susceptibility for S. pneumoniae in children ≤5years of age in Africa prior to widespread introduction of PCV on the continent. The heterogeneity of studies and wide range of incidence rates across the continent indicate that surveillance efforts should be intensified in all regions of Africa to improve the integrity of epidemiologic data, vaccine impact and cost benefit. Although the incidence of IPD in young children in Africa is substantial, currently available conjugate vaccines are estimated to cover the majority of invasive disease-causing pneumococcal serotypes. These data provide a reliable baseline from which to monitor the impact of the broad introduction of PCV.

Genomic Analysis of a Serotype 5 Streptococcus pneumoniae Outbreak in British Columbia, Canada, 2005-2009

Background. Streptococcus pneumoniae can cause a wide spectrum of disease, including invasive pneumococcal disease (IPD). From 2005 to 2009 an outbreak of IPD occurred in Western Canada, caused by a S. pneumoniae strain with multilocus sequence type (MLST) 289 and serotype 5. We sought to investigate the incidence of IPD due to this S. pneumoniae strain and to characterize the outbreak in British Columbia using whole-genome sequencing. Methods. IPD was defined according to Public Health Agency of Canada guidelines. Two isolates representing the beginning and end of the outbreak were whole-genome sequenced. The sequences were analyzed for single nucleotide variants (SNVs) and putative genomic islands. Results. The peak of the outbreak in British Columbia was in 2006, when 57% of invasive S. pneumoniae isolates were serotype 5. Comparison of two whole-genome sequenced strains showed only 10 SNVs between them. A 15.5 kb genomic island was identified in outbreak strains, allowing the design of a PCR assay to track the spread of the outbreak strain. Discussion. We show that the serotype 5 MLST 289 strain contains a distinguishing genomic island, which remained genetically consistent over time. Whole-genome sequencing holds great promise for real-time characterization of outbreaks in the future and may allow responses tailored to characteristics identified in the genome.

Serotype 10A in case patients with invasive pneumococcal disease: a pilot study of PCR-based serotyping in New Jersey

In 2008, the New Jersey Department of Health (NJDOH) identified a 21.1% increase in reported invasive pneumococcal disease (IPD). In 2009, NJDOH piloted nucleic acid-based serotyping to characterize serotypes causing IPD. From April through September, NJDOH received specimens from 149 of 302 (49%) case patients meeting our case definition. An uncommon serotype, 10A, accounted for 25.2% of IPD overall and was identified in 12 counties, but it was associated with one county (rate ratio = 5.4, 95% confidence interval [CI] 2.1, 11.8). NJDOH subsequently conducted a case-control study to assess the presentation of and clinical risk factors for 10A IPD. Case patients with 10A IPD were more likely to have had immunosuppression, asthma, and multiple chronic medical conditions than control subjects had (odds ratio [OR] = 2.6, 95% CI 1.1, 6.3; OR=4.7, 95% CI 1.7, 13.2; and OR=2.3, 95% CI 1.0, 5.2, respectively). State-based pneumococcal serotype testing identified an uncommon serotype in New Jersey. Continued pneumococcal serotype surveillance might help the NJDOH identify and respond to future serotype-specific increases.

Changes in hospitalizations for pneumonia after universal vaccination with pneumococcal conjugate vaccines 7/13 valent and haemophilus influenzae type b conjugate vaccine in a Pediatric Referral Hospital in Uruguay

BACKGROUND

In 1994, Uruguay included Haemophilus influenzae b (Hib) conjugated vaccine in a 3 + 1 schedule. In March 2008, 7-valent pneumococcal conjugate vaccines (PCV7) was included in a 2 +1 schedule. In 2010, 13-valent PCV replaced PCV7. Catch-up immunization was offered. The aim of this study was to describe the etiology of community-acquired pneumonia (CAP) in children 0-14 years of age hospitalized at the Hospital Pediatrico-Centro Hospitalario Pereira Rossell between 2003 and 2012.

METHODS

Annual hospitalization rates (per 10,000 discharges) for CAP and bacterial-confirmed CAP in children 0-14 years of age was described prior PCV7 vaccination (2003-2007), during the year of implementation of PCV7 (2008) and after the introduction of PCV7 (2009-2012). Data regarding age, strains isolated from pleural fluid and/or blood, vaccination status, pneumococcal and H. influenzae serotypes were obtained from Hospital Pediatrico-Centro Hospitalario Pereira Rossell databases and vaccination records.

RESULTS

Hospitalization rates for CAP and pneumococcal CAP between prevaccine years and the last year after introduction of vaccination with PCV (2012) significantly decreased by 78.1% and 92.4%, respectively. Significant reduction for 13-valent PCV vaccine serotypes and significant increase for nonvaccine serotypes was observed. A decrease in Staphylococcus aureus pneumonia was observed. Hospitalization rates for H. influenzae CAP remain stable before and after pneumococcal vaccination.

CONCLUSIONS

Three years after PCV7/13 introduction into the routine vaccination schedule, there was a rapid and significant reduction in rates of CAP and P-CAP. An increase of etiology of CAP by other agents was not observed.

Outbreak of invasive Streptococcus pneumoniae serotype 12F among a marginalized inner-city population in Winnipeg, Canada, 2009-2011

BACKGROUND

In 2010, Winnipeg, Canada, experienced a doubling of invasive pneumococcal disease (IPD) rates, with a significant increase in the number of cases due to Streptococcus pneumoniae serotype 12F, which previously had accounted for very few cases each year.

METHODS

All serotype 12F IPD cases reported between September 2009 and January 2011 were reviewed. Pulsed-field gel electrophoresis (PFGE) and multilocus variable number tandem repeat analysis (MLVA) were conducted on all isolates. PFGE and MLVA patterns identified several possible clusters. Additional interviews were conducted to obtain information on risk factors and outcomes.

RESULTS

Between September 2009 and January 2011, 169 cases of IPD were identified. The number of IPD cases due to 12F serotype increased sharply from about 3-4 cases per year (6% of IPD cases) in 2007-2009 to 28 (29%) in 2010. All 12F isolates belonged to a single sequence type (ST218), and they were generally susceptible to penicillin and fluoroquinolones but not to erythromycin. Compared with cases caused by other serotypes, patients with serotype 12F were more likely to be homeless, reside in low-income inner-city communities, and engage in substance abuse, including intravenous and crack cocaine use. Subclusters identified using MLVA had even higher rates of homelessness and substance use.

CONCLUSIONS

An immunization campaign targeting high-risk groups was undertaken with pneumococcal polysaccharide vaccine, and subsequently rates of serotype 12F decreased. To our knowledge, this is the largest documented community outbreak of serotype 12F IPD and the first report of an outbreak of IPD serotype 12F in a marginalized urban population in Canada.

Epidemiology and population structure of serotypes 1, 5 and 7f carried by children in Portugal from 1996-2010 before introduction of the 10-valent and 13-valent pneumococcal conjugate vaccines

Among the over 90 serotypes of Streptococcus pneumoniae described, serotypes 1, 5, and 7F account for a significant proportion of invasive disease worldwide and are now covered by the most recent 10- and 13-valent pneumococcal conjugate vaccines (PCVs). The epidemiology of these serotypes in carriage remains poorly studied because they are rarely detected. We aimed to gain insights into the epidemiology and population structure of serotypes 1, 5 and 7F carried by children in Portugal before PCV10 and PCV13 became widely used. Isolates obtained in cross-sectional studies carried out over a 15-year period (1996–2010) were retrospectively pooled and characterized. Of 5,123 pneumococci obtained, 70 were associated with serotypes 1 (n = 21), 5 (n = 7), and 7F (n = 42). The highest prevalence detected was 3.3% for serotype 1 in 2006, 1% for serotype 5 in 2009, and 3.3% for serotype 7F in 2006; Serotype 1 was associated with PMEN international clones Sweden¹-28(ST306) and Sweden¹-40(ST304); serotype 5 was associated with Colombia⁵-19(ST289); and serotype 7F was associated with Netherlands^7F-39(ST191). All these isolates were fully susceptible. Most carriers of serotypes 1 (86%), 5 (86%), and 7F (91%) were older than two years but a significant association with older age was only observed for serotype 7F (p = 0.006). Evidence for cross-transmission was obtained. In conclusion, we were able to detect and characterize the rarely carried serotypes 1, 5, and 7F among healthy children in Portugal. These data will constitute an important baseline for upcoming surveillance studies aimed to establish the impact of novel PCVs targeting these serotypes in carriage.

Serotype 5 pneumococci causing invasive pneumococcal disease outbreaks in Barcelona, Spain (1997 to 2011)

In this study, we analyzed the clinical and molecular epidemiology of invasive serotype 5 (Ser5) pneumococcal isolates in four teaching hospitals in the Barcelona, Spain, area (from 1997 to 2011). Among 5,093 invasive pneumococcal isolates collected, 134 (2.6%) Ser5 isolates were detected. Although the overall incidence of Ser5-related invasive pneumococcal disease (IPD) was low (0.25 cases/100,000 inhabitants), three incidence peaks were detected: 0.63/100,000 in 1999, 1.15/100,000 in 2005, and 0.37/100,000 in 2009. The rates of Ser5 IPD were higher among young adults (18 to 64 years old) and older adults (>64 years old) in the first two peaks, whereas they were higher among children in 2009. The majority (88.8%) of the patients presented with pneumonia. Comorbid conditions were present in young adults (47.6%) and older adults (78.7%), the most common comorbid conditions being chronic obstructive pulmonary disease (20.6% and 38.3%, respectively) and cardiovascular diseases (11.1% and 38.3%, respectively). The mortality rates were higher among older adults (8.5%). All Ser5 pneumococci tested were fully susceptible to penicillin, cefotaxime, erythromycin, and ciprofloxacin. The resistance rates were 48.5% for co-trimoxazole, 6.7% for chloramphenicol, and 6% for tetracycline. Two major related sequence types (STs), ST1223 (n = 65) and ST289 (n = 61), were detected. The Colombia(5)-ST289 clone was responsible for all the cases in the Ser5 outbreak in 1999, whereas the ST1223 clone accounted for 73.8% and 61.5% of the isolates in 2005 and 2009, respectively. Ser5 pneumococci are a frequent cause of IPD outbreaks in the community and involve children and adults with or without comorbidities. The implementation of the new pneumococcal conjugated vaccines (PCV10 and PCV13) might prevent such outbreaks.

Postlicensure surveillance for pre-specified adverse events following the 13-valent pneumococcal conjugate vaccine in children

Although no increased risk was detected for serious adverse events in the prelicensure trials for the 13-valent pneumococcal vaccine, Prevnar 13(®) (PCV13), continued monitoring of rare but serious adverse events is necessary. A surveillance system using cohort study design was set up to monitor safety of PCV13 immediately after it was included in the childhood immunization program in the United States. The exposed population included children of 1 month to 2 years old who received PCV13 from April, 2010 to January, 2012 from the eight managed care organizations participating in the Vaccine Safety Datalink Project in the United States. The historical unexposed population was children of the same age who received the 7-valent pneumococcal conjugate vaccine Prevnar 7(®) (PCV7) in 2007 (or 2005 depending on the outcome of interest) to 2009. The risk of pre-specified adverse events in the risk window following PCV13 was repeatedly compared to that in the historical comparison group. The number of doses included in the study was 599,229. No increased risk was found for febrile seizures, urticaria or angioneurotic edema, asthma, thrombocytopenia, or anaphylaxis. An increased risk for encephalopathy was not confirmed following the medical record review. The relative risk for Kawasaki disease in 0-28 days following vaccination was 1.94 (95% confidence interval: 0.79-4.86), comparing PCV13 to PCV7. Comparing to PCV7 vaccine, we identified no significant increased risk of pre-specified adverse events in the Vaccine Safety Datalink study cohort. The possible association between PCV13 and Kawasaki disease may deserve further investigation.

Pneumonia immunization in older adults: review of vaccine effectiveness and strategies

Vaccination remains the primary preventive strategy in the elderly against Streptococcus pneumoniae and influenza infections. The effectiveness of this strategy in preventing pneumonia has been in doubt despite the increase in vaccination coverage among older adults. Randomized controlled trials (RCTs) and observational studies aimed at determining clinical outcomes and immune response following pneumococcal vaccination have yielded conflicting results. The protective efficacy of pneumococcal vaccination against pneumonia in older adults has not been firmly established due to a lack of RCTs specifically examining patients ≥ 65 years of age. Similarly, the reported benefits of influenza vaccination have been derived from observational data. The assessment of clinical benefit from influenza vaccination in the elderly population is complicated by varying cohorts, virulence of the influenza strain, and matching of vaccine and circulating viral strains. The presence of selection bias and use of nonspecific end points in these studies make the current evidence inconclusive in terms of overall benefit. The development of more immunogenic vaccines through new formulations or addition of adjuvants holds the promise of revolutionizing delivery and improving efficacy. Dismantling existing barriers through education, providing technology assistance predominantly to developing countries, and establishing clear regulatory guidance on pathways for approval are necessary to ensure timely production and equitable distribution.

Invasive pneumococcal disease and pandemic (H1N1) 2009, Denver, Colorado, USA

Pneumococcal pneumonia was a complication during previous influenza pandemics but was not evident initially during pandemic (H1N1) 2009. During October 2009 in Denver, Colorado, USA, invasive pneumococcal disease (IPD) and pandemic (H1N1) 2009 peaked simultaneously, which suggests a link. We compared cases of IPD in October 2009 with cases in February 2009, the most recent peak month of seasonal influenza. During October 2009, we observed 58 IPD cases, which was 3× the average number of IPD cases that usually occur in October in Denver. Patients with IPD in October 2009 were younger and more likely to have chronic lung disease than patients who had IPD in February 2009; a total of 10/47 patients had influenza, and 33/53 patients had influenza-like illness. Thus, ≈17%-62% cases of IPD may have been associated with pandemic (H1N1) 2009. Pneumococcal disease prevention strategies should be emphasized during future influenza pandemics.

Epidemic of invasive pneumococcal disease, western Canada, 2005-2009

In Canada before 2005, large outbreaks of pneumococcal disease, including invasive pneumococcal disease caused by serotype 5, were rare. Since then, an epidemic of serotype 5 invasive pneumococcal disease was reported: 52 cases during 2005, 393 during 2006, 457 during 2007, 104 during 2008, and 42 during in 2009. Of these 1,048 cases, 1,043 (99.5%) occurred in the western provinces of Canada. Median patient age was 41 years, and most (659 [59.3%]) patients were male. Most frequently representing serotype 5 cases (compared with a subset of persons with non-serotype 5 cases) were persons who were of First Nations heritage or homeless. Restriction fragment-length polymorphism typing indicated that the epidemic was caused by a single clone, which multilocus sequence typing identified as sequence type 289. Large pneumococcal epidemics might go unrecognized without surveillance programs to document fluctuations in serotype prevalence.

The epidemiology of invasive pneumococcal disease in British Columbia following implementation of an infant immunization program: increases in herd immunity and replacement disease

OBJECTIVES

In 2003, British Columbia (BC) introduced a universal heptavalent pneumococcal conjugate vaccine (PCV-7) program for infants, and in 2007 revised the recommended schedule from four doses to three doses. We describe trends in the incidence of invasive pneumococcal disease (IPD) in association with these program changes.

METHODS

All confirmed cases are reported to the BC Centre for Disease Control (BCCDC) using a standardized data collection process; isolates are forwarded to the BCCDC Public Health and Reference Microbiology Laboratory for serotyping and to the National Reference Laboratory for confirmation. Upon implementation of the reduced dose program in 2007, additional epidemiological data, including immunization history, were collected for children < or = 16 years.

RESULTS

Seven years after implementation of the program, a 78% decline in incidence of IPD among children under five has been achieved; this is largely a direct effect of the PCV-7 program. Among those >16 years of age, herd immunity is evident and decreasing trends of PCV-7 serotypes continued even after the dose reduction program was introduced. However, gains in disease reduction were offset by increases in replacement serotypes, particularly among the over-65 age group. This has resulted in no net change in adult IPD rates.

CONCLUSIONS

The implementation of the PCV-7 program has changed the epidemiology of IPD in BC through direct effects of the vaccine, herd immunity and serotype replacement. The introduction of a three-dose schedule was not associated with an excess of vaccine failures.

The future of pneumococcal disease prevention

Pneumococcal disease (PD) is the leading cause of vaccine preventable deaths in children <5 years of age worldwide, with most of the deaths occurring in the developing world. Prevention of PD in children has been achieved by vaccination with pneumococcal conjugate vaccine (PCV), the basis for which is induction of a protective antibody response against the bacterial polysaccharide capsule. Conjugation of the polysaccharide capsule to a protein carrier enables the generation of an immunologic response to the vaccine in young children, leading to protection against infection. The heptavalent PCV, which contains 7 of the 93 known pneumococcal serotypes (4, 6B, 9V, 14, 18C, 19F, 23F) was the first PCV available, licensed in the US in 2000 and subsequently in many countries worldwide, including Latin American and Caribbean countries. Since its introduction, PCV7 has been documented effective for reducing invasive PD mortality and burden, as well as that of pneumonia and otitis media. Additionally, PD caused by the vaccine serotypes has decreased in the unimmunized population due to herd immunity induced by PCV7. Despite this success, significant disease burden still exists globally due to serotypes not included in PCV7. Currently there are 2 new PCVs that have been approved for use in children, a 10-valent vaccine (includes PCV7 serotypes plus serotypes 1, 5 and 7F) and a 13-valent vaccine (includes PCV7 serotypes plus serotypes 1, 3, 5, 6A, 7F and 19A). The selection of new serotypes to be included was based on importance of these serotypes as causes of PD. An additional 15-valent vaccine (includes PCV 7 serotypes plus serotypes 1, 3, 5, 6A, 7F, 19A, 22F and 33F) is undergoing clinical trial testing. In view of the 93 serotypes that are currently known, it seems clear that vaccines with greater coverage, likely based on proteins common to all serotypes, will be needed in the future. Technical and regulatory challenges to the development and approval of newer PCVs include a need for licensing criteria of common protein vaccines, establishment of correlates of protection for disease manifestations other than invasive disease, comparative efficacy data, and clinical trial testing of concomitant immunization of higher valency PCVs with other vaccines.

Safety and immunogenicity of a 13-valent pneumococcal conjugate vaccine in healthy infants and toddlers given with routine pediatric vaccinations in Canada

BACKGROUND

The global distribution of pneumococcal disease and emergence of nonvaccine pneumococcal serotypes prompted the development of a 13-valent pneumococcal conjugate vaccine (PCV13), with broader coverage than 7-valent PCV (PCV7). This study compared compatibility of PCV13 and PCV7 with concurrently administered diphtheria, tetanus, acellular pertussis, inactivated poliovirus, Haemophilus influenzae type b vaccine, and meningococcal C conjugate vaccine (menC), and assessed the safety and immunogenicity of PCV13.

METHODS

In this double-blind, randomized trial, children received PCV7 or PCV13 at 2, 4, 6, and 12 months with routine vaccinations. One month following the infant series and toddler dose, the responses to Hib, pertussis, menC, and specific pneumococcal serotypes were measured. Safety and tolerability were assessed daily for 4 days by parents.

RESULTS

Subjects received PCV13 (n = 300) or PCV7 (n = 303); immunogenicity assessment was completed in 265 and 268 subjects, respectively. There were no statistically significant differences between the groups in responses to Hib, pertussis, or menC after primary or booster vaccinations. More than 95% of subjects in the PCV13 group produced >0.35 μg/mL antibody to each pneumococcal serotype 1 month after the third dose, except with serotypes 23F (90%), 3 (80%), and 5 (87%). After the fourth dose, 98% to 100% of subjects achieved serotype-specific antibody concentrations >0.35 μg/mL, except for serotype 3 (85%). Safety and tolerability did not differ between groups with respect to local or systemic side effects.

CONCLUSIONS

Responses to routine childhood vaccines did not differ with PCV7 or PCV13 coadministration. Serotype-specific pneumococcal antibody concentrations were protective. The safety profile of PCV13 was favorable.

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

BACKGROUND

Outbreaks 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 FINDINGS

CASPER (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/SIGNIFICANCE

During 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.

Impact of universal pneumococcal vaccination on hospitalizations for pneumonia and meningitis in children in Montevideo, Uruguay

BACKGROUND

In March 2008, Uruguay included PCV7 into the routine vaccination program, in a 2 + 1 schedule for children <2 years of age. Catch-up immunization was offered to children born in 2007. Greater than 95% of children received their first and second doses. The aim of this study was to assess the effect of this strategy.

METHODS

Annual hospitalization rates (per 10,000 discharges) for community-acquired pneumonia (CAP) in children <14 years of age and pneumococcal meningitis are described prior to PCV7 vaccination (2005-2007), during the year of implementation (2008) and following vaccine introduction (2009). Data regarding age, diagnosis, vaccination status, and pneumococcal serotype were obtained from Hospital Pereira Rossell databases and vaccination records.

RESULTS

Comparison of hospitalization rates for CAP and pneumococcal-CAP (P-CAP) between prevaccine years (2005-2007) and the year after vaccination (2009) decreased significantly in all children by 56% and 48.2%, respectively. Significant reduction was observed for vaccine serotype P-CAP (serotype 14 P-CAP decreased from 26.6 to 2.5 per 10,000 discharges) in children <2 years of age. A significant reduction in pneumococcal meningitis of 59% was seen in this age group; median rates prevaccination decreased from 17 (12.2-24.9) to 7 (3-11.8) after the administration of vaccine. No vaccine failures for P-CAP or pneumococcal meningitis were seen in fully immunized children.

CONCLUSIONS

One year after PCV7 introduction into the routine vaccination schedule of Uruguay, there was a rapid and significant reduction in rates of CAP, P-CAP, and pneumococcal meningitis in children <2 years of age.

Invasive pneumococcal disease: association between serotype, clinical presentation and lethality

To ascertain the factors linked to invasive pneumococcal disease (IPD) caused by the different serotypes in the period 2007-2009, following the conjugate vaccine's inclusion in the childhood vaccination schedule, a total of 2013 IPD cases were reviewed. The mean annual incidence in this period was 10.74 cases per 100,000 inhabitans and the lethality was 8.8%. Overall serotype distribution displayed certain peculiarities, such as the high frequency of serotype 5. Serotype 3, male gender, sepsis and presence of risk factors were significantly associated with lethality. Vaccinated children under 5 years of age had a higher risk of disease due to serotype 19A. Serotype 8 was associated with the presence of underlying risk factors.

Nasopharyngeal carriage of individual Streptococcus pneumoniae serotypes during pediatric pneumonia as a means to estimate serotype disease potential

BACKGROUND

We aimed at estimating pneumococcal serotype-specific disease potential in pediatric community-acquired alveolar pneumonia (CAAP), by comparing nasopharyngeal pneumococcal carriage during disease to carriage in healthy children.

METHODS

Pneumococcal nasopharyngeal cultures were obtained from children < 5 years old admitted to the emergency room or hospitalized with radiologically diagnosed CAAP and from healthy controls. Disease potential was estimated by calculating serotype-specific odds ratios (OR) of a given serotype to be carried during disease compared with healthy children (after adjustment for age, ethnicity, previous antibiotic therapy, and season).

RESULTS

A total of 603 and 1504 isolates were obtained from CAAP and healthy children, respectively. A significant OR > 1.0 of a specific serotype being carried during disease (suggesting a higher disease potential) was observed with serotypes (by decreasing rank) 1, 5, 22F, 7F, 14, 9V, and 19A. A significant OR < 1.0 of being carried during disease (suggesting a lower disease potential) was observed with serotypes 6A, 6B, 23A, and 35B. Carriage of PCV7 serotypes (grouped) during CAAP was highest in age group 6 to 17 months. PCV10 and PCV13 provided significantly higher coverage for both 6 to 17 and 18 to 35 month age groups.

CONCLUSIONS

It is suggested that serotypes 1, 5, 7F, 9V, 14, 19A, and 22F have a higher disease potential for childhood pneumonia than do serotypes 6A, 6B, 23A, and 35B.

Control of Streptococcus pneumoniae serotype 5 epidemic of severe pneumonia among young army recruits by mass antibiotic treatment and vaccination

During an outbreak of severe pneumonia among new army recruits, an epidemiological investigation combined with repeated nasopharyngeal/oropharyngeal cultures from sick and healthy contacts subjects was conducted. Fifteen pneumonia cases and 19 influenza-like illness cases occurred among 596 recruits over a 4-week period in December 2005. Pneumonia attack rates reached up to 5.5%. A single pneumococcus serotype 5 clone was isolated from blood or sputum cultures in 4 patients and 30/124 (24.1%) contacts. Immunization with 23-valent polysaccharide vaccine supplemented with a 2-dose azithromycin mass treatment rapidly terminated the outbreak. Carriage rates dropped to <1%, 24 and 45 days after intervention.

Epidemiology of Streptococcus pneumoniae and Staphylococcus aureus colonization in healthy Venezuelan children

Streptococcus pneumoniae and Staphylococcus aureus cause significant morbidity and mortality worldwide. We investigated both the colonization and co-colonization characteristics for these pathogens among 250 healthy children from 2 to 5 years of age in Merida, Venezuela, in 2007. The prevalence of S. pneumoniae colonization, S. aureus colonization, and S. pneumoniae-S. aureus co-colonization was 28%, 56%, and 16%, respectively. Pneumococcal serotypes 6B (14%), 19F (12%), 23F (12%), 15 (9%), 6A (8%), 11 (8%), 23A (6%), and 34 (6%) were the most prevalent. Non-respiratory atopy was a risk factor for S. aureus colonization (p = 0.017). Vaccine serotypes were negatively associated with preceding respiratory infection (p = 0.02) and with S. aureus colonization (p = 0.03). We observed a high prevalence of pneumococcal resistance against trimethoprim-sulfamethoxazole (40%), erythromycin (38%), and penicillin (14%). Semi-quantitative measurement of pneumococcal colonization density showed that children with young siblings and low socioeconomic status were more densely colonized (p = 0.02 and p = 0.02, respectively). In contrast, trimethoprim-sulfamethoxazole- and multidrug-resistant-pneumococci colonized children sparsely (p = 0.03 and p = 0.01, respectively). Our data form an important basis to monitor the future impact of pneumococcal vaccination on bacterial colonization, as well as to recommend a rationalized and restrictive antimicrobial use in our community.

Invasive serotype 1 Streptococcus pneumoniae outbreaks in the South Pacific from 2000 to 2007

In New Caledonia, Wallis and Futuna, and French Polynesia, an active surveillance system was established to monitor pneumococcal serotype prevalence between 2000 and 2007. The most prevalent serotype was serotype 1, which belonged to the major clonal complex sequence type 306 (ST306) and was responsible for invasive pneumococcal disease outbreaks.

The effect of routine vaccination on invasive pneumococcal infections in Canadian children, Immunization Monitoring Program, Active 2000-2007

Active surveillance was conducted by the 12 centers of the Canadian Immunization Monitoring Program, Active from 2000-2007 in children 16 years of age and younger to determine the influence of 7-valent pneumococcal conjugate immunization programs on the prevalence, serotype and antibiotic resistance patterns of invasive pneumococcal disease (IPD) caused by Streptococcus pneumoniae. The absolute number of reported IPD cases decreased 48% (p<0.01) over the 8-year period and 56% (p<0.01) in children 0-4 years of age. The absolute number of reported IPD cases caused by serotypes in the conjugate vaccine decreased 87.5% (p<0.01) overall and 92% (p<0.01) in children 0-4 years. Although 6 non-vaccine serotypes increased over time, only serotype 19A increased significantly (p<0.01). Overall, the proportion of penicillin resistant isolates remained unchanged at 17%. Cefotaxime/ceftriaxone resistance remained unchanged at 2% of isolates annually. Universal pneumococcal conjugate infant immunization programs have dramatically decreased cases of invasive pneumococcal disease.

Pathogenesis, treatment, and prevention of pneumococcal pneumonia

Pneumococcus remains the most common cause of community-acquired pneumonia worldwide. Streptococcus pneumoniae is well adapted to people, and is a frequent inhabitant of the upper airways in healthy hosts. This seemingly innocuous state of colonisation is a dynamic and competitive process in which the pathogen attempts to engage the host, proliferate, and invade the lower airways. The host in turn continuously deploys an array of innate and acquired cellular and humoral defences to prevent pneumococci from breaching tissue barriers. Discoveries into essential molecular mechanisms used by pneumococci to evade host-sensing systems that are designed to contain the pathogen provide new insights into potential treatment options. Versatility of the genome of pneumococci and the bacteria's polygenic virulence capabilities show that a multifaceted approach with many vaccine antigens, antibiotic combinations, and immunoadjuvant therapies will be needed to control this microbe.