Publications by authors named "Tarja Kaijalainen"

43 Publications

Direct and Indirect Effectiveness of the 10-Valent Pneumococcal Conjugate Vaccine Against Carriage in a Cluster Randomized Trial.

Pediatr Infect Dis J 2017 Dec;36(12):1193-1200

From the *Department of Public Health Solutions, National Institute for Health and Welfare, Tampere, Finland; †Department of Health Security, and ‡Department of Public Health Solutions, National Institute for Health and Welfare, Helsinki, Finland.

Finnish invasive pneumococcal disease (FinIP) vaccine trial was designed to evaluate effectiveness of 10-valent pneumococcal conjugate vaccine (PHiD-CV10; GSK; Rixensart, Belgium). We conducted 2 satellite studies to evaluate ten-valent Pneumococcal Haemophilus influenzae protein D conjugate vaccine (PHiD-CV10) effectiveness against pneumococcal carriage in FinIP-vaccinated children (long-term direct and indirect effectiveness combined) and in their unvaccinated siblings (indirect effectiveness within the family). FinIP was a cluster randomized trial, where >47,000 children <19 months of age were recruited in 2009-2010. Children received PHiD-CV10 in 2/3, and control vaccine in 1/3 of clusters according to age-specific infant and catch-up schedules. We obtained nasopharyngeal samples from subgroups of FinIP-vaccinated children at 3-5 years of age in 2013 and their unvaccinated older siblings in 2011 and 2013, and compared carriage in PHiD-CV10 clusters to control clusters in parallel. National Vaccination Programme with PHiD-CV10 for all 3-month-old children started in 2010 resulting in 92% vaccination coverage. To investigate indirect effects, over 2200 nasopharyngeal swabs were obtained during each round from unvaccinated older siblings. In 2011, we observed a 29% (95% confidence interval: 6-47) reduction in vaccine-type carriage in siblings of PHiD-CV10 participants vaccinated according to infant schedules. Vaccine-type carriage prevalences were low with no differences observed in 2013, 3 years after PHiD-CV10 introduction. For estimation of combined direct and indirect effectiveness, 1550 swabs from FinIP-vaccinated children were obtained in 2013. We observed a reduction of 54% (95% confidence interval: 34-68) in vaccine-type carriage in PHiD-CV10-vaccinated children. This study was the first randomized trial to show the indirect effect of extended valency pneumococcal conjugate vaccination on carriage. Also, long-term effectiveness against vaccine-type carriage was demonstrated in vaccinated children.
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http://dx.doi.org/10.1097/INF.0000000000001705DOI Listing
December 2017

Effectiveness of the 10-Valent Pneumococcal Nontypeable Haemophilus influenzae Protein D-Conjugated Vaccine (PHiD-CV) Against Carriage and Acute Otitis Media-A Double-Blind Randomized Clinical Trial in Finland.

J Pediatric Infect Dis Soc 2016 Sep 28;5(3):237-248. Epub 2016 Apr 28.

GSK Vaccines, Wavre , Belgium.

Unlabelled: After administering the 10-valent pneumococcal polysaccharide nontypeable Haemophilus influenzae protein D-conjugated vaccine (PHiD-CV) to children aged 2-18 months, we observed a reduction in vaccine-type nasopharyngeal carriage, resulting in a reduction of overall pneumococcal nasopharyngeal carriage, which may be important for indirect vaccine effects. We noted a trend toward reduction of acute otitis media.

Background: This trial (ClinicalTrials.gov identifier NCT00839254), nested within a cluster-randomized double-blind invasive pneumococcal disease effectiveness study in Finland (ClinicalTrials.gov identifier NCT00861380), assessed the effectiveness of the 10-valent pneumococcal polysaccharide nontypeable Haemophilus influenzae protein D-conjugated vaccine (PHiD-CV or PCV10) against bacterial nasopharyngeal carriage and acute otitis media (AOM).

Methods: Infants (aged 6 weeks to 6 months) received the PHiD-CV or a control vaccine (hepatitis B) (schedule 3+1 or 2+1). Nasopharyngeal swabs were collected at 4 time points post-vaccination from all of the infants and at pre-vaccination from a subset. Parent-reported physician-diagnosed AOM was assessed from first vaccination until last contact (mean follow-up, 18 months). Vaccine effectiveness (VE) was derived as (1 - relative risk)*100, accounting for cluster design in AOM analysis. Significant VE was assessed descriptively (positive lower limit of the non-adjusted 95% confidence interval [CI]).

Results: The vaccinated cohort included 5093 infants for carriage assessment and 4117 infants for AOM assessment. Both schedules decreased vaccine-serotype carriage, with a trend toward a lesser effect from the 2+1 schedule ( VE across timpoints 19%-56% [3+1] and 1%-38% [2+1]). Trends toward reduced pneumococcal carriage (predominantly vaccine serotypes 6B, 14, 19F, and 23F), decreased carriage of vaccine-related serotype 19A, and small increases at later time points (ages 14-15 months) in non-vaccine-serotype carriage were observed. No effects on nontypeable Haemophilus influenzae, Staphylococcus aureus, or Moraxella catarrhalis carriage were observed. There were non-significant trends toward a reduction in the number of infants reporting AOM episodes (VE 3+1: 6.1% [95% CI, -2.7% to 14.1%] and 2+1: 7.4% [-2.8% to 16.6%]) and all AOM episodes (VE 3+1: 2.8% [-9.5% to 13.9%] and 2+1: 10.2% [-4.1% to 22.9%]). PHiD-CV was immunogenic and had an acceptable safety profile.

Conclusions: We observed reduced vaccine-type pneumococcal carriage, a limited increase in non-vaccine-type carriage, and a trend toward AOM reduction.
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http://dx.doi.org/10.1093/jpids/piw010DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5125453PMC
September 2016

Long-term survival of Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis as isolates and in nasopharyngeal specimens in frozen STGG storage medium.

J Microbiol Methods 2015 Jul 30;114:38-9. Epub 2015 Apr 30.

National Institute for Health and Welfare (THL), Department of Health Protection, Finn-Medi I, Biokatu 6, 33520 Tampere, Finland. Electronic address:

We evaluated survival in WHO-recommended STGG storage medium of bacteria causing respiratory-tract infection. Streptococcus pneumoniae and Moraxella catarrhalis survived as single and mixed isolates stored at -70°C for 12.5 years, but Haemophilus influenzae less than 4 years. All the bacteria survived in the nasopharyngeal specimens at -70°C for 11 years.
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http://dx.doi.org/10.1016/j.mimet.2015.04.012DOI Listing
July 2015

Efficacy of the 7-Valent Pneumococcal Conjugate Vaccine Against Acute Otitis Media Caused by Serotype 6C Pneumococcus.

Pediatr Infect Dis J 2015 Jul;34(7):796-7

From the Department of Health Protection, National Institute for Health and Welfare, Finland.

A new pneumococcal serotype 6C, earlier typed as 6A, was discovered in 2007. We retyped all 6A isolates to evaluate vaccine efficacy against 6C acute otitis media (AOM) in the phase III randomized, double-blind Finnish Otitis Media trial conducted in 1995-1999. Efficacy against 6C AOM was -1 (95% confidence interval: -248 to 71) during the per protocol follow-up period. The updated vaccine efficacy estimate for serotype 6A AOM was 65% (95% confidence interval: 31-82). Seven-valent pneumococcal conjugate vaccine offered excellent cross-protection against 6A AOM, but our data do not support cross-protection against 6C AOM.
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http://dx.doi.org/10.1097/INF.0000000000000728DOI Listing
July 2015

Diet as a risk factor for pneumococcal carriage and otitis media: a cross-sectional study among children in day care centers.

PLoS One 2014 5;9(3):e90585. Epub 2014 Mar 5.

Department of Pediatrics, Oulu University Hospital, Oulu, Finland; Department of Pediatrics, University of Oulu, Oulu, Finland.

Background: Pharyngeal bacteria are exposed to different sugar conditions depending on the diet of the child. We hypothesized that dietary factors such as daily intake of carbohydrates could be associated with pneumococcal carriage and the occurrence of otitis media in children.

Methods: Our study design was a cross-sectional study among 1006 children attending child day care centers. Parents filled in a food frequency questionnaire. Oropharyngeal swabs were collected from each child. The primary outcome was the occurrence of pneumococcal carriage and the secondary outcome the number of acute otitis media episodes during life. Principal component analysis was used to group dietary intake into nine factors. The models were adjusted for age, gender of the child and educational level of the mother.

Results: The dietary factor which included high consumption of sweet pastries and jam was associated with an increased risk of pneumococcal carriage (OR 1.17, 95% CI 1.01 to 1.36, P-value 0.04). The factor including frequent consumption of fruit and berries was associated with a decreased risk of acute otitis (regression coefficient -0.51, 95% CI -0.98 to -0.03, P=0.04). A high intake of consumption of sweets and snacks (OR 1.36, 95% CI 1.03 to 1.80, P=0.03) was associated with an increased risk of caries.

Conclusions: Diet was associated with a risk of pneumococcal carriage and the occurrence of otitis media. Diet may thus be a modifiable risk factor for the occurrence of acute otitis media.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0090585PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3944052PMC
January 2015

Incidence and etiology of community-acquired pneumonia in the elderly in a prospective population-based study.

Scand J Infect Dis 2014 Apr 29;46(4):250-9. Epub 2014 Jan 29.

From the National Institute for Health and Welfare , Helsinki , Finland.

Background: We conducted a prospective population-based epidemiological study to prepare a setting for documentation of the efficacy of novel vaccines against pneumococcal (Pnc) community-acquired pneumonia (CAP) in the elderly. Specific objectives were to demonstrate setting feasibility, to construct a case definition for Pnc CAP, and to estimate its incidence.

Methods: We prospectively enrolled patients with clinical and radiological findings compatible with CAP at municipal on-call clinics serving an elderly population (age ≥ 65 y) of approximately 29,500. Sputum, urine, nasopharyngeal swab (NPS), and blood samples were analyzed using diverse methods for the identification of Pnc (culture, PCR, antigen tests, serology) and of other pathogens. The following case definition for Pnc CAP was derived: encapsulated Pnc in blood culture or in high-quality sputum culture or at least 2 of the following: positive urine Pnc antigen; ≥ 2-fold increase in serum anti-PsaA or anti-CbpA antibodies; encapsulated Pnc culture or LytA PCR in either sputum or NPS.

Results: We enrolled 490 clinical CAP patients during the 2-y follow-up, 53% of all clinical CAP patients in the source population; 323 were radiologically confirmed. The incidence of radiologically confirmed CAP was 5.5/1000 person-y (95% confidence interval (CI) 4.9-6.1) and 10.5/1000 person-y when adjusted for non-captured patients. The proportion of radiologically confirmed CAP caused by Pnc was estimated at 17%; i.e. 0.95/1000 person-y (95% CI 0.7-1.2) and 1.8 when adjusted for non-captured patients.

Conclusions: We developed and documented a feasible methodology for capturing endpoints in a vaccine trial for the prevention of pneumonia. CAP incidence in the elderly population remains considerable and Streptococcus pneumoniae was one of the most commonly detected causative agents.
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http://dx.doi.org/10.3109/00365548.2013.876509DOI Listing
April 2014

Antimicrobial resistance in relation to sero- and genotypes among invasive Streptococcus pneumoniae in Finland, 2007-2011.

Microb Drug Resist 2014 Apr 22;20(2):124-30. Epub 2013 Nov 22.

1 Department of Infectious Disease Surveillance and Control, National Institute for Health and Welfare , Helsinki, Finland .

Aim: We studied the serotypes and antimicrobial resistance of the invasive Streptococcus pneumoniae that had been isolated in Finland during 5 years. The 10-valent vaccine was introduced into the National Vaccination Programme in September 2010.

Methods: We examined the antimicrobial resistance and serotype distribution of the invasive pneumococci (n=4,194) that had been isolated in Finland during 2007-2011. The penicillin-resistant (PEN R) (≥4 mg/L) isolates (n=12) were genotyped by MLST.

Results: Serotype 14 was consistently the most prominent serotype, covering 18.0-20.1% of all the isolates. The proportion of serotypes 3, 19A, and 22F increased significantly, while that of 6B and the PCV10 vaccine serotypes combined decreased. PEN nonsusceptibility (≥0.12 mg/L) increased, ranging from 14.4% to 23.2% by year, and was the highest (28.5%) among the 0-2 year olds. The PEN and/or erythromycin (ERY) nonsusceptibility of several vaccine serotypes (4, 6B, 14, and 19F) increased significantly over the study period. The ERY nonsusceptibility was 26.6%. There was limited diversity among the PEN R isolates; all were a part of serotype 19F, 19A, or 14, and two globally disseminated genetic lineages carrying one or both pilus-encoding islets.

Conclusions: High and/or increasing nonsusceptibility rates underline the importance of monitoring the serotype distribution and antimicrobial susceptibility of pneumococci, especially after large-scale vaccination.
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http://dx.doi.org/10.1089/mdr.2013.0156DOI Listing
April 2014

Comparative analysis of Streptococcus pneumoniae transmission in Portuguese and Finnish day-care centres.

BMC Infect Dis 2013 Apr 18;13:180. Epub 2013 Apr 18.

Background: Day-care centre (DCC) attendees play a central role in maintaining the circulation of Streptococcus pneumoniae (pneumococcus) in the population. The prevalence of pneumococcal carriage is highest in DCC attendees but varies across countries and is found to be consistently lower in Finland than in Portugal. We compared key parameters underlying pneumococcal transmission in DCCs to understand which of these contributed to the observed differences in carriage prevalence.

Methods: Longitudinal data about serotype-specific carriage in DCC attendees in Portugal (47 children in three rooms; mean age 2 years; range 1-3 years) and Finland (91 children in seven rooms; mean age 4 years; range 1-7 years) were analysed with a continuous-time event history model in a Bayesian framework. The monthly rates of within-room transmission, community acquisition and clearing carriage were estimated.

Results: The posterior mean of within-room transmission rate was 1.05 per month (Portugal) vs. 0.63 per month (Finland). The smaller rate of clearance in Portugal (0.57 vs. 0.73 per month) is in accordance with the children being younger. The overall community rate of acquisition was larger in the Portuguese setting (0.25 vs. 0.11 per month), in agreement with that the groups belonged to a larger DCC. The model adequately predicted the observed levels of carriage prevalence and longitudinal patterns in carriage acquisition and clearance.

Conclusions: The difference in prevalence of carriage (61% in Portuguese vs. 26% among Finnish DCC attendees) was assigned to the longer duration of carriage in younger attendees and a significantly higher rate of within-room transmission and community acquisition in the Portuguese setting.
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http://dx.doi.org/10.1186/1471-2334-13-180DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3652738PMC
April 2013

Pneumococcemia in children--a retrospective study before universal pneumococcal vaccinations.

Acta Paediatr 2013 May 28;102(5):514-9. Epub 2013 Feb 28.

Paediatric Research Centre, Tampere University and University Hospital, Tampere, Finland.

Aim: To evaluate the incidence and characteristics of blood culture-positive occult pneumococcemia compared with blood culture-positive pneumococcal pneumonia in children.

Methods: In years 2001-2010, 105 children with positive blood cultures for Streptococcus pneumoniae were identified from hospital electronic files. The patient cards were retrospectively charted for clinical and laboratory data, and 38 patients had and 67 had not pneumonia.

Results: The annual incidence of pneumococcemia was, on average, 29.0/10 000 at 0-12 months, 5.3/10 000 at 13-24 months and 1.9/10 000 at 2-4 years of ages, with no increasing or decreasing trend. The incidence of bacteraemic pneumococcal pneumonia increased (p = 0.022) during the study period. The duration of fever before hospitalization (<24 h 73.9% vs. 25.0%, p = 0.022) and the duration of intravenous antibiotics, usually G-penicillin (median 72 vs. 96 h, p = 0.021) was shorter in pneumococcemia patients. On admission, blood leucocyte count was higher in pneumococcemia (mean 26.6 vs. 21.9 × 10E9/L, p = 0.012), but serum CRP was higher in pneumonia (median 160 vs. 67.4 mg/L, p < 0.001). The serotypes 6B and 14 caused 53.2% of pneumococcemia cases.

Conclusion: The incidence of pneumococcemia was highest in 1-2-year-old children, and typical for pneumococcemia was rapid onset of fever, high blood leucocyte count and a modestly elevated CRP on admission.
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http://dx.doi.org/10.1111/apa.12194DOI Listing
May 2013

Adenoidectomy in young children and serum IgG antibodies to pneumococcal surface protein A and choline binding protein A.

Int J Pediatr Otorhinolaryngol 2012 Nov 24;76(11):1569-74. Epub 2012 Jul 24.

Department of Otorhinolaryngology, Helsinki University Central Hospital, Finland.

Objective: We have previously reported that surgical removal of the nasopharyngeal adenoid in young children resulted in increased risk of nasopharyngeal colonization by pneumococci. We now investigated whether adenoidectomy influences the development of serum IgG antibodies to pneumococcal choline-binding protein A (CbpA) and pneumococcal surface protein A (PspA).

Methods: Altogether 217 children aged 12-48 months who had recurrent or persistent otitis media were randomized to undergo or not to undergo adenoidectomy. All the children underwent insertion of tympanostomy tubes. 166 children were followed-up for 3 years. The main outcome measures were concentrations of serum IgG antibodies to CbpA and PspA three years after randomization. Nasopharyngeal colonization by pneumococci was assessed 1, 2, and 3 years after randomization.

Results: Adenoidectomy decreased concentrations of CbpA antibodies by ca. 25% independently of the observed increase in pneumococcal carriage (OR of log(10) transformed concentrations 0.74, 95% CI 0.58-0.94, P=0.016). Concentrations of PspA antibodies were lower and they seemed not to be influenced by adenoidectomy.

Conclusions: Adenoidectomy in young children causes a small but detectable impairment in the development of serum IgG antibodies to pneumococcal CbpA. The adenoid seems to have a role in augmenting systemic immunity against pneumococci.
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http://dx.doi.org/10.1016/j.ijporl.2012.07.013DOI Listing
November 2012

From Quellung to multiplex PCR, and back when needed, in pneumococcal serotyping.

J Clin Microbiol 2012 Aug 12;50(8):2727-31. Epub 2012 Jun 12.

Department of Infectious Disease Surveillance and Control, National Institute for Health and Welfare, Helsinki, Finland.

All currently available vaccines against Streptococcus pneumoniae are based on selections of the over 90 different serotypes, which underlines the importance of serotyping for surveillance and vaccine efficacy monitoring. In this study, we modified and validated a PCR-based scheme for deducing the serotypes of the invasive pneumococci isolated in Finland. For validation, 170 isolates were serotyped using the new protocol with six sequential multiplex PCRs for the deduction of serotypes, supplemented with Quellung testing when needed. The results were compared with those obtained by traditional serotyping methods. We found that 98.8% (168/170) of the isolates were correctly serotyped by the new protocol. Subsequently, the scheme was taken into regular use for serotyping the invasive pneumococci isolated in Finland for serotype-specific surveillance purposes and has been applied in the serotyping of more than 1,500 invasive isolates so far. The sequential multiplex PCRs (mPCRs) have given a result for over 99% of the isolates and allowed us to both handle samples in bulk and noticeably reduce the cost of reagents. While serotyping primarily by PCR is precise and effective, Quellung testing remains the most reliable way to discover possible discrepancies between the DNA deduced and the phenotypic serotype of an isolate. Since implementing the protocol for regular use, two serotype 19F PCR-positive isolates were found to be serotype 19A by the Quellung reaction. While a rare occurrence, this is an important observation, which prompted a revision of our serotyping protocol to prevent possible underreporting of serotype 19A, a potential replacement serotype following large-scale vaccination.
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http://dx.doi.org/10.1128/JCM.00689-12DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3421528PMC
August 2012

Comparison of the severity and outcome of invasive pneumococcal infections in children and adults.

Pediatr Infect Dis J 2012 Jul;31(7):785-8

Department of Pediatrics, University of Oulu, and Department of Internal Medicine, Oulu University Hospital, Oulu, Finland.

In a population-based observational study of 285 patients with positive blood culture for pneumococci, we found that the course and outcome of invasive pneumococcal infections differ considerably between adults and children. None of the children died, whereas the infection was fatal for 15% (35/229) of the adults (P<0.001). The differences are only partly explained by the underlying conditions.
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http://dx.doi.org/10.1097/INF.0b013e318259cab7DOI Listing
July 2012

Nasopharyngeal carriage of Streptococcus pneumoniae and pneumococcal urine antigen test in healthy elderly subjects.

Scand J Infect Dis 2012 Jun 21;44(6):433-8. Epub 2012 Jan 21.

National Institute for Health and Welfare, Helsinki, Finland.

Background: Children frequently carry Streptococcus pneumoniae (pneumococcus) in their nasopharynx, even when healthy. Lower carriage rates have been reported in adults and only sparse data are available for the elderly. We sampled healthy elderly subjects for nasopharyngeal carriage to assess the prevalence of pneumococcal carriage using various assays.

Methods: A deep nasopharyngeal swab sample was taken from 590 healthy elderly subjects aged ≥ 65 y. The samples were stored in STGG (skim milk-tryptone-glucose-glycerol) medium and cultured directly and after incubation in enrichment broth using routine identification methods. Real-time polymerase chain reaction (PCR) assays specific for pneumolysin and pneumococcal surface antigen A genes was performed on the same samples. Urine was also collected and assayed using the commercial Binax Streptococcus pneumoniae NOW urine antigen test.

Results: The prevalence of pneumococcal carriage in healthy elderly persons was 1.5% for encapsulated pneumococci and 5.3% for all presumptive pneumococci. The use of the enrichment broth did not increase the yield of positives. PCR assays gave higher numbers of positives, but pneumolysin PCR in particular gave probable false-positive results. Only 1 urine antigen test was positive, and this was in a person not carrying pneumococcus.

Conclusions: Nasopharyngeal carriage of pneumococci in the elderly was rare. Identification of presumptive pneumococci in culture requires further confirmation, e.g. by serotyping. The urine antigen test was not affected by concurrent carriage. Low carriage prevalence suggests that encapsulated pneumococci detected in a respiratory tract sample during sickness may be the true cause of disease, since contamination from asymptomatic nasopharyngeal carriage seems unlikely.
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http://dx.doi.org/10.3109/00365548.2011.652162DOI Listing
June 2012

Effect of xylitol and other carbon sources on Streptococcus pneumoniae biofilm formation and gene expression in vitro.

APMIS 2011 Feb 1;119(2):135-42. Epub 2010 Dec 1.

National Institute for Health and Welfare, Oulu, Finland.

Xylitol inhibits the growth of Streptococcus pneumoniae. In clinical trials, xylitol decreased the occurrence of acute otitis media in day-care children, but did not decrease nasopharyngeal carriage of pneumococci. We hypothesized that xylitol inhibits biofilm formation of pneumococci, and measured biofilm formation and gene expression levels of the capsule gene cpsB and two other genes: autolysin encoding gene lytA and competence gene comA in different growth media in vitro. Twenty pneumococcal isolates were grown on polystyrene plates for 18 h in test media containing 0.5% xylitol, 0.5% glucose, 0.5% xylitol and 0.5% glucose, 0.5% fructose, 0.5% xylitol and 0.5% fructose or brain heart infusion (BHI) medium supplemented with 10% horse serum. Gene expression levels were measured after 5 h of growth using a relative quantification method with calibrator normalization. Exposure to xylitol lowered OD values, which were used as an indication of biofilm, compared with BHI medium, but when the medium was supplemented with glucose or fructose, biofilm formation was enhanced and the inhibitory effect of xylitol on biofilm formation was not observed. Xylitol also lowered lytA expression levels. Changes in biofilm formation in response to different sugar compounds may partly explain the efficacy of xylitol to prevent acute otitis media in previous clinical trials.
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http://dx.doi.org/10.1111/j.1600-0463.2010.02703.xDOI Listing
February 2011

Pneumococcal carriage is more common in asthmatic than in non-asthmatic young men.

Clin Respir J 2010 Oct;4(4):222-9

Institute of Diagnostics, Department of Medical Microbiology, University of Oulu, Oulu, Finland.

Introduction:   The aim was to investigate the prevalence of oropharyngeal carriage of Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, Neisseria meningitidis and beta-haemolytic streptococci among asthmatic and non-asthmatic young Finnish men and to identify putative risk factors.

Objectives:   A total of 224 asthmatics and 668 non-asthmatic men (mean age 19.6 years) from two intakes of conscripts to the Kainuu Brigade, Finland in July 2004 and January 2005 were enrolled upon entering military service.

Methods:   Oropharyngeal specimens were examined for bacteria by routine culture methods. All the participants filled in questionnaires concerning risk factors for asthma and respiratory infections.

Results:   S. pneumoniae (48 cases, 5.4%), Group A streptococci (16, 1.8%), H. influenzae (45, 5.0%), M. catarrhalis (24, 2.7%) and N. meningitidis (20, 2.2%) were isolated from the 892 participants. Ten putative risk factors for oropharyngeal colonization (asthma, atopy, allergic rhinitis, smoking, current use of asthma medication, history of adeno/tonsillectomy, level of highly sensitive C-reactive protein, peak expiratory flow, results of a 12-min running test and body mass index) were evaluated. The only significant risk factor for S. pneumoniae carriage was asthma (OR, 2.04; 95% CI 1.12 to 3.72).

Conclusions:   Pneumococcal carriage is more common in asthmatic than in non-asthmatic young men.
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http://dx.doi.org/10.1111/j.1752-699X.2009.00179.xDOI Listing
October 2010

Serotype-related variation in susceptibility to complement deposition and opsonophagocytosis among clinical isolates of Streptococcus pneumoniae.

Infect Immun 2010 Dec 20;78(12):5252-61. Epub 2010 Sep 20.

National Institute for Health and Welfare, Department of Vaccination and Immune Protection, Helsinki, Finland.

The polysaccharide capsule is a major virulence factor of Streptococcus pneumoniae; it affects complement resistance and shields the bacterium from phagocytes. Certain capsular serotypes appear to be better able to cause invasive disease than others. Serotypes 1 and 5 are common causes of invasive disease but are rarely isolated from healthy carriers, whereas serotypes 6B and 23F are more frequently isolated from carriage than invasive disease. We have recently shown that serotypes 6B and 19F differ in resistance to complement C3 deposition and opsonophagocytic killing. In this study we assessed the complement resistance and susceptibility to opsonophagocytosis of several other serotypes targeted by the pneumococcal conjugate vaccines. Clinical isolates of serotypes 1, 4, 5, 14, 18C, and 23F were tested along reference strains of corresponding capsular types. The concentration of anticapsular antibodies required for opsonophagocytic killing correlated inversely with C3 deposition on the serotype. Serotype 1 was the most resistant of the clinical isolates to C3 deposition and, along with serotypes 5 and 19F, required the highest concentration of capsule antibodies for opsonophagocytic killing, whereas serotype 23F was the most sensitive to opsonophagocytosis. Sensitivity to C3 deposition and opsonophagocytosis was associated with serotype-specific mortality of invasive pneumococcal disease, suggesting that the primary pathogens, such as serotypes 1 and 5, are more resistant to complement and require a higher concentration of capsule antibodies for opsonophagocytic killing than the opportunistic serotypes such as 6B and 23F, which are associated with a more severe disease outcome.
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http://dx.doi.org/10.1128/IAI.00739-10DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2981318PMC
December 2010

Risk of invasive pneumococcal infections among working age adults with asthma.

Thorax 2010 Aug;65(8):698-702

Department of Infectious Disease Surveillance and Control, National Institute for Health and Welfare, Helsinki, Finland.

Background: Information about the risk of invasive pneumococcal infection (IPI) among adults with asthma is limited and inconsistent. To evaluate this association, a population-based case-control study was conducted.

Methods: Cases of IPI (Streptococcus pneumoniae isolated from blood or cerebrospinal fluid) were identified through national, population-based laboratory surveillance during 1995-2002. To maximise exclusion of chronic obstructive pulmonary disease, the analysis was limited to patients aged 18-49 years and 10 selected age-, sex- and health district-matched controls for each case from the Population Information System. Information on underlying medical conditions was obtained through linking surveillance data to other national health registries. Asthma requiring > or =1 hospitalisation in the past 12 months was defined as high risk asthma (HRA); low risk asthma (LRA) was defined as entitlement to prescription drug benefits and no hospitalisation for asthma in the past 12 months.

Results: 1282 patients with IPI and 12 785 control subjects were identified. Overall, 7.1% of cases and 2.5% of controls had asthma (6.0% and 2.4% had LRA whereas 1.1% and 0.1% had HRA, respectively. After adjustment for other independent risk factors in a conditional logistic regression model, IPI was associated with both LRA (matched OR (mOR) 2.8; 95% CI 2.1 to 3.6) and HRA (mOR, 12.3; 95% CI 5.4 to 28.0). The adjusted population-attributable risk was 0.039 (95% CI 0.023 to 0.055) for LRA and 0.01 (95% CI 0.0035 to 0.017) for HRA.

Conclusions: Working age adults with asthma are at increased risk of IPI. In this population, approximately 5% of disease burden could be attributed to asthma. These findings support adding medicated asthma in adults to the list of indications for pneumococcal vaccination.
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http://dx.doi.org/10.1136/thx.2009.132670DOI Listing
August 2010

Presence of capsular locus genes in immunochemically identified encapsulated and unencapsulated Streptococcus pneumoniae sputum isolates obtained from elderly patients with acute lower respiratory tract infection.

J Med Microbiol 2010 Oct 8;59(Pt 10):1140-1145. Epub 2010 Jul 8.

National Institute for Health and Welfare, Oulu, Finland.

The principal virulence factor of Streptococcus pneumoniae is capsular polysaccharide, and encapsulated pneumococci are more common causes of disease than unencapsulated strains. This study analysed the presence of capsular genes in 59 pneumococcal isolates using two PCR methods targeted at the cpsA and cpsB genes of the capsular biosynthesis locus. The PCR method targeted at the cpsB gene, reported to be essential for encapsulation, was developed in this study. Of 59 pneumococcal isolates, 49 (83 %) were obtained from the sputum samples of elderly patients (≥65 years) with community-acquired pneumonia (CAP) and 10 (17 %) were from those with other acute lower respiratory tract infections (ARIs). Forty (82 %) of the CAP isolates and two (20 %) of the ARI isolates were encapsulated, as assessed by conventional immunochemical methods. Forty-one (98 %) of the 42 encapsulated strains had the cpsB gene present, and in 38 strains the cpsA gene was also detected. One of the unencapsulated isolates gave a positive result for the cpsB gene, and neither of the capsular locus genes were present in all the other unencapsulated strains. The distribution of encapsulated and unencapsulated isolates differed significantly between the two patient groups regardless of whether the presence of capsule was determined immunochemically (P<0.001) or by cpsB PCR (P=0.002). The cpsB PCR developed here was found to be a rapid and reliable method to detect the pneumococcal capsule locus and may have potential in sputum diagnostics when investigating the pneumococcal aetiology of CAP.
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http://dx.doi.org/10.1099/jmm.0.016956-0DOI Listing
October 2010

Adenoidectomy and nasopharyngeal carriage of Streptococcus pneumoniae in young children.

Arch Dis Child 2010 Sep 26;95(9):696-702. Epub 2010 May 26.

Department of Otorhinolaryngology, Helsinki University Central Hospital, Finland.

Objective: The effect of adenoidectomy on nasopharyngeal colonisation of pathogens has not previously been evaluated. The authors studied the effect of adenoidectomy on nasopharyngeal colonisation by bacteria causing otitis media and the effect of adenoidectomy on the development of pneumococcal capsular polysaccharide antibodies.

Design: Randomised controlled study.

Setting: Tertiary care centre.

Patients: 217 children aged 12-48 months who had recurrent or persistent otitis media were randomised. 166 children were followed up for 3 years.

Intervention: Random allocation to undergo adenoidectomy or not to undergo adenoidectomy. All the children underwent insertion of tympanostomy tubes.

Main Outcome Measures: Nasopharyngeal colonisation by pneumococci, Haemophilus influenzae and Moraxella catarrhalis 1, 2 and 3 years after randomisation. Serum IgG antibodies against pneumococcal capsular polysaccharide serotypes 6B, 14, 19F and 23F 3 years after randomisation.

Results: After the first year of randomisation adenoidectomy increased nasopharyngeal carriage of pneumococci (RR, 1.47; 95% CI 1.04 to 2.07) but it did not influence the carriage of H influenzae or M catarrhalis. Among carriers of serotype 6B pneumococci, adenoidectomy resulted in lower concentrations of pneumococcal serotype 6B polysaccharide antibodies (ratio of geometric means of antibody concentrations, 0.37; 95% CI 0.16 to 0.85). Concentrations of serotype 14, 19F and 23F antibodies seemed not to be influenced by adenoidectomy. Despite this, adenoidectomy resulted in a significant increase in nasopharyngeal carriage of serotype 19F pneumococci.

Conclusions: Adenoidectomy increases the risk of nasopharyngeal carriage of pneumococci in children younger than 4 years of age. This may be independent of the development of serum IgG capsular polysaccharide antibodies.
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http://dx.doi.org/10.1136/adc.2009.165654DOI Listing
September 2010

The development of a 16S rRNA gene based PCR for the identification of Streptococcus pneumoniae and comparison with four other species specific PCR assays.

BMC Infect Dis 2010 Apr 29;10:104. Epub 2010 Apr 29.

Laboratory Bacteriology Research, Department of Chemistry, Microbiology and Immunology, University of Ghent, Ghent, Belgium.

Background: Streptococcus pneumoniae is one of the most frequently encountered pathogens in humans but its differentiation from closely related but less pathogenic streptococci remains a challenge.

Methods: This report describes a newly-developed PCR assay (Spne-PCR), amplifying a 217 bp product of the 16S rRNA gene of S. pneumoniae, and its performance compared to other genotypic and phenotypic tests.

Results: The new PCR assay designed in this study, proved to be specific at 57 degrees C for S. pneumoniae, not amplifying S. pseudopneumoniae or any other streptococcal strain or any strains from other upper airway pathogenic species. PCR assays (psaA, LytA, ply, spn9802-PCR) were previously described for the specific amplification of S. pneumoniae, but psaA-PCR was the only one found not to cross-react with S. pseudopneumoniae.

Conclusion: Spne-PCR, developed for this study, and psaA-PCR were the only two assays which did not mis-identify S. pseudopneumoniae as S. pneumoniae. Four other PCR assays and the AccuProbe assay were unable to distinguish between these species.
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http://dx.doi.org/10.1186/1471-2334-10-104DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2874796PMC
April 2010

Biofilm formation by Streptococcus pneumoniae isolates from paediatric patients.

APMIS 2010 Apr;118(4):255-60

Department of Pediatrics, University of Oulu, and Laboratory of Microbiology, Oulu University Hospital, Oulu, Finland.

The clinical significance of pneumococcal biofilm formation is largely unknown. To clarify this, we tested whether the ability of pneumococcal clinical isolates to form biofilm in vitro accounts for the diverse clinical outcomes. Clinical pneumococcal isolates were cultured from the nasopharynx (n=106), middle ear effusion (n=43) and blood (n=55) of 204 children altogether. Biofilm formation, assessed by measuring optical density (OD) values in microtitre plates after crystal violet staining, did not differ between the bacteria from different sources (p=0.18), the mean OD values of the isolates being 0.119 [95% confidence interval (CI) 0.100-0.138] in the nasopharynx samples, 0.094 (95% CI 0.069-0.119) in the acute otitis media cases, 0.109 (95% CI 0.077-0.141) in the secretory otitis media cases, 0.122 (95% CI 0.084-0.160) in those with sepsis and 0.175 (95% CI 0.071-0.280) in those with other invasive infections. Serotypes 33 and 14 were the most efficient in forming biofilms, whereas serotypes 3 and 38 were poor biofilm producers. We conclude that the clinical presentation of pneumococcal disease did not differ in relation to biofilm formation in vitro, even though there was marked variation between the clinical isolates and serotypes.
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http://dx.doi.org/10.1111/j.1600-0463.2010.02587.xDOI Listing
April 2010

An outbreak of pneumonia associated with S. pneumoniae at a military training facility in Finland in 2006.

APMIS 2009 Jul;117(7):488-91

National Institute for Health and Welfare, Helsinki, Finland.

Streptococcus pneumoniae is a well-known cause of community-acquired bacterial pneumonia. The purpose of this study was to assess the cause and extent of the outbreak of pneumonia which occurred among military recruits following a 1-week hard encampment in Finland. We also assessed the carriage rate and molecular characteristics of the S. pneumoniae isolates. All pneumococcal isolates were studied for antibiotic susceptibility, serotyped, genotyped by multilocus sequence typing (MLST), and the presence of pneumococcal rlrA pilus islet was detected. The genotype results defined by MLST corresponded with the serotype results. S. pneumoniae serotype 7F, ST2331, seemed to be associated with an outbreak of pneumonia and nasopharyngeal carriage among 43 military recruits. Of the 43 military recruits, five (12%) were hospitalized with pneumonia and two (40%) of them were positive for S. pneumoniae serotype 7F, ST2331 by blood culture. Eighteen (42%) of the 43 men were found to be positive for S. pneumoniae by nasopharyngeal culture, and nine (50%) of them carried pneumococcal serotype 7F, ST2331. The outbreak strain covered 55% of all the pneumococcal findings. Outbreaks of invasive pneumococcal disease seem to occur in a crowded environment such as a military training facility even among previously healthy young men.
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http://dx.doi.org/10.1111/j.1600-0463.2009.02463.xDOI Listing
July 2009

Xylitol and capsular gene expression in Streptococcus pneumoniae.

J Med Microbiol 2009 Nov 9;58(Pt 11):1470-1473. Epub 2009 Jul 9.

National Institute for Health and Welfare, Oulu, Finland.

Xylitol is a sugar alcohol that inhibits the growth and adherence of Streptococcus pneumoniae. In clinical trials, xylitol has been shown to decrease the occurrence of acute otitis media in day-care children but did not decrease nasopharyngeal carriage of the pneumococci. It has also been shown that xylitol affects the ultrastructure of the pneumococcal capsule. Here, it was hypothesized that xylitol might affect the expression of pneumococcal capsular genes. Capsule gene expression levels were studied in 24 clinical pneumococcal isolates and one ATCC strain (49619) by using a real-time RT-PCR method targeting the mRNA of the second gene of the pneumococcal capsular locus, the cpsB gene. The isolates were exposed to 5 % glucose, 5 % xylitol and control medium (brain heart infusion medium containing 10 % fetal bovine serum) for 2 h. cpsB gene expression levels were measured by using a relative quantification method with calibrator normalization where the 16S rRNA gene of pneumococcus was used as a reference. Exposure to xylitol lowered cpsB gene expression levels significantly compared with those in the control (P=0.035) and glucose (P=0.011) media. This finding supports previous results where exposure to xylitol changed the ultrastructure of the pneumococcal capsule and could explain further the high clinical efficacy of xylitol in preventing otitis media.
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http://dx.doi.org/10.1099/jmm.0.011700-0DOI Listing
November 2009

Temporal trends of antimicrobial resistance and clonality of invasive Streptococcus pneumoniae isolates in Finland, 2002 to 2006.

Antimicrob Agents Chemother 2009 May 9;53(5):2066-73. Epub 2009 Mar 9.

National Institute for Health and Welfare (THL), Department of Infectious Disease Surveillance and Control, PL 30, FI-00271 Helsinki, Finland.

The antimicrobial resistance of Streptococcus pneumoniae, or pneumococcus, is a growing global problem. In our study, 3,571 invasive pneumococcal isolates, recovered from blood and cerebrospinal fluid samples from patients in Finland between the years 2002 and 2006, showed an increase in erythromycin nonsusceptibility from 16% to 28% (P < 0.0001) over the 5-year study period, as well as a doubling of penicillin nonsusceptibility from 8% to 16% (P < 0.0001). Erythromycin nonsusceptibility increased especially in isolates derived from 0- to 2-year-old children and was 46% for this age group in 2006. Although multiresistance, defined as nonsusceptibility to penicillin, erythromycin, and tetracycline, was fairly rare (5.1% in 2006), 38% of the erythromycin-nonsusceptible isolates were also penicillin nonsusceptible, while 74% of the penicillin-nonsusceptible isolates were nonsusceptible to erythromycin. In contrast to the situation in continental Europe, but mirroring that in North America, the most frequent macrolide resistance determinant carried by 56% of the tested macrolide-resistant pneumococci was the mef gene. Serotypes 14, 9V, 19A, 6B, and 19F were most frequently nonsusceptible to erythromycin or penicillin. The penicillin-resistant invasive isolates (n = 88) were genotyped by multilocus sequence typing, which revealed the presence of 25 sequence types, 9 of which were novel. The majority of the isolates were related to one of several globally disseminated penicillin- or multiresistant clones, most importantly the rlrA adhesion pilus carrying clones Spain(9V) ST156 and Taiwan(19F) ST236. The penicillin-resistant pneumococcal population in Finland is therefore a combination of internationally recognized genotypes as well as novel ones.
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http://dx.doi.org/10.1128/AAC.01464-08DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2681517PMC
May 2009

Trends and geographical variation in invasive pneumococcal infections in Finland.

Scand J Infect Dis 2008 ;40(8):621-8

National Public Health Institute (KTL), Department of Infectious Disease Epidemiology, Helsinki, Finland.

We evaluated regional variation and trends in invasive pneumococcal infections (IPI) in Finland by using data from national, population-based laboratory surveillance and number of blood and cerebrospinal fluid (CSF) cultures performed by all microbiology laboratories during 1995-2002. The overall annualized IPI incidence was 10.6/100,000 (range by region, 7.9 15.1): 9.9 for bacteraemias (range 7.3-14.2) and 0.6 for meningitis (range 0.4-1.1). The rate in children aged <5 y was 23.5/100,000. Regional pneumococcal bacteraemia rates were correlated with blood culture sampling rates (p =0.015), but meningitis rates did not correlate with CSF culture rates. During 1995-2002, the overall annual IPI rate increased by 35.1%, from 8.2 to 11.5/100,000 (p<0.001). The annual blood culturing rate increased by 29.6% (p=0.015 for the correlation with IPI rate). Temporal increase and higher regional IPI rates were significantly associated with higher blood culturing rates. Pneumococcal serotypes included in the 7- and 10-valent conjugate vaccines caused 69.8% and 85.2% of IPIs among children aged <5 y and 49.5% and 59.3% in adults, respectively. The true incidence of pneumococcal bacteraemia in Finland may be higher than previously estimated. Introduction of universal childhood pneumococcal conjugate immunization would provide substantial health benefits to Finnish children and adults.
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http://dx.doi.org/10.1080/00365540801938931DOI Listing
December 2008

Distribution of pneumococcal surface protein A families 1 and 2 among Streptococcus pneumoniae isolates from children in finland who had acute otitis media or were nasopharyngeal carriers.

Clin Vaccine Immunol 2008 Oct 27;15(10):1555-63. Epub 2008 Aug 27.

National Public Health Institute (KTL), Department of Vaccines, Mannerheimintie 166, 00300 Helsinki, Finland.

PspA is a structurally variable surface protein important to the virulence of pneumococci. PspAs are serologically cross-reactive and exist as two major families. In this study, we determined the distribution of PspA families 1 and 2 among pneumococcal strains isolated from the middle ear fluid (MEF) of children with acute otitis media and from nasopharyngeal specimens of children with pneumococcal carriage. We characterized the association between the two PspA families, capsular serotypes, and multilocus sequence types (STs) of the pneumococcal isolates. MEF isolates (n = 201) of 109 patients and nasopharyngeal isolates (n = 173) of 49 children were PspA family typed by whole-cell enzyme immunoassay (EIA). Genetic typing (PCR) of PspA family was done for 60 isolates to confirm EIA typing results. The prevalences of PspA families 1 and 2 were similar among pneumococci isolated from MEF (51% and 45%, respectively) and nasopharyngeal specimens (48% each). Isolates of certain capsule types as well as isolates of certain STs showed statistical associations with either family 1 or family 2 PspA. Pneumococci from seven children with multiple pneumococcal isolates appeared to express serologically different PspA families in different isolates of the same serotype; in three of the children the STs of the isolates were the same, suggesting that antigenic changes in the PspA expressed may have taken place. The majority of the isolates (97%) belonged to either PspA family 1 or family 2, suggesting that a combination including the two main PspA families would make a good vaccine candidate.
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http://dx.doi.org/10.1128/CVI.00177-08DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2565924PMC
October 2008

Defining the population-based burden of nosocomial pneumococcal bacteremia.

Arch Intern Med 2007 Aug 13-27;167(15):1635-40

Department of Infectious Disease Epidemiology, National Public Health Institute, Mannerheimintie 166, FIN-00300 Helsinki, Finland.

Background: The characteristics, risk factors, and outcome of patients with nosocomial pneumococcal bacteremia (NPB) have not been described in large, population-based studies.

Methods: All episodes of invasive pneumococcal infections reported by Finnish clinical microbiology laboratories (positive blood or cerebrospinal fluid culture) from January 1, 1995, through December 31, 2002, were linked to data in national health care registries and vital statistics to obtain information on the patient's preceding hospitalizations, comorbidities, and outcome of illness. Pneumococcal bacteremia was defined as nosocomial if the first positive blood culture was obtained more than 2 days after hospital admission, or if the patient had been hospitalized for more than 2 days within 7 days of the first positive blood culture.

Results: Information on hospital admission was available for 4217 of 4357 persons (96.8%) with invasive pneumococcal infections. We identified 387 NPBs (9.7%) among 3973 pneumococcal bacteremias. Patients with NPB were older (median age, 67 years vs 52 years; P < .001) and were more likely to have at least 1 high-risk condition (other than age > or = 65 years), for which 23-valent pneumococcal polysaccharide vaccine is recommended (59.2% vs 34.6%; P < .001), compared with patients who had community-associated pneumococcal bacteremias. The case fatality proportion at 28 days was higher in patients with NPB than in those with community-associated pneumococcal bacteremias (23.8% vs 10.8%; P < .001). Pneumococcal serotypes included in 23-valent polysaccharide vaccine and 7-valent conjugate vaccine caused 71.5% and 46.1% of NPBs, respectively.

Conclusions: A substantial proportion of pneumococcal bacteremias are health care associated. The high prevalence of conditions for which pneumococcal polysaccharide vaccine is recommended provides opportunities for strengthening prevention efforts in these patients at high risk of illness and death.
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http://dx.doi.org/10.1001/archinte.167.15.1635DOI Listing
October 2007

Treatment of acute otitis media with probiotics in otitis-prone children-a double-blind, placebo-controlled randomised study.

Clin Nutr 2007 Jun 13;26(3):314-21. Epub 2007 Mar 13.

Valio Ltd, R&D, FIN-00039 Helsinki, Finland.

Background & Aims: To examine whether probiotics would reduce the occurrence or duration of acute otitis media (AOM), or the nasopharyngeal carriage of otitis pathogens in otitis-prone children.

Methods: During this double-blind, placebo-controlled, randomised, 24-week intervention, 309 otitis-prone children (10 months-6 years) consumed either one probiotic capsule (Lactobacillus rhamnosus GG and LC705, Bifidobacterium breve 99 and Propionibacterium freudenreichii JS) (n=155) or placebo (n=154) daily. Clinical examinations were carried out and nasopharyngeal samples taken three times. Parents recorded the symptoms of upper respiratory infection (URI) in a diary.

Results: Probiotic treatment did not reduce the occurrence (probiotic vs. placebo: 72% vs. 65%, OR=1.48, 95% CI 0.87-2.52, p=n.s.) or the recurrence ( three) of AOM episodes (18% vs. 17%, OR=1.04, 95% CI 0.55-1.96, p=n.s.). The median duration of AOM episodes was 5.6 (IQR 3.5-9.4) vs. 6.0 (IQR 4.0-10.5) days, respectively (p= n.s.). There was a tendency showing a reduction in the occurrence of recurrent (4 to 6) respiratory infections in the probiotic group (OR for 4 URIs: 0.56, 95%CI 0.31-0.99, p=0.046; OR for 6 URIs: 0.59, 95% CI 0.34 to 1.03, p=n.s.). Probiotics did not affect the carriage of Streptococcus pneumoniae or Haemophilus influenzae, but increased the prevalence of Moraxella catarrhalis (OR=1.79, 95% CI 1.06-3.00, p=0.028).

Conclusions: Probiotics did not prevent the occurrence of AOM or the nasopharyngeal carriage of otitis pathogens in otitis-prone children. A tendency showing a reduction in recurrent respiratory infections must be confirmed in further studies.
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http://dx.doi.org/10.1016/j.clnu.2007.01.003DOI Listing
June 2007

Nasal middle meatal specimen bacteriology as a predictor of the course of acute respiratory infection in children.

Pediatr Infect Dis J 2006 Feb;25(2):108-12

Departments of Otorhinolaryngology, PO Box 5000, University of Oulu, Oulu FIN-90014, Finland.

Aims: To test our hypothesis that children with potentially pathogenic bacteria (Streptococcus pneumoniae, Haemophilus influenzae or Moraxella catarrhalis) in the nasal middle meatus might have more prolonged symptoms of acute respiratory infection than children without such bacteria, we conducted a prospective cohort study of such children.

Materials And Methods: We recruited prospectively child volunteers between 6 and 13 years of age with acute respiratory infections present for fewer than 10 days. Nasal middle meatal bacterial culture was taken with a rigid endoscope at enrollment and again after 3 weeks and evaluated for presence or absence of 3 potential pathogens: S. pneumoniae, H. influenzae and M. catarrhalis. The subsequent persistence of acute symptoms (nasal discharge: clear/colored, nasal obstruction and cough) was determined by means of a diary. Viral etiology was studied with polymerase chain reaction methods.

Results: The 82 children had had symptoms for an average of 4 days (range, 1-10) at entry, and viruses were detected in 54% (39 of 72). The endoscopic procedure and bacteriologic sampling succeeded in all cases. Thirty-eight children (46%) had at least 1 of the 3 pathogens in the middle meatus specimen. The children with nasal pathogens present at entry had a significantly longer mean duration of symptoms than those with nonpathogenic bacteria (difference, 3.6 days; 95% confidence interval, 0.7-6.5; P = 0.025). The effect remained significant after adjustment for age, sex, allergic symptoms and the presence of virus (adjusted relative hazard of delayed recovery, 2.0; 95% confidence interval, 1.1-3.6).

Conclusions: We found that the use of endoscopic swab culture sampling from the nasal middle meatus is well-tolerated by children older than 6 years of age and that it can be useful in selected situations to determine pathogenic bacteria in the culture of these specimens.
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http://dx.doi.org/10.1097/01.inf.0000201048.65828.b5DOI Listing
February 2006