PubMed Health⌕ Search

Biomedical subjects

Jussi Mertsola

Publications and source records attributed to Jussi Mertsola.

At least 19 recordsLinked to original sources
PubMed2006

Population dynamics of Bordetella pertussis in Finland and Sweden, neighbouring countries with different vaccination histories.

Pertussis is an infectious disease of the respiratory tract in humans caused by Bordetella pertussis. Despite extensive vaccinations, pertussis has remained endemic and re-emerged. In Finland, a whole-cell pertussis vaccine has been used since 1952 with high coverage. In Sweden, whole-cell vaccinations were introduced in 1953 but ceased in 1979, and pertussis vaccinations with acellular vaccines were introduced in 1996. Two epidemic peaks occurred in Sweden in 1999 and 2002 and in Finland in 1999 and 2003. We compared Finnish (N=193) and Swedish (N=455) B. pertussis isolates circulating in 1998-2003 together with vaccine strains used in these neighbouring countries with different vaccination histories. The isolates were analysed by serotyping, genotyping of pertussis toxin S1 subunit and pertactin, and pulsed-field gel electrophoresis. The results suggest that the sequential epidemics were caused by clonal expansion of a certain B. pertussis strain possibly transmitted from Sweden to Finland. The roles of antigenic variation in immunity-driven evolution of B. pertussis in both countries are discussed.

Adolescent↗
PubMed2006

Ultrasonography after the first febrile urinary tract infection in children.

UNLABELLED: The importance of ultrasonography after the first febrile urinary tract infection has been recently challenged. The aim of this study was to evaluate the role of ultrasonography in detection of significant non-reflux abnormalities in the kidneys and the urinary tract, and to determine whether these findings influence treatment in these children. The clinical data and ultrasonography results of 155 children admitted to a university hospital with the first febrile urinary tract infection were analysed retrospectively. Renal ultrasonography was abnormal in 23 patients (14.8%). The major portion of these patients (81%) were younger than 2 years of age. Management of nine of these patients was changed based primarily on ultrasonography findings. Four of these patients were treated operatively. CONCLUSION: Our findings indicate that ultrasonography performed after the first urinary tract infection may offer clinically important information about non-reflux abnormalities in the kidneys and urinary tract that can affect the management of children with these complications.

Adolescent↗
PubMed2006

Comparison of total white blood cell count and serum C-reactive protein levels in confirmed bacterial and viral infections.

We report the association of reaction in inflammatory markers with the microbiologic etiology of infection in children. Total white blood cell counts were increased in most pneumococcal and Escherichia coli infections, but in less than one-half of Staphylococcus aureus infections. Adenoviruses were the only viral agents that often increased total white blood cell counts or serum C-reactive protein levels.

Adenoviridae Infections↗
PubMed2006

Bordetella holmesii DNA is not detected in nasopharyngeal swabs from Finnish and Dutch patients with suspected pertussis.

Bordetella holmesii is a Gram-negative bacterium first identified in 1995. It can cause pertussis-like symptoms in humans. B. holmesii contains insertion sequences IS481 and IS1001, two frequently used targets in the PCR diagnosis of Bordetella pertussis and Bordetella parapertussis infections. To investigate the prevalence of B. holmesii in Finnish and Dutch patients with pertussis-like symptoms and whether B. holmesii has caused any false-positive results in diagnostic PCRs, B. holmesii-specific real-time PCRs were developed. The Finnish methods were conventional IS481 PCR and B. holmesii-specific real-time PCR (LightCycler, Roche) targeting the B. holmesii recA gene. The Dutch methods were IS481 and IS1001 PCRs with conventional or real-time formats and B. holmesii-specific real-time PCR targeting the homologue of IS1001. Of 11,319 nasopharyngeal swabs, 2804 were collected from Finnish patients from 2000 to 2003, and 8515 from Dutch patients from 1992 to 2003. B. holmesii DNA was not found in the samples analysed. The results suggest that B. holmesii is not among the causative agents of pertussis-like symptoms in Finnish and Dutch patients and thus does not in practice confound IS481 and IS1001 PCRs.

Bacterial Proteins↗
PubMed2006

Bordetella pertussis, Finland and France.

We used pulsed-field gel electrophoresis analysis and genotyping to compare clinical isolates of Bordetella pertussis recovered since the early 1990s in Finland and France, 2 countries with similar histories of long-term mass vaccination with whole-cell pertussis vaccines. Isolates from both countries were similar genetically but varied temporally.

Bacterial Outer Membrane Proteins↗
PubMed2006

[Not Available].

Explore the source record for details and available documents.

Journal Article↗
PubMed2005

No evidence of cross-reactivity of human antibodies to a 33-mer peptide of the alpha-gliadin component of gluten with Bordetella pertussis pertactin.

A 33-mer peptide of the alpha-gliadin component of gluten was recently identified as primary initiator of the inflammatory response to gluten in coeliac disease (CD) patients. This proline-glutamine-rich peptide (PG-peptide) is highly homologous to internal sequence of pertactin, an immunogenic protein of Bordetella pertussis. Using enzyme immunoassays, we measured serum antibodies to pertactin and to PG-peptide in 167 Finnish subjects including pertussis vaccine recipients and pertussis patients, CD and non-CD patients and healthy individuals. We found no cross-reactivity between human antibodies to the two different components, suggesting that neither pertussis immunization nor disease contributes to the pathogenesis of CD.

Adolescent↗
PubMed2005

Pulsed-field gel electrophoresis analysis of Bordetella pertussis populations in various European countries with different vaccine policies.

The increasing incidence of pertussis in a number of countries, despite good vaccination coverage, is a cause for concern. We used pulsed-field gel electrophoresis (PFGE) typing to examine the genetic diversity of 101 clinical isolates of Bordetella pertussis, recovered during 1999-2001, and circulating in five different European countries to evaluate temporal and geographical distribution. This DNA fingerprinting approach seems to be a more discriminative epidemiological tool than sequencing of individual genes. Despite differences in vaccination policies in the five countries, these European isolates were found to be very similar and fell into the same major PFGE profile groups, with a predominance of one profile group. There was no evidence of geographic clustering, except that one new profile subgroup was predominantly found in one country. This study provides a baseline for continued surveillance of the B. pertussis population in Europe.

Bordetella pertussis↗
PubMed2005

Pertussis immunization in the global pertussis initiative European region: recommended strategies and implementation considerations.

Approaches to pertussis diagnosis, surveillance and immunization vary widely across Europe. Nonetheless most countries report high levels of vaccine coverage in infants and toddlers, and significant reductions in infant morbidity and mortality have been achieved. As a consequence of the effective protection of infants and toddlers, the absolute incidence of pertussis has substantially decreased, but the relative proportion of older age groups, adolescents and adults in particular, has increased. These groups, however, are a relevant source of infection of unimmunized or incompletely immunized infants. In addition to efficient childhood vaccination, other approaches to pertussis immunization are required. Among the various strategies evaluated, 3 were recommended by the European participants in the Global Pertussis Initiative that might be adapted to each country's specific needs: the reinforcement of implementation of current schedules, the addition of an extra dose of vaccine to current immunization schedules and the selective immunization of health care workers, which is already included in a European Commission directive. The main barriers to the acceptance of these strategies are low awareness of pertussis in immunized populations, poor recognition of the disease in adults and adolescents, lack of standardized diagnostic criteria and poor access to laboratory confirmation of the diagnosis. These obstacles have led to underreporting of pertussis and an underestimation of the disease burden. Actions to overcome these issues are crucial to the implementation of new or improved immunization strategies to combat pertussis in Europe.

Adolescent↗
PubMed2005

Defining pertussis epidemiology: clinical, microbiologic and serologic perspectives.

In the past decade, numerous sources have noted an increase in reported pertussis in highly immunized populations. This has been accompanied by a perceived change in disease epidemiology, characterized by a significant increase in reported pertussis incidence among adolescents and adults. In populations where children are routinely immunized, adolescents and adults now constitute the main source of infection in infants. However, a range of factors makes delineation of these epidemiologic trends difficult. Reported cases of pertussis represent only a fraction of the actual number of Bordetella pertussis symptomatic infections, because underconsulting, underrecognition and underdiagnosis are widespread and are a particular problem in adolescents and adults. Possible explanations for failure to diagnose pertussis include the heterogeneity in pertussis disease expression and low physician awareness and index of suspicion. Consequently defining pertussis from a clinical perspective is difficult, and this is reflected by a lack of consistency between case definitions. Although case definitions for specific circumstances have been established by the World Health Organization and the United States Centers for Disease Control, these are not universally useful, making intercountry comparisons and global evaluation difficult. Less-than-optimal and poorly performed laboratory tests, or their lack of availability, also make confirmation of B. pertussis infection difficult. To overcome these problems, clinical case definitions should be standardized for outbreak and endemic situations. Rapid, easy-to-use and inexpensive laboratory diagnostic techniques also must be made available and be widely implemented. In particular, polymerase chain reaction and single serum serology are 2 techniques that should be more widely adopted.

Adolescent↗
PubMed2005

Somatic factors at 8 years of age in children with recurrent use of antibiotics in early infancy.

AIM: To examine the influence of recurrent therapy with antibiotics (RTA) in infancy on children's somatic factors at 8 y of age. METHODS: Subject selection was based on stratified randomized cluster sampling. Altogether 1287 infants were potential participants in the follow-up study. Children with 6 courses of antibiotics (100 children) during their first 18 mo of life and children with no (62%) or 2 courses (38%) of antibiotics participated in a clinical examination in a case-control setting (100 matched controls) at the age of 8 y. RESULTS: The children with RTA continued to have more infections and had had more courses of antibiotics compared to controls during the follow-up. There was no clinically significant difference in the somatic and dental status at the age of 8 between the two groups. The parents of the children with RTA reported significantly more often recurrent infections than the parents of the controls. CONCLUSIONS: The children with recurrent therapy with antibiotics in early childhood also continue to be prescribed more antibiotics in later childhood when compared to those who received no or few antibiotics in infancy. However, recurrent infections and medications do not seem to have a marked effect on the somatic and dental status of these children at 8 y of age.

Anti-Bacterial Agents↗
PubMed2005

Strain variation among Bordetella pertussis isolates in finland, where the whole-cell pertussis vaccine has been used for 50 years.

Pertussis is an infectious disease of the respiratory tract caused by Bordetella pertussis. Despite the introduction of mass vaccination against pertussis in Finland in 1952, pertussis has remained an endemic disease with regular epidemics. To monitor changes in the Finnish B. pertussis population, 101 isolates selected from 1991 to 2003 and 21 isolates selected from 1953 to 1982 were studied together with two Finnish vaccine strains. The analyses included serotyping of fimbriae (Fim), genotyping of the pertussis toxin S1 subunit (ptxA) and pertactin (prn), and pulsed-field gel electrophoresis (PFGE) after digestion of B. pertussis genomic DNA with XbaI restriction enzyme. Strains isolated before 1977 were found to harbor the same ptxA as the strains used in the Finnish whole-cell pertussis vaccine, and strains isolated before 1982 harbored the same prn as the strains used in the Finnish whole-cell pertussis vaccine. All recent isolates, however, represented genotypes distinct from those of the two vaccine strains. A marked shift of predominant serotype from Fim serotype 2 (Fim2) to Fim3 has been observed since the late 1990s. Temporal changes were seen in the genome of B. pertussis by PFGE analysis. Three PFGE profiles (BpSR1, BpSR11, and BpSR147) were distinguished by their prevalence between 1991 and 2003. The yearly emergence of the three profiles was distributed periodically. Our study stresses the importance of the continuous monitoring of emerging strains of B. pertussis and the need to obtain a better understanding of the relationship of the evolution of B. pertussis in vaccinated populations.

Bordetella pertussis↗
PubMed2004

Anti-diphtheria antibody seroprotection rates are similar 10 years after vaccination with dTpa or DTPa using a mathematical model.

The reduced antigen content diphtheria, tetanus and pertussis (dTpa) vaccine (Boostrixtrade mark) has been shown to induce a strong booster response to all the vaccine components in 4-6 year olds. However, anti-diphtheria antibody levels were observed to be lower when compared to the "full strength" paediatric DTPa vaccine. To assess the impact of this difference on long-term protection, a mathematical model was developed to predict diphtheria antibody decay over time. The model was based on a linear decrease in log-transformed antibody concentrations after the first year post-vaccination. When applied to data collected 3.5 years after vaccination of 4-6 year olds with either DTPa or dTpa, the model predicted that 10 years post-vaccination, 98.6% of subjects vaccinated with dTpa were likely to remain seroprotected against diphtheria, compared to 99.6% vaccinated with DTPa. Therefore, the difference observed in diphtheria antibody geometric mean concentrations 1 month after booster vaccination at 4-6 years with dTpa or DTPa is unlikely to be of clinical relevance 10 years later at the time of the adolescent booster.

Adult↗
PubMed2004

Clinical response to antibiotic therapy for community-acquired pneumonia.

UNLABELLED: Childhood community-acquired pneumonia is a common and potentially serious problem worldwide. Unless the patient has bacteraemia or pleural empyema, aetiological diagnostics are limited and antibiotic treatment is empirical. Published data on expected response to therapy are scarce. To determine the clinical response to antibiotic treatment in a developed country in otherwise healthy children with community-acquired pneumonia, we conducted a prospective study of 153 hospitalised children with pneumonia. The role of 17 microbes as potential causative agents was evaluated. The duration of fever (>37.5 degrees C) and hospitalisation were studied as objective measures of recovery. A potential aetiology was found in 83% of 153 patients: 29% of the patients had sole viral and 26% sole bacterial and 29% mixed viral-bacterial infections. The median duration of fever after the onset of antibiotic treatment (mainly penicillin G) was 14 h and the median duration of hospitalisation was 48 h. Patients with mixed viral-bacterial infection became afebrile more slowly than those with either sole viral or sole bacterial infections. CONCLUSION: the findings indicate that in a developed country, children with pneumonia make a rapid, uneventful recovery needing only a short hospital stay. Expensive and time-consuming microbiological investigations are not required once bacterial sepsis has been excluded.

Anti-Bacterial Agents↗
PubMed2004

Recurrent antibiotic use in a small child and the effects on the family.

OBJECTIVE: To determine the typical characteristics of small children on recurrent therapy with antibiotics (RTA) and the effects RTA have on the families. DESIGN: Stratified randomised cluster sampling. SETTING: An unselected population-based questionnaire study in Finland. SUBJECTS: Parents (n = 1443) expecting their first child were followed prospectively from the mother's early pregnancy until the child was 18 months of age. MAIN OUTCOME MEASURES: The outcome measure was the number of courses of antibiotic therapy (options: 011-51 > or = 6) during the child's first 18 months of life. Six or more courses were considered RTA. Associated variables were child- and family-related factors during the child's first 18 months of life. RESULTS: Children on RTA were taken to see a physician more often than other children when they had fever or a common cold. RTA was significantly associated with the child's day care outside the home, allergy and need for a special diet. The father's severe stress was associated with the child's RTA. Breastfeeding lasting more than 3 months was found to have a protective effect against RTA. CONCLUSION: The threshold for seeking medical help was low in the families of children on RTA, which is best avoided by breastfeeding and day care at home. Health care staff should not forget to support families, especially the fathers, with children experiencing recurrent infections.

Anti-Bacterial Agents↗