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Biomedical subjects

L Kröger

Publications and source records attributed to L Kröger.

10 recordsLinked to original sources
PubMed2000

Development of tuberculin reactivity and sensitization to M. scrofulaceum and M. fortuitum in children BCG-vaccinated at birth.

Since the incidence of tuberculosis is steadily declining in Finland and infections by environmental mycobacteria may be increasing, the aim of the present study was to evaluate the development of tuberculin reactivity and sensitization to environmental mycobacteria. Healthy Finnish schoolchildren aged 10.4-12.4 yrs (n=201) were tested with tuberculin purified protein derivative RT23, Mycobacterium scrofulaceum RS95 and M. fortuitum RS20 sensitins. The same children had been previously tested with the same antigens and methods at the age of 4-6 yrs in 1989. Rapid waning of tuberculin reactivity and decrease in sensitization to environmental mycobacteria were observed between 4-6 yrs. Both tuberculin and sensitin skin reaction sizes decreased significantly over the 6-yrs period. The mean tuberculin skin reaction size was 3.2 mm in diameter, which was significantly (p<0.001) smaller than the mean induration size (4.8 mm) at the age of 4-6 yrs. Similarly, the mean skin reaction sizes to M. scrofulaceum and M. fortuitum sensitins were 3.4 and 1.7 mm, respectively, which were significantly (p<0.001) smaller than 6 yrs earlier (mean 4.5 and 3.1 mm). The number of zero reactions to all antigens increased significantly during the follow-up period. Contacts with pets or farm animals were associated with larger reactions. In contrast, children suffering from allergic symptoms had smaller reactions. Contacts with mycobacteria, either with Mycobacterium tuberculosis or environmental mycobacteria, seem to be too rare to maintain tuberculin responsiveness and a high sensitivity to other mycobacteria. Different bacille Calmette-Guérin vaccine products and dosages used, the declining incidence of tuberculosis and geographical factors, which can influence environmental mycobacterial exposure, may explain the disparity between the present and previous Finnish studies.

BCG Vaccine↗
PubMed1995

Osteitis caused by bacille Calmette-Guérin vaccination: a retrospective analysis of 222 cases.

To evaluate the frequency, clinical features, and prognosis of patients with osteitis caused by bacille Calmette-Guérin (BCG) vaccination, medical records from Finnish children based on nationwide registration from 1960 to 1988 were retrospectively analyzed. During the study period, three different BCG vaccine preparations were used. In 222 children, diagnostic criteria of BCG osteitis were fulfilled. The age at onset of BCG osteitis varied from 0.25 to 5.7 years. The most common sites of osteitis were metaphyses of the long bones. The lower extremity (58%) was affected more often than the upper (14%). Osteitis was situated in the sternum in 36 patients (15%) and in the ribs in 27 (11%). The frequency of BCG osteitis, but not the clinical parameters, was closely associated with the vaccine preparation used. Only 6 children were left with some sequelae. With adequate treatment, the prognosis for children vaccinated with BCG is good.

BCG Vaccine↗
PubMed1994

Osteitis after newborn vaccination with three different Bacillus Calmette-Guérin vaccines: twenty-nine years of experience.

Newborns in Finland have been vaccinated with Bacillus Calmette-Guérin (BCG) since the 1950s. Until the end of 1970 the vaccine was made from BCG strain Gothenburg by the Swedish BCG laboratory in Gothenburg and from 1971 on from the same strain in Copenhagen, Denmark. It was replaced by the Glaxo vaccine in 1978. Complications caused by BCG vaccination have been under follow-up, and the data have been collected from nationwide registers. In this study we analyzed the incidence rates of BCG osteitis between the years 1960 and 1988. From 1960 to 1970 the incidence rate was from 2.7 to 13.0/100,000 BCG-vaccinated infants (mean, 7.3; median, 6.9). The incidence increased during the years 1971 to 1978 when it varied between 15.3 and 72.9/100,000 BCG-vaccinated infants (mean, 36.9; median, 30.4). Since 1978 the incidence has varied between 1.7 and 10.1/100,000 BCG-vaccinated infants (mean, 6.4; median, 7.2). In Britain no reports of BCG osteitis have been published despite the use of the same Glaxo vaccine. Our results indicate that the incidence of BCG osteitis in a given population depends on the BCG vaccine used. The follow-up of BCG complications is an essential part of BCG vaccination program.

Animals↗
PubMed1994

Influence of MPR revaccination on tuberculin and sensitin skin reactions in children.

Many viral diseases, as well as viral vaccines, have a transient effect in depressing cell-mediated immunity. The study group consisted of 52 children, aged 6.0-6.3 years. Thirty (57%) of them had been revaccinated against measles, parotitis and rubella (MPR vaccination). In MPR-revaccinated children, the mean skin reaction sizes were 4.7 mm, 4.1 mm, 4.3 mm and 2.1 mm to tuberculin, Mycobacterium avium, M. scrofulaceum and M. fortuitum sensitins, respectively. In non-revaccinated children (n = 22), the respective mean skin reaction sizes were 3.0 mm, 2.8 mm, 2.9 mm and 0.8 mm. The difference between re- and non-revaccinated children was statistically significant with regard to reactions to M. fortuitum sensitin (p < 0.05). These results suggest that the influence of viral revaccination is different from natural infection or primary vaccination. The mechanism of stimulation of cell-mediated immunity--either specific or non-specific--is unknown.

Antigens↗
PubMed1993

Development of bone mass and bone density of the spine and femoral neck--a prospective study of 65 children and adolescents.

The bone mineral density (BMD, g/cm2) of the lumbar spine (L2-L4) and femoral neck was measured twice with a 1-year interval by dual energy X-ray absorptiometry (DEXA) in 65 healthy children and adolescents aged 7-20 years. In addition, the BMD values were corrected for the size of bones to obtain the bone volumetric density (BMDvol, g/cm3) using a method developed previously. The annual increases of BMD and BMDvol in both spine and femoral neck were most marked in females at the time of menarche (during the age of 11-13 years), and in males between the ages of 13 and 17 years. The males showed significantly higher values in their mean annual increment rates of femoral bone mineral content (BMC) and femoral neck width, whereas no differences in spinal parameters were found. The acquisition of bone mass and bone density stopped or markedly diminished before the age of 20 years, supporting the theory that the major portion of the peak bone mass is attained in late adolescence. We could not find any significant relationship between the increment rate of bone density, and physical activity or calcium intake. This study emphasizes the significant effect of puberty and genetic factors on the development of bone mass and density.

Absorptiometry, Photon↗
PubMed1993

C-reactive protein in viral and bacterial respiratory infection in children.

C-reactive protein (CRP) was studied in 209 children treated in hospital due to middle or lower respiratory tract infection with serologically demonstrated viral or bacterial aetiology. Of the 110 patients with serological evidence of bacterial infection, either alone or in association with viral infection, 52% had CRP > 20 mg/l, 35% > 40 mg/l and 15% > 80 mg/l. Of the 99 patients with serological evidence of viral infection alone, 35% had CRP > 20 mg/l, but only 12% > 40 mg/l and 5% > 80 mg/l. Nearly all, 88%, of the 25 patients with CRP > 40 mg/l in association with viral infection had either an infectious focus, specific microbial or non-specific laboratory evidence suggestive of bacterial infection. By calculating diagnostic parameters at 3 cut-off levels of CRP, the level 40 mg/l seemed more useful than 20 mg/l or 80 mg/l for differentiation between viral and bacterial infections. By using a CRP value of 40 mg/l as a screening limit sensitivity was 0.55, specificity 0.88, positive predictive value 0.76, negative predictive value 0.55, and likelihood ratios of a positive and negative test result 2.9 and 0.74, respectively. It is concluded that low CRP values do not rule out bacterial aetiology of respiratory infection in children. On the other hand viral infection without bacterial involvement is very improbable if CRP is > 40 mg/l. Our results suggest that high CRP values rule out viral infection as a sole aetiology of infection; bacterial infection and antibiotic treatment should be considered in these cases.

Adolescent↗
PubMed1993

White blood cell and differential counts in acute respiratory viral and bacterial infections in children.

White blood cell (WBC) and differential counts were studied in 201 children hospitalized for acute viral or bacterial respiratory infection. The aetiology of infection was studied with a comprehensive set of serological tests. WBC and granulocyte counts were higher in patients with bacterial infection than in those with viral infection. Lymphocyte counts, by contrast, had no such aetiological association. The 95% confidence limits for WBCs and granulocytes distinguished bacterial and pneumococcal cases completely from viral cases with no bacterial involvement. The sensitivity of WBC counts, as well as granulocyte or lymphocytes counts, for distinguishing bacterial from viral cases was low at all cut-off levels. Specificity, in contrast, was 86% and 95% for WBCs at the cut-off levels 15.0 and 20.0 x 10(9)/l, and 84% and 97% for granulocytes at the cut-off levels 10.0 and 15.0 x 10(9)/l, respectively. It is concluded that high WBC and granulocyte counts are clear evidence of the bacterial aetiology of respiratory infection, but low or normal values do not rule it out. Lymphocyte counts are of no value for distinguishing between viral and bacterial infections.

Acute Disease↗
PubMed1992

Skin test reactivity to atypical mycobacteria among healthy Finnish preschool children vaccinated with BCG vaccine at birth.

Skin test reactivity to three mycobacterial sensitins (M. avium, M. fortuitum and M. scrofulaceum) was studied in 353 healthy children vaccinated with the BCG vaccine at birth. A significant waning of reactivity to all of the three sensitins was found to occur with increasing age. Revaccination against measles, parotitis and rubella had been given to 31 (9%) of the children, all aged > 5.5 years. They had significantly larger reactions sizes, which was contrary to what was expected. Children with atopic dermatitis (n = 19) had significantly smaller reaction sizes to the M. fortuitum sensitin. Neither respiratory viral infections during the preceding six months nor contact with pets or farm animals had any influence on reaction sizes. The variation of sensitin reactions was large in preschool children vaccinated with the BCG vaccine at birth. The diagnostic value of sensitin reactions in preschool children needs to be elaborated in clinical studies in children with clinically demonstrable mycobacteriosis.

Animals↗
PubMed1992

Rapid decrease in tuberculin skin test reactivity at preschool age after newborn vaccination.

A study of tuberculin sensitivity was performed in 353 children aged 4-6 years, all vaccinated at birth with British BCG vaccine. Significant waning of tuberculin reactions with increasing age was found (p < 0.05). In the age group < 4.5 years, the mean tuberculin reaction was 6.6 mm, in the age group 4.5-5.5 years 5.2 mm and in the age group of > 5.5 years 3.5 mm. The number of children with positive reactions (> or = 5 mm) was 165 (40%) and those with strong reactions (> or = 10 mm) 49 (14%). None of the latter children had active tuberculosis during a follow-up period of 12 months. Eighty-three (24%) of the children had no reaction. The children who had been revaccinated with the MPR vaccine against measles, rubella and parotitis (n = 31) had significantly larger tuberculin reactions than the non-revaccinated children. Atopic dermatitis or infections during the preceding six months did not have any significant influence on reaction sizes. Our results demonstrate that the variation in size of tuberculin reactions after BCG vaccination at birth is large. We conclude that tuberculin sensitivity wanes rapidly by the age of 4.0-6.3 years.

Age Factors↗