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Biomedical subjects

B Trollfors

Publications and source records attributed to B Trollfors.

At least 37 records · Page 2Linked to original sources
PubMed1998

Aetiology of acute epiglottitis in adults.

In order to determine the aetiology of acute epiglottitis in adults, blood cultures, paired sera and a urine sample were obtained from 54 patients with fever and epiglottitis visualized by indirect laryngoscopy or by direct fibreoptic nasolaryngoscopy. Antibodies were determined against the capsular polysaccharide of Haemophilus influenzae type b (Hib), 3 pneumococcal antigens (a mixture of 23 capsular polysaccharides, C-polysaccharide and pneumolysin) and antistreptolysin O. Acute sera were examined by the polymerase chain reaction (PCR) for DNA of Hib and pneumococci. The urine samples were examined for Hib capsular antigen. Blood cultures were positive in 15 patients. In another 16, serology and/or PCR verified the aetiology. Hib was the cause in 14, pneumococci in 12 and group A streptococci in 5 patients. The aetiology remained unknown in 23/54 patients (43%). In conclusion, the addition of serology and PCR to blood cultures doubled the possibilities of verifying the aetiology of acute epiglottitis in adults.

Acute Disease↗
PubMed1998

Immunization of children with pertussis toxoid decreases spread of pertussis within the family.

OBJECTIVE: In a previously reported double blind placebo-controlled trial it was shown that vaccination with pertussis toxoid during infancy reduced the incidence of pertussis in the vaccinees. Parents and siblings of participants in the trial were followed for pertussis to determine whether vaccination provided indirect protection of close contacts in a nonvaccinating country with a high incidence of pertussis. STUDY DESIGN: A group of 3450 infants were randomized to vaccination with diphtheria, tetanus and pertussis toxoids (DTPtxd) or to diphtheria and tetanus toxoids (DT). Pertussis cases were actively sought and diagnosed by cultures and serology in vaccinees (previously reported) and in family members during 2 years after the third vaccination. RESULTS: Pertussis as defined by the World Health Organization (paroxysmal cough of > or = 21 days and certain laboratory criteria) was diagnosed in 11 parents of DTPtxd recipients and in 26 parents of DT recipients; indirect protection was 60% (95% confidence intervals, 16 to 82%). In nonvaccinated younger siblings of DTPtxd and DT recipients there were 10 and 18 cases of pertussis, respectively; indirect protection was 43% (95% confidence intervals, -31 to 76%). When all cases of pertussis with cough > or = 7 days were included, the indirect protection was 44% (95% confidence intervals, 7 to 67%) in parents and 56% (95% confidence intervals, 9 to 81%) in younger siblings. CONCLUSION: Vaccination of children with pertussis toxoid reduces spread of pertussis to close contacts, which suggests that mass vaccination with pertussis toxoid would induce herd immunity.

Family Health↗
PubMed1998

Evaluation of PCR for diagnosis of Bordetella pertussis and Bordetella parapertussis infections.

PCR, using primers Plp1 and Plp2, was evaluated for the detection of DNA from Bordetella pertussis in bacterial strains and in nasopharyngeal samples from patients with a cough lasting at least 7 days. The assay could detect DNA from 6 CFU of B. pertussis/10 microl of sample. Results of the PCR assay were compared with those of cultures, a determination of serum antibodies against pertussis toxin and filamentous hemagglutinin, and a clinical evaluation of 2,442 coughing episodes. The overall sensitivity of PCR was 65% (623 of 956), which was higher than the sensitivity of cultures (58%) (P < 0.001). Factors influencing the sensitivity of PCR were the interval between the onset of symptoms and sampling and the vaccination status of the patient. The specificity of PCR was 98% (1,451 of 1,486). The positive and negative predictive values were 95 and 81%, respectively. Parapertussis PCR, using primers BPPA and BPPZ, was positive in 11 of 18 culture-positive cases and was confirmed by serology in another 4 cases. In conclusion, PCR is a valuable complement to cultures and can probably replace cultures for diagnosis of B. pertussis and Bordetella parapertussis infections.

Antibodies, Bacterial↗
PubMed1998

Standardization of acellular pertussis vaccine by assay of serum neutralizing antibodies to pertussis toxin (antitoxin): analogy with diphtheria toxoid.

Immunity conferred by vaccination with cellular pertussis vaccines and pertussis wanes so that adults are now the main reservoir of B. pertussis. Similar to diphtheria toxoid, acellular pertussis vaccines are suitable for vaccination of adults and it is probable that addition of pertussis toxoid to DT will be recommended for this age group. If this can be achieved, it is easy to predict that pertussis will be eliminated and the possibility of eradicating B. pertussis will become feasible. We propose that, despite the relative inaccuracy of correlating levels of antitoxin with individual immunity, a standardized assay and reference antiserum for pertussis toxoid will control acellular pertussis vaccines as was achieved with diphtheria toxoid.

Adult↗
PubMed1998

Immunity to pertussis. Not all virulence factors are protective antigens.

As with diphtheria, immunity to pertussis is complex because it involves both individual and community protection against infection with B. pertussis. Although B. pertussis has at least five proteins required for virulence and an additional two "toxic" components, only serum neutralizing antibodies to PT (antitoxin) have been shown to confer immunity to pertussis.

Bordetella pertussis↗
PubMed1997

Efficacy of a monocomponent pertussis toxoid vaccine after household exposure to pertussis.

In a double-blind, placebo-controlled efficacy trial of a monocomponent pertussis toxoid vaccine, 3450 infants were randomly assigned to vaccination with diphtheria-tetanus toxoids with or without pertussis toxoid at 3, 5, and 12 months of age. Study children and family members were investigated for possible pertussis with cultures, serology, and polymerase chain reaction. Efficacy was 71% after 3 dose when the World Health Organization case definition of pertussis (which includes paroxysmal cough for 21 days or longer) was used. We report the efficacy in the subgroup of children who were exposed to pertussis in the household. Among study children exposed to pertussis in the household from the day of the third vaccination, 20 of 99 (20%) recipients of diphtheria-tetanus-pertussis toxoids vaccine and 64 of 79 (81%) recipients of diphtheria-tetanus toxoids vaccine had pertussis fulfilling criteria of the World Health Organization. The vaccine efficacy was 75% (95% confidence intervals 64% to 84%). In children who had received only two doses at the time of household exposure, vaccine efficacy was 66% (95% confidence intervals 15% to 90%) based on 4 cases among 32 household-exposed recipients of diphtheria-tetanus-pertussis toxoids vaccine and 13 cases among 35 household-exposed recipients of diphtheria-tetanus toxoids vaccine. In conclusion, the pertussis toxoid vaccine provides protection against pertussis both after household and community exposure.

Diphtheria Toxoid↗
PubMed1997

Unchanged efficacy of a pertussis toxoid vaccine throughout the two years after the third vaccination of infants.

BACKGROUND: In a previously reported double blind efficacy trial of a pertussis toxoid vaccine, 3450 infants were randomized to receive diphtheria-tetanus toxoids with or without pertussis toxoid at 3, 5 and 12 months of age. Efficacy against pertussis as defined by the World Health Organization was 71% from 30 days after the third vaccination with an average follow-up of 17.5 months. We now report efficacy for an additional 6 months of open follow-up. METHODS: Parents were contacted monthly by a nurse. If a participant or a family member coughed for > or = 7 days, a nasopharyngeal sample and paired sera were obtained. RESULTS: Efficacy during this open follow-up period was 77% (95% confidence intervals, 66 to 85%) based on 29 and 110 cases fulfilling the WHO definition of pertussis in vaccinated and control children, respectively. Efficacy against household exposure was 76% (95% confidence intervals, 51 to 91%). Pertussis in vaccinated children had a significantly shorter duration than pertussis in control children. Determination of pertussis toxin antibodies in paired sera with enzyme-linked immunosorbent assay had a lower diagnostic sensitivity in vaccinated (45%) than in control (92%) children, while determination of antibodies against filamentous hemagglutinin (not included in the vaccine) was highly sensitive for diagnosing pertussis in both groups (100 and 90%, respectively). CONCLUSIONS: A monocomponent pertussis toxoid vaccine induces significant protection against pertussis for at least 2 years after the third injection. To obtain an unbiased estimate of vaccine efficacy it is important to determine antibodies against an antigen that is not included in the vaccine.

Antibodies, Bacterial↗
PubMed1997

Towards better pertussis vaccines.

Several recently completed trials have shown that acellular pertussis vaccines induce substantial protection against pertussis. They are considerably less reactogenic than whole-cell vaccines and, as they consist of only one or a few purified proteins, they can be expected to cause less severe adverse events. The optimal composition of acellular vaccines has not yet been determined. The number of vaccine antigens varies from one to five. All vaccines contain detoxified pertussis toxin. Other antigens included in several vaccines are filamentous haemagglutinin, pertactin and fimbriae, but it remains to be proven that these antigens contribute significantly to protection. Postlicensure studies will be of importance in order to study possible rare adverse events after acellular vaccines and to study the induction of herd immunity.

Humans↗
PubMed1997

Adverse reactions of a pertussis toxoid vaccine in a double-blind placebo-controlled trial.

In the Gothenburg study, 3,450 infants were randomly assigned to receive three subcutaneous injections of acellular pertussis vaccine consisting of peroxide-inactivated pertussis toxin with diphtheria and tetanus toxoids (DTP-toxoids) or DT-toxoids alone under blind conditions at three, five and 12 months of age. Safety of the vaccinations was assessed by direct contact with the families in the week following each injection. No serious vaccine-associated adverse reactions were observed, in either group. The frequency of fever and local reactions increased by dose. Redness and swelling were slightly but significantly more frequent in recipients of DTP-toxoids compared to the DT group.

Diphtheria Toxoid↗
PubMed1997

Factors influencing antibody responses to acellular pertussis vaccines.

There are several factors which can potentially affect the immune response of humans to vaccination with acellular pertussis vaccines. The only way to study these responses at present is by serology. Only for a few of these factors has the effect on humoral immunogenicity been studied in any way, making conclusions difficult. Nonetheless, at least gender and pre-existing, maternal antibody appear not to influence the serological response to acellular pertussis vaccination.

Adhesins, Bacterial↗