Correlation between pertussis toxin IgG antibodies in postvaccination sera and subsequent protection against pertussis.
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All acellular pertussis vaccines contain pertussis toxoid and induce protection against pertussis. This study investigated the relation between the postvaccination levels of pertussis toxin (PT) serum IgG and protection against pertussis. PT IgG was determined in sera obtained 21-77 days after the third vaccination from 813 children who received 3 doses of pertussis toxoid. The children were followed for 21-33 months after vaccination for the occurrence of pertussis. Of the children, 126 were exposed to pertussis in their households. The median PT IgG concentration was 79 U/mL in those who developed severe pertussis (>/=21 day of paroxysmal cough), 156 U/mL with mild pertussis (<21 days of paroxysmal cough), and 246 U/mL in those who did not develop pertussis (79 vs. 246, P<.0001). Corresponding values in the 687 children with no household exposure were 99, 124, and 155 U/mL, respectively (99 vs. 155, P<.0001). Thus, there is a highly significant correlation between the level of vaccine-induced serum PT IgG and protection against pertussis. (+info)
Prolonged afebrile nonproductive cough illnesses in American soldiers in Korea: a serological search for causation.
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A serological study was undertaken to investigate infections in active-duty United States soldiers with illnesses characterized by prolonged, afebrile, nonproductive coughs. Fifty-four soldiers were enrolled with such illness of >/=2 weeks' duration (case patients) along with 55 well soldiers (control subjects). Serum samples were tested for IgG and IgA antibody to 3 Bordetella pertussis antigens, pertussis agglutinins, IgM antibodies to Mycoplasma pneumoniae, IgM and IgG antibodies to Chlamydia pneumoniae, and IgM antibody to adenoviruses. Forty-six case patients (85%) had evidence of recent infection with Bordetella species, M. pneumoniae, or C. pneumoniae, and many had evidence of mixed infections; there were 27 Bordetella species, 20 C. pneumoniae, and 33 M. pneumoniae recent infections. Fifteen case patients had high titers of IgG or IgA to B. pertussis filamentous hemagglutinin without high titers of antibodies to other B. pertussis antigens, which suggested the presence of cross-reacting antibodies to M. pneumoniae and perhaps C. pneumoniae or unidentified infectious agent or agents. Since illnesses due to Bordetella species, M. pneumoniae, and C. pneumoniae can all be treated with macrolide antibiotics and B. pertussis illness can be prevented by immunization, and since military readiness was affected in 63% of the cases, it seems important to conduct further studies in military populations. (+info)
Prenatal diagnosis of tracheal obstruction: possible association with maternal pertussis infection.
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A fetus with the sonographic appearance of echogenic and enlarged lungs and dilated trachea and bronchi, indicating laryngotracheal obstruction, is reported. Additionally, the fetus had ascites and subcutaneous edema and the amniotic fluid volume was reduced. Doppler flow investigation of the systemic venous circulation revealed signs of heart failure, and color Doppler visualized possible increased pulmonary flow. Following termination of pregnancy, autopsy confirmed the sonographic observations and revealed a hypoplastic thymus. During the present pregnancy the mother suffered from sustained cough, and serological tests revealed acute pertussis infection. Polymerase chain reaction investigation for Bordetella pertussis in the amniotic fluid was negative. The possibilities of pertussis toxins as noxious factors and of an atypical presentation of DiGeorge anomaly are discussed. (+info)
Comparison of five commercial enzyme-linked immunosorbent assays for detection of antibodies to Bordetella pertussis.
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Measuring antibodies to Bordetella pertussis antigens is mostly done by enzyme-linked immunosorbent assays (ELISAs). We compared the performance of five commercially available ELISA kits with the help of 65 serum specimens which were repetitively tested for evaluation of the kits. The specimens contained 20 paired serum samples from patients with clinical pertussis, 15 samples were from children vaccinated with a diphtheria-tetanus-acellular pertussis vaccine, seven specimens were taken from an interlaboratory comparison of ELISAs, and there were three reference preparations from the Food and Drug Administration's (FDA's) Laboratory of Pertussis and from our laboratory. Reference values were obtained from the FDA or from results obtained with an in-house ELISA. Commercial ELISAs were compared with respect to their reproducibility and variability, their ability to detect significant titer rises in paired serum samples, their ability to detect an immune response after vaccination, and the comparability of semiquantitative and quantitative results. Reproducibility was generally good (>89%), intra-assay variation ranged from 2.4 to 28.7%, and indeterminate results were recorded in up to 18.5% of all specimens. Most kits correctly identified the antibody response to an acellular pertussis vaccine. None of the commercial kits identified all cases of pertussis correctly, and the sensitivity ranged between 60 and 95%. All five commercial ELISAs showed great discrepancies when comparing semiquantitative results and contained obviously different antigen preparations. Our data suggest that the five commercial ELISAs tested here need further improvement and standardization. (+info)
Seroprevalence of pertussis antibodies among adolescents in Israel.
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BACKGROUND: There is an increasing number of reports of pertussis among older children and adults. The development and licensure of an acellular pertussis vaccine offer the possibility of adult vaccination against the disease. Information on immunity to pertussis in this age group is needed before any vaccination policy can be considered. OBJECTIVES: To study the seroepidemiology of pertussis antibodies in a random sample of adolescents. METHODS: Serum IgG antibodies to whole-cell lysate of Bordetella pertussis were measured by enzyme-linked immunosorbent assay in sera of 533 Israeli military recruits aged 17-18 years. Epidemiologic variables were collected by a questionnaire and analyzed for correlation with pertussis antibodies. RESULTS: Of the sera tested 58.6% were positive for pertussis IgG antibodies, while 35.4% were negative and 6% were borderline. The seropositivity rate was significantly higher among females and non-smokers than among males and smokers. Serum samples of subjects found negative to Bordetella pertussis on recruitment were tested again, using the same ELISA assay, 2-3 years later. Seroconversion during the 3 year military service was detected in 12.5% of 40 subjects. Using the pertussis toxin as the antigen in a subsample of 160 sera, the seroprevalence was lower than that detected by the whole-cell lysate on the same sera (45% vs. 58%). CONCLUSIONS: A significant part of the adolescent population in Israel has low titer of serum IgG antibodies to the multiple antigens of B. pertussis. The relatively low concentration of anti-pertussis antibodies, together with the serological evidence of exposure to the disease indicates that booster immunization with the acellular pertussis vaccine of military recruits should be considered after more information on the incidence of clinical cases of pertussis will be available. (+info)
Use of pertussis toxin encoded by ptx genes from Bordetella bronchiseptica to model the effects of antigenic drift of pertussis toxin on antibody neutralization.
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Recently, concern has been voiced about the potential effect that antigenic divergence of circulating strains of Bordetella pertussis might have on the efficacy of pertussis vaccines. In order to model antigenic drift of pertussis toxin, a critical component of many pertussis vaccines, and to examine the effects of such drift on antibody neutralization, we engineered a strain of B. pertussis to produce a variant pertussis toxin molecule that contains many of the amino acid changes found in the toxin encoded by Bordetella bronchiseptica ptx genes. This altered form of the toxin, which is efficiently secreted by B. pertussis and which displays significant biological activity, was found to be neutralized by antibodies induced by vaccination as readily as toxin produced by wild-type B. pertussis. These findings suggest that significant amino acid changes in the pertussis toxin sequence can occur without drastically altering the ability of antibodies to recognize and neutralize the toxin molecule. (+info)
Failure of physicians to consider the diagnosis of pertussis in children.
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To determine the ability of physicians to make a diagnosis of pertussis and factors associated with improved diagnosis, 8,235 children from 88 child care centers and 14 elementary schools from Quebec City, Quebec, Canada, were evaluated by using a questionnaire completed by parents and a medical record review. Children must have consulted a physician to be included in the evaluation. There were 558 children meeting the surveillance case definition and 416 meeting a modified World Health Organization case definition who consulted a physician. A diagnosis of pertussis was considered in 24%-26% of children meeting either case definition, made in 12%-14%, and reported for 6%. Pertussis diagnosis was significantly associated with having a history of pertussis exposure (P < or = .003), four pertussis-related symptoms (P < .001), and a cough for > or = 5 weeks (P < or = .05) and consulting in a hospital setting (P < or = .03). The proportion of cases of pertussis diagnosed and reported is low even when children present with classical symptoms. (+info)
Recovery of Bordetella holmesii from patients with pertussis-like symptoms: use of pulsed-field gel electrophoresis to characterize circulating strains.
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A 4-year retrospective study showing that we isolated Bordetella holmesii, but not Bordetella pertussis, from patients with pertussis-like symptoms was performed. From 1995 through 1998, we isolated B. holmesii from 32 nasopharyngeal specimens that had been submitted from patients suspected of having pertussis. Previously, B. holmesii had been associated mainly with septicemia and was not thought to be associated with respiratory illness. A study was undertaken to describe the characteristics of the B. holmesii isolates recovered and why we were successful in detecting the organism in nasopharyngeal specimens. B. holmesii isolates were characterized for drug sensitivities and for genetic relatedness by pulsed-field gel electrophoresis (PFGE). These isolates, an additional strain of B. holmesii isolated from a blood culture and previously confirmed by the Centers for Disease Control and Prevention, Atlanta, Ga., and 14 other clinical isolates of Bordetella spp., including 4 of B. bronchiseptica, 5 of B. parapertussis, and 5 of B. pertussis, were studied. They were all separately inoculated on three Bordet Gengou (BG) selective media containing either 0.625 microgram of oxacillin per ml, 40 microgram of cephalexin per ml, or 2.5 microgram of methicillin per ml, on BG agar with no antibiotic (control), and on charcoal agar (CA) with and without 40 microgram of cephalexin per ml. We found that cephalexin, the antibiotic commonly incorporated in both CA and BG agar for the recovery of Bordetella spp., is inhibitory to the growth of B. holmesii. In addition, the genotypic analysis of the 32 B. holmesii isolates by PFGE following restriction with XbaI and SpeI identified the dominant strains circulating during the study period. (+info)