Rapid identification of Corynebacterium diphtheriae clonal group associated with diphtheria epidemic, Russian Federation.
(57/321)
We used 199 Corynebacterium diphtheriae isolated from 1995 to 1997 in Russia to evaluate the ability of random amplified polymorphic DNA (RAPD) to identify the unique clonal group that emerged there in 1990. Our data show that RAPD can reliably, reproducibly, and rapidly screen a large number of strains to identify the epidemic clonal group. (+info)
Persistence of a distinct Corynebacterium diphtheriae clonal group within two communities in the United States and Canada where diphtheria is endemic.
(58/321)
Molecular characterization of 53 U.S. and Canadian Corynebacterium diphtheriae isolates by multilocus enzyme electrophoresis, ribotyping, and random amplified polymorphic DNA showed that strains with distinct molecular subtypes have persisted in the United States and Canada for at least 25 years. These strains are endemic rather than imported from countries with current endemic or epidemic diphtheria. (+info)
Diphtheria antitoxin levels among children primed with a diphtheria and tetanus toxoids and acellular pertussis vaccine lot with a subpotent diphtheria toxoid component.
(59/321)
One lot of a nationally distributed diphtheria and tetanus toxoids and acellular pertussis (DTaP) vaccine was recalled in January 1999 because of a subpotent diphtheria toxoid component. To evaluate vaccine immunogenicity, children who had received the recalled lot for at least 2 of the 3 doses of their primary series were identified. Diphtheria antitoxin (DAT) levels were then prospectively assessed before and after dose 4 of (fully potent) DTaP vaccine. Of the 105 children evaluated, 84% had prevaccination DAT levels <0.10 IU/mL, which is the level generally accepted as protective. DAT levels rose a mean of 92-fold after dose 4; 100% of subjects had DAT levels >or=0.10 IU/mL, and 69% had DAT levels >or=1.0 IU/mL. These results indicate that diphtheria potency testing can identify vaccine that is less immunogenic when administered during the primary series. The booster response to dose 4, although reduced, was sufficient to confer adequate protection in the interval before receipt of the fifth dose of DTaP. (+info)
The prevalence of diphtheria immunity in healthy population in Poland.
(60/321)
The degree of seroprotection against diphtheria in Poland was evaluated by determination of IgG antibodies to Corymebacterium diphtheriae toxin (IgG-DTAb). The study population consisted of 4,829 healthy subjects aged from 1 day to 85 years from 7 regions of Poland. Serum samples collected between 1996 and 1998 were assayed for IgG-DTAb antibodies using a toxoid enzyme immunoassay. Neutralization of toxin in Vero cells was performed as a reference method with the WHO standard for human diphtheria antitoxin. The study revealed a lack of seroprotection (IgG-DTAb < 0.1 IU/ml) in 23% of individuals, basic seroprotection (0.1-1.0 IU/ml) in 64%, and effective seroprotection (> 1.0 IU/ml) in 13%. The non-protected group consisted of non-vaccinated children below 2 months of age (10%), individuals between 2 months and 18 years old (20%) and greater than 19 years old (70%). Of the adults, 32% were seronegative, 63% had basic seroprotection and only 5% were fully protected; 43% of adults between 30 and 64 years, who had not been vaccinated at least during the previous 10 years were not protected against diphtheria. The geometric mean titre (GMT) of IgG-DTAb was 0.25 IU/ml in the total population. Age-related GMTs differed significantly from each other and were higher (0.44 IU/ml) in individuals from 2 months to 18 years old, compared with 014 IU/ml and 0.17 lU/ml in children under 2 months and adults, respectively. No significant difference was found in the GMTs of men and women in all age groups. We conclude that the currently used vaccination programme in Poland is highly effective and assures protection against diphtheria in the majority of the population in the 10-year period following the last booster. However, a significant proportion of adults between 30 and 64 years lack protection and this indicates a need for booster immunization for this group. (+info)
The influence of prematurity and low birthweight on transplacental antibody transfer in a rural West African population.
(61/321)
OBJECTIVE: To determine the influence of prematurity and low birthweight (LBW) on transplacental antibody transfer. METHOD: In a physician-blinded, cross-sectional study of 213 mother--baby pairs in the labour ward of Bansang Hospital, The Gambia, paired maternal and cord serum samples were tested for specific IgG antibody titres for measles virus (MeV), herpes simplex virus type 1 (HSV1), respiratory syncytial virus (RSV), varicella-zoster virus (VZV), tetanus toxoid (TT) and diphtheria toxoid (DT) antigens using enzyme linked immunosorbent assay (ELISA). RESULTS: Prematurity was significantly associated with reduced placental antibody transfer for MeV, HSV1, TT, DT, RSV and VZV. Maternal antibody transfer for MeV, HSV1, TT, DT, RSV and VZV was significantly lower in neonates with LBW than in babies with adequate birthweight (ABW). CONCLUSION: Materno--foetal transfer of antibodies is impaired in prematurity and LBW babies in this Gambian population. Reduction in antibody transfer may further predispose these already vulnerable neonates to bacteria and viral infections. Therefore, alternative vaccination strategies, including earlier vaccination schedules, are needed to provide better protection to these young infants. (+info)
Infection of the skin caused by Corynebacterium ulcerans and mimicking classical cutaneous diphtheria.
(62/321)
Extrapharyngeal infections caused by Corynebacterium ulcerans have rarely been reported previously, and diphtheria toxin production has usually not been addressed. This case demonstrates that strains of C. ulcerans that produce diphtheria toxin can cause infections of the skin that completely mimic typical cutaneous diphtheria, thereby potentially providing a source of bacteria capable of causing life-threatening diseases in the patient's environment. Therefore, it is recommended to screen wound swabs for coryneform bacteria, identify all isolates, carefully assess possible toxin production, and send questionable strains to a specialist or a reference laboratory. (+info)
Diphtheria in Thailand in the 1990s.
(63/321)
Diphtheria remains endemic in developing countries, but there are limited published data on the subject. Thailand's diphtheria surveillance data are relatively complete and may give a fuller picture of the situation in similar countries. After routine immunization began in 1977, the incidence of reported diphtheria decreased by >98% to <0.1 case per 100,000 persons annually in the 1990s. Despite infant immunization coverage of >90%, diphtheria cases were reported throughout the 1990s, primarily among children <15 years old. Outbreaks were linked to both persistent endemic circulation and to importation of toxigenic Corynebacterium diphtheriae; suboptimal immunization coverage in minority and disadvantaged groups contributed. A serologic survey found 25% of adults 20-39 years old and 14% of adolescents 10-19 years old lacked immunity to diphtheria; these data indicate an accumulation of susceptible adolescents and adults. Diphtheria remains a threat in Thailand; improvements in diphtheria control will depend on improving childhood immunization coverage in Thailand and the surrounding region. (+info)
Magnitude of interference after diphtheria-tetanus toxoids-acellular pertussis/Haemophilus influenzae type b capsular polysaccharide-tetanus vaccination is related to the number of doses administered.
(64/321)
We compared the antibody response to Haemophilus influenzae type b capsular polysaccharide (PRP) after 1, 2, or 3 doses of a diphtheria-tetanus toxoids-acellular pertussis (DTaP) vaccine combined with a PRP-tetanus conjugate (PRP-T) vaccine, followed by separate injections of DTaP and PRP-T vaccines for the last 1 or 2 doses. Healthy infants were recruited from pediatric practices and were immunized according to recommended schedules. A significant decrease in the mean anti-PRP (from 5.25 to 2.68 microg/mL) and anti-tetanus toxoid antibody responses (from 0.13 to 0.09 Eq/mL) was observed as the number of doses of the DTaP/PRP-T combination vaccine increased (P<.02 and P=.01, respectively). In contrast, the mean anti-diphtheria toxoid antibody response increased with increasing numbers of DTaP/PRP-T doses (P=.0001). The effects of interference were not eliminated by the completion of the primary series with 1 or 2 doses of the DTaP and PRP-T vaccines given separately. (+info)