This article provides background information on bacterial diseases and discusses those that are candidates for elimination or eradication. Only one disease, neonatal tetanus, is a strong candidate for elimination. Others, including Haemophilus influenzae b infection, leprosy, diphtheria, pertussis, tuberculosis, meningococcal disease, congenital syphilis, trachoma and syphilis are important causes of morbidity and mortality in industrialized and developing countries. For all these diseases, eradication/elimination is not likely because of the characteristics of the disease and limitations in the interventions. (+info)
Use of molecular subtyping to document long-term persistence of Corynebacterium diphtheriae in South Dakota.
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Enhanced surveillance of patients with upper respiratory symptoms in a Northern Plains community revealed that approximately 4% of them were infected by toxigenic Corynebacterium diphtheriae of both mitis and gravis biotypes, showing that the organism is still circulating in the United States. Toxigenic C. diphtheriae was isolated from five members of four households. Four molecular subtyping methods-ribotyping, multilocus enzyme electrophoresis (MEE), random amplified polymorphic DNA (RAPD), and single-strand conformation polymorphism-were used to molecularly characterize these strains and compare them to 17 archival South Dakota strains dating back to 1973 through 1983 and to 5 isolates collected from residents of diverse regions of the United States. Ribotyping and RAPD clearly demonstrated the household transmission of isolates and provided precise information on the circulation of several distinct strains within three households. By MEE, most recent and archival South Dakota strains were identified as closely related and clustered within the newly identified ET (electrophoretic type) 215 complex. Furthermore, three recent South Dakota isolates and eight archival South Dakota isolates were indistinguishable by both ribotyping and RAPD. All of these molecular methods showed that recent South Dakota isolates and archival South Dakota isolates were more closely related to each other than to the C. diphtheriae strains isolated in other parts of the United States or worldwide. The data also supported the improbability of importation of C. diphtheriae into this area and rather strongly suggest the long-term persistence of the organism in this region. (+info)
Resurgent diphtheria--are we safe?
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Diphtheria, one of the major causes of morbidity and mortality in the past, seemed nearly eliminated from industrialized countries, thanks to improved hygienic conditions and large scale vaccinations. In 1990, a large epidemic started in Eastern Europe, mainly in Russia and Ukraine, with over 70,000 cases reported within a 5 year period. The main factors leading to the epidemic included low immunization coverage among infants and children, waning immunity to diphtheria among adults, and profound social changes in the former Soviet Union. The possibility of new virulence factors in the epidemic strain has not yet been ruled out. Even though immunity among adults is far from complete in Western Europe, the epidemic did not spread there. The main reason for this might be the good immune status of children and lack of social turbulence favouring the spread of infection. Several countries have also taken preventive measures, which may also have played a role in protection against the potential epidemic. (+info)
Experience with diphtheria toxoid-tetanus toxoid-acellular pertussis vaccine in Japan.
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In Japan, the morbidity rate for pertussis per 100,000 population was 147.6 in 1950 when whole cell pertussis vaccine was introduced but dropped to 0.2 in 1972 when routine immunization with a combined vaccine consisting of diphtheria toxoid, tetanus toxoid, and whole cell pertussis had been widely accepted. Thereafter, adverse reactions to the whole cell pertussis vaccine became a social problem and lowered the acceptance of the vaccine. As a result, the morbidity rate increased to 11.3 in 1979. Introduction of the safer yet efficacious acellular pertussis vaccine, consisting of mainly pertussis toxoid and filamentous hemagglutinin, into the routine childhood vaccination in combination with diphtheria and tetanus toxoids in 1981 increased the acceptance rate. The lowest morbidity rate, 0.1, was achieved in 1993. During the next 16 years, almost all cases were in unvaccinated or incompletely vaccinated persons. Regardless of whether whole cell or acellular pertussis vaccine was used, > 90% of the reported pertussis cases were in children < 10 years of age until 1990. However, since 1991, the rate of pertussis in young adults 20-44 years of age has been clearly increasing. To control pertussis, booster vaccination with diphtheria toxoid-tetanus toxoid-acellular pertussis vaccine in adults should be considered. (+info)
Similarities between the pathogenesis of and immunity to diphtheria and pertussis: the complex nature of serum antitoxin-induced immunity to these two diseases.
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Despite data from animal studies, seroepidemiological surveys, and controlled clinical trials, skepticism persists about immunity to pertussis conferred by serum IgG neutralizing antibodies (antitoxin). This is largely prompted by the absence of a "protective" level of antitoxin. Examination of the similarities between the pathogenesis and immunity to pertussis and diphtheria provides an explanation for this dilemma. As with pertussis, diphtheria toxoid vaccination confers only approximately 70% immunity on an individual basis, individuals with protective levels of antitoxin may contract diphtheria, and about 50% of the entire population, especially adults, have less than protective levels of antitoxin. The virtual disappearance of diphtheria followed vaccination of the entire population with diphtheria toxoid, which blocked transmission of toxigenic Corynebacterium diphtheriae and thus reduced the pathogen to almost undetectable levels. The individual and community-based immunity induced by diphtheria toxoid, we hypothesize, is similar to that of pertussis and pertussis toxoid. (+info)
Diphtheritic polyneuropathy: a clinical study and comparison with Guillain-Barre syndrome.
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OBJECTIVES AND METHODS: Clinical features of 50 adults with diphtheritic polyneuropathy (DP) were studied in Riga, Latvia and compared with 21 patients with Guillain-Barre syndrome (GBS). RESULTS: Neurological complications occurred in 15% of patients admitted to hospital with diphtheria and usually after severe pharyngeal infection. Bulbar dysfunction occurred in 98% of patients with DP and only 10% of patients with GBS. Limb weakness was mild or absent in 30% of patients with DP. Ventilation dependent respiratory failure occurred in 20% of patients with DP. The first symptoms of DP occurred 2-50 days after the onset of local diphtheria infection. Neurological deterioration in DP continued for a median of 49 (range 15-83) days and improvement started 73 (range 20-115) days after onset. In 66% of patients with DP, the neuropathy was biphasic with a secondary worsening after 40 days. By contrast patients with GBS worsened for only 10 days on average (range 2-28 days) and improved after 21 (range 4-49) days. Eight patients with DP died, four from severe cardiomyopathy and four from multiple diphtheritic organ failure. Prolonged distal motor latencies (DMLs) were common to both DP and GBS, and more pronounced than motor conduction slowing. Limb symptoms continued after 1 year in 80% of the patients with DP, 6% were unable to walk independently, but independent respiratory and bulbar function had returned in all survivors. By comparison no patients with GBS died and none were severely disabled after 1 year. No death, in patients with DP occurred after antitoxin on days 1 or 2 after onset of diphtheria symptoms, whereas identical rates of death and peak severity of DP were seen both in those who received antitoxin on days 3-6 and those who did not receive it at all. CONCLUSION: Diphtheric polyneuropathy is much more likely than GBS to have a bulbar onset, to lead to respiratory failure, to evolve more slowly, to take a biphasic course, and to cause death or long term disability. Antitoxin seems ineffective if administered after the second day of diphtheritic symptoms. (+info)
Diphtheria in the Republic of Georgia: use of molecular typing techniques for characterization of Corynebacterium diphtheriae strains.
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Sixty-six Corynebacterium diphtheriae strains (62 of the gravis biotype and 4 of the mitis biotype) isolated during the Georgian diphtheria epidemic of 1993 to 1998 and 13 non-Georgian C. diphtheriae strains (10 Russian and 3 reference isolates) were characterized by (i) biotyping, (ii) toxigenicity testing with the Elek assay and PCR, (iii) the randomly amplified polymorphic DNA (RAPD) technique, and (iv) pulsed-field gel electrophoresis (PFGE). Fifteen selected strains were ribotyped. Six RAPD types and 15 PFGE patterns were identified among all strains examined, and 12 ribotypes were found among the 15 strains that were ribotyped. The Georgian epidemic apparently was caused by one major clonal group of C. diphtheriae (PFGE type A, ribotype R1), which was identical to the predominant epidemic strain(s) isolated during the concurrent diphtheria epidemic in Russia. A dendrogram based on the PFGE patterns revealed profound differences between the minor (nonpredominant) epidemic strains found in Georgia and Russia. The methodologies for RAPD typing, ribotyping, and PFGE typing of C. diphtheriae strains were improved to enable rapid and convenient molecular typing of the strains. The RAPD technique was adequate for biotype differentiation; however, PFGE and ribotyping were better (and equal to each other) at discriminating between epidemiologically related and unrelated isolates. (+info)
Diphtheria antitoxin levels in the Netherlands: a population-based study.
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In a population-based study in the Netherlands, diphtheria antitoxin antibodies were measured with a toxin-binding inhibition assay in 9, 134 sera from the general population and religious communities refusing vaccination. The Dutch immunization program appears to induce long-term protection against diphtheria. However, a substantial number of adults born before the program was introduced had no protective diphtheria antibody levels. Although herd immunity seems adequate, long-term population protection cannot be assured. As more than 60% of orthodox reformed persons have antibody levels lower than 0.01 IU/ml, introduction of diphtheria into religious communities refusing vaccination may constitute a danger of spread of the bacterium. (+info)