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Biomedical subjects

R Diel

Publications and source records attributed to R Diel.

At least 19 recordsLinked to original sources
PubMed2006

Tuberculosis contact investigation with a new, specific blood test in a low-incidence population containing a high proportion of BCG-vaccinated persons.

BACKGROUND: BCG-vaccination can confound tuberculin skin test (TST) reactions in the diagnosis of latent tuberculosis infection. METHODS: We compared the TST with a Mycobacterium tuberculosis specific whole blood interferon-gamma assay (QuantiFERON-TB-Gold In Tube; QFT-G) during ongoing investigations among close contacts of sputum smear positive source cases in Hamburg, Germany. RESULTS: During a 6-month period, 309 contacts (mean age 28.5 +/- 10.5 years) from a total of 15 source cases underwent both TST and QFT-G testing. Of those, 157 (50.8%) had received BCG vaccination and 84 (27.2%) had migrated to Germany from a total of 25 different high prevalence countries (i.e. >20 cases/100,000). For the TST, the positive response rate was 44.3% (137/309), whilst only 31 (10%) showed a positive QFT-G result. The overall agreement between the TST and the QFT-G was low (kappa = 0.2, with 95% CI 0.14.-0.23), and positive TST reactions were closely associated with prior BCG vaccination (OR 24.7; 95% CI 11.7-52.5). In contrast, there was good agreement between TST and QFT-G in non-vaccinated persons (kappa = 0.58, with 95% CI 0.4-0.68), increasing to 0.68 (95% CI 0.46-0.81), if a 10-mm cut off for the TST was used instead of the standard 5 mm recommended in Germany. CONCLUSION: The QFT-G assay was unaffected by BCG vaccination status, unlike the TST. In close contacts who were BCG-vaccinated, the QFT-G assay appeared to be a more specific indicator of latent tuberculosis infection than the TST, and similarly sensitive in unvaccinated contacts. In BCG-vaccinated close contacts, measurement of IFN-gamma responses of lymphocytes stimulated with M. tuberculosis-specific antigen should be recommended as a basis for the decision on whether to perform subsequent chest X-ray examinations or to start treatment for latent tuberculosis infection.

Adult↗
PubMed2006

Cost-optimisation of screening for latent tuberculosis in close contacts.

The aim of the present study was to perform cost-minimisation analysis of contact investigation from a public health perspective using the tuberculin skin test (TST) and a new blood assay, QuantiFERON-TB Gold (QFT-G). A decision-analysis model simulated the costs of investigating a cohort of adult close tuberculosis contacts by the public health service following the current German guidelines over a period of 2 yrs. The economic outcomes were compared with alternative screening strategies. These were: 1) QFT-G instead of TST; 2) TST followed by QFT-G; and 3) TST followed by QFT-G in vaccinated (bacille Calmette-Guérin (BCG)) subjects. In a base-case analysis, the costs of TST-based screening were 91.06 Euros (EUR).contact(-1), assuming a 1% tuberculosis-case-finding incidence. The least expensive strategy was TST screening plus subsequent QFT-G testing (52.05 EUR), resulting in a 43% cost reduction. Using QFT-G alone in BCG-vaccinated subjects who tested positive in the TST led to a 39% cost reduction. The savings using QFT-G alone instead of TST amounted to 29.77 EUR.contact(-1). The results depended on the acquisition costs assumed and the proportion of positive results in TST-based screening. Screening for tuberculosis by combining tuberculin skin testing and QuantiFERON-TB Gold markedly reduces public health costs compared with tuberculin skin test screening alone.

Antigens, Bacterial↗
PubMed2006

Avoiding the effect of BCG vaccination in detecting Mycobacterium tuberculosis infection with a blood test.

Bacille Calmette-Guérin (BCG) vaccination can confound tuberculin skin test (TST) reactions in the diagnosis of latent tuberculosis infection (LTBI). The TST was compared with a Mycobacterium tuberculosis (MTB)-specific enzyme-linked immunospot (ELISPOT) assay during an outbreak of MTB infection at a police academy in Germany. Participants were grouped according to their risk of LTBI in close (n = 36) or occasional (n = 333) contacts to the index case. For the TST, the positive response rate was 53% (19 out of 36) among close and 16% (52 out of 333) among occasional contacts. In total, 56 TST-positive contacts (56 out of 71 = 78.9%) and 27 TST-negative controls (27 out of 298 = 9.1%) underwent ELISPOT testing. The odds ratio (OR) of a positive test result across the two groups was 29.2 (95% confidence interval (CI) 3.5-245.0) for the ELISPOT and 19.7 (95% CI 2.0-190.2) for the TST with a 5 mm cut-off. Of 369 contacts, 158 (42.8%) had previously received BCG vaccination. The overall agreement between the TST and the ELISPOT was low, and positive TST reactions were confounded by BCG vaccination (OR 4.8 (95% CI 1.3-18.0)). In contrast, use of a 10-mm induration cut-off for the TST among occasional contacts showed strong agreement between TST and ELISPOT in nonvaccinated persons. In bacille Calmette-Guérin-vaccinated individuals, the Mycobacterium tuberculosis-specific enzyme-linked immunospot assay is a better indicator for the risk of latent tuberculosis infection than the tuberculin skin test.

Adolescent↗
PubMed2005

Transmission of hepatitis B in Hamburg, Germany, 1998-2002: a prospective, population-based study.

To study the pattern of transmission of HBV in a large urban community, an in-depth prospective study was performed in Hamburg between 1 January 1998 and 31 December 2002. In total, 524 patients were classified as hepatitis B cases according to the case definition of the Robert Koch Institute, comprising 197 foreign-born and 327 German-born persons. The principal risk factor was parenteral drug use, with 17.7% (n=93/524) of all documented cases of hepatitis B, followed by immigration as refugees (13.9%; n=73). Of all 524 cases, 72 (13.7%) were associated with heterosexual (n=41) or homosexual (n=31) transmission. Household contacts of HBV carriers or of patients with acute infectious disease contributed to 9.0% of the cases (n=47). Medical procedures were most probably the source in 7.4% (n=39), although only 3.2% (n=17) of all patients were health-care workers. In multivariate analysis of household contacts, male-male sexual activity was found to be the greatest risk factor for acquiring an acute HBV infection, followed by asylum-seeking status and the number of contacts. The incidence was 3.5-fold higher among foreign-born persons (16.1 per 100,000) than among German-born individuals (4.5 per 100,000) suggesting that a targeted intervention in this population group is a public-health need. The current national policy of vaccination in defined age groups should be extended to the immunization of all children of foreign-born parents as well as the screening and immunisation of susceptible foreign-born adults.

Adolescent↗
PubMed2005

[Contribution of the Public Health Service to cost of illness studies].

This paper reflects on the different approach-es of top-down and bottom-up analysis when calculating sickness costs. Following an analysis of the standard procedures to be followed in tuberculosis contact tracing performed by public health bureaux in Hamburg, a top-down estimate is presented de-spite some accounting limitations. The val-ue of epidemiologic data on infectious dis-eases held by the Public Health Service for bottom-up-modelling is shown by a cost-of-illness study on hepatitis A in Germany.However, broader efforts may be required by local service providers to justify their existence from an economic perspective. This could also contribute to improving cooperation between public health authorities and schools of public health in this rapidly developing scientific field.

Accounting↗
PubMed2005

Cost-effectiveness of isoniazid chemoprevention in close contacts.

The aim of the present study was to perform a cost-effectiveness analysis in young and middle-aged adults with latent tuberculosis (TB) infection in Germany. A Markov model simulated the progression of 20- and 40-yr-old close contacts of active TB cases over 20 yrs. Health and economic outcomes of isoniazid (INH) chemoprevention versus no intervention were compared. The analysis determined the incremental cost-effectiveness ratio in terms of cost per quality-adjusted life year and the difference between numbers of TB cases and of TB-related deaths. INH chemoprevention prevented 79% of expected TB cases in both age groups, and saved 9,482 and 9,142 in the lower and higher age groups, respectively, per case prevented. Quality-adjusted life expectancy was slightly extended by 8 days in the lower age group and 7 days in the higher age group, at a cost saving of 417 and 375, respectively, per person. Annual savings were 20,862 and 18,742 per 1,000 contacts, respectively. The number needed to be treated to prevent one TB case in the lower age group was 23 and 25 in the higher age group. The programme also prevented three TB-related deaths in the younger and two in the older cohort. The results are highly sensitive to treatment-cost assumptions. In conclusion, isoniazid chemoprevention in Germany is a highly cost-effective approach for reducing the burden of tuberculosis in recently converted young and middle-aged adults.

Adolescent↗
PubMed2004

The species Mycobacterium africanum in the light of new molecular markers.

The findings of recent studies addressing the molecular characteristics of Mycobacterium tuberculosis complex isolates have initiated a discussion on the classification of M. africanum, especially of those isolates originating from East Africa (cluster F, subtype II) and displaying phenotypic and biochemical characteristics more similar to those of M. tuberculosis. To further address this question, we analyzed a representative collection of 63 M. tuberculosis complex strains comprising 30 M. africanum subtype I strains, 20 M. africanum subtype II strains, 10 randomly chosen M. tuberculosis isolates, and type strains of M. tuberculosis, M. bovis, and M. africanum for the following biochemical and molecular characteristics: single-nucleotide polymorphisms (SNPs) in gyrB and narGHJI and the presence or absence of RD1, RD9, and RD12. For all molecular markers analyzed, subtype II strains were identical to the M. tuberculosis strains tested. In contrast, the subtype I strains as well as the M. africanum type strain showed unique combinations of SNPs in gyrB and genomic deletions (the absence of RD9 and the presence of RD12), which proves their independence from M. tuberculosis and M. bovis. Accordingly, all subtype I strains displayed main biochemical characteristics included in the original species description of M. africanum. We conclude that the isolates from West Africa were proved to be M. africanum with respect to the phenotypic and genetic markers analyzed, while the isolates from East Africa must be regarded as phenotypic variants of M. tuberculosis (genotype Uganda). We propose the addition of the molecular characteristics defined here to the species description of M. africanum, which will allow clearer species differentiation in the future.

Africa↗
PubMed2004

The transmission of tuberculosis in the light of new molecular biological approaches.

This review briefly summarises the recent achievements in tuberculosis epidemiology associated with the introduction of molecular methods, and considers the implications of these methods for the understanding of occupational tuberculosis transmission. Special attention is paid to the relative contribution of recently transmitted tuberculosis; risk factors for recent transmission; and the occurrence and frequency of exogenous reinfection. There is a need for occupational epidemiological studies, which should combine the methods of "classical" epidemiology with those of molecular epidemiology.

Bacterial Typing Techniques↗
PubMed2004

Ongoing outbreak of tuberculosis in a low-incidence community: a molecular-epidemiological evaluation.

SETTING: Federal State of Hamburg, Germany, 1997-2002. OBJECTIVE: To identify the pathways of tuberculosis (TB) transmission and to evaluate possible risk factors for recent transmission in Hamburg. DESIGN: A prospective, molecular-epidemiological study was performed. Conventional contact tracing and an indepth epidemiological analysis were conducted. RESULTS: A predominant cluster of Mycobacterium tuberculosis strains was identified by IS6110 DNA fingerprinting of 828 TB cases notified during the study period. The cluster expanded from seven cases in 1997 to 38 in June 2002. A single source case could not be identified. Transmission links were confirmed in 20 cases. Twenty-five patients were regular customers at a bar close to the red-light district. Seven patients, including one regular customer in the bar, were staying at a nearby hostel for homeless men, and four were living in a far-away hostel for alcoholic men. Of the 421 close contact persons investigated, 169 (40.1%) had positive tuberculin skin tests, and eight became ill (1.9%). Twelve of 20 cases with confirmed recent transmission could only be determined a posteriori by fingerprinting. CONCLUSIONS: An ongoing outbreak at a local bar indicates chronic alcoholism as a high-risk factor for the dissemination of TB in a large metropolitan area. The fact that conventional contact tracing is insufficient for the detection of chains of transmission in this milieu indicates the need for an improved, location-based approach, e.g., the implementation of an outreach strategy.

Adult↗
PubMed2003

Outcome of tuberculosis treatment in Hamburg: a survey, 1997-2001.

SETTING: Federal State of Hamburg, Germany, 1997-2001. OBJECTIVE: To determine risk factors affecting the treatment outcome for tuberculosis according to the WHO/IUATLD classification. DESIGN: Prospective evaluation among patients with culture-confirmed pulmonary disease due to Mycobacterium tuberculosis during the period 1997-1999. RESULTS: Five hundred and eighteen (467 new and 51 re-treatment) cases started a course of treatment (average duration 36.1 +/- 15.5 weeks), resulting in cure for 416 (80.3%) and treatment completed for three (0.6%) patients; 449 patients (86.7%) initially received a three-drug regimen. Treatment interruption occurred in 54 (10.4%), and failure in 12 (2.3%) cases; 32 (6.2%) patients died (irrespective of cause). Alcohol dependence appeared to be the strongest risk factor for persistence of disease, followed by homelessness and unemployment. The risk of treatment interruption was six times higher among alcoholics (OR = 6.0), five times higher among drug abusers (OR = 5.2) and three times higher among the homeless (OR = 3.0) than in other patients. CONCLUSION: Although the current treatment management in Hamburg is considered to be effective, a further improvement in the proportion of patients who complete treatment can be achieved by increased public health surveillance of subpopulations with the above-mentioned risk factors.

Adolescent↗
PubMed2001

Transmission of hepatitis A in hamburg, germany, 1998-1999--A prospective population based study.

To study the pattern of transmission of HAV in a large urban community a prospective cohort study was conducted in Hamburg between 1 January 1998 and 31 December 1999. Four hundred and eleven patients were classified as hepatitis A cases comprising 144 foreign and 267 German persons. Univariate analyses were carried out to examine differences between socio-demographic, clinical and behavioural characteristics. To determine independent predictors for HAV infection a multiple logistic-regression model was used. The principal risk factor was travel to areas where hepatitis A is endemic, with 32.6% (n= 134/411) of all documented cases of hepatitis A. Foreign patients who had acquired the infection abroad, mostly children, accounted for the majority of these cases. Of all 411 cases, 42 (10.2%) were associated with parenteral drug, followed by day-care or school contact (8.3%; n = 34). Outbreaks contributed to 11.4% of cases (n = 47), but only 7.1% (n = 29) were household contacts. The low incidence rate among exposed persons in the households of those infected was similar in the groups of foreign and German nationals (17/384 = 4.4% and 12/231 = 5.2%, respectively), which may demonstrate a good hygienic level in general. Our findings suggest that preventive measures such as the improvement of hygienic conditions in a defined general population may contribute to a reduced incidence of hepatitis A. Nevertheless, because hygienic standards may change with time, this policy should be supplemented by targeted vaccination of groups at risk.

Adolescent↗
PubMed2000

Stability of IS6110 restriction fragment length polymorphism patterns of Mycobacterium tuberculosis strains in actual chains of transmission.

The stability of IS6110 restriction fragment length polymorphism (RFLP) patterns of Mycobacterium tuberculosis strains in actual transmission chains has been assessed by analyzing the variability of IS6110 RFLP patterns of strains in fingerprint clusters that have been confirmed by classical epidemiological data. Forty susceptible and 35 drug-resistant (including 17 multidrug-resistant) M. tuberculosis strains obtained from 75 patients living in Germany have been analyzed. The epidemiological relationship among strains within the fingerprint clusters has been verified by family contacts (14 clusters) or by contact tracing of the public health offices (7 clusters). The time spans between the first and the last isolate of one cluster ranged from less than 1 to 29 months. Of the 75 strains only 1 showed a one-band variation when compared to the other nine isolates grouped in the same cluster, corresponding with a rate of change of approximately 1.9% per possible transmission (one index patient per cluster was subtracted from the total number of isolates). These results confirm a high degree of stability of IS6110 RFLP patterns of transmitted M. tuberculosis strains. Furthermore, the data presented indicate that isolates with identical IS6110 DNA fingerprint patterns are a good indicator for the rate of recent transmission in a study population.

Antitubercular Agents↗
PubMed1995

[Disability payments in diabetes mellitus in social security: what is necessary?].

Since their publication in 1974 the recommendations of the "German Society for Public and Private Welfare" are regarded as competent guideline for the allocation of grants concerning the diet for diabetic subjects according to section 23 part 4, position 2 BSHG (Federal German Law for Social Security). The former nutrition concepts are compared to the current international conceptions regarding the diet of diabetic individuals. Possible variations concerning food plans are shown in model plans considering realistic habits of consumption. Our analysis justifies additional expenses limited to about 20 to 30% for insulin-dependent diabetic subjects compared to an isocaloric regular diet. Additional expenses for obese non-insulin-dependent diabetic subjects are not necessary. There is an extremely slim portion allocated for food within the social security benefit according to section 22 BSHG. That will require an comprehensive supply of education for the realisation of the current recommendations for nutrition. The education programmes for compiling suitable food plans to remain within the scheduled cost limits need to be organized by regional carriers of social welfare, whereby public Health offices could make an important contribution.

Costs and Cost Analysis↗
PubMed1992

[Pedicle torsion of the accessory spleen within the scope of the "polysplenia-asplenia complex" as a rare differential diagnosis of acute abdomen].

A 25 year old female patient with a painful palpable tumour in the right flank was admitted to our hospital presenting signs and symptoms of an acute abdomen. During explorative laparotomy unexpected haemorrhagic infarction of a splenula caused by a volvulus of the vascular pedicle was found. In spite of the documentation of multiple positional abnormalities of visceral organs preoperative diagnostic imaging techniques were unable to point to the diagnosis because of an uncommon rightsideness of the polysplenism. In the case of an indefinite rightsided abdominal mass defects of embryonic morphogenesis should be always taken into consideration.

Abdominal Neoplasms↗
PubMed1991

[Acute abdomen in hemorrhage into a twisted pedicled ectopic second spleen in the right mesogastrum].

A woman patient of 25 years of age was admitted with a tumour in the right meogastrium that was painful on pressure, the clinical pattern being that of an acute abdomen. At exploratory laparotomy we were surprised to find haemorrhagic infarction of a second spleen by volvulus of the vascular peduncle. Preoperative imaging had not yielded any pointer despite documentation of multiple positional anomalies of visceral organs, since the polysplenic status was exceptionally located at the right side. If abdominal findings on the right side cannot be interpreted quite clearly, differential diagnosis should always consider the possibility of unusual embryonal lateral positioning of organs.

Abdomen, Acute↗