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Biomedical subjects

Klaus Stark

Publications and source records attributed to Klaus Stark.

16 recordsLinked to original sources
PubMed2006

Clinical features and pitfalls in the laboratory diagnosis of dengue in travellers.

BACKGROUND: Several enzyme-linked immunosorbent assay (ELISA)-kits are commercially available for the rapid diagnosis of dengue infection, and have demonstrated good sensitivity and specificity in paired serum samples. In practice, however, often only one blood sample is available from febrile travellers returning from dengue endemic areas. METHODS: To evaluate the diagnostic value of positive dengue antibody-titres performed by a standard ELISA (PanBio IgM- and IgG-ELISA) in single serum samples (regarded as "probable infection"), 127 positive samples were further analyzed using envelope/membrane IgM-, and nonstructural protein 1 IgM- and IgG-ELISAs, immunofluorescence assays, and real-time reverse transcription polymerase chain reaction assays (RT-PCR). A combination of the test-results served as the diagnostic "gold standard". A total of 1,035 febrile travellers returning from dengue-endemic countries with negative dengue-serology and RT-PCR served as controls to compare clinical and haematological features. RESULTS: Overall, only 64 (positive predictive value = 50%) of the probable cases were confirmed by additional analysis and 54 (42.5%) were confirmed to be "false-positive". Rash was the only clinical feature significantly associated with confirmed dengue fever. The combination of thrombocytopenia and leucopenia was present in 40.4% of confirmed and in 6.1% of false-positive cases. Thus, the positive predictive value for the combination of positive PanBio-ELISA plus the two haematological features was 90.5%. CONCLUSION: The examination of paired serum samples is considered the most reliable serodiagnostic procedure for dengue. However, if only one blood sample is available, a single positive ELISA-result carries a high rate of false-positivity and should be confirmed using a second and more specific diagnostic technique. In the absence of further testing, platelet and white blood cell counts are helpful for the correct interpretation.

Adolescent↗
PubMed2006

Chemoprophylaxis and malaria death rates.

To determine the effect of chemoprophylaxis on the case-fatality rate of malaria, we analyzed all cases of Plasmodium falciparum malaria in nonimmune persons reported from 1993 to 2004 in Germany. In univariate and multivariate logistic regression analysis, we determined the effect of age, sex, chemoprophylaxis, chemoprophylactic regimen, compliance for chemoprophylactic regimen, exposure prophylaxis, country of infection, and year of reporting on the outcome. Of 3,935 case-patients, 116 (3%) died of malaria. Univariate analysis showed significant associations with death for chemoprophylaxis with chloroquine plus proguanil compared to no chemoprophylaxis. The multivariate model showed that patients who had taken chemoprophylaxis were less likely to die compared to those who had not taken chemoprophylaxis, adjusted for patient age and reporting year. The study demonstrated that chemoprophylaxis significantly reduced fatality rates among nonimmune malaria patients and supports the importance of existing guidelines for malaria prevention.

Antimalarials↗
PubMed2005

Notifiable disease surveillance and practicing physicians.

Primary care physicians in Germany are essential participants in infectious disease surveillance through mandatory reporting. Feedback on such surveillance should reflect the needs and attitudes of these physicians. These issues were investigated in a questionnaire survey among 8,550 randomly sampled physicians in Germany in 2001. Of the 1,320 respondents, 59.3% claimed not to have received any feedback on infectious disease surveillance, and 3.7% perceived feedback as not important. Logistic regression analysis showed that physicians in the former East Germany were 2.2 times more likely to have received feedback than those in the former West Germany. Physicians preferred to receive occasional reports (e.g., in case of outbreaks, 31.6%) as opposed to actively having to search for constantly updated information on the Internet (7.8%). The preferred formats were fax (31.7%), mail (30.9%), and the official organ of the German Medical Association (Deutsches Arzteblatt) (30.5%). Feedback of surveillance data to physicians should be delivered through occasional nonelectronic reports on current issues of local public health importance.

Adult↗
PubMed2005

Dengue antibody prevalence in German travelers.

We studied 2,259 German citizens after they returned from dengue-endemic countries from 1996 to 2004. Serotype-specific dengue antibodies indicated acute infections in 51 (4.7%) travelers with recent fever and 13 (1.1%) travelers with no recent fever, depending largely on destination and epidemic activity in the countries visited.

Adolescent↗
PubMed2005

Salmonella agona outbreak from contaminated aniseed, Germany.

A nationwide outbreak of Salmonella Agona caused by aniseed-containing herbal tea occurred from October 2002 through July 2003 among infants in Germany. Consumers should adhere strictly to brewing instructions, although in exceptional cases this precaution may not be protective, particularly when preparing tea for vulnerable age groups.

Beverages↗
PubMed2005

Leptospirosis in Germany, 1962-2003.

Epidemiologic trends of human leptospirosis in Germany were investigated by analyzing national surveillance data from 1962 to 2003 and by conducting a questionnaire-based survey from 1997 to 2000. After a steady decrease of leptospirosis incidence from 1962 to 1997, surveillance data indicate an increase in disease incidence to 0.06 per 100,000 (1998-2003). Of 102 laboratory-confirmed cases in humans from 1997 to 2000, 30% were related to occupational exposures. Recreational exposures were reported in 30% (including traveling abroad in 16%), whereas residential exposure accounted for 37% of the cases. Direct contact with animals, mostly rats and dogs, was observed in 31% of the cases. We conclude that recent changes in transmission patterns of leptospirosis, partially caused by an expanding rat population and the resurgence of canine leptospirosis, may facilitate the spread of the disease in temperate countries like Germany. Preventive measures should be adapted to the changing epidemiology of leptospirosis.

Adolescent↗
PubMed2004

Limited influence of haemoglobin variants on Plasmodium falciparum msp1 and msp2 alleles in symptomatic malaria.

Haemoglobin (Hb) S, HbC, and alpha(+)-thalassaemia confer protection from malaria. Accordingly, these traits may influence the multiplicity of infection (MOI) of Plasmodium falciparum and the presence of distinct parasite genotypes. In 840 febrile children in northern Ghana, we typed the P. falciparum merozoite surface protein genes (msp1, msp2) and examined effects of the Hb variants on MOI and parasite diversity. HbAC, HbAS, heterozygous, and homozygous alpha(+)-thalassaemia occurred in 21, 5, 29 and 4% of the children, respectively. Plasmodium falciparum was detected in 95%. The haemoglobinopathies did not influence MOI, nor did the Hb type bias the distribution of the msp allelic families. However, IC type parasites were most common among patients with homozygous alpha(+)-thalassaemia (93%), less frequent in heterozygotes (89%), and least frequent in alpha-globin normal children (84%, P(chi2 trend) = 0.03). The opposite was seen for Mad20 type parasites (34%, 47%, 53%, P(chi2 trend) = 0.02). Only a few of the 72 individual msp alleles were selected by the haemoglobinopathies. HbC and alpha(+)-thalassaemia are frequent in northern Ghana. In symptomatic children, the effect of Hb variants on parasite multiplicity and diversity appears to be limited. This may reflect an actual lack of influence or indicate abrogation in symptomatic malaria.

Adolescent↗
PubMed2004

The bacterial paromomycin resistance gene, aphH, as a dominant selectable marker in Volvox carteri.

The aminoglycoside antibiotic paromomycin that is highly toxic to the green alga Volvox carteri is efficiently inactivated by aminoglycoside 3'-phosphotransferase from Streptomyces rimosus. Therefore, we made constructs in which the bacterial aphH gene encoding this enzyme was combined with Volvox cis-regulatory elements in an attempt to develop a new dominant selectable marker--paromomycin resistance (PmR)--for use in Volvox nuclear transformation. The construct that provided the most efficient transformation was one in which aphH was placed between a chimeric promoter that was generated by fusing the Volvox hsp70 and rbcS3 promoters and the 3' UTR of the Volvox rbcS3 gene. When this plasmid was used in combination with a high-impact biolistic device, the frequency of stable PmR transformants ranged about 15 per 106 target cells. Due to rapid and sharp selection, PmR transformants were readily isolated after six days, which is half the time required for previously used markers. Co-transformation of an unselected marker ranged about 30%. The chimeric aphH gene was stably integrated into the Volvox genome, frequently as tandem multiple copies, and was expressed at a level that made selection of PmR transformants simple and unambiguous. This makes the engineered bacterial aphH gene an efficient dominant selection marker for the transformation and co-transformation of a broad range of V. carteri strains without the recurring need for using auxotrophic recipient strains.

Drug Resistance↗
PubMed2004

Disease management programs for depression: a systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: Substantial deficits in the care of depression make the provision of new evidence-based care models a matter of increasing importance. So far, disease management programs (DMPs) have not been systematically assessed. OBJECTIVE: This study was a systematic review and meta-analysis of randomized controlled trials investigating the effectiveness of DMP for depression as compared with usual primary care. METHODS: Criteria for study selection were depression as main diagnosis in adults, the intervention DMP (evidence-based guidelines, patient/provider education, collaborative care, reminder systems, and monitoring), and trial quality A/B (Cochrane Collaboration guidelines) rated by 2 observers. Measurement instruments had to be published in peer-reviewed journals and filled out by the participants, their relations, or independent raters. Meta-analyses were conducted by using dichotomous outcomes within forest plots. Tests of heterogeneity, sensitivity analyses, and funnel plots were performed. Economic evaluations were descriptively summarized. RESULTS: DMP had a significant effect on depression severity, with a relative risk of 0.75 (95% confidence interval 0.70-0.81) in a homogeneous dataset of 10 high-quality trials. It was robust in all sensitivity analyses (evidence level 1A). Funnel plot symmetry indicated a low probability of publication bias. Patient satisfaction and adherence to the treatment regimen improved significantly, but only in heterogeneous models. The costs per quality adjusted life year ranged between US 9,051 dollars and US 49,500 dollars. CONCLUSION: DMP significantly enhance the quality of care for depression. Costs are within the range of other widely accepted public health improvements. Future research should focus on the effect of long-term interventions, and the compatibility with health care systems other than managed-care driven ones.

Antidepressive Agents↗
PubMed2004

Increase in imported dengue, Germany, 2001-2002.

Dengue fever is a reportable disease in Germany. Surveillance data from 2001 and 2002 were analyzed and compared to travel patterns. Imported dengue fever increased strongly in this time. Most infections were acquired in Southeast Asia, specifically Thailand. The 2002 epidemic in Brazil was also reflected in these data.

Adolescent↗
PubMed2002

Immunisations in solid-organ transplant recipients.

Solid-organ transplant recipients are at increased risk of various infectious diseases, some of which are vaccine preventable mmunisations are among the most efficient interventions available. Solid-organ tranplant recipients would greatly benefit from effective immunisations, provided the recommendations are based on a careful risk-benefit analysis in which the effectiveness of the vaccine is weighed against possible adverse reactions, including graft rejection. In this review, we summarise the data from studies on relevant immunisations in solid-organ transplant recipients. The major issues are the immunogenicity and safety of immunisations, the factors associated with poor immune response, and recommendations for immunisation schemes.

Adult↗
PubMed2002

Is early BCG vaccination associated with less atopic disease? An epidemiological study in German preschool children with different ethnic backgrounds.

We investigated the association of bacille Calmette-Guérin (BCG) vaccination and atopic manifestations among children. Because many children in the study area were from minority ethnic groups, the effect of ethnicity on disease prevalence was also analyzed. A mandatory health survey included all preschool children from Berlin in 1994. Trained medical personnel asked parents whether their child had ever had a diagnosis of atopic dermatitis (AD), bronchial asthma (BA), and hay fever (HF) or symptoms suggestive of these conditions. BCG-vaccination status was recorded from official vaccination documents. Ethnicity of the child was defined by maternal citizenship. We included 38 808 children in our study (20 813 children from former west Berlin), on average aged 6 years. The proportion of children with a foreign family background was 2.1% in East Berlin and 27.5% in West Berlin. BCG vaccination was more common in East Berlin than in West Berlin (94.2% vs. 16.5%) and in West Berlin more common among children with a foreign family background compared with Germans (25.3% vs. 13.2%). The adjusted odds ratio (95% CI) for BA was 0.85 (0.71-1.00) for BCG-vaccinated individuals. BCG vaccination was not significantly associated with AD or HF. Among non-German children, the odds ratios were 0.35 (0.30-0.42) for AD, 0.58 (0.48-0.70) for BA, and 0.72 (0.54-0.92) for HF. The OR for AD among children living in eastern Berlin was 1.19 (1.04-1.36), no significant regional differences were found for BA or HF. This study demonstrated a weak protective effect of BCG vaccination against asthma but a much stronger protective effect of non-German ethnicity against atopic manifestations among preschool children from Germany.

Asthma↗
PubMedDate not supplied

Nationwide survey of the role of travel medicine in primary care in Germany.

BACKGROUND: With more persons traveling to (sub)tropical destinations, travel medicine is an increasing challenge for the health care system in many countries. This study investigated the role and scope of travel medicine provided by general practitioners (GPs) in primary health care, assessed the determinants of specific prophylactic recommendations, and identified the needs of GPs regarding training and cooperation in travel medicine. METHODS: A national survey was conducted among randomly selected GPs in Germany. Information on the type and extent of activities in travel medicine, the number and characteristics of patients, the use of specific information systems, and training and cooperation, was obtained with a standardized postal questionnaire. Representativeness was assessed by a computer-assisted telephone survey among nonrespondents. Univariate and multivariate statistical analysis was performed. RESULTS: Of all GPs (n=1,320), 95% provided medical pretravel advice or post-travel counseling (13.2 patients/month). The most common topics in pretravel consultation were immunizations (95%), malaria chemoprophylaxis (94%), advice on exposure prophylaxis (41%), and advice on protection from sexually transmitted infections (STIs) (43%). GPs frequently advised certain patient groups (e.g., cardiovascular patients 68%, pregnant women 20%). Travelers' diarrhea was the most common topic in post-travel consultation (89%), followed by fever (38%). Of the GPs, 25% cooperated regularly with institutions with special expertise in travel medicine or tropical diseases. Sixty-four percent had received some training in travel medicine, and 86% stated a need for additional training. In the multivariate analysis, independent determinants for advice on exposure prophylaxis and STI risks included special training in travel medicine, use of country-specific information sources, and location of the practice in the former West Germany and urban areas. CONCLUSIONS: Travel medicine is of importance in primary health care in Germany. There is a need for improved counseling on exposure and STI prophylaxis. GPs' training in travel medicine and cooperation with institutions such as institutes, clinics and laboratories for tropical medicine should be improved.

Adult↗