A European approach to infection prevention and control goals

The current pandemic caused by COVID-19 has underlined the importance of a joint effort and approach to ensure patient and health care worker safety in medical care throughout Europe. In addition, the recent flood disasters in Germany and other countries called for immediate joint action, in this case with regard to the prevention of water-borne infections. Environmental disasters will increase with consequences for hospitals and nursing homes. Cooperative efforts are needed for preventing and controlling associated infection outbreaks, new pathogens will appear and a geographic shift of infectious diseases previously not detected in certain areas has already been observed. This approach to infection prevention and control must entail structural as well as regulatory aspects. The principle of equal protection against infections in all European countries must be implemented. Prevention and control of infections, including nosocomial infections, infections caused by antibiotic-resistant bacteria as well as pandemics, need to be based on equal standards in all of Europe. Protection against infections and other public health risks in all European countries is the best guarantor for building trust and identification of citizens in our common Europe. Experts in the fields of hygiene, microbiology, infectiology and epidemiology have to pool the expertise on the prevention and control of infections from different European countries and define key targets for achieving a high standard of hygiene measures throughout Europe. The participants of the Rudolf Schülke Foundation International Symposium call for immediate action and priority to be given to the realization of the proposed 16-point plan.

Chemical disinfection in healthcare settings: critical aspects for the development of global strategies

Chemical disinfection is an indispensable means of preventing infection. This holds true for healthcare settings, but also for all other settings where transmission of pathogens poses a potential health risk to humans and/or animals. Research on how to ensure effectiveness of disinfectants and the process of disinfection, as well as on when, how and where to implement disinfection precautions is an ongoing challenge requiring an interdisciplinary team effort. The valuable resources of active substances used for disinfection must be used wisely and their interaction with the target organisms and the environment should be evaluated and monitored closely, if we are to reliable reap the benefits of disinfection in future generations. In view of the global threat of communicable diseases and emerging and re-emerging pathogens and multidrug-resistant pathogens, the relevance of chemical disinfection is continually increasing. Although this consensus paper pinpoints crucial aspects for strategies of chemical disinfection in terms of the properties of disinfectant agents and disinfection practices in a particularly vulnerable group and setting, i.e., patients in healthcare settings, it takes a comprehensive, holistic approach to do justice to the complexity of the topic of disinfection.

Antibiotic resistance: What is so special about multidrug-resistant Gram-negative bacteria?

In the past years infections caused by multidrug-resistant Gram-negative bacteria have dramatically increased in all parts of the world. This consensus paper is based on presentations, subsequent discussions and an appraisal of current literature by a panel of international experts invited by the Rudolf Schülke Stiftung, Hamburg. It deals with the epidemiology and the inherent properties of Gram-negative bacteria, elucidating the patterns of the spread of antibiotic resistance, highlighting reservoirs as well as transmission pathways and risk factors for infection, mortality, treatment and prevention options as well as the consequences of their prevalence in livestock. Following a global, One Health approach and based on the evaluation of the existing knowledge about these pathogens, this paper gives recommendations for prevention and infection control measures as well as proposals for various target groups to tackle the threats posed by Gram-negative bacteria and prevent the spread and emergence of new antibiotic resistances.

Lesser-known or hidden reservoirs of infection and implications for adequate prevention strategies: Where to look and what to look for

In developing hygiene strategies, in recent years, the major focus has been on the hands as the key route of infection transmission. However, there is a multitude of lesser-known and underestimated reservoirs for microorganisms which are the triggering sources and vehicles for outbreaks or sporadic cases of infection. Among those are water reservoirs such as sink drains, fixtures, decorative water fountains and waste-water treatment plants, frequently touched textile surfaces such as private curtains in hospitals and laundry, but also transvaginal ultrasound probes, parenteral drug products, and disinfectant wipe dispensers. The review of outbreak reports also reveals Gram-negative and multiple-drug resistant microorganisms to have become an increasingly frequent and severe threat in medical settings. In some instances, the causative organisms are particularly difficult to identify because they are concealed in biofilms or in a state referred to as viable but nonculturable, which eludes conventional culture media-based detection methods. There is an enormous preventative potential in these insights, which has not been fully tapped. New and emerging pathogens, novel pathogen detection methods, and hidden reservoirs of infection should hence be given special consideration when designing the layout of buildings and medical devices, but also when defining the core competencies for medical staff, establishing programmes for patient empowerment and education of the general public, and when implementing protocols for the prevention and control of infections in medical, community and domestic settings.

The role of surface disinfection in infection prevention

Background: The Rudolf Schuelke Foundation addresses topics related to hygiene, infection prevention and public health. In this context a panel of scientists from various European countries discussed “The Role of Surface Disinfection in Infection Prevention”. The most important findings and conclusions of this meeting are summarised in the present consensus paper.

Aim: Although the relevance of surface disinfection is increasingly being accepted, there are still a number of issues which remain controversial. In particular, the following topics were addressed: Transferral of microbes from surface to patients as a cause of infection, requirements for surface disinfectants, biocidal resistance and toxicity, future challenges.

Methods and findings: After discussion and review of current scientific literature the authors agreed that contaminated surfaces contribute to the transmission of pathogens and may thus pose an infection hazard. Targeted surface disinfection based on a risk profile is seen as an indispensable constituent in a multibarrier approach of universal infection control precautions. Resistance and cross-resistance depend on the disinfectant agent as well as on the microbial species. Prudent implementation of surface disinfection regimens tested to be effective can prevent or minimize adverse effects.

Conclusions: Disinfection must be viewed as a holistic process. There is a need for defining standard principles for cleaning and disinfection, for ensuring compliance with these principles by measures such as written standard operating procedures, adequate training and suitable audit systems. Also, test procedures must be set up in order to demonstrate the efficacy of disinfectants including new application methods such as pre-soaked wipes for surface disinfection.

Neue Infektionserreger mit pandemischem Potential: Ursache – Verbreitung – Management

Die im vergangenen Jahrhundert errungenen Erfolge bei der Reduzierung der Mortalität durch Infektionskrankheiten können nicht verdecken, dass beständig neue Infektionskrankheiten mit weltweiter Verbreitung auftreten. Diese gehen entweder auf „neue“ Erreger zurück („emerging diseases“), oder sind durch bekannte Erreger bedingt, die neue Verbreitungsgebiete erobert haben. Bei der Expansion der endemischen Zirkulation von Infektionserregern spielen anthropogene Faktoren eine entscheidende Rolle, und eine große Zahl völlig unterschiedlicher Erreger kommt für solche Geschehen in Betracht (Kaufmann 2010).

Mikrobiologische Labordiagnostik – Verlässlichkeit und Grenzen

Fieber ist ein wichtiges Leitsymptom für viele Infektionskrankheiten, das einen ersten Hinweis auf eine bestehende Infektion geben kann. Hierbei spielen sowohl die Höhe der Temperatur als auch der Verlauf der Fieberkurve eine Rolle, wie z. B. bei der Malaria mit zyklisch auftretenden Fieberanfällen. Bei Infektionen mit Exanthem, wie z. B. Varizellen, ist das klinische Bild des Sternenhimmelphänomens mit Erythem, Papeln und Pusteln richtungweisend und bedarf nur in Ausnahmefällen einer weiteren labordiagnostischen Abklärung. Eine Schwellung der peripheren Lymphknoten und der Milz kann jedoch bei vielen Infektionskrankheiten auftreten und sollte labordiagnostisch näher untersucht werden.

Implementation of practice guidelines for antifungal therapy in a surgical intensive care unit and its impact on use and costs

BACKGROUND

Considering the complexity of diagnosis, high costs of therapy and high morbidity and mortality of systemic fungal infections, antifungal therapy of intensive care patients should follow clearly defined guidelines. We outline the impact of a standardised practice of antifungal treatment in an interdisciplinary surgical intensive care unit of a university hospital.

METHODS

Therapy was intended to be optimised by implementation of standardised practice guidelines supported by the clinical pharmacist. Costs for antifungal agents during a period of 18 months before and after implementation of the practice guidelines were compared, respectively.

RESULTS

The intervention was associated with a significant decrease in use of antifungal agents. Analysis of data revealed a reduction in costs by 50%. This could substantially be attributed to the implementation of the practice guidelines.

CONCLUSION

The implementation of standardised practice guidelines for antifungal therapy in intensive care units decreased the use of selected antifungal agents and resulted in substantial reduction in expenditure on antifungal agents.

Tissue penetration of moxifloxacin into human gallbladder wall in patients with biliary tract infections

OBJECTIVES

Moxifloxacin, the newest fourth-generation fluoroquinolone, has a broad spectrum of antibacterial activity covering both Gram-positive and Gram-negative aerobic and anaerobic bacteria and is therefore very well suited for the treatment of biliary tract infections. The present study aimed to determine the penetration of moxifloxacin into gallbladder tissue to evaluate its antibiotic potential in this indication.

PATIENTS AND METHODS

Hospitalized patients with acute cholecystitis received a single, 1 h infusion of 400 mg of moxifloxacin before cholecystectomy. Serum and gallbladder wall tissue samples were collected during surgery, and the moxifloxacin concentrations were measured by HPLC.

RESULTS

Sixteen patients (eight men and eight women) were included between January 2007 and April 2008. The time between start of infusion and gallbladder removal ranged from 50 min to 21 h 10 min. The serum concentration at the time of cholecystectomy was between 0.39 and 4.37 mg/L, and the tissue concentration between 1.73 and 17.08 mg/kg. The tissue-to-serum concentration ratio ranged from 1.72 to 6.33.

CONCLUSIONS

The results show that moxifloxacin penetrates well into gallbladder tissue and is therefore a therapeutic option for biliary tract infection. The highest concentrations in serum and gallbladder tissue were measured shortly after the end of a 1 h infusion. As perioperative prophylaxis, moxifloxacin should therefore be administered 30-60 min before the first surgical incision.

Corynebacterium diphtheriae

Diphtheriebakterium

Survey of attitudes towards curriculum reforms among medical teachers in different socio-economic and cultural environments

BACKGROUND

Curriculum reforms in medical schools require cultural and conceptual changes from the faculty.

AIMS AND METHODS

We assessed attitudes towards curriculum reforms in different academic, economic, and social environments among 776 teachers from 2 Western European medical schools (Belgium and Denmark) and 7 medical schools in 3 countries in post-communist transition (Croatia, Slovenia, Bosnia and Herzegovina). The survey included a 5-point Likert-type scale on attitudes towards reforms in general and towards reforms of medical curriculum (10 items each).

RESULTS

Teaching staff from medical schools in Bosnia and Herzegovina had a more positive attitude towards reforms of medical curriculum (mean score 36.8 out of maximum 50 [95% CI 36.1 to 37.3]) than those from medical schools in Croatia or Slovenia (30.7 [29.8 to 31.6]) or Western Europe (27.7 [27.1 to 28.3]) (P < 0.001, ANOVA). Significant predictors of positive attitudes towards medical curriculum reform in post-communist transition countries, but not in Western European schools, was younger age, as well as female gender in Bosnia and Herzegovina.

CONCLUSIONS

Factors influencing faculty attitudes may not be easy to identify and may be specific for different settings. Their identification and management is necessary for producing sustainable curriculum reform.

Prevention is in! Surveillance is out!

There has been a major change in the basic approach taken to hospital hygiene practices, and indeed to infection control within the hospital on the whole. Whereas as recently as the 1990s lectures on the topic of hand disinfection at international congresses were confined to "the periphery of the congress", today several keynote speakers address this issue with the full attention of the audience. This trend is also reflected in publications, and going beyond the domain of hand disinfection, has highlighted the important role of surface disinfection as well as of instrument disinfection in the prevention of nosocomial infections. The role of preventive as opposed to evidence-based hospital hygiene measures has for decades triggered lively discussions. The enormous rise in nosocomial infections due to antibiotic-resistant infections (MRSA, VRE, ESBL, etc.) will, no doubt, have made a significant contribution to bringing about a change in attitude. Even if of all the transmission channels implicated, the hands are the chief vehicles, there is in the meantime widespread evidence that contaminated instruments and surfaces can play a role in transmission. Surveillance is no doubt suitable for analyzing pathogenic transmission channels or shortcomings in infection control measures, but it is no substitute for the requisite preventive use of disinfection measures, since as a rule by the time the results of infectiology diagnostic measures are available, microbial spread will already have taken place. Prevention has had a long tradition in Germany and, in respect of infectious diseases, can be traced back to the 1880s (Robert Koch). It was therefore not surprising that it was Germany, where such efforts were initiated already in already in 1959, that began to formulate guidelines for efficacy testing of disinfection procedures. Since 1989 such guidelines have been compiled for the whole of Europe, thus assuring the preconditions for provision of high-quality disinfectants and, above all, for disinfection procedures whose efficacy has been verified. For the future it must be advocated that industry, on the one hand, will continue to develop more environmentally compatible disinfectants with broader spectra of action and that, on the other hand, the test methods for efficacy testing will be further improved in order to meet the requirements for efficacy testing of such agents.

A comprehensive assessment of medical schools in Bosnia and Herzegovina

OBJECTIVES

To perform internal and external evaluations of all 5 medical schools in Bosnia and Herzegovina against international standards.

METHODS

We carried out a 2-stage survey study using the same 5-point Likert scale for internal and external evaluations of 5 medical schools in Bosnia and Herzegovina (Banja Luka, Foca/East Sarajevo, Mostar, Sarajevo and Tuzla). Participants consisted of managerial staff, teaching staff and students of medical schools, and external expert assessors. Main outcome measures included scores on internal and external evaluation forms for 10 items concerning aspects of school curriculum and functioning: 'School mission and objectives'; 'Curriculum'; 'Management'; 'Staff'; 'Students'; 'Facilities and technology'; 'Financial issues'; 'International relationships'; 'Internal quality assurance', and 'Development plans'.

RESULTS

During internal assessment, schools consistently either overrated their overall functioning (Foca/East Sarajevo, Mostar and Tuzla) or markedly overrated or underrated their performance on individual items on the survey (Banja Luka and Sarajevo). Scores for internal assessment differed from those for external assessment. These differences were not consistent, except for the sections 'School mission and objectives', 'Curriculum' and 'Development plans', which were consistently overrated in the internal assessments. External assessments was more positive than internal assessments on 'Students' and 'Facilities and technology' in 3 of 5 schools.

CONCLUSIONS

This assessment exercise in 5 medical schools showed that constructive and structured evaluation of medical education is possible, even in complex and unfavourable conditions. Medical schools in Bosnia and Herzegovina have successfully formed a national consortium for formal collaboration in curriculum development and reform.

Can soda fountains be recommended in hospitals?

Mineral water (soda water) is very popular in Germany. Therefore, soda fountains were developed as alternatives to the traditional deposit bottle system. Nowadays, different systems of these devices are commercially available. For several years, soda fountains produced by different companies have been examined at the University Hospital of Heidelberg. In 1998, it was possible for the first time to observe and evaluate one of these systems over a period of 320 days in a series of microbiological examinations. The evaluation was implemented on the basis of the German drinking water regulation (Anonymous, 1990. Gesetz über Trinkwasser und Wasser für Lebensmittelbetriebe (Trinkwasserverordnung - TrinkwV) vom 12. Dezember 1990. Bundesgesetzblatt 66, 2613ff). Initially, the bacteria counts exceeded the reference values imposed by the German drinking water regulation in almost 50% of the analyses. Pseudomonas aeruginosa was also detected in almost 38% of the samples. After a re-arrangement of the disinfection procedure and the removal of the charcoal filter, Pseudomonas aeruginosa was not detectable any more. However, the bacteria counts still frequently exceeded the reference values of the German drinking water regulation. Following our long-term analysis, we would not recommend soda fountains in high-risk areas of hospitals. If these devices are to be used in hospitals, the disinfection procedures should be executed in weekly or fortnightly intervals and the water quality should be examined periodically.

Bacterial contamination of preserved and non-preserved metal working fluids

Metal working fluids (MWFs) are important facilities for certain industrial processes. Besides their advantage concerning the effective technical applicability it is disadvantageous that they are excellent culture media for bacterial and fungal growth and may therefore act as an infectious source for employees getting in contact with them. As a matter of prevention most of MWFs are nowadays treated with preservatives to eliminate the contamination of possible human pathogenic bacteria and fungi. Own investigations were concerned with the objectives of the actual and long-term study of the bacterial contamination of preserved and non-preserved MWFs from different MWF systems, the development of a standardized bacterial biotope in non-preserved MWFs and its efficacy to eliminate bacteria which caused infectious diseases in humans, the development of bacterial resistance against preservatives in preserved MWFs and the occurrence of infections and allergies in employees working with MWFs. Our results show: high numbers of different bacteria can be found in non-preserved as well as preserved MWFs; bacteria with a possible human pathogenic potential (category 2, TRBA 466) could almost exclusively be found in preserved MWFs. Those bacteria besides others were able to develop resistance against biocides and could therefore be detected in preserved MWFs for weeks and months; non-preserved MWFs develop stable bacterial biotopes which can be controlled by an artificial inoculation of bacteria. Those biotopes are able to eliminate bacteria which induce infectious diseases in humans; there are only very few data published concerning MWF caused infections or allergies. According to our results of a questionnaire 10% of employees getting in contact with MWFs, complain skin irritations/reactions. There was no difference working with preserved or non-preserved MWFs nor a clear cut correlation to the MWF contact. These data may motivate for more intensive epidemiological studies in this field. The results of our investigations point out that taking into consideration safe working conditions non-preserved MWFs even contaminated with a standardized combination of waterborne bacteria like Pseudomonas spec. up to 10(8) CFU/ml are an alternative to preserved MFWs.

Temptation of academic medicine: second alma mater and "shared employment' concepts as possible way out?

Apparently, in developing and in well-developed societies we are confronted with a crisis of academic medicine in all aspects: health care, teaching, and research. Health care providers in teaching hospitals are under pressure to generate revenues, academic research is pressed to keep pace with institutions devoted solely to research, and teaching is often understood not as privilege and honor but as burden and nuisance. The key problem and the principal cause of the crisis are low interest of the best young graduates to follow an academic career in a world where the benefits and values of the private sector are prevailing. Confronted with these circumstances and the continuous perils of permanent brain-drain, we developed an innovative concept of "shared employment' where two academic institutions (one in a developed and one in a developing country) will collaborate in development and support of fresh talents, building elite academic staff. Most academic exchange programs developed so far have proved to be ineffective and of poor vitality, in spite of loud exclamations, high expectations, and a huge amount of good will involved. In contrast, the suggested cooperation will be based exclusively on mutual interest and clearly defined benefits for all involved parties.

Description of new mutations in the rpoB gene in rifampicin-resistant Neisseria meningitidis selected in vitro in a stepwise manner

Fourteen meningococcal strains were selected towards rifampicin resistance in a stepwise manner in vitro; final MICs were between 8 and >256 microg ml(-1). Sequence analysis of a 295 bp subgenic fragment of the RNA polymerase beta-subunit (rpoB) gene from the original and the fully resistant strains revealed that, with one exception, the strain pairs differed by just one position in the deduced amino acid sequence. Transformation of a PCR-amplified subgenic rpoB fragment harbouring the mutated site into a susceptible strain demonstrated the resistance-conferring mechanism.

Disinfection of surfaces by photocatalytic oxidation with titanium dioxide and UVA light

Particularly in microbiological laboratories and areas in intensive medical use, regular and thorough disinfection of surfaces is required in order to reduce the numbers of bacteria and to prevent bacterial transmission. The conventional methods of disinfection with wiping are not effective in the longer term, cannot be standardized, are time- and staff-intensive and use aggressive chemicals. Disinfection with hard ultraviolet C (UVC) light is usually not satisfactory, as the depth of penetration is inadequate and there are occupational medicine risks. Photocatalytic oxidation on surfaces coated with titanium dioxide (TiO2) might offer a possible alternative. In the presence of water and oxygen, highly reactive OH-radicals are generated by TiO2 and mild ultraviolet A (UVA). These radicals are able to destroy bacteria, and may therefore be effective in reducing bacterial contamination. Direct irradiation with UVC however can produce areas of shadow in which bacteria are not inactivated. Using targeted light guidance and a light-guiding sheet (out of a UVA-transmittant, Plexiglas, for example), as in the method described in the present study, bacterial inactivation over the entire area is possible. The effectiveness of the method was demonstrated using bacteria relevant to hygiene such as Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Enterococcus faecium. For these bacteria, a reduction efficiency (RE) more than 6log10 steps in 60 min was observed. Using Candida albicans, a RE of 2log10 steps in 60 min was seen. Light and scanning electron microscopic examinations suggest that the germ destruction achieved takes place through direct damage to cell walls caused by OH-radicals.

Immunogenicity of recombinant L7/L12 ribosomal protein of Neisseria meningitidis--high prevalence of specific antibodies in humans but limited immunogenicity for T cells

The rplL gene, coding for ribosomal protein L7/L12 of Neisseria meningitidis was cloned and expressed as a fusion protein. The recombinant protein was used in Western blots and lymphocyte proliferation assays to study the prevalence of specific antibodies in human sera and the immunogenicity for the cellular immune system. Most of the serum samples studied were found to be positive for L7/L12-specific antibodies. A number of peripheral blood mononuclear cell preparations tested displayed activation in lymphocyte proliferation assays. The magnitude of activation (stimulation index) was moderate, and there was no correlation with a history of meningococcal disease. The high prevalence of specific antibodies is explained by the high carriage rate of meningococci in the normal population or cross-reactivity to ribosomal proteins of other bacteria, thus indicating immunogenicity. However, meningococcal L7/L12 does not seem to be a potential T cell antigen.

Tissue and serum concentrations of levofloxacin in orthopaedic patients

The level of levofloxacin was determined in serum, bone and several tissues after a single dose of 500 mg i.v. Twenty-one patients (mean age: 56.8 years) undergoing bone surgery (nine patients) or surgical debridement of a decubitus ulcer (12 patients) who received levofloxacin as perioperative prophylaxis were included in the study. During surgery, blood and tissue samples were obtained approximately 1.5 h (range 40-210 min) postdosing. Levofloxacin concentrations in 87 specimens including 21 serum samples were determined using high-performance liquid chromatography (HPLC). The mean serum concentration at 1.5 h was 8.6+/-2.3 microg/ml. Concentrations above the MIC of common pathogens were reached in all tissues during the collection period with a maximum in skin samples (19.9+/-9.9 microg/g) followed by wound tissue and granulation tissue with 17.3+/-6.5 and 13.7+/-6.4 microg/g respectively. In muscle and fatty tissue mean levofloxacin concentrations of 8.0+/-0.9 and 4.0+/-2.2 microg/g were attained. Mean levels in cancellous bone were 6.6+/-3.6 microg/g, lowest levels were measured in cortical bone (2.8+/-1.1 microg/g). Twenty-two different pathogens were cultivated from the lesions of 11 of 12 patients with pressure ulcers. MIC values for levofloxacin were determined and compared with the corresponding tissue concentrations. Levofloxacin may be useful for perioperative prophylaxis and treatment in orthopaedic patients due to its good tissue penetration.

An HPLC assay and a microbiological assay to determine levofloxacin in soft tissue, bone, bile and serum

A simple, specific and sensitive HPLC assay for levofloxacin in serum, bile, soft tissue and bone was evaluated and validated. The samples were prepared by protein precipitation with acids and methanol, which yielded high recoveries (for serum and bile>98% and for bone and soft tissue>90%). The compounds were separated on a reversed phase column with an acidic mobile phase containing triethylamine. The eluate was monitored by fluorescence detection. The HPLC assay is linear over the usable concentration range (0.1-40 microg/ml) and it provides good validation data for accuracy and precision. Although comparison of HPLC results to the results of a microbiological assay showed congruent results (regression coefficients>0.967). HPLC should be the method of choice for determination of levofloxacin in biological matrices.

[A new test for the detection of pyrogens in pharmaceutical products. Examinations for the validation of the human whole blood assay]

The human whole blood assay utilises the natural fever response to detect pyrogens by determination of the release of IL-1beta. In order to replace the official method, the rabbit pyrogen test, a validation of the whole blood assay is necessary. A comparison of the results obtained from many blood samples has revealed the following: 1) Blood not stimulated by LPS does not produce IL-1beta. 2) Stimulation by LPS induces a concentration-dependent release of IL-1( beginning at a concentration of between 2-5 pg/mL LPS. 3) The amount of IL-1beta released varies greatly between samples obtained from different individuals. 4) Storing blood samples results in a right shifted LPS/IL-1beta curve with a steeper gradient and higher maximum value of IL-1beta. In this paper we suggest an experimental method for the determination of pyrogens based on the established semi-quantitative LAL gelation method as detailed in the European Pharmacopeia. Using this methodology, we were able to show that the amount of endotoxin in a number of different infusion solutions was below the LAL-endotoxin limit concentration. LPS was quantitatively determined from spiked samples.

[Evaluation and further development of a pyrogenicity assay based on human whole blood]

When cells of the immune system, i.e. primarily blood monocytes and macrophages, come into contact with pyrogens (fever inducing contaminations) they release mediators transmitting the fever reaction within the organism. A new pyrogen test exploits this reaction for the detection of pyrogens: human whole blood taken from healthy volunteers is incubated in the presence of the test sample. In case of pyrogen contamination, the formation of interleukin-1 is induced, which is determined by ELISA. According to the various pharmacopoeia, the rabbit pyrogen test determines the fever reaction following injection of a test sample. In comparison, the new whole blood assay is more sensitive, less expensive and determines the reaction of the targeted species. In contrast to the well established in vitro alternative, i.e. the limulus amebocyte lysate assay (LAL), the blood assay is not restricted to endotoxins of Gram-negative bacteria and is not to the same extent disturbed by endotoxin-binding blood proteins. Here, interim results of the ongoing optimisation and prevalidation are demonstrated. Preliminary data of the evaluation for biological and pharmaceutical drugs are presented.

Simple and rapid detection of Candida albicans DNA in serum by PCR for diagnosis of invasive candidiasis

A rapid and sensitive PCR assay for the detection of Candida albicans DNA in serum was established. DNA from human serum samples was purified using the QIAamp blood kit, which proved to be a fast and simple method for isolating minute amounts of Candida DNA from clinical specimens for diagnosis of invasive candidiasis. Universal primer sequences used in the PCR assay are derived from the internal transcribed spacer rRNA gene of fungi, whereas the biotinylated hybridization probe used in a DNA enzyme immunoassay (DEIA) binds specifically to C. albicans DNA. The sensitivity of this PCR-DEIA method is very high; the detection limit for genomic Candida DNA is one C. albicans genome per assay. Blood from uninfected and infected persons, ranging from healthy volunteers, patients with mucocutaneous infections, and patients at risk to develop a systemic Candida infection to patients with an established systemic candidiasis, was analyzed for the presence of C. albicans to diagnose fungal infection. Candida DNA could not be detected in sera of 16 culture-negative controls and from 11 nonsystemic candidal infections by PCR or DEIA. Blood cultures from patients at risk were all negative for Candida, whereas all blood cultures from systemic candidiasis patients were positive. However, Candida DNA could be detected by PCR and DEIA in the serum from three out of nine patients who were at risk for a systemic infection and in the serum of all seven patients who had already developed an invasive Candida infection. PCR is more sensitive than blood culture, since some of the patients at risk for invasive yeast infection, whose blood cultures were all negative for Candida, tested positive in the PCR amplification. These results indicate the potential value of PCR for detecting C. albicans in serum samples and for identifying patients at risk for invasive candidiasis.

Detection of endotoxins and other pyrogens using human whole blood

When cells of the immune system, i.e. primarily blood monocytes and macrophages, come into contact with pyrogens (fever-inducing contaminations) they release mediators transmitting the fever reaction through the organism to the thermoregulatory centres of the brain. The new test discussed here exploits this reaction for the detection of pyrogens: human whole blood taken from healthy volunteers is incubated in the presence of the test sample. If there is pyrogen contamination, the endogenous pyrogen interleukin-1 is released, which is then determined by ELISA. According to the pharmacopoeia, the rabbit pyrogen test determines the fever reaction following injection of a test sample. In comparison, the new whole blood assay is more sensitive, less expensive and determines the reaction of the targeted species. Compared to the well established in vitro alternative, i.e. the limulus amebocyte lysate assay (LAL), the new blood assay is not restricted to endotoxins of gram-negative bacteria, it is not affected by endotoxin-binding blood proteins and it reflects the potency of different endotoxin preparations in mammals. Here, interim results of the ongoing optimization and pre-validation are reported and the present state of the evaluation for biological and pharmaceutical drugs are presented.

[Quality assurance (general) at the medical school of Heidelberg as a model]

Because of new social and professional challenges, especially in the developed countries, there is a trend towards change and quality assurance is taking place in medical education over the past 20 years. In Heidelberg, the new way of teaching the students by general practitioners includes quality assurance by questionnaires, reports of practice visits, quality conferences of the teachers, and co-operation of the students. 90% of the students recommended the practice-based structured program as very useful, especially the work with the patients in the general practices, 87% of the teaching general practitioners accepted special criteria for teaching; by this way an academic general practice can be established to meet the future expectations of primary medical care.

[Meningococcal infections: aspects of microbiology, epidemiology and prevention]

Neisseria meningitidis (meningococcus) is responsible for an average of 40% of all cases of bacterial meningitis in Germany. Cerebrospinal fluids, blood cultures, throat swabs and scratches, aspirations and biopsies of the skin rash are appropriate materials for the diagnosis of meningococcal disease. The materials should reach the laboratory without delay. Since 1993, the incidence of meningococcal disease in Germany is less than 1 case per 100,000 inhabitants. The case fatality rate is about 10%. Most cases of meningococcal disease occur in the first quarter of the year. Almost half of all invasive N. meningitidis isolates are from children under five years of age. In the period 1990-1998, in Germany an average of 74% of cases were caused by serogroup B and 21% by serogroup C. In serogroup B disease, isolates of serotype 15, in group C disease strains of serotype 2a are predominating. Chemoprophylaxis should be given to all household members and all contacts living in institutions with household-like character, contacts in institutions for children under six years of age and all persons who had contact with the oropharyngeal secretions of the patient. At present, only capsular polysaccharide vaccines against serogroups A, C, Y and W135 are available for immunoprophylaxis in Germany.

Ceftazidime in combination with glycopeptide antibiotic is an effective first-line therapy for patients undergoing high-dose therapy with autologous peripheral blood stem cell support

It was the objective of this study to evaluate the efficacy and toxicity of an empirical antibiotic therapy consisting in ceftazidime and a glycopeptide antibiotic. All patients enrolled in the study had hematological malignancies and underwent high-dose therapy with peripheral blood stem cell (PBSC) support. In this retrospective study, 183 of 207 patients who had received a PBSC-supported high-dose therapy were evaluable. Any patients who had fever higher than 38.5 degrees C received ceftazidime in combination with vancomycin (105 patients) or teicoplanin (69 patients). In 80 of 174 patients with fever (45%) the fever resolved within 72 h as a result of the treatment with ceftazidime and the glycopeptide antibiotic. In nonresponding patients, the changes included the replacement of ceftazidime by imipenem/cilastin (94 patients) and the addition of erythromycin (12 patients) or metronidazole (3 patients). Amphotericin B was administered in 29 patients. Following hematological reconstitution, the fever and clinical signs, including radiographic findings, resolved in 20 primarily nonresponding patients. In blood cultures, a significantly higher incidence of gram-positive than of gram-negative bacteria was observed (26 vs 7). The toxicity of the first-line antibiotic therapy was limited to allergic skin reactions in 12 patients. Ceftazidime in combination with a glycopeptide antibiotic provides an effective and safe first-line therapy for patients with neutropenic fever following PBSC-supported high-dose therapy.

Chlorate as an inorganic disinfection by product in swimming pools

Chlorate and chlorite concentrations were determined in water samples taken from 33 swimming pools. In the pools under investigation, disinfection of the water is carried out either by gaseous chlorine (n = 14) or hypochlorite solution in conjunction with flocculation and sand filtration. A number of the pools also use ozone treatment to augment the disinfection process. Chlorite was not detectable in any of the samples (detection limit 1 mg/l). High concentrations of chlorate were detected in samples from a number of the pools; in one case as high as 40 mg/l. Higher chlorate concentrations were found to be associated with those pools using hypochlorite solution as a disinfecting agent. In contrast, relatively low chlorate concentrations were found in pools treated with gaseous chlorine. In order to elucidate any relationship between the chlorate content of pool water and that of the respective hypochlorite stock solution, chlorate and bromate concentrations were determined in the hypochlorite stock solutions of nine pools. Bromate concentration in the stock solutions were not found to exceed 1.2 g/l, chlorate was measured in concentrations of up to 44.5 g/l. The additional use of ozone as part of the water purification process appears to have no significant influence on chlorate concentration. Chlorate has no bactericidal properties and does not interfere with the measurement of certain parameters relevant to hygiene in swimming pools such as free and combined chlorine, pH or redox potential. At present, the effects of high chlorate concentrations in swimming pool water are unclear. Our initial investigations indicate that chlorate has no cytotoxic (Neutral-Red assay) or irritating properties (HET-CAM assay). However, both chlorate and chlorite are known to interfere with the haematopoetic system. In Germany, the MCL for chlorite in drinking water is 0.2 mg/l. It is therefore strongly recommended that measures should be taken to reduce chlorate concentrations in swimming pool water.

Systematic analysis and controlling of health care organisations lead to numerical health care improvements

The EFQM model for organisational excellence is used in the health care sector as a tool to diagnose and assess the starting position for the effective QM programme. Feedback reports cover the fields of acute medical care, rehabilitation and ambulant care and contain strengths areas for improvement. Building on the EFQM feedback reports, the Modular Concept for Quality in Health Care ("Heidelberg Model") improves QM both holistically and specifically by implementing so-called "Modules for Excellence". The implementation process follows principles of project management covering medical, nursing and managing issues and the performance is periodically evaluated against targets. QM projects that are designed in the dichotomic way follow three goals. Organisational diagnosis and therapy lead to numerical health care improvements in "Prevention of nosocomial infections" and "Optimising out-patient treatment". Different assessment approaches lead to a diagnosing feedback report for QM in health care. The Modular Concept for Quality in Health Care ("Heidelberg Model") clusters, priorities, implements and evaluates the organisation's key areas for improvement.

Detecting legionellosis by unselected culture of respiratory tract secretions and developing links to hospital water strains

For a 13-month period, all respiratory tract secretions submitted for routine bacteriology from a large hospital complex were cultured for legionella, irrespective of clinical diagnosis and laboratory requests. Ten cases of legionellosis were detected in this manner, three of which met a strict epidemiological definition of hospital-acquired. Therefore, the 16 warm-water systems of the hospitals, spread out over two locations, were examined for the presence of legionella. Legionella pneumophila was found in 15 warm water systems, with a distinct pattern of serogroups between the two locations. Legionella of the same serogroups as those isolated from patients were present in each hospital water supply. The isolates were further typed by monoclonal antibodies and by genomic macrorestriction analysis. Similarity between clinical and environmental isolates was found in seven cases. In these cases, acquisition from the hospital water supply appears very likely. The strains of the remaining three patients did not match those in hospital water, suggesting that community-acquired legionellosis was occurring as well. This study suggests that routinely culturing respiratory tract secretions of pneumonia patients for legionella can help diagnose unsuspected cases of legionellosis. Typing legionella strains beyond the serogroup level with tools such as macrorestriction analysis is useful to define sources of infection, which can then be targeted for control measures.

[Fungal nucleic acid detection for invasive aspergillosis]

A universal PCR-assay for the detection of fungal DNA was compared with microscopy and culture for the diagnosis of invasive aspergillosis using 78 samples from 42 patients. Eighteen patients were suffering from invasive aspergillosis, 5 patients were colonized with Aspergillus in the respiratory tract, 19 patients did not show any sign of aspergillosis. Samples from 6 of the 18 patients with invasive aspergillosis were microscopically positive with true mycelia, 15 of 18 grew Aspergillus in culture, 16 of 18 were PCR-positive. The combination of microscopy and culture led to the diagnosis in 17 of 18 patients, the combination of microscopy and PCR in 16 of 18 and the combination of culture and PCR in all the 18 patients. For 3 of 18 patients, PCR was the diagnostic key: in 2 biopsies the histologically detected fungal elements were identified as Aspergillus, in 3 bronchial lavages from 1 patients nothing but PCR was positive for Aspergillus. Four out of 5 culture positive patients with Aspergillus colonization were also PCR positive; one out of 19 patients without aspergillosis was culture positive, 3 out of 19 were falsely PCR positive. Candida colonization in the upper respiratory tract or Pneumocystis carinii pneumonia did not lead to false positive Aspergillus-PCR results. In conclusion, the evaluated fungal PCR-assay can supplement conventional methods for the diagnosis of invasive aspergillosis.

Catheter-related infections in long-term catheterized dogs. Observations on pathogenesis, diagnostic methods, and antibiotic lock technique

BACKGROUND

Intravascular catheters are associated with severe infections in patients, but only few reports on this problem in animal research exist.

OBJECTIVE

We report on catheter-related bacterial colonization and its consequences in long-term catheterized animals.

MATERIAL AND METHOD

Foxhounds were instrumented with intravascular catheters and flow probes to study the regulation of renal blood flow and pressures.

RESULTS

After flushing the catheters, alterations in renal blood flow were observed and these could be related to bacterial colonization of intravascular catheters with Pseudomonas species. After attention had been focused on aseptic technique in all experimental phases and prophylactic antibiotic lock instituted, the occurrence of Pseudomonas bacteremia ceased, and the magnitude and incidence of catheter-related colonization and infection by Pseudomonas species dropped considerably.

CONCLUSION

The catheter-related colonization that occurred spontaneously in these animals resembled findings in animal experiments in which catheter-related infections were deliberately induced as well as observations made with regard to catheter-related infections in patients. This report emphasizes the importance of asepsis when working with animals with long-term intravascular catheters. We suggest that monitoring for this complication, e.g., by means of catheter cultures at the time of removal, should routinely be part of protocols for animal experiments using long-term intravascular catheters.

Comparative evaluation of a commercial system for identification of gram-positive cocci

The performance of a new commercial system for the identification of different groups of gram-positive cocci [BBL Crystal Gram-Positive (GP) Identification System; Becton Dickinson Microbiology Systems, Germany] was evaluated in comparison with two currently used commercial systems, the API Staph and the API Strep (bioMérieux Diagnostic, Germany). A total of 191 strains from seven different gram-positive genera comprising 32 different species were tested. For the BBL Crystal GP system, the correct identification rate without additional tests was 89.5% at the species level and 97.9% at the genus level. The findings suggest that the newly introduced BBL Crystal GP ID system provides an accurate method for the identification of gram-positive cocci, with an overall rate of correct species identification of about 90%, similar to that of the established API systems. Its major advantage is the extended spectrum of taxa included in a single test panel in contrast to the two different API test kits. Furthermore, the simplicity of use and the safe and rapid handling in a closed system conveniently accommodate existing laboratory workflow.

Ribosomal genes of Histoplasma capsulatum var. duboisii and var. farciminosum

A total of 1704 basepairs of the 18S rDNA of Histoplasma capsulatum var. duboisii (HCD, strain CBS175.57) and H. capsulatum var. farciminosum (HCF, strain CBS478.64) were sequenced (EMBL accession no. Z75306 and no. Z75307). The 18S rDNA of HCD was 100% identical to a published sequence of H. capsulatum var. capsulatum (HCC). The 18S rDNA of HCF showed one transversional point mutation at the nucleotide position 114 (ref. Saccharomyces cerevisiae). Hybridization confirmed that, in the 18S rDNA of two out of five strains of HCF, guanine was substituted for cytosine at the nucleotide position 114. Furthermore, identical group 1C1 introns (403 bp) were found to be inserted after position 1165 in four out of five strains of HCF, including the two strains with point mutations in the 18S rDNA, and a slightly different group 1C1 intron (408 bp) was detected in one strain of HCC without this point mutation. Intraspecific sequence variability in the highly conserved 18S rDNA because of occurrence of introns and mutations as a possible source of error in molecular diagnostics is discussed. In addition, internal transcribed spacer regions between the 18S rDNA and the 5.8S rDNA (ITS1) of three strains of HCF, and one strain each of HCC and HCD showed significant sequence variability between varieties and strains of H. capsulatum.

Molecular probes for the detection of pathogenic fungi in the presence of human tissue

Four primer systems, amplifying fragments of the gene coding for the small ribosomal subunit (18S rRNA) were characterised with pure cultures of 65 medically relevant fungal species plus two mushrooms. A primer cocktail (TR1/CA1-TR2/AF2) amplified 59 of 67 fungal species; the universal fungal primer 1 (UF1) in combination with the eukaryotic primers S3 or EU1 amplified 64 and 65 of 67 fungal species, respectively. The design of an additional primer (RZY1) enabled the amplification of the missing members of the zygomycetes. The primer systems amplified all the medically relevant fungi tested. These included eight Candida spp. and seven other yeast species, 13 dermatophytes, 32 moulds (including six zygomycetes and five dimorphic fungi) and two mushrooms. Eleven controls including DNA from Schistosoma mansoni, Escherichia coli, Mycobacterium tuberculosis and man were not amplified. The oligonucleotide CA hybridised with C. albicans, C. tropicalis and C. parapsilosis; the oligonucleotide TR hybridised with the 13 dermatophytes; the oligonucleotide AF hybridised with Aspergillus fumigatus, A. flavus, A. terreus, A. nidulans, A. versicolor, A. tamarii, A. clavatus, A. fischeri, but not with A. niger or A. versicolor; and the oligonucleotide HC hybridised with three varieties of Histoplasma capsulatum. These oligonucleotides did not hybridise with the other fungi nor the controls. The specificity of the newly designed primer systems was confirmed by selective amplification of fungal DNA from human lung tissue spiked with fungal biomass and from vitrectomy fluid of a patient with candida endophthalmitis.

Identification and analysis of a new vacA genotype variant of Helicobacter pylori in different patient groups in Germany

The vacuolating cytotoxin of Helicobacter pylori (VacA) is known to cause cell damage to mammalian cells and is suspected to give rise to gastric epithelial lesions that might lead to peptic ulcer disease. As shown recently, the gene encoding VacA exhibits genetic variation, with three different families of signal sequences (s1a, s1b, and s2) and two families of midregion sequences (m1 and m2). In order to investigate the relationship between the presence of specific vacA genotypes and peptic ulceration, the vacA genotypes of 158 clinical isolates of H. pylori were determined. The study group consisted of 106 patients with duodenal ulceration; 52 patients with nonulcer dyspepsia (NUD) were used as controls. H. pylori of genotype s1 was isolated from 96% of the patients with ulcerations, whereas genotype s2 was only present in 4%, indicating a strong correlation between the vacA genotype and peptic ulceration (P < 0.001). In contrast, 31% of the patients from the NUD control group were infected with strains of vacA genotype s2. Particular midregion genotypes (m1 and m2) were not associated with clinical manifestations. The midregions from 18% of the isolates could not be classified by the proposed scheme. DNA sequencing revealed high homology between the untypeable midregions and that of genotype m1, with multiple base pair exchanges, some affecting the primer annealing site. Compared to those of m1 and m2 alleles, the divergent midregions from untypeable strains showed clustering, indicating the presence of a further subfamily of sequences in the midregion of vacA in German isolates, for which we propose the term "m1a." A new specific primer that we designed for typing m1a isolates might be useful in other studies.

[Irritating effects of disinfection by-products in swimming pools]

Compounds which can occur as disinfection by-products (DBP's) in swimming pool water were examined for their mucous membrane irritating potential. Previous studies using the rabbit eye test (Draizé test) have shown that the irritating potential of typical concentrations of free and combined chlorine are insufficient to explain the degree of eye irritation that can result from exposure to swimming pool water. Other DBP's which may be responsible for eye irritation include halogenated carboxyl compounds (HCC's) which act as precursors during the formation of chloroform. In this study, a modified HET-CAM Test (Hens Egg Test at the Chorion Allantois Membrane) has been used to investigate the mucous membrane irritating effects of HCC's. Some of the compounds tested were found to have a significantly increased irritating effect when compared to a chlorine/chloramine mixture of the same concentration, several mixtures of HCC's where even more active at lower concentrations than single compounds. However, the irritating effects of individual compounds as well as of mixtures of HCC's were not sufficiently intense to allow the identification of those compounds specifically responsible for the overall observed increase in irritation. HCC's were therefore tested in the presence of aqueous chlorine solution. When combined with aqueous chlorine, a number of compounds exhibited significantly enhanced effects. Our results show that the eye irritating effects of low concentrations of DBP's can be investigated using a modified HET-CAM assay. Moreover, results obtained using this assay suggest that the mucous membrane irritating potential of swimming pool water is a consequence of the effects and synergistic action of a number of DBP's in the presence of chlorine. Further work should be carried out in order to establish an indicator for eye irritating effects of swimming pool water.

Western blot analysis of the immune response to Candida albicans antigens in 391 long-term intensive care patients

The aim of this study was to determine, using Western blot, the prevalence of anti-Candida albicans antibodies in long-term intensive care patients and to characterize specific immune responses that may only occur in patients with invasive candidosis. A total of 1751 serum samples from 391 patients of a German multicentre study, which was designed to determine the incidence of systemic candidosis, was examined. Significantly enhanced antibody production against specific antigens was observed in several subgroups of patients, i.e. those with underlying disease of the pancreas (29 kDa, P = 0.006), cholecystolithiasis (47 kDa, P = 0.029), gastrointestinal tract disease (47 kDa, P = 0.03), steroid therapy (58 kDa, P = 0.02), thrush (58 kDa, P = 0.032), urogenital infection (58 kDa, P = 0.034), Candida antigen titre > or = 1:4 (58 kDa, P = 0.002) and positive fungal culture (36 kDa, P = 0.033) and those who had died (36 kDa, P = 0.011). In contrast to earlier publications, an immune response against the 29 and 47 kDa antigens was relatively common among long-term intensive care patients (37% and 70% antibody positive respectively). A single antigen that provided satisfactory sensitivity and specificity for the discrimination between fungal infection and no fungal infection or between superficial and invasive fungal infection was not identified in this study.

[Potassium as an indicator of anthropogenic contamination of swimming pool water]

Swimming pool water is processed, filtered and disinfected repeatedly in order to maintain hygienic conditions. Additionally, fresh water is added. However, it cannot be avoided, that the concentrations of certain components of swimming pool water will increase in the course of time. DIN 19,643 regulates that fresh water supply can be measured by nitrate concentration. Nitrate is mainly formed by oxidation of nitrogen containing organic compounds. Oxidation reactions are complex and the amount of nitrate formed by this process depends on specific factors which may vary in swimming pools with different technical equipment. Therefore nitrate is only of limited reliability to estimate fresh water addition in public swimming pools. Main sources for nitrogen containing compounds in pool water are sweat and urine which contain inorganic compounds like potassium. Potassium is a direct indicator of contamination. Its concentration is not influenced by chemical reactions because it is an inert compound. The urine release into the water of indoor pools was estimated by this parameter to be 77.5 ml/person, in outdoor pools about 60 ml. Potassium concentration in swimming pools will reach an equilibrium concentration, depending on the size of the pool, the number of bathers and the amount of fresh water added. This equilibrium concentration is mathematically calculated in a general approach. In none of 36 swimming pools where potassium concentration was measured, this calculated value was exceeded. The results indicate that the potassium concentration is a new valuable parameter to assess the quality of swimming pool water under hygienic aspects.

[Haloforms in hot spring pools]

Chloroforme is formed during disinfection of swimming pool water in certain amounts depending on several cofactors. Because of its carcinogenic properties this compound has been frequently a subject of public discussion over the last couple of years. Little is known about chloroforme concentrations in spas. Spas are operated at significantly higher temperatures as compared to other pools, and the organic contamination may be higher. Therefore, chloroforme is possibly produced in higher amounts than in regular swimming pools. On the other hand the air that is blown through the bassin may reduce the concentration of this low volatile substance. In order to investigate the average concentration, 21 water samples from spas in public indoor pools were analyzed as to their chloroforme contend. The median of concentration was 3.8 micrograms/l. The maximum measured chloroforme concentration was 6.4 micrograms/l. The average chloroforme concentration in the filtered water was slightly higher than before filtration. The use of spas does not implicate an increase in chloroforme uptake by bathers.

Influence of n-6 and n-3 polyunsaturated fatty acids on the resistance to experimental tuberculosis

It has previously been shown that the n-3 polyunsaturated fatty acids (PUFAs) eicosapentaenoic acid (20:5(n-3)) and docosahexaenoic acid (22:6(n-3)) possess antiinflammatory properties and can interfere with immune functions. To evaluate whether this would affect resistance to infection, we studied the influence of different types of fatty acids (FAs) on experimental tuberculosis in an animal model. Three groups of 26 weanling guinea pigs were fed isocaloric diets with 26 cal% fat that differed in FA composition with respect to saturated FAs, linoleic acid (18:2(n-6)), eicosapentaenoic acid (20:5(n-3)), and docosanexaenoic acid (22:6(n-3)) as follows: (1) reference (REF) group: 14.8 cal% saturated FAs and 2.8 cal% linoleic acid; (2) n-6 group: 4.6 cal% saturated FAs and 15.4 cal% linoleic acid; (3) n-3 group: 6.3 cal% saturated FAs, 10 cal% linoleic acid, 1.4 cal% eicosapentaenoic acid, and 0.9 cal% docosahexaenoic acid. After 13 weeks, 18 animals from each group were intramuscularly injected with 180 colony-forming units (CFU) Mycobacterium tuberculosis strain H37Rv. Eight noninfected animals per group served as controls. Seven weeks later, the mean number of mycobacteria recovered from the spleens of the n-3 group (log 4.34 CFU, standard error of the mean [SEM], 0.12) was significantly higher than from the REF group (log 3.90 CFU; SEM, 0.15) and the n-8 group (log 3.93 CFU; SEM, 0.13; P < .05). In addition, the Root Index of Virulence (RIV) showed the most pronounced progression of the disease in the n-3 group. The mean size of the tuberculin reaction was larger in the n-3 group than in the other groups (P < .05). There was no significant difference between the n-6 group and the REF group. We conclude that supplementing the diet with n-3 FAs eicosapentaenoic acid and docosahexaenoic acid can affect resistance to M tuberculosis, whereas supplementing with n-6 FAs does not.

In-use contamination of propofol. A clinical study

Reports about post-operative infections associated with the use of propofol prompted us to investigate the in-use contamination of lipid-formulated intravenous (i.v.) anaesthetics used for general anaesthesia or for sedation of intensive care patients in this department. The level and incidence of extrinsic contamination of propofol ('Diprivan') and of another intravenous anaesthetic, etomidate, formulated in lipid solution ('Etomidat-lipuro') was found to be low during two study periods. However, the need to observe strict aseptic precautions in handling these intravenous drugs must be emphasized.

[Diagnosis in environmental medicine: basic principles and problems]

Diagnosis in environmental medicine only differs from the conventional medical diagnosis in a more detailed expositional evaluation on the basis of a respectively expanded anamnesis and a possible local visit, a surrounding examination as well as a so-called biological monitoring. Thus, the essential element of the "diagnosis" in environmental medicine consists in the resolving of a possible internal exposure (and occasionally resulting effects). From this point of view, physicians in environmental medicine could give an advisory contribution to the conventional medicine in selected cases. In contrast to frequently occurring assertions, there are practically no typical environmental diseases due to usual environmental toxicants. At present, a causality between environmental agents and health related disturbances can only be made plausible in less than 10% of out-patients of environmental medicine. These figures are in total contrast to the expansion of the out-patient and clinical environmental medicine. The expansion of the diagnostic offer gives not only to the public but also to the patients and the physicians the impression of a specific competence in diagnostic and therapy of environmental medicine which to this extent does not exist. The consequences are unnecessary and unsuccessful examinations. This is of no help to the patient. Most of the "environmental patients" suffer from civilization caused/psychosomatic and psychosocial disturbances like e.g. phobias, and somatoforme or depressive disturbances. In the genesis probable an increasing readiness for fear, unrealistic threatening convictions (arranged by media, homeopathists, physicians and other authorities), growing fear disturbances as a consequence to this as well as the cognitive connection of "normal" inner disturbances with the suspicious agens play a decisive role. For these patients the clinical environmental medicine lead astray. This is significantly more valid for the numerous "clinical ecologists" who apply scientifically doubtful methods. Considering the clinical approach to environmental medicine urgently needs a critical evaluation by independent research groups.