Trends in social, political and technological impact factors of hygienic risks in German households.

This paper considers actual German trends of impact factors contributing to hygienic risks in domestic settings: Have there been or are there still alterations which may be relevant and which should have consequences for hygiene behavior? How is hygiene consciousness organized in the German society? Each of the alterations of hygiene determinants described below may appear to be marginal when looked at separately, thus disregarding any relationship to hygiene. However, as a whole to anticipate the conclusion they have clearly altered the hygiene risks in the household; some risks have decreased but others have grown worse. The author intends to initiate an objective discussion on home hygiene in Germany. The intention is not creating a sterile environment in the home but to realize the "hot spots" of hygiene in modern domestic settings in order to develop a targeted hygiene.

[Virucidal effectiveness of some commercial products for chemothermal disinfection methods for temperature resistant viruses and bacteriophages--evaluation of a test model]. / Viruzidieprüfung einiger Handelsprodukte im chemothermischen Desinfektionsverfahren an temperaturresistenten Viren und Bakteriophagen--Erprobung eines Testmodells.

In the laboratory assay of chemothermal virus disinfection procedures a test system is required which allows to differentiate between the physical effects of the temperature and the chemical effects by the disinfectant used. From the four test viruses recommended by the German Association for the Control of Virus Diseases (Deutsche Vereinigung zur Bekämpfung der Viruskrankheiten) only SV 40 tumor virus showed a sufficient thermal stability at 55 degrees C to take it in consideration as test virus for chemothermal disinfection procedures. Bacteriophage Phi x 174 and lactococci phages P001, P008 and P109 are suggested for the evaluation of chemothermal disinfection procedures in food processing industries because of their thermal stability at 55 degrees C, for short exposition times even at 60 degrees C. For procedures which work at 60 degrees C, e.g. laundry disinfection, especially bovine parvovirus can be recommended as test virus. In case of a binary product consisting of two different compounds for mechanically cleaning and disinfection of surgical instruments we were able to evaluate the virucidal effectivity at 55 degrees C for both parts separately. Generally our results showed that products with insufficient virucidal activity against naked viruses even at 60 degrees C may not be assumed as sure virucidal disinfectants.

Studies on the stability of selected viruses in cosmetics.

Synopsis Information concerning the risks emerging from the use of cosmetics contaminated with viruses is rarely reported. Therefore, we investigated the stability of viruses within different types of cosmetics. Test products were artificially contaminated with different viruses, which, due to the application of the products, have hygienic relevance. Virus persistence was observed by determining the reisolation rate. With this knowledge we were able to estimate the initial contamination of finished products and raw materials. Viruses with hygienic relevance could neither be detected in finished products nor in raw materials. We can conclude from this that cosmetics seem to be safe with regard to initial contamination. However, our results clearly showed that secondary contamination with viruses can have a persistence which is high enough to pose a hygienic risk through cross contamination.

[Chronic systemic toxicity of oral photochemotherapy using 8-methoxypsoralen and UVA]. / Untersuchungen zur chronisch-systemischen Toxizität einer oralen Photochemotherapie mit 8-Methoxypsoralen und UVA.

The purpose of the study conducted was to clarify the question of chronic, systemic toxicity from PUVA therapy. Five groups of patients, classified according to length of treatment were examined with respect to 43 laboratory parameters. The results indicated that PUVA had no chronic toxic influence on the liver, kidneys, bone marrow, metabolism, or immune response.

On the influence of different growth conditions to the resistance of some methylotrophic bacteria to aldehydes.

The resistance to formaldehyde of several facultatively methylotrophic bacteria has been investigated. The MIC-values were in the range of formaldehyde concentrations used for preservation purposes. The resistance could be explained partly by the action of aldehyde dehydrogenase found in two of the strains and by the development of a penetration barrier by the cell envelopes described formerly.

[Microbiological investigations with decentral dosing apparatuses for disinfectants. Part 2: Resistance-behaviour of isolated bacteria (author's transl)]. / Mikrobiologische Untersuchungen an dezentralen Dosiergeräten für Desinfektionsmittel. Teil 2: Resistenzverhalten der isolierten Bakterien.

When bacteria were isolated from disinfectant solutions of dosing apparatuses their resistance observed in those solutions is rapidly lost during few passages on nutrient agar (Table 1). Bacteria in tap-water, too, show an increased resistance against that disinfectant (Table 2) but it could be reversed by EDTA (Table 3). Therefore, the resistance of bacteria observed in tap-water and disinfectant solution is not determined genetically but results from a temporary adaptation which may be caused by an increased secretion of slime. This resistance is only observed in solution but not after application of the disinfectant to surfaces; it is not dependent from the dosing apparatus but from the product used. Only one species (Corynebacterium rubrum) which occasionally was found showed a primarily increased resistance which is stable during isolation.

[Microbiological investigations with decentral dosing apparatuses for disinfectants. Part 1: investigations of cell number (author's transl)]. / Mikrobiologische Untersuchungen an dezentralen Dosiergeräten für Desinfektionsmittel. Teil 1: Keimgehaltsuntersuchungen.

Cell numbers have been investigated for several months in disinfectant solutions which were measured out with tap water by decentral automatically dosing apparatuses. They differed not only quantitatively but also qualitatively with respect to the products used: With one product on the bases of aldehydes + organic tin compound 3 h after samples have been collected up to 100 bacteria/100 ml could be cultivated. Thus, cell numbers in disinfectant solutions were in the same range of cell numbers of tap water. Sometimes the cell numbers in both substrates seem to go parallel (Fig. 1). The bacterial compositions in both were similar (Table 3); gramnegative, yellow bacteria of the genera Pseudomonas and Flavobacterium dominated. After the disinfectant in one apparatus has been substituted by one which is composed of aldehydes + a quaternary ammonium compound cell numbers rapidly and permanently decreased to the limit of detectability. Only coryneform bacteria survived for a longer time which were characterized (Tab. 4) but not determined taxonomically. Their facultatively methylotrophic growth was conspicuously.