Wasser als Infektionsquelle in medizinischen Einrichtungen, Prävention und Kontrolle

[Update on outbreaks reported from neonatal intensive care units: Serratia marcescens, Klebsiella pneumoniae, Acinetobacter baumannii, and Pseudomonas aeruginosa]

In terms of the unique risk profile, the clinical course of nosocomial infections, and the most prevalent bacterial pathogens, literature on outbreaks of potentially pathogenic bacteria on neonatal intensive care units (NICUs) needs to be analyzed separately from reports derived from other intensive care units. With the purpose of updating important information for those involved in outbreak management and fostering preventive efforts, this article summarizes the results of a systematic literature analysis, referring to an earlier publication by Gastmeier et al. This review focuses on NICU outbreaks caused by Serratia marcescens, Klebsiella pneumoniae, Acinetobacter baumannii, and Pseudomonas aeruginosa.

[Experiences with outbreaks of nosocomial infections]

Ten years after the publication of the recommendation: "Outbreak management and structural proceedings in case of cumulative occurrence of nosocomial infections" of the federal commission of hospital hygiene, these recommendations are now being re-evaluated. To date, the recommendations have proven valid and have maintained their significance for an effective management. However, besides new hygienic-microbiological methods and an increased sensitivity of the perception of nosocomial outbreaks by the public, by politicians and by the press, it is necessary to consider new issues in this field. Outbreaks are tragic events placing an extraordinary burden on all persons involved, which can have significant consequences. Therefore, it is necessary to ensure prompt outbreak management by experienced professionals who must combine a systematic on-site inspection, hygienic-microbiological investigation and typing methods used with epidemiological approaches. To assure these requirements, the support of independent reference centres such as universal hygiene institutes should be guaranteed. Politicians should be involved only after a scientific evaluation of the details of the outbreak has been made. A national documentation centre, e.g. at the Robert Koch Institute, should be established, thereby making experiences with outbreaks widely available.

[Experience with prevention and control of legionellosis in Germany : plea for proactive risk management]

Legionellosis is meanwhile the most important specific water-associated infectious disease in developed countries, which is completely preventable, if water distribution systems are correctly planned and operated. This assumes clear criteria for risk regulation and for verification, including microbiological monitoring for Legionella. There are different reactive and proactive strategies in the USA and in Europe. The common premises for prevention and control of legionellosis in Germany, relevant facts for risk regulation, experience in Germany toward proactive risk regulation, and the current approach of the amended drinking water ordinance are discussed. The article concludes with a short discussion of the controversial approaches for the prevention of legionellosis in Germany.

Detection of Helicobacter pylori in biofilms by real-time PCR

Helicobacter pylori is a cause of peptic ulcer disease and a causative agent of gastric cancer. Currently, a possible waterborne route of transmission or a possible survival in drinking water biofilms is discussed. H. pylori, like many other bacterial strains, has the ability to enter the viable but nonculturable state (vbnc) in case of unfavorable conditions. Therefore it is necessary to develop new analysis tools for vbnc bacteria. We established a fast and reliable method to detect H. pylori in drinking water biofilms by quantitative real-time PCR which makes it redundant to use difficult cultivation methods for nonculturable bacteria. With this method it was possible to identify water biofilms as a niche for H. pylori. The real-time PCR analysis targets the ureA subunit of the Helicobacter pylori urea gene which showed high specificity and sensitivity. The quantitative real-time PCR was used to detect H. pylori in biofilms of different age, unspiked and spiked with predetermined levels of cells. The drinking water biofilms were generated in a silicone-tube model. The DNA-sequences for probe and primers showed no cross-homologies to other related bacteria and it was possible to detect less than 10 genomic units of H. pylori. This novel method is a useful tool for a fast screening of drinking water biofilms for H. pylori. The results suggest that drinking water biofilms may act as a reservoir for H. pylori which raises new concerns about the role of biofilms as vectors for pathogens like Helicobacter pylori.