Successful combat of an outbreak due to Clostridium difficile PCR ribotype 027 and recognition of specific risk factors.

In the period April-September 2005, an outbreak of Clostridium difficile infection (CDI) due to PCR ribotype 027 occurred among 50 patients in a 341-bed community hospital in Harderwijk, The Netherlands. A retrospective case-control study was performed to identify risk factors specific for CDI, using a group of patients with CDI (n = 45), a group of randomly selected control patients without diarrhoea (n = 90), and a group of patients with non-infectious diarrhoea (n = 109). Risk factors for CDI and for non-CDI diarrhoea were identified using multiple logistic regression analysis. Independent risk factors for CDI were: age above 65 years (OR 2.6; 95% CI 1.0-5.7), duration of hospitalization (OR 1.04 per additional day; 95% CI 1.0-1.1), and antibiotic use (OR 12.5; 95% CI 3.2-48.1). Of the antibiotics used, cephalosporins and fluoroquinolones were identified as the major risk factors for development of CDI. The risk of developing CDI was particularly high in people receiving a combination of a cephalosporin and a fluoroquinolone (OR 57.5; 95% CI 6.8-483.6). The main factors affecting the risk of non-CDI diarrhoea were proton-pump inhibitors, immunosuppressive drugs, underlying digestive system disease, previous surgery, and gastric tube feeding. The outbreak ended only after implementation of restricted use of cephalosporins and a complete ban on fluoroquinolones, in addition to general hygienic measures, cohorting of patients in a separate ward, education of staff, and intensified environmental cleaning. The results of this study support the importance of appropriate antimicrobial stewardship in the control of hospital outbreaks with C. difficile PCR ribotype 027.

Malignancies in inflammatory bowel disease: fact or fiction?

BACKGROUND: The association between ulcerative colitis (UC), Crohn disease (CD) and colorectal cancer (CRC) has been confirmed in several studies. The aim of this study was critical analysis of the relation between IBD and malignancy. METHODS: Review of the literature. RESULTS: In UC, the extent of the disease, its duration and start at a young age are risk factors for the development of CRC. Primary sclerosing cholangitis and colonic strictures are additional risk factors for development of CRC. The relation between azathioprine or 6-MP and the development of lymphomas is a subject of debate. The administration of anti-TNF-alpha has produced some concern about the development of lymphomas in CD. However, at present there is no evidence of lymphomas caused by anti-TNF-alpha in CD. On the contrary, some drugs seem to have a preventive effect on CRC development in UC. 5-aminosalicylic acid in particular and to a lesser extent sulphasalazine have prevented the development of CRC significantly in retrospective studies. In CD, there is no strong relationship between the disease and the development of CRC or other malignancies. Only the development of small-bowel carcinoma is reported with a much higher frequency. CONCLUSIONS: There is a correlation with UC and the development of CRC. For CD, this correlation is less firmly established. There is a possible, but not proven, relation between AZA/6-MP use and the development of lymphoma in IBD. There is also a probable relationship between CD and the development of small-bowel carcinoma. In some retrospective studies, the use of 5-aminosalicylic or sulphasalazine has been shown to prevent the development of CRC in UC.

Digital holographic interferometry of convective heat transport.

Real-time holographic interferometry has been used to study the convective heat transport in a flat plate solar collector. The analysis and interpretation of the interferograms using digital techniques are discussed. This study aims to develop an automated digital process for interference pattern analysis, and thus special attention is given to those optical and physical aspects that are relevant to this goal. This includes the structural systematics of the fringes, noise due to spurious optical effects, and the accuracy of digitized optical signals. Some experimental results on automated analysis of interferograms will be discussed.