To elucidate the prevalence, characteristics and risk factors of community-onset Clostridium difficile infection (CO-CDI), an uncontrolled prospective study was performed. For 3 months in 2007-2008, three laboratories in The Netherlands tested all unformed stool samples submitted by general practitioners (GPs) for C. difficile by enzyme immunoassay for toxins A and B, irrespective of whether GPs specifically requested this. Patients with positive results were asked to complete a questionnaire. Positive stool samples were cultured for C. difficile, and isolates were characterized. In all, 2443 stool samples from 2423 patients were tested, and 37 patients (1.5%) with positive toxin test results were identified. Mixed infections were not found. Age varied from 1 to 92 years, and 18% were under the age of 20 years. Diarrhoea was typically frequent and watery, sometimes with admixture of blood or fever. Eight of 28 patients (29%) suffered recurrences. Among 31 patients with toxin-positive stool samples for whom information was available, 20 (65%) had not been admitted to a healthcare institution in the year before, 13 (42%) had not used antibiotics during the 6 months before, and eight (26%) had neither risk factor. A separate analysis for patients whose samples were both toxin-positive and culture-positive produced similar results. Cultured C. difficile isolates belonged to 13 different PCR ribotypes, and 24% of the isolates were non-typeable (rare or new) PCR ribotypes. In conclusion, CO-CDI can affect all age groups, and many patients do not have known risk factors. Several PCR ribotypes not encountered in hospital-associated outbreaks were found, suggesting the absence of a direct link between outbreaks and community-onset cases.

Inoculation of an automated system for rapid identification (ID) and antimicrobial susceptibility testing (AST) directly from positive blood culture bottles will reduce the turnaround time of laboratory diagnosis of septicemic patients, which benefits clinical outcome and decreases patient costs. Direct test results, however, must always be confirmed by testing a pure overnight culture, which is the "gold standard." We studied the accuracy of direct testing versus repeat testing in order to investigate the possibility of refraining from repeat testing. We also assessed the clinical risk of reporting results based on direct testing only. We inoculated Vitek 2 (bioMérieux) directly from 410 positive BACTEC 9240 (BD) blood culture bottles containing gram-negative rods and studied the ID and AST results. In a comparison of direct inoculation with the standard method, a total of 344 isolates of Enterobacteriaceae and Pseudomonas aeruginosa were tested, and 93.0% were correctly identified. Of the 39 (10.2%) samples that contained bacilli not identifiable by Vitek 2, only 1 gave a conclusive, correct result. The overall MIC agreement among 312 isolates was 99.2%, with 0.8% very major and 0.02% major error rates. Of only three (polymicrobial) samples, the direct susceptibility pattern would be reported to the clinician as too sensitive. Vitek 2 results obtained from direct inoculation of blood culture bottles containing gram-negative bacilli are safe enough for immediate reporting, provided that ID and AST are consistent. Repeat testing is not necessary, unless Gram stain or overnight subculture results raise doubt about the purity of the culture.Shortening the turnaround time of microbiological analyses with an automated system for rapid identification and susceptibility testing of bacteria leads to a significant reduction of patient morbidity, mortality, and cost (1, 2). In particular, for patients with septicemia, rapid laboratory results are essential for appropriate treatment and improving clinical outcome (21). An automated blood culture system that monitors culture bottles for microbial growth minimizes the time necessary to detect positive blood cultures. Another way to save time might be to inoculate an automated system for rapid identification and susceptibility testing directly from positive blood culture bottles. The conventional way is to wait for the overnight subculture on agar to prepare a standard inoculum according to the manufacturer's guidelines.Of all bacteria involved in bloodstream infections, the fastgrowing Enterobacteriaceae will probably produce the quickest and best-correlating results for direct and standard inoculation. Several studies have compared direct and standard methods for different (combinations of) automated systems, but to our knowledge no study has yet done this for Vitek 2 (7,8,18,20,22).We routinely inoculate Vitek 2 directly from BACTEC 9240 blood culture bottles that are positive for gram-negative rods. To check the direct results, we repeat the tests the next day with suspe...

Clostridium difficile infections (CDIs) are frequent in hospitals, but also seem to increase in the community. Here, we aim to determine the incidence of CDI in general practice and to evaluate current testing algorithms for CDI. Three Dutch laboratories tested all unformed faeces (12,714) for C. difficile when diagnostic testing (for any enteric pathogen) was requested by a general practitioner (GP). Additionally, a nested case-control study was initiated, including 152 CDI patients and 304 age and sex-matched controls. Patients were compared using weighted multivariable logistic regression. One hundred and ninety-four samples (1.5%) were positive for C. difficile (incidence 0.67/10,000 patient years). This incidence was comparable to that of Salmonella spp. Compared with diarrhoeal controls, CDI was associated with more severe complaints, underlying diseases, antibiotic use and prior hospitalization. In our study, GPs requested a test for C. difficile in 7% of the stool samples, thereby detecting 40% of all CDIs. Dutch national recommendations advise testing for C. difficile when prior antibiotic use or hospitalization is present (18% of samples). If these recommendations were followed, 61% of all CDIs would have been detected. In conclusion, C. difficile is relatively frequent in general practice. Currently, testing for C. difficile is rare and only 40% of CDI in general practice is detected. Following recommendations that are based on traditional risk factors for CDI, would improve detection of CDI.

Enhanced surveillance of infections due to the pandemic A(H1N1) influenza virus, which included monitoring for antiviral resistance, was carried out in the Netherlands from late April 2009 through late May 2010. More than 1100 instances of infection with the pandemic A(H1N1) influenza virus from 2009 and 2010 [A(H1N1) 2009] distributed across this period were analyzed. Of these, 19 cases of oseltamivir-resistant virus harboring the H275Y mutation in the neuraminidase (NA) were detected. The mean 50% inhibitory concentration (IC50) levels for oseltamivir- and zanamivir-susceptible A(H1N1) 2009 viruses were 1.4-fold and 2-fold, respectively, lower than for the seasonal A(H1N1) influenza viruses from 2007/2008; for oseltamivir-resistant A(H1N1) 2009 virus the IC50 was 2.9-fold lower. Eighteen of the 19 patients with oseltamivir-resistant virus showed prolonged shedding of the virus and developed resistance while on oseltamivir therapy. Sixteen of these 18 patients had an immunodeficiency, of whom 11 had a hematologic disorder. The two other patients had another underlying disease. Six of the patients who had an underlying disease died; of these, five had received cytostatic or immunosuppressive therapy. No indications for onward transmission of resistant viruses were found. This study showed that the main association for the emergence of cases of oseltamivir-resistant A(H1N1) 2009 virus was receiving antiviral therapy and having drug-induced immunosuppression or an hematologic disorder. Except for a single case of a resistant virus not linked to oseltamivir therapy, the absence of detection of resistant variants in community specimens and in specimens from contacts of cases with resistant virus suggested that the spread of resistant A(H1N1) 2009 virus was limited. Containment may have been the cumulative result of impaired NA function, successful isolation of the patients, and prophylactic measures to limit exposure.