The public health response to the re-emergence of syphilis in Wales, UK.

During the 1990s, cases of infectious syphilis were uncommon in Wales. In 2002, an outbreak occurred in a sexual network of men who have sex with men (MSM) attending a sauna. A multidisciplinary outbreak control team was convened to raise awareness of the outbreak among MSM and health professionals, assess the extent of outbreak, and initiate surveillance measures. It is likely that early intensive control efforts dampened the epidemic curve. However, since 2006 the number of cases has increased steadily to a peak of four cases per 100,000 population in 2008. The majority of cases continue to occur in MSM (81% in 2009) and in those attending genitourinary (GU) medicine clinics in south east Wales (76%). Traditional sexual networks such as saunas, bars/clubs and cruising grounds remain frequently reported, but Internet-based networks are assuming increasing importance. Public health interventions have been sustained, using traditional partner notification, health promotion initiatives, and more innovative Internet network tracing methods.

Calibration of a Hall effect displacement measurement system for complex motion analysis using a neural network.

Biomechanics studies often require the analysis of position and orientation. Although a variety of transducer and camera systems can be utilized, a common inexpensive alternative is the Hall effect sensor. Hall effect sensors have been used extensively for one-dimensional position analysis but their non-linear behavior and cross-talk effects make them difficult to calibrate for effective and accurate two- and three-dimensional position and orientation analysis. The aim of this study was to develop and calibrate a displacement measurement system for a hydraulic-actuation joystick used for repetitive motion analysis of heavy equipment operators. The system utilizes an array of four Hall effect sensors that are all active during any joystick movement. This built-in redundancy allows the calibration to utilize fully connected feed forward neural networks in conjunction with a Microscribe 3D digitizer. A fully connected feed forward neural network with one hidden layer containing five neurons was developed. Results indicate that the ability of the neural network to accurately predict the x, y and z coordinates of the joystick handle was good with r(2) values of 0.98 and higher. The calibration technique was found to be equally as accurate when used on data collected 5 days after the initial calibration, indicating the system is robust and stable enough to not require calibration every time the joystick is used. This calibration system allowed an infinite number of joystick orientations and positions to be found within the range of joystick motion.

A modified pulsed-field gel electrophoresis (PFGE) protocol for subtyping previously non-PFGE typeable isolates of Clostridium difficile polymerase chain reaction ribotype 001.

A modified pulsed-field gel electrophoresis (PFGE) protocol was developed and applied to 50 isolates of the UK epidemic strain of Clostridium difficile, polymerase chain reaction (PCR) ribotype 001, to develop a PFGE-based subtyping scheme. This protocol overcame the inherent DNA degradation problems associated with typing this strain of C. difficile by this method, and whole genomic digestion with SmaI restriction enzyme yielded seven distinct and reproducible PFGE banding patterns. Modified PFGE is an appropriate method for subtyping C. difficile PCR ribotype 001 that could be used to improve epidemiological investigations.

Subtyping of Clostridium difficile polymerase chain reaction (PCR) ribotype 001 by repetitive extragenic palindromic PCR genomic fingerprinting.

Fifty isolates of the most common UK strain of Clostridium difficile [polymerase chain reaction (PCR) ribotype 001] were analysed by three PCR-based typing methods in order to determine genomic diversity within this strain that may form the basis of a subtyping method. The three methods used were repetitive extragenic palindromic elements (REP), conserved repetitive DNA elements (BOX), and enterobacterial repetitive PCR intergenic consensus sequences (ERIC). The performance of each typing method was assessed by comparing powers of discrimination, typeability and reproducibility. All methods had satisfactory levels of typeability and reproducibility as determined by blind-coded repeats, but REP-PCR typing proved to be the most discriminatory method, yielding seven distinct amplicon profiles consisting of up to eight major bands. BOX-PCR generated between two and five major amplicons with four distinct BOX profiles. ERIC-PCR primers, however, could not discriminate between isolates. These results suggest that PCR ribotype 001 is not clonal in nature at present, and that REP-PCR subtyping methods offer promise to further our understanding of the epidemiology of C. difficile PCR ribotype 001 disease in UK hospitals.