Evaluating wildlife as a potential source of Salmonella serotype Newport (JJPX01.0061) contamination for tomatoes on the eastern shore of Virginia.

Eastern Shore of Virginia red, round tomatoes contaminated with Salmonella serotype Newport pattern JJPX01.0061 have been a source of several multistate outbreaks within the last 10 years. No source of the contamination has yet been identified. The goal of this study was to evaluate wildlife as a potential source of contamination. Faecal samples from deer, turtles and birds were collected between November 2010 and July 2011 from seventeen locations on the Eastern Shore of Virginia. A total of 262 samples were tested for the presence of Salmonella using an enzyme-linked immunosorbent assay (ELISA). A total of 23 (8.8%) samples tested positive for Salmonella spp. and were further characterized by serotyping and pulsed-field gel electrophoresis (PFGE) subtyping. Overall, twelve serotypes were identified, including Salmonella serotype Javiana, another common serotype associated with tomato-related outbreaks. Only one avian sample collected in July 2011 was determined to be positive for S. Newport pattern 61. This sample was collected from the ground at a site where birds, mostly gulls, were congregating. Although many of the avian samples from this site were dry, the site yielded eleven positive Salmonella samples. This suggests that certain Salmonella serotypes may persist in the environment despite extreme conditions. The recovery of one Newport pattern 61 isolate alone does not yield much information regarding the environmental reservoirs of this pathogen, but when combined with other data including the recovery of several isolates of Javiana from birds, it suggests that birds might be a potential source of Salmonella contamination for tomatoes on the Eastern Shore.

A transputer based three-dimensional dynamic cardiac imaging system.

In Aberdeen, a single-section transverse emission scanner has been adapted to trigger off patient ECG signals, allowing for the acquisition of gated blood pool tomograms at a number of slice levels through the patient's heart. This paper describes a system for the routine generation and display of surface rendered images derived from this data using a transputer based hardware system. Surface rendering algorithms have been implemented to provide an indication of the distribution of the cardiac blood pool in three dimensions, whilst the additional use of colour and/or cine sequences provide a succinct method of representing the extra information provided by gated acquisition. The transputer provides sufficient computing power to produce rendered views at a rate of about 1 frame per second, thus putting view selection fully under operator control. The success of the system described is reflected in its routine use in a busy clinical department.

Response of latent syphilis or neurosyphilis to ceftriaxone therapy in persons infected with human immunodeficiency virus.

OBJECTIVE: To evaluate the effect of ceftriaxone in treating latent syphilis or asymptomatic neurosyphilis in patients infected with the human immunodeficiency virus (HIV). DESIGN: Follow-up study of patients treated at two HIV-based clinics during 16 months from 1989 to 1991. PATIENTS: Patients were those in whom a clinical diagnosis of latent syphilis or asymptomatic neurosyphilis was made, who received all recommended doses of antimicrobial therapy, and who returned for follow-up visits for 6 or more months. RESULTS: Forty-three patients were treated with ceftriaxone, 1 to 2 g daily for 10 to 14 days. Thirteen underwent lumbar puncture before treatment; 7 (58%) had documented neurosyphilis (pleocytosis in 5, elevated protein levels in 6, VDRL reactive in cerebrospinal fluid [CSF] in 7), and 6 had documented latent syphilis (entirely normal CSF). The remaining 30 were said to have presumed latent syphilis. There was no relation between the diagnosis and the selected dosage of ceftriaxone. Response rates were similar in those who had documented neurosyphilis and documented or presumed latent syphilis. Overall, 28 patients (65%) responded to therapy, 5 (12%) were serofast, 9 (21%) had a serologic relapse, and 1 (2%) who experienced progression to symptomatic neurosyphilis was a therapeutic failure. Thirteen patients received benzathine penicillin for presumed latent syphilis; results were similar to those observed after ceftriaxone therapy, with 8 (62%) responders, 1 (8%) serofast, 2 (15%) relapses, and 2 (15%) failures. CD4 cell counts in responders were not different from those who failed to respond. CONCLUSIONS: Even in the absence of neurologic symptoms, half of the HIV-infected persons who have serologic evidence of syphilis may have neurosyphilis. Although ceftriaxone achieves high serum and CSF levels, 10 to 14 days of treatment with this drug were associated with a 23% failure rate in HIV-infected patients who had latent syphilis or asymptomatic neurosyphilis. Three doses of benzathine penicillin did not have a significantly higher relapse rate and may provide appropriate therapy, at least for documented latent syphilis in persons co-infected with HIV. Studies comparing ceftriaxone with 10 to 14 doses of procaine penicillin are needed to determine the most cost-effective treatment for asymptomatic neurosyphilis or presumed latent syphilis in this group of patients.

Esophageal stricture after cytomegalovirus ulcer treated with ganciclovir.

A 49-year-old man with the acquired immune deficiency syndrome (AIDS) developed epigastric pain, nausea, vomiting, and gastrointestinal bleeding secondary to a cytomegalovirus (CMV)-induced ulceration in the distal esophagus and proximal stomach. All symptoms improved on treatment with ganciclovir. However, 1 month later severe dysphagia led to discovery of a fibrous stricture in the area of the healed ulcer. The dysphagia was controlled by esophageal dilation. Ulcerative lesions caused by CMV can heal with ganciclovir treatment but, as with other esophageal ulcers, healing may be associated with fibrosis and stricture.

Detection and quantification of hyperfluorescent leakage by computer analysis of fundus fluorescein angiograms.

Digital imaging systems can be used for direct acquisition of images of the ocular fundus or for their indirect acquisition from fundus photographs or transparencies. Computerised image processing techniques can then be used to manipulate and quantify features of interest. We describe a method for the detection and quantification of macular leakage in fluorescein angiograms. The rate of change in fluorescence over time is examined on a pixel-by-pixel basis and used to provide a gradient threshold that discriminates pixels displaying leakage from normal pixels. A region-growing technique is then used to enhance the detection of leakage missed by gradient thresholding alone. This report discusses the potential applications of the technique and highlights the methodology required to obtain reproducible results.

Quantification of diabetic maculopathy by digital imaging of the fundus.

Measurement of the extent of diabetic retinopathy is an essential part of assessing the efficacy of local or systemic treatment regimens. Current clinical studies use empirical grading of retinopathy which is performed by a trained observer using standard photographs. This method is relatively arbitrary, as well as time consuming and vulnerable to observer error. We have developed a digital fundus imaging system and image processing programs which provide objective, quantitative measures of macular oedema, retinal exudates, and microaneurysms in diabetic retinopathy. Using fluorescein angiograms, the degree of macular oedema is quantified both in terms of area of fundus involved and severity of oedema by analysis of the temporal changes in intensity of fluorescence. Fluorescein angiograms are also used for the detection and counting of microaneurysms, by a combination of shade correction, matched filtering, and shape algorithms. For detection and measurement of retinal exudates, a colour transparency projected through a red free filter is analysed using a combination of shade correction and thresholding techniques. The system described is in clinical use, and has potential for a wide variety of applications. With further development, digital analysis of fundus images should supercede the currently used manual semi-quantitative methods, providing faster, more accurate, objective quantitative results.

Use of temporal information to quantify vascular leakage in fluorescein angiography of the retina.

Vascular leakage causing macular oedema is an important cause of visual loss in retinal vascular disorders such as diabetic retinopathy and retinal vein occlusion. By digitising selected frames from fundus fluorescein angiographic sequences we have developed a technique which uses the observed rate of change of fluorescence to detect and quantify areas of leakage. Reproducibility studies yielded a coefficient of variation of less than 6% for large areas of leakage, and 27% for very small areas of leakage. We believe this technique is sufficiently sensitive and robust for clinical use, and should find a significant role in the management of retinal vascular disorders.

A simple filtering routine for radionuclide bone images.

The evaluation is carried out of a simple filtering routine for improving the detectability of low contrast lesions in bone scans. With this routine, the unprocessed image is displayed together with three filtered versions, the final decision on the presence of abnormalities being made by comparing the four images. Emphasis is placed on producing a routine which is quick in implementation and, therefore, only small filter arrays are used. Using a routine consisting of a low-pass, a median, and a differential filter, 73% more lesions are detected when the filtered images are also used. The whole routine takes less than 1 min to run.