Nurse-delivered universal point-of-care testing for HIV in an open-access returning traveller clinic.

BACKGROUND: Early diagnosis of HIV infection reduces morbidity and mortality associated with late presentation. Despite UK guidelines, the HIV testing rate has not increased. We have introduced universal HIV screening in an open-access returning traveller clinic. METHODS: Data were prospectively recorded for all patients attending the open-access returning traveller clinic between August 2008 and December 2010. HIV testing was offered to all patients from May 2009; initially testing with laboratory samples (phase 1) and subsequently a point-of-care test (POCT) (phase 2). RESULTS: A total of 4965 patients attended the clinic; 1342 in phase 0, 792 in phase 1 and 2831 in phase 2. Testing rates for HIV increased significantly from 2% (38 of 1342) in phase 0 to 23.1% (183 of 792) in phase 1 and further increased to 44.5% (1261 of 2831) during phase 2 (P < 0.0001). Two new diagnoses of HIV-1 were identified in phase 1 (1.1% of tested); seven patients had a reactive POCT test in phase 2, of whom five (0.4% of those tested) were confirmed in a 4th generation assay. The patients with false reactive tests had a concurrent Plasmodium falciparum infection. Patients travelling to the Middle East and Europe were less likely to accept an HIV test with POCT. CONCLUSIONS: A nurse-delivered universal point-of-care HIV testing service has been successfully introduced and sustained in an acute medical clinic in a low-prevalence country. Caution is required in communicating reactive results in low-prevalence settings where there may be alternative diagnoses or a low population prevalence of HIV infection.

A system for rapid identification of respiratory abnormalities using a neural network.

Potential victims of Sudden Infant Death Syndrome (SIDS) can usefully be monitored in the home environment. Conventional respiration movement monitors can be helpful but may not detect potentially dangerous hypoxaemic episodes. Thus oxygen monitoring is to be preferred but can be difficult to use in the home. In an attempt to overcome these difficulties this paper presents the results of an exploratory experiment into the use of a neural network to link the output of a respiration pressure monitor to the classification of breathing patterns as effective or otherwise. It has been shown that it is possible to predict changes in oxygen saturation, which could signify potentially dangerous episodes earlier than when other methods are employed.

Accurate segmentation of respiration waveforms from infants enabling identification and classification of irregular breathing patterns.

Although the precise causes of Sudden Infant Death Syndrome (SIDS) are still unclear there is evidence to suggest that hypoxaemia may be a contributory factor. Transcutaneous oxygen monitors can be used but are unsatisfactory for young babies in the home. As an alternative approach, respiratory patterns can be studied but attempts at classification of individual breaths are often unsuccessful particularly during periods of extraneous noise or movement artefact. We have developed a robust algorithm which provides accurate segmentation and classification of breaths even in the presence of noise or movement. This improves on previous techniques by deferring the decision on an uncertain candidate breath until more information is available; yet the delay incurred is two breaths at most. The use of look-up tables and decision trees means that computational requirements are kept to a minimum and implementation in a simple home monitor is quite possible.

Perivascular regions of the rat neural lobe.

Neural lobes and portions of occipital cortex from rats were examined electron microscopically following fixation in 4% tannic acid in 2.5% glutaraldehyde. The procedure allowed a clear demonstration of the perivascular space and intercellular spaces in both tissues. The perivascular spaces in the neurosecretory tissue was far more extensive than in the neural tissue and the role of this region in relation to the process of neurosecretion is discussed.