Routine HIV testing in acute care hospitals: Changing practice to curb a local HIV epidemic in Vancouver, BC

Early treatment of HIV infection increases life expectancy and reduces infectivity; however, delayed HIV diagnosis remains common. Implementation and sustainability of hospital-based routine HIV testing in Vancouver, British Columbia, was evaluated to address a local HIV epidemic by facilitating earlier diagnosis and treatment. Public health issued a recommendation in 2011 to offer HIV testing to all patients presenting to three Vancouver hospitals as part of routine care, including all patients admitted to medical/surgical units with expansion to emergency departments (ED). We evaluated acceptability, feasibility, and effectiveness from 2011 to 2014 and continued monitoring through 2016 for sustainability. Between October 2011-December 2016, 114,803 HIV tests were administered at the three hospitals; an 11-fold increase following implementation of routine testing. The rate of testing was sustained and remained high through 2018. Of those tested, 151 patients were diagnosed with HIV for a testing yield of 0.13%. Review of 12,996 charts demonstrated 4935/5876 (96·9%) of admitted patients agreed to have an HIV test when offered. People diagnosed in hospital were significantly more likely to be diagnosed with acute stage (aOR 1·96, 95% CI 1·19, 3·23) infection, particularly those diagnosed in the ED. This study provides practice-based evidence of the feasibility, acceptability, and effectiveness of implementing a recommendation for routine HIV testing among inpatient and emergency department admissions, as well as the ability to normalize and sustain this change. Routine hospital-based HIV testing can increase diagnoses of acute HIV infection and facilitate earlier initiation of antiretroviral treatment.

Neuropeptide gene families in the nematode Caenorhabditis elegans

Neuropeptides have diverse roles in the function and development of the nervous system. With the completion of the sequencing of the C. elegans genome, rapid identification of nematode neuropeptide genes is possible. To date, 41 C. elegans neuropeptide genes have been identified. Of these genes, 20 genes, named flp (FMRFamide-like peptide) genes, encode FMRFamide-related proteins (FaRPs). Deletion of one of the flp genes, flp-1, results in several behavioral defects, suggesting that at least one flp gene is not functionally redundant with other flp genes. Twenty-one genes, named neuropeptide-like protein (nlp) genes, encode peptides distinct from the FaRP family. The predicted nlp-1 and nlp-2 neuropeptides have modest similarity to buccalin and myomodulin, respectively. Cellular expression patterns and genetic analysis of flp and nlp genes suggest that neuropeptides in nematodes also have widespread and varied roles in nervous system function.

Slowing due to acute hypoxia originates early in the visual system

BACKGROUND

Experiments in the visual modality show that acute hypoxia slows the earliest stage of information processing-preprocessing. It is unknown, however, whether a later stage, feature extraction, is also slowed.

METHODS

To answer this question, an additive factors method (AFM) experiment was conducted which employed seven well trained subjects whose arterial oxyhaemoglobin saturation was controlled at 63% with low oxygen mixtures. The subjects responded to oddball names presented on a computer screen and both reaction time (RT) and the event-related brain potential P300 were measured. The luminance and quality of the names was varied factorially to influence the preprocessing and feature extraction stages, respectively.

RESULTS

RT and P300 latency showed the same pattern of results: stimulus luminance and signal quality were additive, indicating that AFM assumptions were met; hypoxia and stimulus luminance were interactive but hypoxia and signal quality were additive.

CONCLUSION

In conjunction with other evidence, we interpret these results to indicate that the locus of slowing produced by hypoxia is largely at the preprocessing stage, at least in the visual modality. Slowing at the preprocessing stage can be explained by hypoxia shifting the function relating RT and stimulus luminance to the right by a constant amount.

An AFM investigation of the effects of acute hypoxia on mental rotation

To determine if the stimulus identification stage of information processing is slowed by hypoxia, eight highly trained subjects performed a mental rotation task involving same or different responses to pairs of two-dimensional figures rotated in the picture plane. They breathed low oxygen mixtures adjusted to maintain arterial blood oxygen saturation at 64%. The results showed that hypoxia increased the intercept rather than the slope of the linear function relating reaction time to angle of rotation. According to Additive Factors Method logic, this result indicates that hypoxia does not slow stimulus identification. This is further evidence against the long-held view that hypoxia impairs information processing mechanisms throughout the system--the multiple loci hypothesis. The authors propose instead the early slowing hypothesis. According to this view, the slowing produced by hypoxia is highly specific to one or two early stages of visual processing, and this early slowing acts as a bottleneck to later processing.