Feasibility and acceptability of HIV screening through the use of rapid tests by general practitioners in a Brussels area with a substantial African community.

OBJECTIVES: To assess:1) if HIV screening with rapid tests in neighbourhoods with a substantial African community is feasible and acceptable among GPs and patients; 2) HIV seroprevalence. METHODS: Multicenter prospective study with 10 trained physicians. Use of HIV standard test and INSTI Ultrarapid test. INCLUSION CRITERIA: MSM, sex worker, multiple sexual partners, having returned or coming from a country with high HIV prevalence, IVDU, Indicator conditions as defined by HIV Indicator Diseases across Europe Study, having an AIDS-defining illness, having had a recent pregnancy or abortion; or presenting other risks. RESULTS: From August 2010 to August 2011, 10 trained GPs offered an HIV test to 224 patients: 51% ♀, 48% ♂, 43% Caucasians, 45% Africans. INCLUSION CRITERIA: 32% "high risk group", 9% returning from an endemic country, 29% with an indicator condition; 12 patients (6%) refused the standard test. The INSTI was offered to 217(97%), 197 performed with 2 reactive rapid tests confirmed. The seroprevalence according to ethnic origin was 0% among Caucasians and 2.2% among Africans and was 1.5% among patients with an indicator condition. 1087 consecutive consultations of the same GPs were recorded: 42% patients had ≥ 1 inclusion criteria among which 41% of offered tests, that is to say 59% of "missed opportunities". The reasons for not offering the test as recorded for 55% of patients:"not indicated" 44.5%, "no time" 33%, "impossible to propose" 15%, test completed previously 11%, known HIV-positive 4%. CONCLUSIONS: Standard and rapid tests are well received by patients but were usually not offered by doctors who have been trained.

The human primary somatosensory cortex response contains components related to stimulus frequency and perception in a frequency discrimination task.

Somatosensory stimulation of primary somatosensory cortex (SI) using frequency discrimination offers a direct, well-defined and accessible way of studying cortical decisions at the locus of early input processing. Animal studies have identified and classified the neuronal responses in SI but they have not yet resolved whether during prolonged stimulation the collective SI response just passively reflects the input or actively participates in the comparison and decision processes. This question was investigated using tomographic analysis of single trial magnetoencephalographic data. Four right-handed males participated in a frequency discrimination task to detect changes in the frequency of an electrical stimulus applied to the right-hand digits 2+3+4. The subjects received approximately 600 pairs of stimuli with Stim1 always at 21 Hz, while Stim2 was either 21 Hz (50%) or varied from 22 to 29 Hz in steps of 1 Hz. Both stimuli were 1 s duration, separated by a 1 s interval of no stimulation. The left-SI was the most consistently activated area and showed the first activation peak at 35-48 ms after Stim1 onset and sustained activity during both stimulus periods. During the Stim2 period, we found that the left-SI activation started to differ significantly between two groups of trials (21 versus 26-29 Hz) within the first 100 ms and this difference was sustained and enhanced thereafter (approximately 600 ms). When only correct responses from the above two groups were used, the difference was even higher at later latencies (approximately 650 ms). For one subject who had enough trials of same perception to different input frequencies, e.g. responded 21 Hz to Stim2 at 21 Hz (correct) and 26-29 Hz (error), we found the sustained difference only before 650 ms. Our results suggest that SI is involved with the analysis of an input frequency and related to perception and decision at different latencies.