Leptospirosis in French Polynesia: 11 years of surveillance data, 2007-2017.

Leptospirosis is a worldwide zoonosis with higher incidence in tropical areas and is a neglected disease in the Pacific region. French Polynesia (FP) is a French overseas territory located in the South Pacific. Data on the epidemiology in FP are scarce. In this study, we describe our understanding of leptospirosis epidemiology in FP and discuss the prospects concerning this disease and its surveillance to better address preventive actions. We report 11 years of surveillance data between 1 January 2007 and 31 December 2017. Over the study period, 1356 confirmed and probable leptospirosis cases were reported. The mean annual incidence rate was 46.0 (95% confidence interval, 43.6-48.5) cases per 100 000 inhabitants. We registered 864 (63.7%) hospitalizations; of these, at least 270 (19.9%) were in the intensive care unit, and 24 patients (1.8%) died. Even if the incidence of leptospirosis is lower in FP compared to most of other Pacific countries and territories, our data confirm that the disease is highly endemic in FP. Despite all the preventive measures taken, leptospirosis remains a major public health concern in FP, thus highlighting the need to maintain intensive leptospirosis surveillance, medical staff training and provision of information to the general population.

Surgical site infection after valvular or coronary artery bypass surgery: 2008-2011 French SSI national ISO-RAISIN surveillance.

BACKGROUND: Multisite information regarding surgical site infection (SSI) rates for cardiac surgery programmes is not widely available. Ward characteristics that may affect outcomes have not been analysed previously. AIM: To determine individual- and ward-level factors associated with SSI occurrence after coronary artery bypass grafting (CABG) and valvular surgery. METHODS: A dataset from the French national SSI database ISO-RAISIN 2008-2011 was used. Only adult patients were included. A standardized questionnaire was completed for each patient who underwent surgery, and patients with and without SSI were characterized. Patients and ward risk factors for SSI were analysed using a multilevel logistic regression model with SSI as binary outcome (two levels: patient and ward). RESULTS: Out of 8569 patients from 39 wards, the SSI rate was 2.2%. Micro-organisms were isolated in 144 patients (74%): 35% coagulase-negative staphylococci (N = 51), 23% Staphylococcus aureus (N = 33), 6% Escherichia coli (N = 8). Higher probability of SSI was associated with the duration of preoperative hospitalization, the duration of follow-up, the duration of surgery >75th percentile and the SSI rate in the surgery ward. The residual heterogeneity between wards (median odds ratio: 1.53) was as relevant as duration of preoperative hospitalization (odds ratio: 1.57). CONCLUSION: Although patient risk factors were more strongly associated with SSI occurrence, this study provided evidence for the existence of a ward-level effect. This should be taken into account when considering possible corrective interventions.

Effect of prism adaptation on left dichotic listening deficit in neglect patients: glasses to hear better?

Unilateral neglect is a disabling syndrome frequently observed following right hemisphere brain damage. Symptoms range from visuo-motor impairments through to deficient visuo-spatial imagery, but impairment can also affect the auditory modality. A short period of adaptation to a rightward prismatic shift of the visual field is known to improve a wide range of hemispatial neglect symptoms, including visuo-manual tasks, mental imagery, postural imbalance, visuo-verbal measures and number bisection. The aim of the present study was to assess whether the beneficial effects of prism adaptation may generalize to auditory manifestations of neglect. Auditory extinction, whose clinical manifestations are independent of the sensory modalities engaged in visuo-manual adaptation, was examined in neglect patients before and after prism adaptation. Two separate groups of neglect patients (all of whom exhibited left auditory extinction) underwent prism adaptation: one group (n = 6) received a classical prism treatment ('Prism' group), the other group (n = 6) was submitted to the same procedure, but wore neutral glasses creating no optical shift (placebo 'Control' group). Auditory extinction was assessed by means of a dichotic listening task performed three times: prior to prism exposure (pre-test), upon prism removal (0 h post-test) and 2 h later (2 h post-test). The total number of correct responses, the lateralization index (detection asymmetry between the two ears) and the number of left-right fusion errors were analysed. Our results demonstrate that prism adaptation can improve left auditory extinction, thus revealing transfer of benefit to a sensory modality that is orthogonal to the visual, proprioceptive and motor modalities directly implicated in the visuo-motor adaptive process. The observed benefit was specific to the detection asymmetry between the two ears and did not affect the total number of responses. This indicates a specific effect of prism adaptation on lateralized processes rather than on general arousal. Our results suggest that the effects of prism adaptation can extend to unexposed sensory systems. The bottom-up approach of visuo-motor adaptation appears to interact with higher order brain functions related to multisensory integration and can have beneficial effects on sensory processing in different modalities. These findings should stimulate the development of therapeutic approaches aimed at bypassing the affected sensory processing modality by adapting other sensory modalities.

Risk factors for delayed HIV diagnosis at the Hospital of Tropical Diseases in Ho Chi Minh City, Vietnam.

The objective was to identify factors associated with delayed diagnosis of HIV infection in Vietnam, defined as having a CD4 cell count of <200/mm(3) at the time of the first positive test. Data were collected retrospectively from the medical records of HIV-infected outpatients who received their initial care at the Hospital for Tropical Diseases in Ho Chi Minh City between July 2004 and August 2005. Among the 204 included patients, 58.3% had a delayed diagnosis. Independent factors associated with a delayed diagnosis were male gender (adjusted odds ratio [AOR] = 2.10; 95% confidence interval [CI] = 1.03-4.41) and having an opportunistic infection at the time of the first positive HIV test (AOR = 3.07; 95% CI = 1.71-5.53). Counselling for early HIV screening is important in populations at risk of infection. Facilitating access to care should be reinforced for symptomatic patients.

[Orion (Outbreak Reports and Intervention studies of Nosocomial Infection) used for evaluating interventions and investigations of nosocomial infection outbreaks]. / Orion (Outbreak Reports and Intervention Studies of Nosocomial Infection) pour l'évaluation des interventions et des investigations d'épidémie dans le domaine des infections nosocomiales.

INTRODUCTION: British colleagues have developed the Outbreak Reports and Intervention studies of Nosocomial Infection (Orion) guidelines with the aim to promote transparency of publications in the field of health-care associated infections and particularly for reports of outbreak investigation or intervention studies. The aim of this study was to translate the Orion criteria and to promote their use in France. RESULTS: The Orion guidelines include a checklist of 22 commented items related to the title, abstract, introduction, methods, results, and discussion sections of a scientific article. Specific points for each item are developed to enhance its relevance. CONCLUSION: The use of Orion guidelines by authors and editors should be encouraged and should improve the quality of standards in research, intervention studies, and publications on nosocomial infections and health-care associated infections.

Incidence of methicillin-resistant Staphylococcus aureus nosocomial infections in intensive care units in Lyon University hospitals, France, 2003-2006.

We describe the trends in the incidence of methicillin-resistant Staphylococcus aureus nosocomial infection in intensive care units in Lyon hospitals from January 1, 2003, through December 31, 2006. The incidence rate decreased from 1.77 cases per 100 ICU patients in 2003 to 1.16 cases per 100 ICU patients in 2006, a reduction of 38.0% (P = .05).

Cross-modal processing of auditory-visual stimuli in a no-task paradigm: a topographic event-related potential study.

OBJECTIVE: The aim of this study was to investigate in healthy adults the electrophysiological correlates of auditory-visual interactions involved in perception of bimodal events in a no-task paradigm. METHODS: Event-related potentials were recorded in response to unimodal auditory (A), unimodal visual (V) and bimodal (AV) stimuli. Cross-modal interactions were estimated using the additive [AV-(A+V)] model. RESULTS: The spatio-temporal analysis of ERPs and scalp current densities revealed several interaction patterns occurring at both early and late stages of sensory cortical processing: (1) amplitude decrease of the unimodal auditory N1 wave as early as 55ms, (2) amplitude increase of the unimodal auditory P2 wave from 150 to 195ms concomitant with new neural activity over the right fronto-temporal region, and (3) amplitude increase of the late unimodal visual response within 245-350ms post-stimulus. CONCLUSIONS: Our study provides evidence that several patterns of cross-modal interactions can be generated even if no task is required from subjects. SIGNIFICANCE: The paradigm used here can thus be utilized for studying the maturation of the cross-modal processes in young children and in children with pathological development.

[Treatment interruption in HIV infected patients: clinical and biological evolution]. / Interruption thérapeutique chez des patients infectés par le virus de l'immunodéficience humaine: évolution clinique et biologique.

OBJECTIVE: The authors had for aim to evaluate the clinical and biological evolution in HIV-infected patients with viraemia lower than 30,000 copies/mL having decided to interrupt their treatment. PATIENTS AND METHODS: Patients with highly active antiretroviral therapy (HAART) for more than 3 months followed by treatment interruption longer than 1 month were included in a retrospective analysis. RESULTS: Forty-six patients having stopped treatment between November 1999 and July 2003 were included. The median duration of treatment interruption was 9.5 months. During the study, no clinical event occurred for 21 patients, and at least 1 clinical event occurred for the 25 others. The median CD4(+) cell counts (CD4) before and at the end of treatment interruption were 597/mm(3) and 437/mm(3), respectively (P<0.001). The median values of viral load before and at the end of treatment interruption were <50 and 23749 copies/mL, respectively (P<0.001). Among the 26 patients having started a new HAART, pre-treatment interruption and post-new HAART median CD4 (with a median delay after HAART of 9.7 months) were 548 and 432.5/mm(3) (P=0.02). Pre-treatment interruption and post-new HAART median viral load were 131.5 and 94.5 copies/mL (NS). CONCLUSIONS: Treatment interruption must be used with caution in spite of the absence of virological impact, because CD4 cell count after new HAART is lower than CD4 preceding treatment interruption. Treatment interruption is contraindicated for patients with AIDS. Physicians must carefully follow other patients who decide on a treatment interruption.

[Factors associated with the late management of HIV-infected patients: literature review]. / Facteurs associés à une prise en charge tardive des patients infectés par le VIH: revue de la littérature.

In the United States, Australia and Europe, many HIV infected individuals are still diagnosed and/or treated late in the course of the disease. This literature review of studies published over a ten year period between 1993 and 2003 has identified the following principle factors associated with the late diagnosis of HIV: male gender, aged older than 45 years, heterosexual intercourse, the lack of previous screening. It also identified the factors linked to the delay in beginning anti-retroviral treatment as being male gender, the lack of awareness or denial of the possibility of HIV infection, intravenous drug use, lack of post-screening follow-up or counseling, lack of social protection, and the lack of regular medical visits and care. Early detection and suitable early treatment of the HIV virus are the main determining factors which will effectively contribute to the control and maintenance of the virus in as much as they are focused upon these particular at-risk populations.

Electrophysiological correlates of age and gender perception on human faces.

In a previous experiment using scalp event-related potentials (ERPs), we have described the neuroelectric activities associated with the processing of gender information on human faces (Mouchetant-Rostaing, Giard, Bentin, Aguera, & Pernier, 2000). Here we extend this study by examining the processing of age on faces using a similar experimental paradigm, and we compare age and gender processing. In one session, faces were of the same gender (women) and of one age range (young or old), to reduce gender and age processing. In a second session, faces of young and old women were randomly intermixed but age was irrelevant for the task, hence, age discrimination, if any, was assumed to be incidental. In the third and fourth sessions, faces had to be explicitly categorized according to their age or gender, respectively (intentional discrimination). Neither age nor gender processing affected the occipito-temporal N170 component often associated with the detection of physiognomic features and global structural encoding of faces. Rather, the three age and gender discrimination conditions induced similar fronto-central activities around 145-185 msec. In our previous experiment, this ERP pattern was also found for implicit and explicit categorization of gender from faces but not in a control condition manipulating hand stimuli (Mouchetant-Rostaing, Giard, Bentin, et al., 2000). Whatever their exact nature, these 145-185 msec effects therefore suggest, first, that similar mechanisms could be engaged in age and gender perception, and second, that age and gender may be implicitly processed irrespective of their relevance to the task, through somewhat specialized mechanisms. Additional ERP effects were found at early latencies (45-90 msec) in all three discrimination conditions, and around 200-400 msec during explicit age and gender discrimination. These effects have been previously found in control conditions manipulating nonfacial stimuli and may therefore be related to more general categorization processes.

Cerebral mechanisms underlying orienting of attention towards auditory frequency changes.

Brain mechanisms underlying detection of auditory frequency changes were studied with event-related potentials (ERPs) in 14 human subjects discriminating visual stimuli. Scalp-current density mapping revealed bilateral components of mismatch negativity (MMN) in frontal and auditory cortices. Deviance-related activations in frontal and temporal cortex began to be significant at 94 ms and 154 ms in the right hemisphere, and at 128 ms and 132 ms in the left hemisphere. The magnitude of MMN-neuroelectric currents from the left temporal cortex correlated significantly (r = -0.56, p < 0.05) with distraction caused by MMN-eliciting deviant tones. These results suggest a complex cerebral circuitry involved in frequency change detection and strongly support the role of this circuitry in driving attention involuntarily towards potentially relevant frequency changes in the acoustic environment.

Maturation of frontal and temporal components of mismatch negativity (MMN) in children.

The mismatch negativity (MMN) response of auditory ERPs in adults appears to result from several overlapping components involving both frontal and temporal brain areas. Our aim was to test whether a similar configuration could be observed in children, and to examine the maturation rates of the different components. MMN (standard tones: 1000 Hz, deviants: 1100 Hz) was recorded from 28 scalp electrodes in 24 healthy children aged from 5 to 10 and in eight adults for comparison. Scalp current density analysis revealed both temporal and frontal components in children of all ages as well as in adults. Moreover the amplitudes of the temporal components were significantly greater in children than in adults, whereas the frontal components were similar at all ages. The results strongly suggest that MMN is mediated by at least two separate neural systems, and that the frontal system matures earlier than the sensory-specific system.

Early signs of visual categorization for biological and non-biological stimuli in humans.

In a previous experiment aimed at studying gender processing from faces, we had found unexpected early ERP differences (45-85 ms) in task-irrelevant stimuli between a condition in which the stimuli of each gender were delivered in separate runs, and a condition in which the stimuli of both genders were mixed. Similar effects were observed with hand stimuli. These early ERP differences were tentatively related to incidental categorization processes between male and female stimuli. The present study was designed to test the robustness of these early effects for faces, and to examine whether similar effects can also be generated between two classes of non-biological stimuli. We replicated the previous findings for faces, and found similar early differential effects (50-65 ms) for non-biological stimuli (grey and hatched geometrical shapes) only, however, when the two shape categories were separated by conspicuous visual characteristics. While these results can partly be explained by phenomena related to neuronal habituation in the visual cortex, they may also suggest the existence of coarse and automatic categorization processes for rapid distinction between two wide classes of stimuli with strong psychosocial significance for humans.

Auditory distraction: event-related potential and behavioral indices.

OBJECTIVE: The aim of this study was to illuminate behavioral and event-related potential (ERP) effects of attentional orienting and reorienting obtained in a newly developed auditory distraction paradigm, to provide more precise indicators about the neural generators of the ERP effects using scalp current density (SCD) analysis, and to evaluate the stability of the distraction effects. METHODS: In two sessions separated by 25 days, 10 subjects were presented with tones being of short (200 ms) and long (400 ms) duration equiprobably; tones were of high-probability standard or of low-probability deviant frequency. In Distraction condition, subjects had to behaviorally discriminate short from long tones. In Ignore condition, subjects were reading a book. Behavioral performance and multi-channel EEG were recorded. RESULTS: Task-irrelevant frequency deviations prolonged reaction times in the duration discrimination task by more than 35 ms and elicited the MMN and P3a components of the event-related potential. The P3a was followed by a negative deflection called RON (reorienting negativity). P3a and RON were absent in Ignore condition. All effects were found to be highly stable between sessions (product-moment correlations between 0.76 and 0.90). SCD analysis suggested frontal generators for P3a and for RON. CONCLUSIONS: It is demonstrated that small frequency deviations may yield distinct distraction effects in a tone duration discrimination task on a behavioral and on an electrophysiological level. Results support the hypothesis that frontal areas are involved in the exogenous orienting of attention (P3a) and in the reorienting of attention (RON). Due to the high stability of the deviance-related behavioral and ERP effects, this distraction paradigm may be utilized for clinical research.

Mismatch negativity and N100 in comatose patients.

Mismatch negativity (MMN) and N100 auditory evoked potential were recorded in 52 healthy subjects and in 128 severely comatose patients. The MMN was present in 33/128 patients and N100 in 84/128. A ratio of 30/33 patients with MMN and 70/84 with N100 regained consciousness in a mean time of 6.3 +/- 4 days after the recording session. Thus, in terms of predicting return to consciousness, the MMN was more specific (90.9%) than the N100 (57.6%), but its sensitivity was lower (31.6% for MMN and 73.7% for N100, respectively). The amplitudes of MMN and N100 in comatose patients were smaller than those of healthy subjects. It is concluded that MMN and N100 can be very useful in predicting whether or not a comatose patient will regain consciousness.

Neurophysiological mechanisms of auditory selective attention in humans.

This chapter reviews the main data on the physiological substrates of auditory selective attention and their contribution to theoretical models of cognitive psychology. While event-related potentials, magnetoencephalography, and more recently neuroimaging techniques have provided fundamental information on the neural correlates of attention in the central cortical system, measurements of the frequency-following responses in the brainstem and evoked otoacoustic emissions at the cochlea strongly suggest attentional phenomena at the auditory periphery. We propose an adaptive filtering mechanism for selective auditory attention that can be flexibly and dynamically tuned depending on the attentional demand.

Neurophysiological correlates of face gender processing in humans.

Event-related potentials (ERPs) were recorded while subjects were involved in three gender-processing tasks based on human faces and on human hands. In one condition all stimuli were only of one gender, preventing any gender discrimination. In a second condition, faces (or hands) of men and women were intermixed but the gender was irrelevant for the subject's task; hence gender discrimination was assumed to be incidental. In the third condition, the task required explicit gender discrimination; gender processing was therefore assumed to be intentional. Gender processing had no effect on the occipito-temporal negative potential at approximately 170 ms after stimulation (N170 component of the ERP), suggesting that the neural mechanisms involved in the structural encoding of faces are different from those involved in the extraction of gender-related facial features. In contrast, incidental and intentional processing of face (but not hand) gender affected the ERPs between 145 and 185 ms from stimulus onset at more anterior scalp locations. This effect was interpreted as evidence for the direct visual processing of faces as described in Bruce and Young's model [Bruce, V. & Young, A. (1986) Br. J. Psychol., 77, 305-327]. Additional gender discrimination effects were observed for both faces and hands at mid-parietal sites around 45-85 ms latency, in the incidental task only. This difference was tentatively assumed to reflect an early mechanism of coarse visual categorization. Finally, intentional (but not incidental) gender processing affected the ERPs during a later epoch starting from approximately 200 ms and ending at approximately 250 ms for faces, and approximately 350 ms for hands. This later effect might be related to attention-based gender categorization or to a more general categorization activity.

Auditory-visual integration during multimodal object recognition in humans: a behavioral and electrophysiological study.

The aim of this study was (1) to provide behavioral evidence for multimodal feature integration in an object recognition task in humans and (2) to characterize the processing stages and the neural structures where multisensory interactions take place. Event-related potentials (ERPs) were recorded from 30 scalp electrodes while subjects performed a forced-choice reaction-time categorization task: At each trial, the subjects had to indicate which of two objects was presented by pressing one of two keys. The two objects were defined by auditory features alone, visual features alone, or the combination of auditory and visual features. Subjects were more accurate and rapid at identifying multimodal than unimodal objects. Spatiotemporal analysis of ERPs and scalp current densities revealed several auditory-visual interaction components temporally, spatially, and functionally distinct before 200 msec poststimulus. The effects observed were (1) in visual areas, new neural activities (as early as 40 msec poststimulus) and modulation (amplitude decrease) of the N185 wave to unimodal visual stimulus, (2) in the auditory cortex, modulation (amplitude increase) of subcomponents of the unimodal auditory N1 wave around 90 to 110 msec, and (3) new neural activity over the right fronto-temporal area (140 to 165 msec). Furthermore, when the subjects were separated into two groups according to their dominant modality to perform the task in unimodal conditions (shortest reaction time criteria), the integration effects were found to be similar for the two groups over the nonspecific fronto-temporal areas, but they clearly differed in the sensory-specific cortices, affecting predominantly the sensory areas of the nondominant modality. Taken together, the results indicate that multisensory integration is mediated by flexible, highly adaptive physiological processes that can take place very early in the sensory processing chain and operate in both sensory-specific and nonspecific cortical structures in different ways.

ERP manifestations of processing printed words at different psycholinguistic levels: time course and scalp distribution.

The aim of the present study was to examine the time course and scalp distribution of electrophysiological manifestations of the visual word recognition mechanism. Event-related potentials (ERPs) elicited by visually presented lists of words were recorded while subjects were involved in a series of oddball tasks. The distinction between the designated target and nontarget stimuli was manipulated to induce a different level of processing in each session (visual, phonological/phonetic, phonological/lexical, and semantic). The ERPs of main interest in this study were those elicited by nontarget stimuli. In the visual task the targets were twice as big as the nontargets. Words, pseudowords, strings of consonants, strings of alphanumeric symbols, and strings of forms elicited a sharp negative peak at 170 msec (N170); their distribution was limited to the occipito-temporal sites. For the left hemisphere electrode sites, the N170 was larger for orthographic than for nonorthographic stimuli and vice versa for the right hemisphere. The ERPs elicited by all orthographic stimuli formed a clearly distinct cluster that was different from the ERPs elicited by nonorthographic stimuli. In the phonological/phonetic decision task the targets were words and pseudowords rhyming with the French word vitrail, whereas the nontargets were words, pseudowords, and strings of consonants that did not rhyme with vitrail. The most conspicuous potential was a negative peak at 320 msec, which was similarly elicited by pronounceable stimuli but not by nonpronounceable stimuli. The N320 was bilaterally distributed over the middle temporal lobe and was significantly larger over the left than over the right hemisphere. In the phonological/lexical processing task we compared the ERPs elicited by strings of consonants (among which words were selected), pseudowords (among which words were selected), and by words (among which pseudowords were selected). The most conspicuous potential in these tasks was a negative potential peaking at 350 msec (N350) elicited by phonologically legal but not by phonologically illegal stimuli. The distribution of the N350 was similar to that of the N320, but it was broader and including temporo-parietal areas that were not activated in the "rhyme" task. Finally, in the semantic task the targets were abstract words, and the nontargets were concrete words, pseudowords, and strings of consonants. The negative potential in this task peaked at 450 msec. Unlike the lexical decision, the negative peak in this task significantly distinguished not only between phonologically legal and illegal words but also between meaningful (words) and meaningless (pseudowords) phonologically legal structures. The distribution of the N450 included the areas activated in the lexical decision task but also areas in the fronto-central regions. The present data corroborated the functional neuroanatomy of word recognition systems suggested by other neuroimaging methods and described their timecourse, supporting a cascade-type process that involves different but interconnected neural modules, each responsible for a different level of processing word-related information.