Introduced Siberian chipmunks (Tamias sibiricus barberi) harbor more-diverse Borrelia burgdorferi sensu lato genospecies than native bank voles (Myodes glareolus).

Little attention has been given in scientific literature to how introduced species may act as a new host for native infectious agents and modify the epidemiology of a disease. In this study, we investigated whether an introduced species, the Siberian chipmunk (Tamias sibiricus barberi), was a potentially new reservoir host for Borrelia burgdorferi sensu lato, the causative agent of Lyme disease. First, we ascertained whether chipmunks were infected by all of the B. burgdorferi sensu lato genospecies associated with rodents and available in their source of infection, questing nymphs. Second, we determined whether the prevalence and diversity of B. burgdorferi sensu lato in chipmunks were similar to those of a native reservoir rodent, the bank vole (Myodes glareolus). Our research took place between 2006 and 2008 in a suburban French forest, where we trapped 335 chipmunks and 671 voles and collected 743 nymphs of ticks that were questing for hosts by dragging on the vegetation. We assayed for B. burgdorferi sensu lato with ear biopsy specimens taken from the rodents and in nymphs using PCR and restriction fragment length polymorphism (RFLP). Chipmunks were infected by the three Borrelia genospecies that were present in questing nymphs and that infect rodents (B. burgdorferi sensu stricto, B. afzelii, and B. garinii). In contrast, voles hosted only B. afzelii. Furthermore, chipmunks were more infected (35%) than voles (16%). These results may be explained by the higher exposure of chipmunks, because they harbor more ticks, or by their higher tolerance of other B. burgdorferi sensu lato genospecies than of B. afzelii. If chipmunks are competent reservoir hosts for B. burgdorferi sensu lato, they may spill back B. burgdorferi sensu lato to native communities and eventually may increase the risk of Lyme disease transmission to humans.

Lyme snap: A feasibility study of on-line declarations of erythema migrans in a rural area of France.

The incidence of Lyme borreliosis remains a matter of debate, but it can be estimated using the incidence of erythema migrans (EM), which is pathognomonic of the first phase. The aim of this prospective pilot study was to assess the feasibility of the on-line declaration of EM in rural areas where the incidence of Lyme borreliosis was previously estimated at 85 per 100,000 inhabitants per year. The study was limited to a rural area (Les Combrailles, Auvergne) of approximately 52,800 inhabitants and was preceded by an information campaign for the inhabitants and the healthcare professionals. Patients who sent a photo of the suspected EM by email or MMS message between April 2017 and April 2018 and who accepted to answer a questionnaire were included in the study. Two physicians then evaluated the quality of the photographs and the probability of EM. In parallel, the number of EM seen by physicians and pharmacists in the area over the given period was recorded. Out of the 113 emails and MMS messages received, 73 people were outside of the trial area or period and 9 did not complete the questionnaire. The photos of the remaining 31 people were analysed. The median age was 51.5 years old ([38-58] IQR) and 18 (58%) were women. Seven people (25%) stated that they did not have a smartphone and in 9 cases (29%) the photo was sent by a third party. The quality of the photos was considered very good in 22 (71%) cases, good in 7 (23%) cases, and average in 2 (6%) cases. The probability of EM was determined to be strong or possible in 12 (38%) cases, i.e. an estimated incidence of 22.7 per 100,000 inhabitants. Over the study period, 40 physicians and 20 pharmacists were contacted on a monthly basis. A median of 5 physicians [3;7] and 4 pharmacists [3 ;7] answered each month for a total of 18 and 36 declared EM respectively. The EM (strong probability/possible) collected by on-line declaration and those declared by healthcare professionals were all sent between April and October 2017. The total time spent on the information campaign and collection has been estimated at 265 h (divided between 10 people) for an overall cost of 10,669 Euros. The incidence of EM recorded by on-line self-declaration in our study seems to be lower than in previous studies, the under-reporting was probably linked to the low use of new technologies in the rural areas. Increasing the human resources and finances appears difficult to achieve in practice over a longer time period but the development of an application for the automatic recognition of EM could be one method for a more exhaustive collection in the long term and at lower cost.

Mapping human risk of infection with Borrelia burgdorferi sensu lato, the agent of Lyme borreliosis, in a periurban forest in France.

Lyme borreliosis is a major zoonosis in Europe, with estimates of over 26,000 cases per year in France alone. The etiological agents are spirochete bacteria that belong to the Borrelia burgdorferi sensu lato (s. l.) complex and are transmitted by hard ticks among a large range of vertebrate hosts. In Europe, the tick Ixodes ricinus is the main vector. In the absence of a vaccine and given the current difficulties to diagnose and treat chronic Lyme syndromes, there is urgent need for prevention. In this context, accurate information on the spatial patterns of risk of exposure to ticks is of prime importance for public health. The objective of our study was to provide a snapshot map of the risk of human infection with B. burgdorferi s. l. pathogens in a periurban forest at a high resolution, and to analyze the factors that contribute to variation in this risk. Field monitoring took place over three weeks in May 2011 in the suburban Sénart forest (3,200ha; southeast of Paris), which receives over 3 million people annually. We sampled ticks over the entire forest area (from 220 forest stands with a total area of 35,200m(2)) and quantified the density of questing nymphs (DON), the prevalence of infection among nymphs (NIP), and the density of infected nymphs (DIN), which is the most important predictor of the human risk of Lyme borreliosis. For each of these response variables, we explored the relative roles of weather (saturation deficit), hosts (abundance indices of ungulates and Tamias sibiricus, an introduced rodent species), vegetation and forest cover, superficial soil composition, and the distance to forest roads. In total, 19,546 questing nymphs were collected and the presence of B. burgdorferi s. l. was tested in 3,903 nymphs by qPCR. The mean DON was 5.6 nymphs per 10m(2) (standard deviation=10.4) with an average NIP of 10.1% (standard deviation=0.11). The highest DIN was 8.9 infected nymphs per 10m(2), with a mean of 0.59 (standard deviation=0.6). Our mapping and modeling revealed a strong heterogeneity of risk within the forest. The highest risk was found in the eastern part of the forest and localized patches in the northwestern part. Lyme borreliosis risk was positively associated with stands of deciduous trees (mainly oaks) and roe deer abundance. Contrary to expectations, DIN actually increased with distance from the point of introduction of T. sibiricus (i.e., DIN was higher in areas with potentially lower abundances of T. sibiricus). Thus, despite the fact that T. sibiricus is an important reservoir host for B. burgdorferi s. l., our study found that other explanatory factors played a more important role in determining the density of infected ticks. Precise mapping of the risk of exposure to Lyme borreliosis in a highly visited forest represents an important tool for targeting prevention and control measures, as well as making the general public and local health officials aware of the risks.

Prevalence of Anaplasma phagocytophilum in small rodents in France.

Anaplasma phagocytophilum is an emerging zoonotic tick-borne pathogen affecting a wide range of mammals. Rodents are suspected to be natural reservoirs for this bacterium, but their role in the epidemiologic cycles affecting domestic animals and wild ungulates has not been demonstrated. This study aimed to improve our knowledge on A. phagocytophilum prevalence in Apodemus sylvaticus, A. flavicollis and Myodes glareolus using data collected in 2010 in one area in eastern France and in 2012-2013 in two others areas in western France. Rodents were captured in each site and infection was tested using qualitative real-time PCR assays on either blood or spleen samples. Prevalence showed high variability among sites. The highest prevalence was observed in the most eastern site (with an average infection rate of 22.8% across all species), whereas no rodent was found to be PCR positive in the south-west site and only 6.6% were positive in the north-west of France. Finally, a significant increase in prevalence was observed in autumn samples compared to spring samples in the north-west, but no change was found in the other two sites.

Indications and technique for endoscopic laser resections in bronchology. A critical analysis based upon 2,284 resections.

Over a period of 6 years, we have treated 1,310 patients in 2,284 sessions using a neodymium-yttrium aluminum garnet laser. Indications are more often palliative than curative, with the primary goal to relieve an obstructed airway in a single treatment. The effectiveness of such resections is widely recognized, but indications for such a technique with its limitations deserve emphasis. The use of a rigid bronchoscope is important to provide satisfactory operating conditions and especially to manage hemorrhage rapidly while maintaining a satisfactory airway.

Changes in intrathoracic pressures induced by positive end-expiratory pressure ventilation after cardiac surgical procedures.

The consequences of controlled ventilation with positive end-expiratory pressure (PEEP) were studied, after cardiac surgical procedures, in two groups of patients supposed to have different lung and chest wall mechanical properties. The first group included 6 patients who had undergone coronary artery graft surgical procedures (CGS). The second group included 5 patients who had undergone a mitral valve replacement (MVR). Postoperatively, static lung and chest wall compliance was measured by stepwise inflation and deflation of the thorax. Esophageal, pericardial, and pleural pressures were then measured, and cardiac output was determined while PEEP was increased from 0 to 20 cm H2O. Lung and chest wall compliance values sharply decreased in MVR patients. This accounts for the lower values for pleural and pericardial pressures in this group than in the CGS patient group, but the transmission of airway pressure was identical in the two groups when PEEP was increased. The decrease in cardiac output induced by PEEP was similar in the two groups. The results suggest that the opposing influences of lung and chest wall compliance on airway pressure transmission could at least partly explain the hemodynamic effects of PEEP in patients in whom the mechanical properties of the lung and thorax are impaired. PEEP ventilation should be used cautiously in patients suspected of having thoracic rigidity.

The implications of a national study of risk of anaesthesia.

In order to set up measures to improve safety in anesthesia, the French Ministry of Health charged the Institut National de la Santé et de la Recherche Médicale (I.N.S.E.R.M.) with conducting an epidemiological survey of complications associated with anaesthesia. A prospective survey was carried out from 1978 to 1982 in a representative sample of 198,103 anaesthesias performed in 460 public and private institutions randomly selected throughout the country. There were 268 major complications associated with anaesthesia occurring during or within 24 hours after anaesthesia (incidence 1.35 per 1000), among these 67 were followed by death and 16 by coma. The incidence of deaths and comas totally attributable to anaesthesia was one per 7924. Half of the deaths and comas totally attributable to anaesthesia were from post-anaesthetic respiratory depression which could be directly linked to a dramatic lack of recovery rooms. The extension of the study to all institutions revealed that 25% of teaching hospitals, 43% of non-teaching hospitals and 20% of private clinics did not have a recovery room available. A total number of 12,000 recovery beds was estimated to be necessary in France; 40% being currently available leaving 60% to be created.

[Comparison of the clinical effects of vecuronium and pancuronium bromide in general surgery]. / Comparaison des effets cliniques du vécuronium et du bromure de pancuronium en chirurgie générale.

50 patients selected at random were given vecuronium (group A) or pancuronium bromide (group B) at an initial dose of 0.05 mg X kg-1, followed by repeat injections of 0.0125 mg X kg-1. 34 other patients, separated in two groups: group C (vecuronium) and group D (pancuronium), received stronger doses of both drugs: 0.07 mg X kg-1 initially, followed by 0.022 mg X kg-1 repeat injections. The four groups were anaesthetized according to the same protocol; the patients underwent gastrointestinal and gynaecological surgery, lasting 122 +/- 50 min. The results showed that the time of onset and the duration of action of vecuronium were shorter, and that increasing the dose did not increase significantly the duration of action of these repeat doses: time of onset: 104 +/- 42 s (group A), 205 +/- 36 s (group B), 96 +/- 23 s (group C), 255 +/- 36 s (group D); duration of action: 19 +/- 6 min (group A), 36 +/- 6 min (group B), 24 +/- 7 min (group C), 43 +/- 13 min (group D); mean time between doses: 26 +/- 10 min (group A), 55 +/- 5 min (group B), 33 +/- 7 min (group C), 49 +/- 3 min (group D). The degree of muscle relaxation was always satisfactory in the four groups. Decurarization appeared to be particularly sudden with vecuronium. Neither an abnormally prolonged duration of action, nor any haemodynamic effect, nor any signs of histamine release were seen.

[Role of vecuronium in comparison with curariform drugs used in man]. / Place du vécuronium par rapport aux curares utilisés en clinique humaine.

Vecuronium, a new non-depolarizing muscle relaxant, was more powerful than d-tubocurarine, gallamine and alcuronium. Its muscle blocking effect was similar to that of pancuronium. It had a smaller distribution volume and a quicker elimination half-life than the other non-depolarizing muscle blocking drugs. The time of onset and duration of action, as well as the time for recovery were also shorter, being 3-5 min, 17-22 min and 25 min respectively. The accumulation of vecuronium in the body was low; increasing the dose increases the duration of action, but not the recovery time. No adverse effect has been reported as yet. Compared with suxamethonium, a depolarizing muscle relaxant, it had a longer time of onset and duration of action. Vecuronium cannot therefore replace suxamethonium for endotracheal intubation.

[Relation of the fall in PO2 in ventilation of the lower lung in pulmonary surgery and the preoperative distribution of respiratory function]. / Relation entre la chute de PaO2 lors de la ventilation du poumon inférieur en chirurgie pulmonaire et la répartition préopératoire de la fonction respiratoire.

Hypoxaemia during one-lung ventilation is influenced by the anatomic distribution of lung perfusion and hypoxic vasoconstriction. This study aimed to assess whether preoperative selective bronchospirometry could predict the degree of peroperative hypoxaemia. Twelve patients scheduled for pneumonectomy, lobectomy, wedge resection or decortication were included in the study. Preoperative data included the usual spirometric parameters, oxygen consumption, minute ventilation of each lung and arterial blood gases. A Carlens or Robertshaw tube was inserted in each case; the patients were ventilated with 100% oxygen and halothane was used for anaesthesia. Blood gases were measured during surgery before and after upper lung exclusion. When both lungs were ventilated, mean PaO2 was 390.5 +/- 92.4 mmHg; during one-lung ventilation, it fell to 210.8 +/- 109.2 mmHg. Routine spirometry could not predict the magnitude of fall in PaO2; however, it was correlated with the bronchospirometric oxygen consumption of each lung (r = 0.83; p less than 0.01). The anatomical distribution of lung perfusion seemed to be the predominant factor influencing the decrease in PaO2 during one-lung ventilation.

[Development of anesthetic technics for resection-anastomosis of the trachea]. / Evolution des techniques d'anesthésie pour résection-anastomose de trachée.

A series is reported of 109 patients, 45 +/- 18 yr old, undergoing tracheal sleeve resection. 101 patients had iatrogenic tracheal stenosis, 5 tracheal cylindroma, 2 tracheal cancer and 1 tracheal trauma. 84 patients underwent preoperative laser coagulation to increase the airway internal diameter. Anaesthesia for the sleeve resection was induced by thiopentone, and maintained by an opiate, nitrous oxide and, if necessary, a volatile anesthetic. Patients were intubated, after having been given a muscle relaxant, with either a normal length and diameter tube with a low pressure cuff, or a narrow (internal diameter less than 6 mm) 50 cm long tube with or without a low pressure cuff. Patients with long tubes were ventilated with intermittent positive pressure, and the others with high frequency jet ventilation (HFJV) via a urethral catheter within the endotracheal tube. 20% of the long tubes had to be replaced during surgery because of perforation of the cuff by a tracheal stitch. In all, six patients died, one as a result of a pneumothorax and air embolus due to HFJV. Preoperative photocoagulation reduced the risk of induction and intubation; the choice of endotracheal tube no longer depended on the tracheal diameter, but on the method of ventilation chosen. However, HFJV has tended to be phased out, except for the surgery of lesions close to the carena; it has been replaced by intermittent positive pressure ventilation via long tubes. Because laser photocoagulation can completely cure small stenoses, these patients requiring surgery were those with long stenoses which were difficult to treat.(ABSTRACT TRUNCATED AT 250 WORDS)

[Comparative clinical study of the effects of vecuronium and suxamethonium during oto-rhino-laryngeal and tracheobronchial laser surgery]. / Etude clinique comparative des effets du vécuronium et du suxaméthonium au cours des chirurgies oto-rhino-laryngologique et trachéo-bronchique par laser.

52 patients selected at random were assigned to four groups according to the surgery and muscle relaxant used: vecuronium (group A) and suxamethonium (group B) in ENT, vecuronium (group C) and suxamethonium (group D) for laser surgery. The first dose of vecuronium was 0.05 mg X kg-1, followed by repeat doses of 0.0125 mg X kg-1; suxamethonium was first given in a dose of 1 mg X kg-1, this being followed by a drip of 3 mg X kg-1. The anaesthetic protocol was the same for all groups. The results showed a shorter onset of action with suxamethonium (group A: 210 +/- 30 s, group B: 75 +/- 15 s, group C: 200 +/- 50 s, group D: 80 +/- 20 s) and a similar duration of action for the initial doses of the two drugs (group A: 9 +/- 3 min, group B: 6 +/- 3 min, group C: 11 +/- 4 min, group D: 7 +/- 2 min). Continuing the muscle relaxation proved easier with the suxamethonium; signs of decurarization occurred rather unexpectedly with vecuronium. No adverse effect was seen with vecuronium, whilst the diastolic blood pressure rose 20% during the first 25 min following the administration of suxamethonium. It can be concluded that, in the absence of monitoring of the curarization, the repeated administration of vecuronium with a first dose of 0.05 mg X kg-1 brought few advantages compared with the continuous infusion of suxamethonium.

[Hypoxia secondary to the failure of an oxygen-air-nitrous oxide mixer]. / Hypoxie secondaire à la défaillance d'un mélangeur oxygéne/air/protoxyde d'azote.

A case is reported of hypoxia occurring during anaesthesia in a spontaneously breathing ASA I patient. The patient became cyanotic twice when breathing a gas mixture delivered by a safety mixer. Changing the machine solved the immediate problem. The diagnosis was difficult to make because the rotameters all showed normal delivery of oxygen and nitrous oxide. Oximetry elucidated the cause, which was found to be a defective rapid oxygen control. Because these machines do not appear to be absolutely reliable, the use of gas analysers should become more systematic.

[Experimental study of the cerebrovascular effects of sodium nitroprusside in the baboon Papio papio. Its action on the experimental vasospasm]. / Etude expérimentale des effets cérébro-vasculaires du nitroprussiate de soude chez le babouin Papio papio. Son action sur le vasospasme expérimental

Sodium nitroprusside (SNP) has been suggested as hypotensive agent in the surgery of cerebral aneurysms. As a preliminary step to neurosurgery, a study of its cerebro-vascular and EEG action had been carried out in 42 papio-papio baboons. On the unanaesthetized analgesic-free animal, doses below 20 mumg/kg/min. induce only a moderate decrease of mean arterial blood pressure (MABP), a slight rise of intracranial pressure (ICP) and a neat fall of cerebro-vascular resistance (CVR) without EEG modifications. Doses above 50 mumg/kg/min. induce a neat fall of MABP with a rise of cerebral blood flow (CBF), of ICP and signs of poisoning with metabolic acidosis and prolonged EEG disturbances. Beyond 90 mumg/kg/min. irreversible hypotension occured accompanied by metabolic acidosis and progressive abolition of cerebral electrogenesis. The hypotensive action of SNP is potentiated by neuroleptanalgesic drugs (phenoperidine and dehydrobenzoperidol). Using this combination marked hypotension was achieved with non toxic doses of SNP (6 to 10 mumg/kg/min.). During those hypotensions cerebral auto-regulation was maintained up to a MABP of 50 mmHg. Deeper brief hypotensions up to a MABP of 25 to 45 mmHg induce a 23% fall of CBF (p less than 0, 05) but without major EEG alterations. During experimental arterial spasms induced by injection of blood in the cisterna magna or serotonin infusion, SNP has a vasodilating action. It induces a significant rise of CBF (p less than 0, 01) for doses between 8 and 19 mumg/kg/min.

[Long-term peridural morphine analgesia in neoplastic and vascular pathology]. / Analgésie péridurale morphinique de longue durée en pathologie néoplasique et vasculaire.

Epidural analgesia using morphine has been used on 44 patients with intractable chronic pain, resistant to analgesics (including opiates). The pain was due to cancer in 24 cases, of vascular origin in 20. An indwelling tunnelized epidural catheter afforded repeated injections of morphine for a long period (up to 129 days) either in hospital or at home. The quality of analgesia achieved was rated as excellent or good, in 68 p. 100 of cases. Two cases only were total failures. Side effects, relatively common, were usually transient and minor; no case of respiratory depression or of infection has been recorded.

Which forest bird species are the main hosts of the tick, Ixodes ricinus, the vector of Borrelia burgdorferi sensu lato, during the breeding season?

Wild birds are important hosts for vector-borne pathogens, especially those borne by ticks. However, few studies have been conducted on the role of different bird species within a community as hosts of vector-borne pathogens. This study addressed individual and species factors that could explain the burden of Ixodes ricinus on forest birds during the reproductive periods of both vectors and hosts. The goal was to identify which bird species contribute the most to the tick population at the community level. Birds were mist-netted on four plots in 2008 and on seven plots in 2009 in two forests (Sénart and Notre Dame, near Paris, France). The dependence of the tick load per bird upon environmental conditions (questing nymph density, year and plot) and on host species traits (species, age, sex, body size, vertical space use, level of innate and acquired immunity) was analysed. Finally, the relative contribution of each bird species to the local dynamics of ticks was estimated, while accounting for their respective abundance. Tick burden differed markedly between bird species and varied according to questing nymph density. Bird species with a high body mass, those that forage low in the vegetation, and those that had a high innate immune response and a high spleen mass were more likely to have a high tick burden. Four species (the Common Blackbird, Turdus merula, the European Robin, Erithacus rubecula, the Song Thrush, Turdus philomelos, and the Winter Wren, Troglodytes troglodytes) hosted more than 90% of the ticks in the local bird community. These species, and particularly T. merula which was host to a high proportion of the nymphs, are likely to contribute significantly to the circulation of pathogens for which they are competent, such as the agent of Lyme borreliosis.

Introduced Siberian chipmunks are more heavily infested by ixodid ticks than are native bank voles in a suburban forest in France.

By serving as hosts for native vectors, introduced species can surpass native hosts in their role as major reservoirs of local pathogens. During a 4-year longitudinal study, we investigated factors that affected infestation by ixodid ticks on both introduced Siberian chipmunks Tamias sibiricus barberi and native bank voles Myodes glareolus in a suburban forest (Forêt de Sénart, Ile-de-France). Ticks were counted on adult bank voles and on adult and young chipmunks using regular monthly trapping sessions, and questing ticks were quantified by dragging. At the summer peak of questing Ixodes ricinus availability, the average tick load was 27-69 times greater on adult chipmunks than on adult voles, while average biomass per hectare of chipmunks and voles were similar. In adult chipmunks, individual effects significantly explained 31% and 24% of the total variance of tick larvae and nymph burdens, respectively. Male adult chipmunks harboured significantly more larvae and nymphs than adult females, and than juveniles born in spring and in summer. The higher tick loads, and more specifically the ratio of nymphs over larvae, observed in chipmunks may be caused by a higher predisposition--both in terms of susceptibility and exposure--to questing ticks. Tick burdens were also related to habitat and seasonal variation in age- and sex-related space use by both rodents. Introduced chipmunks may thus have an important role in the dynamics of local vector-borne pathogens compared with native reservoir hosts such as bank voles.