17.2 Cardiac resynchronization: Multicenter experience with a new coronary sinus lead

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Occurrence and identification of risk areas of Ixodes ricinus-borne pathogens: a cost-effectiveness analysis in north-eastern Italy

<p>Abstract</p> <p>Background</p> <p><it>Ixodes ricinus</it>, a competent vector of several pathogens, is the tick species most frequently reported to bite humans in Europe. The majority of human cases of Lyme borreliosis (LB) and tick-borne encephalitis (TBE) occur in the north-eastern region of Italy. The aims of this study were to detect the occurrence of endemic and emergent pathogens in north-eastern Italy using adult tick screening, and to identify areas at risk of pathogen transmission. Based on our results, different strategies for tick collection and pathogen screening and their relative costs were evaluated and discussed.</p> <p>Methods</p> <p>From 2006 to 2008 adult ticks were collected in 31 sites and molecularly screened for the detection of pathogens previously reported in the same area (i.e., LB agents, TBE virus, <it>Anaplasma phagocytophilum, Rickettsia </it>spp., <it>Babesia </it>spp., "<it>Candidatus Neoehrlichia mikurensis</it>"). Based on the results of this survey, three sampling strategies were evaluated <it>a</it>-<it>posteriori</it>, and the impact of each strategy on the final results and the overall cost reductions were analyzed. The strategies were as follows: tick collection throughout the year and testing of female ticks only (strategy A); collection from April to June and testing of all adult ticks (strategy B); collection from April to June and testing of female ticks only (strategy C).</p> <p>Results</p> <p>Eleven pathogens were detected in 77 out of 193 ticks collected in 14 sites. The most common microorganisms detected were <it>Borrelia burgdorferi </it>sensu lato (17.6%), <it>Rickettsia helvetica </it>(13.1%), and "<it>Ca. N. mikurensis</it>" (10.5%). Within the <it>B. burgdorferi </it>complex, four genotypes (i.e., <it>B. valaisiana, B. garinii, B. afzelii</it>, and <it>B. burgdorferi </it>sensu stricto) were found. Less prevalent pathogens included <it>R. monacensis </it>(3.7%), TBE virus (2.1%), <it>A. phagocytophilum </it>(1.5%), <it>Bartonella </it>spp. (1%), and <it>Babesia </it>EU1 (0.5%). Co-infections by more than one pathogen were diagnosed in 22% of infected ticks. The prevalences of infection assessed using the three alternative strategies were in accordance with the initial results, with 13, 11, and 10 out of 14 sites showing occurrence of at least one pathogen, respectively. The strategies A, B, and C proposed herein would allow to reduce the original costs of sampling and laboratory analyses by one third, half, and two thirds, respectively. Strategy B was demonstrated to represent the most cost-effective choice, offering a substantial reduction of costs, as well as reliable results.</p> <p>Conclusions</p> <p>Monitoring of tick-borne diseases is expensive, particularly in areas where several zoonotic pathogens co-occur. Cost-effectiveness studies can support the choice of the best monitoring strategy, which should take into account the ecology of the area under investigation, as well as the available budget.</p

DDDR versus DDD and VVIR pacing: A single blind randomised evaluation of symptoms and effort performance

The aim of this study was to evaluate effort performance and subjective symptoms in a within-patient comparison of DDDR, DDD and VVIR pacing. A DDDR pacemaker (Synergyst II, Medtronic) was implanted in 14 patients (mean age 66.5 ± 5.0 yrs.) with sick sinus syndrome or II-III degree AV block. Seven subjects had chronotropic incompetence (maximum heart rate on exercise < 100 beats/min or maximum heart rate after i.v. atropine < 100 beats/min). All the patients underwent a symptom limited exercise test and a questionnaire score after 1 month of DDDR, DDD and VVIR pacing, in random order. The mean effort duration in DDDR was 12.6 ± 3.1 min, in VVIR 11.4 ± 3.4 min (p < 0.01 vs DDDR) and in DDD = 11.0 ± 2.9 min (p < 0.01 vs DDDR). Considering the subgroup of patients with chronotropic incompetence the same differences persisted whilst in the 6 subjects without chronotropic incompetence who completed the study DDDR pacing was statistically superior only to DDD and not to VVIR pacing. VVIR pacing was poorly tolerated since in all the groups of patients its symptom score was significantly higher compared with either DDDR or DDD pacing. In conclusion DDDR pacing is characterised by a superior maximal effort capacity in comparison with DDD pacing and VVIR pacing. In patients with chronotropic incompetence these differences are more marked. Moreover VVIR pacing appears poorly tolerated in subjective terms and in occurrence of side effects

Understanding the impact on human and wildlife health of the invasive alien mosquito species Aedes albopictus in Northern Italy

Aedes albopictus is among the most widespread alien species in the world and its introduction and spread in northern Italy has been documented since 1990. While its impact on human health is well known in this area not only for its nuisance but also for being the most important vector involved in the 2007 epidemics of Chikungunya (CHIKV), its role as a bridge vector of infections impacting both human health and wildlife is less understood. In fact, extensive epidemics of West Nile virus (WNV) and Usutu Virus (USUV) have been recently documented within the study area. Although referred to as an anthropophilic species, there is evidence of its relative ornithophily. To better understand its role as bridge vector for human and wildlife diseases in Italy, we carried out mosquito samplings within two regions (Trentino and Veneto) from 2011 to 2013. A total of 4613 unfed female and 1976 males were screened for Flaviviruses, while 86 fed females were screened to identify the host used by the mosquito for its blood meal. The virological screening identified the occurrence of Aedes flavivirus (AeFV) in a significant number of pools tested (14.6% in Trentino and 19.3% in Veneto) while no positive samples were obtained for West Nile virus or Usutu virus. Blood meal analysis of the engorged females identified the following host species: Homo sapiens (88.3%), Erinaceus europaeus (2.3%), Coturnix japonica (1.2%), Passer montanus (1.2%) and Turdus merula (1.2%). These preliminary finding indicate the ability of this species to feed also on non-human hosts and thus act as an additional potential bridge vector of pathogens among wildlife and humans, although in this study we could not identify West Nile or Usutu virus in our sample

Acute corticosterone sexually dimorphically facilitates social learning and inhibits feeding in mice

In numerous species social learning is predominant and adaptive, yet, we know little of its neurobiological mechanisms. Social learning is modulated by motivations and emotions, in a manner that is often sexually dimorphic. Additionally, stress hormones acutely modulate the related social cognitive process of social recognition. Whether this is true even for social learning is currently unknown.We investigated the acute effects of the stress hormone corticosterone (CORT) on the social transmission of food preferences (STFP) in male and female mice. During a brief social interaction an observer (OBS) acquires a food preference from a same-sex demonstrator (DEM). CORT (1.0, 2.5, 5.0 mg/kg), its ethanol vehicle (0.1%), and saline solution (0.9%) were administered intraperitoneally to the OBS, 10 min before a 30-min social interaction. Levels of plasma CORT were assessed in other mice that had received the same doses of CORT and either had or had not gone through a 30 min social interaction 10 min post-treatment. Exogenous CORT elicited levels of plasma level comparable to those seen at the peak of the circadian cycle and facilitated the STFP with males responding more than females both in terms of the duration of the food preference and the minimum effective dose. CORT also sexually dimorphically inhibited feeding, with females showing a greater doseeresponse than males. Saline solution and ethanol vehicles also sexually dimorphically facilitated the STFP and reduced feeding, but less than CORT did. These results indicate that CORT facilitates social learning, like social recognition. Hence, CORT may generally increase social information processing

Risk of canine and human exposure to Dirofilaria immitis infected mosquitoes in endemic areas of Italy

BACKGROUND: The occurrence of infections by Dirofilaria immitis in canine and human populations depends on several factors linked to both the definitive and intermediate hosts. Little data are available on the risk of human and dog exposure to D. immitis in endemic areas. Data collected on dog- and human-bait traps in endemic areas of north-eastern Italy were used to estimate the likelihood of a receptive host coming into contact with an infected vector. METHODS: From 1997 to 1999, mosquitoes were collected from three sampling sites of north-eastern Italy on D. immitis microfilaraemic dogs and on human baits. The bite/night/host rates were determined based on the number of feeding and probing mosquitoes on dogs and humans, respectively. The survival/mortality rates of different species of mosquitoes following the blood meal, and the rate of natural Dirofilaria infection in unfed specimens were estimated. The risk of exposure of dogs and humans to infected mosquito species was determined by combining the bite/host/night and the mosquito infection rates. RESULTS: A total of 1,165 mosquitoes were collected on human (n=815) and dog (n=350) baits with varying species composition (i.e., Culex pipiens, 87.3% and Ochlerotatus caspius, 11.6%). Overall, dogs were more attractive to Cx pipiens than humans (feeding rate 70.2% vs probing rate 25.9%). The highest bite/night/host rate was 84.0 for dogs and 26.5 for humans. Cx pipiens displayed a mortality rate of 76.3% within 13 days and Oc. caspius of 100% within two days following the infective blood meal. In addition, D. immitis DNA was detected in unfed Cx pipiens (infection rate of 0.26%-2.07%). The infection rate adjusted for mosquito mortality was 0.38%. Based on data collected, the contact between an infected mosquito and a host can occur as often as every four nights for D. immitis infected-mosquitoes in dogs and within two weeks for humans. CONCLUSIONS: Cx pipiens was confirmed as the most efficient natural vector of D. immitis in the studied area. In endemic areas, the risk of transmission can be very high for dogs and relevant for humans. Despite the increased awareness of veterinarians and owners on canine dirofilarioses, dogs from rural areas still maintain the natural life cycle of Dirofilaria spp., therefore acting as a source of infection to humans through vector bites

Variability of Left Ventricular Electromechanical Activation during Right Ventricular Pacing: Implications for the Selection of the Optimal Pacing Site

BACKGROUND: The right ventricular septum (RVS) and Hisian area (HA) are considered more "physiological" pacing sites than right ventricular apex (RVA). Studies comparing RVS to RVA sites have produced controversial results. There are no data about variability of electromechanical activation obtained by an approach using fluoroscopy and electrophysiological markers. This study compared the variability of left ventricular (LV) electromechanical activation in patients undergoing short-term RVA and RVS with that measured during HA pacing based on fluoroscopy and electrophysiological markers. METHODS: Tissue Doppler echocardiography was performed in 142 patients before and after RVA (54), RVS (44), and HA (44) pacing. Electromechanical activation was assessed by: (1) electromechanical latency (EML)-interval between QRS onset and mechanical activation of basal LV; (2) intra-LV dyssynchrony (intra-LV)-interval between earliest to the latest LV basal motion. The intra- and interpatients variability among pacing groups were assessed. RESULTS: Pacing from RVA showed longer EML and higher degree of intra-LV than RVS and HA pacing. RVA and RVS showed a higher variability than HA pacing with regard to intrapatient changes of EML (RVA vs RVS, P = 0.4; RVS vs HA, P = 0.01, RVA vs HA, P = 0.0002) and intra-LV (RVA vs RVS, P = 0.2; RVS vs HA, P = 0.04; RVA vs HA, P = 0.005). Similar results were found in interpatients variability from paced-values. CONCLUSIONS: RVA and RVS pacing produce a variable effect on LV electromechanical activation that is significantly more pronounced than HA pacing. A pacing site such as HA selected by fluoroscopic and electrophysiological markers maintains baseline and homogeneous LV activation patter

Left Ventricular Dyssynchrony Resulting from Right Ventricular Apical Pacing: Relevance of Baseline Assessment

OBJECTIVES: Evaluation of left ventricular (LV) dyssynchrony in patients undergoing short-term right ventricular apical (RVA) pacing and correlation with baseline echocardiographic and clinical characteristics. BACKGROUND: RVA pacing causes abnormal ventricular depolarization that may lead to mechanical LV dyssynchrony. The relationships between pacing-induced LV dyssynchrony and baseline echocardiographic and clinical variables have not been fully clarified. METHODS: Tissue Doppler echocardiography was performed in 153 patients before and after RVA pacing. LV dyssynchrony was measured by the time between the shortest and longest electromechanical delays in the five basal LV segments (intra-LV). The prevalence and degree of LV dyssynchrony after RVA pacing was evaluated in three groups: baseline LV ejection fraction (LVEF) or=55%. The intrapatient effect of RVA pacing was determined as the percent increase in intra-LV value (Deltaintra-LV%). The pacing-induced intra-LV was correlated with baseline variables. RESULTS: The prevalence and degree of LV dyssynchrony after RVA pacing was significantly higher in patients with lower LVEF (P < 0.001). DeltaIntra-LV% was inversely correlated with baseline intra-LV and LVEF (B =-2.6, B =-4.2, P < 0.001). Baseline intra-LV and LV end-systolic volume correlated positively with intra-LV after RVA pacing (B = 0.49, B = 0.6, P < 0.001), whereas LVEF showed an inverse correlation. CONCLUSIONS: The degree of LV dyssynchrony induced by RVA is variable. Patients with higher baseline LV dyssynchrony, more dilated LV, and more depressed LVEF showed a higher degree of LV dyssynchrony during pacing. These findings may assume importance in predicting the risk of heart failure in pacemaker patients