Association between canine leishmaniosis and Ehrlichia canis co-infection: a prospective case-control study

Abstract Background In the Mediterranean basin, Leishmania infantum is a major cause of disease in dogs, which are frequently co-infected with other vector-borne pathogens (VBP). However, the associations between dogs with clinical leishmaniosis (ClinL) and VBP co-infections have not been studied. We assessed the risk of VBP infections in dogs with ClinL and healthy controls. Methods We conducted a prospective case-control study of dogs with ClinL (positive qPCR and ELISA antibody for L. infantum on peripheral blood) and clinically healthy, ideally breed-, sex- and age-matched, control dogs (negative qPCR and ELISA antibody for L. infantum on peripheral blood) from Paphos, Cyprus. We obtained demographic data and all dogs underwent PCR on EDTA-blood extracted DNA for haemoplasma species, Ehrlichia/Anaplasma spp., Babesia spp., and Hepatozoon spp., with DNA sequencing to identify infecting species. We used logistic regression analysis and structural equation modelling (SEM) to evaluate the risk of VBP infections between ClinL cases and controls. Results From the 50 enrolled dogs with ClinL, DNA was detected in 24 (48%) for Hepatozoon spp., 14 (28%) for Mycoplasma haemocanis, 6 (12%) for Ehrlichia canis and 2 (4%) for Anaplasma platys. In the 92 enrolled control dogs, DNA was detected in 41 (45%) for Hepatozoon spp., 18 (20%) for M. haemocanis, 1 (1%) for E. canis and 3 (3%) for A. platys. No Babesia spp. or “Candidatus Mycoplasma haematoparvum” DNA was detected in any dog. No statistical differences were found between the ClinL and controls regarding age, sex, breed, lifestyle and use of ectoparasitic prevention. A significant association between ClinL and E. canis infection (OR = 12.4, 95% CI: 1.5–106.0, P = 0.022) was found compared to controls by multivariate logistic regression. This association was confirmed using SEM, which further identified that younger dogs were more likely to be infected with each of Hepatozoon spp. and M. haemocanis, and dogs with Hepatozoon spp. were more likely to be co-infected with M. haemocanis. Conclusions Dogs with ClinL are at a higher risk of co-infection with E. canis than clinically healthy dogs. We recommend that dogs diagnosed with ClinL should be tested for E. canis co-infection using PCR

Local and non-local controls on a persistent cold-air pool in the Arve River Valley

A numerical model is used to simulate a persistent cold-air pool (PCAP) event that occurred in the section of the Arve River Valley around Passy in the French Alps. During this period, an upper-level ridge from the Atlantic moved over Europe, allowing a PCAP to form and persist over time. The impact of the upper-level ridge on the PCAP and on the dynamics within the valley section is quantified by examining the mass and heat budgets of the valley atmosphere. During the persistent stage, the magnitude of the flow through the tributary valleys is enhanced by the large-scale flow. Also, the direction of the flow through one of the tributaries is found to be determined by the height of the PCAP with respect to that of the tributary above the valley floor. The tributary flows, together with subsiding motions at the valley top, control by and large the night-time valley-scale circulation and the thermal structure of the upper part of the PCAP, whereas thermally driven valley flows control its lower part. When the upper-level ridge passes over the Arve River Valley, warm air advection through the tributaries continuously erodes the upper part of the PCAP during night-time, thereby reducing its depth, while down-valley flows export the air mass out of the valley. As the ridge moves away from the valley, the near-surface air is found to be trapped within the valley. This trapping results from the advection of warm air in the upper part of the PCAP by the large-scale flow channelled through one of the tributaries. This reduces the thermally induced pressure difference in the down-valley direction, thereby suppressing the near-surface down-valley flow. The study therefore highlights the interplay between the large-scale flow, the tributary flows and the thermal structure of the PCAP.Peer reviewedFinal Published versio

Can functional cardiac age be predicted from the ECG in a normal healthy population?

We hypothesized that in a normal healthy population changes in several ECG parameters together might reliably characterize the functional age of the heart. Data from 377 healthy subjects (209 men, 168 women, aged 4 to 75 years) were included in the study. In all subjects, ECG recordings (resting 5-minute 12-lead high fidelity ECG) were evaluated via custom software programs to calculate up to 120 different conventional and advanced ECG parameters. Using factor analysis, those 5 parameters that exhibited the highest linear correlations with age and that were mutually the least correlated were evaluated by multiple linear regression analysis to predict the functional electrical age of the heart. Ignoring small differences between males and females, functional electrical age was best predicted (R2 of 0.76, P < 0.001) by multiple linear regression analysis incorporating the RR-interval normalized high frequency variability of RRV; the RR-interval normalized value of a QT variability parameter called QTcor; the mean high frequency QRS (150-250 Hz) amplitude; the mean ST segment level at the J point; and the body mass index. In apparently healthy subjects, functional cardiac age can be estimated by multiple linear regression analysis of mostly advanced ECG parameters