An updated meta-analysis of the distribution and prevalence of <Emphasis Type="Italic">Borrelia burgdorferi</Emphasis> s.l. in ticks in Europe

Background

The bacteria of the group Borrelia burgdorferi s.l. are the etiological agents of Lyme borreliosis in humans, transmitted by bites of ticks. Improvement of control measures requires a solid framework of the environmental traits driving its prevalence in ticks.

Methods

We updated a previous meta-analysis of the reported prevalence of Borrelia burgdorferi s.l. in questing nymphs of Ixodes ricinus with a literature search from January 2010–June 2017. This resulted in 195 new papers providing the prevalence of Bb for 926 geo-referenced records. Previously obtained data (878 records, years 2000–2010) were appended for modelling. The complete dataset contains data from 82,004 questing nymphs, resulting in 558 records of B. afzelii, 404 of B. burgdorferi s.s. (only 80 after the year 2010), 552 of B. garinii, 78 of B. lusitaniae, 61 of B. spielmanii, and 373 of B. valaisiana. We associated the records with explicit coordinates to environmental conditions and to a categorical definition of European landscapes (LANMAP2) looking for a precise definition of the environmental niche of the most reported species of the pathogen, using models based on different classification methods.

Results

The most commonly reported species are B. afzelii, B. garinii and B. valaisiana largely overlapping across Europe. Prevalence in ticks is associated with portions of the environmental niche. Highest prevalence occurs in areas of 280°–290° (Kelvin) of mean annual temperature experiencing a small amplitude, steady spring slope, together with high mean values and a moderate spring rise of vegetation vigor. Low prevalence occurs in sites with low and a noteworthy annual amplitude of temperature and the Normalized Difference Vegetation Index (colder areas with abrupt annual changes of vegetation). Models based on support vector machines provided a correct classification rate of the habitat and prevalence of 89.5%. These results confirm the association of prevalence of the three most commonly reported species of B. burgdorferi s.l. in Europe to parts of the environmental niche and provide a statistically tractable framework for analyzing trends under scenarios of climate change.

     

Soil surface colonization by phototrophic indigenous organisms,in two contrasted soils treated by formulated maize herbicide mixtures

Soil phototrophic microorganisms, contributors to soil health and food webs, share their particular metabolism with plants. Current agricultural practices employ mixtures of pesticides to ensure the crops yields and can potentially impair these non-target organisms. However despite this environmental reality, studies dealing the susceptibility of phototrophic microorganisms to pesticide mixtures are scarce. We designed a 3 months microcosm study to assess the ecotoxicity of realistic herbicide mixtures of formulated S-metolachlor (Dual Gold Safeneur^®), mesotrione (Callisto^®) and nicosulfuron (Milagro^®) on phototrophic communities of two soils (Limagne vertisol and Versailles luvisol). The soils presented different colonizing communities, with diatoms and chlorophyceae dominating communities in Limagne soil and cyanobacteria and bryophyta communities in Versailles soil. The results highlighted the strong impairment of Dual Gold Safeneur^® treated microcosms on the biomass and the composition of both soil phototrophic communities, with no resilience after a delay of 3 months. This study also excluded any significant mixture effect on these organisms for Callisto^® and Milagro^® herbicides. We strongly recommend carrying on extensive soil studies on S-metolachlor and its commercial formulations, in order to reconsider its use from an ecotoxicological point of view.     

From confrontation to cooperation in the doctor—Patient relationship

Received from the Department of Medicine, Mount Auburn Hospital, Cambridge, Massachusetts, and Harvard Medical School, Boston, Massachusetts.     

Molecular epidemiology of Burkitt's lymphoma from South America: differences in breakpoint location and Epstein-Barr virus association from tumors in other world regions.

We have previously shown that the endemic (African) and sporadic (North American) forms of Burkitt's lymphoma (BL) differ at a molecular level. We have now extended our studies to the molecular epidemiology of BL in South America, specifically to two climatic regions: temperate (Argentina and Chile) and tropical (Brazil). We have examined the patterns of chromosomal breakpoint locations in 39 tumors with respect to geography and Epstein-Barr virus (EBV) association. The result of these analyses provide further support for the existence of pathogenetically distinct subtypes of BL in different world regions. The majority of breakpoints on chromosome 8 in South American BL (41%) occurred in the immediate flanking region of c-myc, ie, further 5' of the "typical" sporadic breakpoints, in the first exon/intron region, and further 3' of the "typical" endemic breakpoints, which are usually distant from c-myc. However, the distribution of breakpoints on chromosome 14 in tumors from the temperate and tropical regions of South America is similar to that observed in sporadic and endemic tumors. Interestingly, only one tumor with an unrearranged c-myc gene joined to the S mu region of chromosome 14 was observed. This combination was also rarely observed in our earlier series and presumably is either less readily generated by the mechanism that mediates 8;14 translocation or requires other, infrequent genetic changes to provide the necessary selective advantage for lymphomagenesis. The frequency of EBV association in South American BL (51%) is also intermediate with respect to tumors from the United States (30%) and Africa (100%). No correlation with the breakpoint location on chromosome 8 was discernable. Surprisingly, only 54% of tumors with breakpoint outside c-myc were EBV positive. This is in contrast to endemic tumors and suggests that any pathogenetic contribution of EBV is not dependent on breakpoint location, but is more likely to complement additional pathogenetic elements that differ in different world regions.     

Measurement of radiographic joint space width in the tibiofemoral compartment of the osteoarthritic knee: comparison of standing anteroposterior and Lyon schuss views

OBJECTIVE: To evaluate progression of joint space narrowing in radiographs of osteoarthritic (OA) knees imaged in both the standing anteroposterior (AP) and the Lyon schuss positions, using alternative methods to measure joint space width (JSW). METHODS: Standing AP (extended view) and Lyon schuss (posteroanterior [PA] view, with 20-30 degrees of flexion) radiographic images of 58 OA knees were obtained twice (at baseline and 2 years later). With both methods, fluoroscopy was used to align the anterior and posterior margins of the medial or lateral tibial plateau with the central x-ray beam. Minimum JSW, mean JSW, and joint space area (JSA) of the medial or lateral femorotibial joint space were measured using a new digital image analysis system. The effects of knee flexion versus extension and parallel versus nonparallel tibial plateau alignment were evaluated with respect to the reproducibility of JSW in repeated examinations (intraclass correlation coefficient [ICC]), the mean of within-knee standard deviations of repeated measurements (SD(m)), and the sensitivity to changes in JSW in serial radiographs (standardized response mean [SRM]). RESULTS: The performance of the new software, as assessed by the reproducibility of repeated measurements of minimum JSW on the same image, was excellent in both the standing AP (ICC = 0.98) and Lyon schuss radiographs (2 SD(m) = 0.5 mm, ICC = 0.98). The reproducibility in different radiographs of the same knee was not evaluated. However, over 2 years, the mean (+/- SD) decrease in the minimum JSW of OA knees was 0.17 +/- 0.75 mm in standing AP radiographs (P not significant) and 0.24 +/- 0.50 mm in Lyon schuss views (P = 0.007), with SRMs of 0.23 and 0.48, respectively. The quality of alignment of the tibial plateau was satisfactory (<1 mm between anterior and posterior margins of the medial tibial plateau) in 66% of the pairs of Lyon schuss radiographs and in 57% of the pairs of standing AP radiographs. In the Lyon schuss radiographs, SRM was highly dependent on tibial plateau alignment. Minimum JSW was more sensitive to change than was mean JSW or JSA, in paired Lyon schuss radiographs that exhibited satisfactory alignment. CONCLUSION: Compared with the standing AP radiograph, PA imaging of the knee in 20-30 degrees flexion (the schuss position) increases the reproducibility of radiographic JSW measurements in OA knees and the sensitivity to change in JSW in serial radiographs. Sensitivity to change in minimum JSW is notably increased by aligning the medial tibial plateau with the central x-ray beam in the Lyon schuss radiograph.     

Predictors of voluntary HIV counselling and testing services utilization among people with disabilities in Addis Ababa,Ethiopia

The study investigated HIV testing prevalence and factors associated with the utilization of voluntary HIV counselling and testing (VCT) services among individuals with disabilities in Addis Ababa. The analysis was based on a survey of 209 men and 203 women with disabilities, aged 15–49, who had ever heard about HIV and AIDS in four sub-cities in Addis Ababa. HIV testing prevalence was 53.2%, with no significant difference between males and females. Comprehensive HIV knowledge, living with spouse, and religious affiliations positively predicted utilization of VCT services among participants. Living with both parents and having physical or mental/intellectual disabilities were negative predictors of VCT services utilization. More research on the predictors of utilization of VCT services by gender and urban/rural divides are needed among people with disabilities.