scholarly journals Tracking animal reservoirs of pathogenic Leptospira: the right test for the right claim.

2021 ◽  
Author(s):  
Yann Gomard ◽  
Koussay Mohamed Dellagi ◽  
Steven Goodman ◽  
Patrick Mavingui ◽  
Pablo Tortosa

Leptospirosis, caused by a pathogenic Leptospira bacteria, is the most prevalent zoonosis worldwide and in this context has been extensively investigated through a One Health framework. Diagnosis of human leptospirosis includes molecular and serological tools, with serological Microscopic Agglutination Test (MAT) still being considered as a gold standard. Mammals considered as biological reservoirs include species or populations that are able to maintain chronic infection and shed the bacteria via their urine in the environment. Leptospira bacteria are often investigated using the same diagnosis tool, serological MAT. However, MAT testing of putative animal reservoirs can lead to mis-interpretations as it can signal previous infection and not necessarily bring in robust information regarding the capacity of such sero-positive animals to maintain chronic infection. We use previously published data and present new results on introduced and endemic small mammals to show that MAT should not be used for the identification of reservoirs. By contrast, serological data are informative on the level of exposure of animals occupying a specific environment. Finally, we present a sequential methodology to investigate human leptospirosis in a One Health framework that associates molecular detection in humans and animals, together with MAT of human samples using Leptospira isolates obtained from reservoir animals occurring in the same environment.

2021 ◽  
Vol 6 (4) ◽  
pp. 205
Author(s):  
Yann Gomard ◽  
Koussay Dellagi ◽  
Steven M. Goodman ◽  
Patrick Mavingui ◽  
Pablo Tortosa

Leptospirosis is the most prevalent bacterial zoonosis worldwide and, in this context, has been extensively investigated through the One Health framework. Diagnosis of human leptospirosis includes molecular and serological tools, with the serological Microscopic Agglutination Test (MAT) still being considered as the gold standard. Mammals acting as reservoirs of the pathogen include species or populations that are able to maintain chronic infection and shed the bacteria via their urine into the environment. Animals infected by Leptospira are often identified using the same diagnosis tool as in humans, i.e., serological MAT. However, this tool may lead to misinterpretations as it can signal previous infection but does not provide accurate information regarding the capacity of animals to maintain chronic infection and, hence, participate in the transmission cycle. We employ in this paper previously published data and present original results on introduced and endemic small mammals from Indian Ocean islands to show that MAT should not be used for the identification of Leptospira reservoirs. By contrast, serological data are informative on the level of exposure of animals living in a specific environment. We present a sequential methodology to investigate human leptospirosis in the One Health framework that associates molecular detection in humans and animals, together with MAT of human samples using Leptospira isolates obtained from reservoir animals occurring in the same environment.


2021 ◽  
Author(s):  
Yann Gomard ◽  
Steven Michael Goodman ◽  
Voahangy Soarimalala ◽  
Magali Turpin ◽  
Guenaelle Lenclume ◽  
...  

Leptospirosis is one of the most prevalent bacterial zoonoses in the world. The disease is caused by pathogenic Leptospira that are maintained in the kidney lumen of infected animals, mostly mammals, acting as reservoirs and contaminating the environment via infected urine. The investigation of leptospirosis through a One Health framework has been stimulated by notable genetic diversity of pathogenic Leptospira together with a high infection prevalence in certain animal reservoirs. Extensive sampling and associated microbiological and molecular studies of Madagascar's native mammal fauna have revealed a diversity of pathogenic Leptospira with high levels of host-specificity. Native rodents, tenrecids, and bats shelter a number of distinct lineages and species of Leptospira, some of which have also been detected in acute human cases. Specifically, L. mayottensis, first discovered in humans on Mayotte, an island neighboring Madagascar, was subsequently identified in a few species of Malagasy tenrecids, an endemic family. Distinct L. mayottensis lineages were identified in shrew tenrecs (Microgale cowani and Nesogale dobsoni) on Madagascar, and later in spiny tenrecs (Tenrec ecaudatus) on Mayotte. These findings suggest that L. mayottensis (i) has experienced co-evolutionary processes during the radiation of tenrecids on Madagascar, and (ii) has recently emerged in human populations on Mayotte following the introduction of T. ecaudatus from Madagascar. Hitherto, L. mayottensis has not been detected in spiny tenrecs on Madagascar. In the present study, we broaden the investigation of Malagasy tenrecids and describe the presence of L. mayottensis in Malagasy populations of T. ecaudatus, as well as in M. thomasi. These results confirm the hypothesis that L. mayottensis was introduced to Mayotte, presumably via T. ecaudatus, and provide additional data on the co-evolution of Leptospira and Tenrecidae.


2020 ◽  
Author(s):  
Luis Anunciacao ◽  
janet squires ◽  
J. Landeira-Fernandez

One of the main activities in psychometrics is to analyze the internal structure of a test. Multivariate statistical methods, including Exploratory Factor analysis (EFA) and Principal Component Analysis (PCA) are frequently used to do this, but the growth of Network Analysis (NA) places this method as a promising candidate. The results obtained by these methods are of valuable interest, as they not only produce evidence to explore if the test is measuring its intended construct, but also to deal with the substantive theory that motivated the test development. However, these different statistical methods come up with different answers, providing the basis for different analytical and theoretical strategies when one needs to choose a solution. In this study, we took advantage of a large volume of published data (n = 22,331) obtained by the Ages and Stages Questionnaire Social-Emotional (ASQ:SE), and formed a subset of 500 children to present and discuss alternative psychometric solutions to its internal structure, and also to its subjacent theory. The analyses were based on a polychoric matrix, the number of factors to retain followed several well-known rules of thumb, and a wide range of exploratory methods was fitted to the data, including EFA, PCA, and NA. The statistical outcomes were divergent, varying from 1 to 6 domains, allowing a flexible interpretation of the results. We argue that the use of statistical methods in the absence of a well-grounded psychological theory has limited applications, despite its appeal. All data and codes are available at https://osf.io/z6gwv/.


2020 ◽  
Vol 8 (1) ◽  
pp. 9-15
Author(s):  
Petrov Nikolay ◽  
◽  
Marinova R. ◽  
Odiseeva Ev.

Abstract: Intracranial aneurysm is one of the most common neurovascular complications. During the recent years the accepted treatment of enraptured cranial aneurysm is noninvasive endovascular coiling. This technique is modern but it is not without complications which can be serious and life-threatening. A clinical case of a patient admitted to the ICU of Military Medical Academy - Sofia with sub arachnoid hemorrhage is described. After a positive clinical course, the check-up magnetic resonance showed intracranial aneurism of the right carotid artery. The patient underwent angiographic endovascular treatment. Vasospasm of the middle and right brain artery and thrombosis were detected during the procedure. Attempt of thromboaspiration was made without success. This article reviews published data on broad-spectrum researches concerning complications of endovascular coiling of intracranial aneurysms and the ways to prevent and reduce them.


Animals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 2290
Author(s):  
Danny Franciele da Silva Dias Moraes ◽  
João R. Mesquita ◽  
Valéria Dutra ◽  
Maria São José Nascimento

Brazil is the fifth largest country in the world with diverse socioeconomic and sanitary conditions, also being the fourth largest pig producer in the world. The aim of the present systematic review was to collect and summarize all HEV published data from Brazil (from 1995 to October 2020) performed in humans, animals, and the environment, in a One Health perspective. A total of 2173 papers were retrieved from five search databases (LILACs, Mendeley, PubMed, Scopus, and Web of Science) resulting in 71 eligible papers after application of exclusion/inclusion criteria. Data shows that HEV genotype 3 (HEV-3) was the only retrieved genotype in humans, animals, and environment in Brazil. The South region showed the highest human seroprevalence and also the highest pig density and industry, suggesting a zoonotic link. HEV-1 and 2 were not detected in Brazil, despite the low sanitary conditions of some regions. From the present review we infer that HEV epidemiology in Brazil is similar to that of industrialized countries (only HEV-3, swine reservoirs, no waterborne transmission, no association with low sanitary conditions). Hence, we alert for the implementation of HEV surveillance systems in swine and for the consideration of HEV in the diagnostic routine of acute and chronic hepatitis in humans.


1949 ◽  
Vol 22 (1) ◽  
pp. 259-262
Author(s):  
J. F. Morley

Abstract These experiments indicate that softeners can influence abrasion resistance, as measured by laboratory machines, in some manner other than by altering the stress-strain properties of the rubber. One possible explanation is that the softener acts as a lubricant to the abrasive surface. Since this surface, in laboratory abrasion-testing machines, is relatively small, and comes repeatedly into contact with the rubber under test, it seems possible that it may become coated with a thin layer of softener that reduces its abrasive power. It would be interesting in this connection to try an abrasive machine in which a long continuous strip of abrasive material was used, no part of it being used more than once, so as to eliminate or minimize this lubricating effect. The fact that the effect of the softener is more pronounced on the du Pont than on the Akron-Croydon machine lends support to the lubrication hypothesis, because on the former machine the rate of wear per unit area of abrasive is much greater. Thus in the present tests the volume of rubber abraded per hr. per sq. cm. of abrasive surface ranges from 0.03 to 0.11 cc. on the du Pont machine and from 0.0035 to 0.0045 cc. on the Akron-Croydon machine. On the other hand, if the softener acts as a lubricant, it would be expected to reduce considerably the friction between the abrasive and the rubber and hence the energy used in dragging the rubber over the abrasive surface. The energy figures given in the right-hand columns of Tables 1 and 3, however, show that there is relatively little variation between the different rubbers. As a test of the lubrication hypothesis, it would be of interest to vary the conditions of test so that approximately the same amount of rubber per unit area of abrasive is abraded in a given time on both machines; this should show whether the phenomena observed under the present test conditions are due solely to the difference in rate of wear or to an inherent difference in the type of wear on the two machines. This could most conveniently be done by considerably reducing the load on the du Pont machine. In the original work on this machine the load was standardized at 8 pounds, but no figures are quoted to show how abrasion loss varies with the load. As an addition to the present investigation, it is proposed to examine the effect of this variation with special reference to rubbers containing various amounts and types of softener. Published data on the influence of softeners on the road wear of tire rubbers do not indicate anything like such large effects as are shown by the du Pont machine. This throws some doubt on the value of this machine for testing tire tread rubbers, a conclusion which is confirmed by information obtained from other workers.


2021 ◽  
Vol 11 (20) ◽  
pp. 9427
Author(s):  
Mihaela Camelia Tîrnovanu ◽  
Vlad Gabriel Tîrnovanu ◽  
Bogdan Florin Toma ◽  
Elena Cojocaru ◽  
Carmen Ungureanu ◽  
...  

Struma ovarii is a rare condition with scarce published data regarding clinical, morphological, and therapeutic approaches. This study reports the experience of 25 patients with struma ovarii who received surgical treatment in a gynecology department in Romania. The study was conducted from January 1999 to September 2021 and included patients with confirmed struma ovarii whose medical records were retrospectively reviewed and evaluated. Struma ovarii represented 2.8% of the total number of benign ovarian tumors treated by surgery. The age of the patients was between 24 and 71 years. The tumor was unilateral in 24 cases, 13 cases on the left ovary, 11 on the right side, and bilateral in 1 case. Tumor dimensions ranged between 1 cm and 20 cm. In two cases, the patients had symptoms of hyperthyroidism. The procedure was performed on four women for diagnoses other than an ovarian tumor. In another five situations, there was suspicion of ovarian malignancy. In addition, struma ovarii was associated with other clinical conditions in 22 cases. These lesions represent a diagnostic challenge with heterogeneous clinical and imaging manifestations. Complete information of clinical, morphologic, and surgical findings may improve the diagnostic algorithm and better predict patient outcomes.


2013 ◽  
Vol 6 (4) ◽  
pp. 266 ◽  
Author(s):  
Darby Cassidy ◽  
Keith Jarvi ◽  
Ethan Grober ◽  
Kirk Lo

Introduction: Varicocele remains the most commonly identifiedcorrectable cause of male factor infertility. Surgical correction isthe most commonly performed technique to treat varicoceles with a technical failure rate of less than 5%. An attractive alternative to surgery is the selective catheterization and embolization of the gonadal vein. This data are limited by small series.Methods: We reviewed a total of 158 patients. These patientsunderwent embolization for clinical varicoceles and male factorinfertility between 2004 and 2008. Of these, 56% underwentattempted bilateral embolization, 43% unilateral left-sided embolization and 1.3% unilateral right-sided embolization.Results: Of these patients who underwent attempted bilateralembolization, 19.3% did not experience a successful obliterationof the right gonadal vein and 2.3% (2/88) experienced a failure rate in the embolization of the left gonadal vein. Of the 2 attempts at unilateral right-sided embolization, there were no failures. Of the 68 unilateral left-sided embolization attempts, there was a 4.4% failure rate. Of all of the right-sided embolization attempts, 18.9% failed, while 3.2% of the left-sided attempts failed.Conclusion: This review represents the largest contemporary series of varicocele embolization outcomes currently in the literature. Our 19.3% technical failure rate for bilateral varicocele embolization is higher than the current published rate of 13% and is largely related to failure to successfully occlude the right gonadal vein. This supports our belief that bilateral varicoceles are best managed with a primary microsurgical approach, where technical failure rates are expected to be less than 5% based on published data. Men withunilateral left-sided varicoceles should be offered both options as they have similar failure rates, but with embolization offering some clear advantages to the patient.


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