The HepHIV 2023 Madrid conference: A call to action for political leadership in reaching the sustainable development goals on earlier testing and linkage to care for HIV, viral hepatitis, and sexually transmitted infections.

INTRODUCTION AND OBJECTIVES: The HepHIV 2023 Conference, held in Madrid in November 2023, highlighted how Europe is not on track to meet the United Nations (UN) sustainable development goals and Joint UN Programme on HIV/AIDS (UNAIDS) targets. This article presents the outcomes of the conference, which focus on ways to improve testing and linkage to care for HIV, viral hepatitis, and other sexually transmitted infections. HIV-related stigma and discrimination, a major barrier to progress, was a key concept of the conference and on the agenda of the Spanish Presidency of the European Union. METHODS: The HepHIV 2023 organizing committee, alongside the Spanish Ministry of Health, oversaw the conference organization and prepared the scientific programme based on abstract rankings. Key outcomes are derived from conference presentations and discussions. RESULTS: Conference presentations covered the obstacles that HIV-related stigma and discrimination continue to pose to access to services, models for data collection to better monitor progress in the future, and examples of legislative action that can be taken at national levels. Diversification of testing approaches was also highlighted, to reach key populations, (e.g. migrant populations), to increase testing offered in healthcare settings (e.g. emergency departments), and to account for different stages of epidemics across the region. CONCLUSION: With a strong call for intensified action to address the impact of HIV-related stigma and discrimination on testing uptake, the conference concluded that strengthened collaboration is required between governments and implementers around testing and linkage to care. There is also an ongoing need to ensure sustainable political commitment and appropriate resource allocation to address gaps and inequalities in access for key populations and to focus on the implementation of integrated responses to HIV, viral hepatitis, and sexually transmitted infections.

Hardware Implementations of a Deep Learning Approach to Optimal Configuration of Reconfigurable Intelligence Surfaces.

Reconfigurable intelligent surfaces (RIS) offer the potential to customize the radio propagation environment for wireless networks, and will be a key element for 6G communications. However, due to the unique constraints in these systems, the optimization problems associated to RIS configuration are challenging to solve. This paper illustrates a new approach to the RIS configuration problem, based on the use of artificial intelligence (AI) and deep learning (DL) algorithms. Concretely, a custom convolutional neural network (CNN) intended for edge computing is presented, and implementations on different representative edge devices are compared, including the use of commercial AI-oriented devices and a field-programmable gate array (FPGA) platform. This FPGA option provides the best performance, with ×20 performance increase over the closest FP32, GPU-accelerated option, and almost ×3 performance advantage when compared with the INT8-quantized, TPU-accelerated implementation. More noticeably, this is achieved even when high-level synthesis (HLS) tools are used and no custom accelerators are developed. At the same time, the inherent reconfigurability of FPGAs opens a new field for their use as enabler hardware in RIS applications.

Effects of the Argentine ant venom on terrestrial amphibians.

Invasive species have major impacts on biodiversity and are one of the primary causes of amphibian decline and extinction. Unlike other top ant invaders that negatively affect larger fauna via chemical defensive compounds, the Argentine ant (Linepithema humile) does not have a functional sting. Nonetheless, it deploys defensive compounds against competitors and adversaries. We estimated levels of ant aggression toward 3 native terrestrial amphibians by challenging juveniles in field ant trails and in lab ant foraging arenas. We measured the composition and quantities of toxin in L. humile by analyzing pygidial glands and whole-body contents. We examined the mechanisms of toxicity in juvenile amphibians by quantifying the toxin in amphibian tissues, searching for histological damages, and calculating toxic doses for each amphibian species. To determine the potential scope of the threat to amphibians, we used global databases to estimate the number, ranges, and conservation status of terrestrial amphibian species with ranges that overlap those of L. humile. Juvenile amphibians co-occurring spatially and temporally with L. humile die when they encounter L. humile on an ant trail. In the lab, when a juvenile amphibian came in contact with L. humile the ants reacted quickly to spray pygidial-gland venom onto the juveniles. Iridomyrmecin was the toxic compound in the spray. Following absorption, it accumulated in brain, kidney, and liver tissue. Toxic dose for amphibian was species dependent. Worldwide, an estimated 817 terrestrial amphibian species overlap in range with L. humile, and 6.2% of them are classified as threatened. Our findings highlight the high potential of L. humile venom to negatively affect amphibian juveniles and provide a basis for exploring the largely overlooked impacts this ant has in its wide invasive range.

Efectos del Veneno de la Hormiga Argentina sobre los Anfibios Terrestres Resumen Las especies invasoras tienen un impacto importante sobre la biodiversidad y son una de las causas principales del declive y extinción de los anfibios. A diferencia de otras hormigas super-invasoras que afectan negativamente a animales más grandes por medio de compuestos químicos de defensa, la hormiga argentina (Linepithema humile) no tiene unaguijón funcional. Sin embargo, esta hormiga despliega compuestos defensivos contra sus competidores y adversarios. Estimamos los niveles de agresión de las hormigas hacia tres anfibios terrestres nativos exponiendo a los anfibios juveniles en pistas de hormigas en el campo y en las arenas de forrajeo de las hormigas en el laboratorio. Medimos la composición y las cantidades de toxina que presenta L. humile por medio del análisis de las glándulas pigidiales y el contenido en el cuerpo completo. Examinamos los mecanismos de la toxicidad en los anfibios juveniles cuantificando la toxina en el tejido del anfibio, buscando daños histológicos y calculando las dosis tóxicas para cada especie de anfibio. Para determinar el alcance potencial de la amenaza para los anfibios usamos bases de datos mundiales para estimar el número, distribución y estado de conservación de las especies terrestres de anfibios con distribuciones que se solapan con la de L. humile. Los anfibios juveniles que co-ocurren temporal y espacialmente con L. humile mueren al encontrarse con esta especie de hormiga en sus pistas. En el laboratorio, cuando un anfibio juvenil entró en contacto con L. humile, las hormigas reaccionaron rápidamente rociando a estos juveniles con veneno proveniente de las glándulas pigidiales. La iridomyrmecina fue el compuesto tóxico que encontramos en las glándulas pigidiales. Después de ser absorbida por la piel del anfibio, se acumuló en el cerebro, los riñones y el hígado. La dosis tóxica para los anfibios depende de la especie. A nivel mundial, se estima que 817 especies de anfibios terrestres tienen una distribución que se solapa con la de L. humile, y el 6.2% de estas especies se encuentran clasificadas como amenazadas. Nuestros hallazgos resaltan el potencial alto del veneno de L. humile para tener efectos negativos sobre los anfibios juveniles y también proporcionan una base para la exploración de los impactos de esta hormiga en su amplio rango invasivo, los cuales generalmente son ignorados.

Provox 2® and Provox Vega® device life-time: a case-crossover study with multivariate analysis of possible influential factors and duration.

INTRODUCTION: Tracheoesophageal speech is considered the gold standard for rehabilitation following total laryngectomy. Current literature is limited and contradictory about the possible causes of device failure. The aim of the study is to compare the device life-time between the Provox 2 and Provox Vega and to examine possible related factors that influence their duration. METHODS: Retrospective case-crossover study in 34 laryngectomized patients who had undergone tracheoesophageal voice rehabilitation using indwelling Provox 2 and Provox Vega voice prostheses between 2010 and 2016 in a tertiary care centre. RESULTS: A total of 440 prostheses were evaluated. The most frequent reason for replacement was due to an endoprosthesis leakage (n = 221, 64.2%) in both models. Radiotherapy increases the risk of prosthesis replacement (IRR = 1.88, p = 0.007) as well as bilateral neck dissection (IRR = 1.56, p = 0.017) in Provox 2. Age and unilateral neck dissection do not seem to influence the duration of the prosthesis. Mean life-time of Provox 2 was 106.64 days and 124.19 days for Provox Vega (p = 0.261). Complementary treatment with radiotherapy demonstrated a lower device survival (p < 0.001). DISCUSSION: Results confirmed the non-significant differences on device life between Provox Vega and Provox 2, as well as the relevant role of radiotherapy treatment in the increase of replacements and diminution of the device duration.

Multi-event capture-recapture modeling of host-pathogen dynamics among European rabbit populations exposed to myxoma and Rabbit Hemorrhagic Disease Viruses: common and heterogeneous patterns.

Host-pathogen epidemiological processes are often unclear due both to their complexity and over-simplistic approaches used to quantify them. We applied a multi-event capture-recapture procedure on two years of data from three rabbit populations to test hypotheses about the effects on survival of, and the dynamics of host immunity to, both myxoma virus and Rabbit Hemorrhagic Disease Virus (MV and RHDV). Although the populations shared the same climatic and management conditions, MV and RHDV dynamics varied greatly among them; MV and RHDV seroprevalences were positively related to density in one population, but RHDV seroprevalence was negatively related to density in another. In addition, (i) juvenile survival was most often negatively related to seropositivity, (ii) RHDV seropositives never had considerably higher survival, and (iii) seroconversion to seropositivity was more likely than the reverse. We suggest seropositivity affects survival depending on trade-offs among antibody protection, immunosuppression and virus lethality. Negative effects of seropositivity might be greater on juveniles due to their immature immune system. Also, while RHDV directly affects survival through the hemorrhagic syndrome, MV lack of direct lethal effects means that interactions influencing survival are likely to be more complex. Multi-event modeling allowed us to quantify patterns of host-pathogen dynamics otherwise difficult to discern. Such an approach offers a promising tool to shed light on causative mechanisms.

Remote fruit fly detection using computer vision and machine learning-based electronic trap.

Introduction: Intelligent monitoring systems must be put in place to practice precision agriculture. In this context, computer vision and artificial intelligence techniques can be applied to monitor and prevent pests, such as that of the olive fly. These techniques are a tool to discover patterns and abnormalities in the data, which helps the early detection of pests and the prompt administration of corrective measures. However, there are significant challenges due to the lack of data to apply state of the art Deep Learning techniques. Methods: This article examines the detection and classification of the olive fly using the Random Forest and Support Vector Machine algorithms, as well as their application in an electronic trap version based on a Raspberry Pi B+ board. Results: The combination of the two methods is suggested to increase the accuracy of the classification results while working with a small training data set. Combining both techniques for olive fly detection yields an accuracy of 89.1%, which increases to 94.5% for SVM and 91.9% for RF when comparing all fly species to other insects. Discussion: This research results reports a successful implementation of ML in an electronic trap system for olive fly detection, providing valuable insights and benefits. The opportunities of using small IoT devices for image classification opens new possibilities, emphasizing the significance of ML in optimizing resource usage and enhancing privacy protection. As the system grows by increasing the number of electronic traps, more data will be available. Therefore, it holds the potential to further enhance accuracy by learning from multiple trap systems, making it a promising tool for effective and sustainable fly population management.

Fully Parallel Stochastic Computing Hardware Implementation of Convolutional Neural Networks for Edge Computing Applications.

Edge artificial intelligence (AI) is receiving a tremendous amount of interest from the machine learning community due to the ever-increasing popularization of the Internet of Things (IoT). Unfortunately, the incorporation of AI characteristics to edge computing devices presents the drawbacks of being power and area hungry for typical deep learning techniques such as convolutional neural networks (CNNs). In this work, we propose a power-and-area efficient architecture based on the exploitation of the correlation phenomenon in stochastic computing (SC) systems. The proposed architecture solves the challenges that a CNN implementation with SC (SC-CNN) may present, such as the high resources used in binary-to-stochastic conversion, the inaccuracy produced by undesired correlation between signals, and the complexity of the stochastic maximum function implementation. To prove that our architecture meets the requirements of edge intelligence realization, we embed a fully parallel CNN in a single field-programmable gate array (FPGA) chip. The results obtained showed a better performance than traditional binary logic and other SC implementations. In addition, we performed a full VLSI synthesis of the proposed design, showing that it presents better overall characteristics than other recently published VLSI architectures.

[Personal and vaccination history as factors associated with SARS-CoV-2 infection]. / Antecedentes personales y vacunales como factores asociados a la infección por SARS-CoV-2.

BACKGROUND AND OBJECTIVE: SARS-CoV-2 has been and is a major global Public Health challenge. Since the beginning of the pandemic, different comorbidities have been postulated and associated with spectra of increased severity and mortality. The objectives of this research are: 1) to analyse the factors associated with SARS-CoV-2 infection (COVID-19) in a health area in northern Spain; 2) to understand the possible role of influenza vaccination and pneumococcal vaccination in the development of COVID-19. MATERIALS AND METHOD: A test-negative case-control study was conducted. Variables related to personal and vaccination history were considered. Although the epidemiological definition of the case varied over time, the reference definition was that corresponding to 31/01/2020 in Spain. A bivariate and multivariate analysis was performed. RESULTS: The sample included 188 patients, of which 63 were cases and 125 controls. The results show that obesity increases the risk 2.4-fold of suffering this infection (IC 95% 1,301-4,521) and ARA-2 increases it 2.2-fold (95% CI 1,256-6,982). On the other hand, anti-pneumococcal vaccination of 13 serotypes showed results close to statistical significance (OR = 0.4; 95% CI 0.170-1,006). CONCLUSION: Obesity and the use of ARA-2 increases the risk of COVID-19. Scientific knowledge about factors associated with COVID-19 should be expanded. The authors consider that the present research raises the need further investigate the role of vaccines in this infection and their possible heterologous properties.

Personal and vaccination history as factors associated with SARS-CoV-2 infection.

BACKGROUND AND OBJECTIVE: SARS-CoV-2 has been and is a major global Public Health challenge. Since the beginning of the pandemic, different comorbidities have been postulated and associated with spectra of increased severity and mortality. The objectives of this research are: 1) to analyse the factors associated with SARS-CoV-2 infection (COVID-19) in a health area in northern Spain; 2) to understand the possible role of influenza vaccination and pneumococcal vaccination in the development of COVID-19. MATERIALS AND METHOD: A test-negative case-control study was conducted. Variables related to personal and vaccination history were considered. Although the epidemiological definition of the case varied over time, the reference definition was that corresponding to 31/01/2020 in Spain. A bivariate and multivariate analysis was performed. RESULTS: The sample included 188 patients, of which 63 were cases and 125 controls. The results show that obesity increases the risk 2.4-fold of suffering this infection (IC 95% 1,301-4,521) and ARA-2 increases it 2.2-fold (95% CI 1,256-6,982). On the other hand, anti-pneumococcal vaccination of 13 serotypes showed results close to statistical significance (OR = 0.4; 95% CI 0.170-1,006). CONCLUSION: Obesity and the use of ARA-2 increases the risk of COVID-19. Scientific knowledge about factors associated with COVID-19 should be expanded. The authors consider that the present research raises the need further investigate the role of vaccines in this infection and their possible heterologous properties.

ANTECEDENTES Y OBJETIVO: El SARS-CoV-2 ha supuesto un importante reto de salud pública. Desde el inicio de la pandemia, se han postulado diferentes comorbilidades que se han asociado con espectros de mayor gravedad y mortalidad. Los objetivos de la presente investigación son: 1) analizar los factores asociados a la infección por SARS-CoV-2 (COVID-19) en un área sanitaria del norte de España; 2) conocer el posible papel de la vacunación antigripal y antineumocócica en el desarrollo de la COVID-19. MATERIALES Y MÉTODOS: Se ha realizado un estudio de casos y controles de test negativo. Se tuvieron en cuenta variables relacionadas con los antecedentes personales y vacunales. A pesar de que la definición epidemiológica de caso fue variando a lo largo del tiempo, se tuvo como referencia la correspondiente al 31 de enero del 2020 en España. Se efectuó un análisis bivariante y multivariante. RESULTADOS: La muestra incluyó a 188 pacientes, de los cuales 63 fueron casos y 125 controles. Los resultados muestran que la obesidad aumenta 2,4 veces el riesgo de padecer esta infección (IC 95% 1.301 a 4.521) y los antagonistas de los receptores de la angiotensina II (ARA-2) lo aumentan 2,2 veces (IC 95% 1.256 a 6.982). Por otro lado, la vacunación antineumocócica conjugada de 13 serotipos mostró resultados cercanos a la significación estadística (OR = 0,4; IC 95% 0,170 a 1.006). CONCLUSIONES: La obesidad y el uso de fármacos ARA-2 aumentan el riesgo de la COVID-19. El conocimiento científico sobre los factores asociados a la COVID-19 debe seguir ampliándose. La presente investigación plantea la necesidad de profundizar en el papel de las vacunas sobre esta infección y sus posibles propiedades heterólogas.

Compact Hardware Synthesis of Stochastic Spiking Neural Networks.

Spiking neural networks (SNN) are able to emulate real neural behavior with high confidence due to their bio-inspired nature. Many designs have been proposed for the implementation of SNN in hardware, although the realization of high-density and biologically-inspired SNN is currently a complex challenge of high scientific and technical interest. In this work, we propose a compact digital design for the implementation of high-volume SNN that considers the intrinsic stochastic processes present in biological neurons and enables high-density hardware implementation. The proposed stochastic SNN model (SSNN) is compared with previous SSNN models, achieving a higher processing speed. We also show how the proposed model can be scaled to high-volume neural networks trained by using back propagation and applied to a pattern classification task. The proposed model achieves better results compared with other recently-published SNN models configured with unsupervised STDP learning.

Unusual Nasal Insufficiency in an Infant: What's Behind the Nostril?

OBJECTIVES: Inflammatory myofibroblastic tumor (IMT) is a rare benign lesion, especially in the pediatric age. There are several cases described in pulmonary, digestive and renal localizations, but involvement in head and neck area is infrequent. METHODS: Case report and review of the literature. RESULTS: A 1 year and 11 months old child, during 2 months had clinical signs of nasal respiratory insufficiency and epistaxis subsequently developing a purulent rhinorrhea and a sleep apnea. His pediatrician previously requested a sinus and cavum X-ray with the finding of an image compatible with an intranasal mass. Endoscopic resection was performed of the mass with further immunohistochemical analysis showing the result of a lesion compatible with IMT. CONCLUSIONS: Even though there are very few cases in scientific literature of a tumor with these characteristics in infants, IMT must be present as a differential diagnosis of intranasal masses. The role of the pathologist is essential to reach the definitive diagnosis and the performance of an early surgical treatment decreases aesthetic consequences in this pathology.

[Bronchoscopy in children with foreign body aspiration]. / Broncoscopia en población infantil tras aspiración de cuerpo extraño.

INTRODUCTION AND OBJECTIVES: Aspiration of foreign body presents a high incidence of mortality during the paediatric life period. Family suspect and detection of specific symptoms and signs determine the need of bronchoscopy. The objective of this study is to establish the clinical parameters that indicate foreign body in airway. METHODS: Retrospective study in 44 children with foreign body aspiration. We reviewed age, sex, family suspect, blood analysis, chest x-ray, time to consulting, location, type, complications, and time to discharge. RESULTS: Decisive clinical factors that indicate foreign body in airway are family suspect and respiratory clinic. Findings after auscultation and chest x-ray support suspect, but final diagnostic only can be made after bronchoscopy. Bronchoscopy with foreign body removal was performed during first 24 hours in 86.36 % of patients, and founded that those with delayed diagnosis had increased morbidity. CONCLUSIONS: Family's suspect is the most important parameter that indicates foreign body located in airway. Bronchoscopy performed during the first hours avoids morbidity. This is a secure technique when performed in adequate place with trained personnel.

[Treatment of chin deformities]. / Tratamiento de las deformidades del mentón.

Facial beauty depends on the form, proportion and position of its various units. The chin is the most prominent element of the lower third of the face, both in the frontal view and in profile. The surgical approach to chin deformities did not start until the second half of the twentieth century. The development of silicone prostheses and the emergence of sliding genioplasty offered surgeons a whole new range of options to modify the size and position of the chin. We have performed a historical review of chin surgery, the multiple aesthetic analyses available and the advantages and disadvantages of the different alloplastic materials and osteotomies. To do so, a comprehensive search through current scientific literature on the topic has been carried out, focusing on large series, long-term follow-up studies, research in animal models and medical evidence. As happens in almost any topic in facial plastic surgery, no strong evidence useful in ENT practice for handling chin deformities can be found in today's scientific literature. Ethnicity influences the aesthetic analysis; the type and degree of deformity to be corrected will determine the allo-plastic augmentation of the chin or the suitability of osteotomy. Porous polyethylene (Medpor, Porex Surgical, Newman, Ca, USA) and solid silicone (Silastic, Michigan Medical Corporation, Santa Barbara, Ca, USA) show a clear advantage over other alloplastic materials. Moderate-to-severe retrogenia benefits from sliding genioplasty strategies rather than prosthetic enlargement.

Improving the quality of a collective signal in a consumer EEG headset.

This work focuses on the experimental data analysis of electroencephalography (EEG) data, in which multiple sensors are recording oscillatory voltage time series. The EEG data analyzed in this manuscript has been acquired using a low-cost commercial headset, the Emotiv EPOC+. Our goal is to compare different techniques for the optimal estimation of collective rhythms from EEG data. To this end, a traditional method such as the principal component analysis (PCA) is compared to more recent approaches to extract a collective rhythm from phase-synchronized data. Here, we extend the work by Schwabedal and Kantz (PRL 116, 104101 (2016)) evaluating the performance of the Kosambi-Hilbert torsion (KHT) method to extract a collective rhythm from multivariate oscillatory time series and compare it to results obtained from PCA. The KHT method takes advantage of the singular value decomposition algorithm and accounts for possible phase lags among different time series and allows to focus the analysis on a specific spectral band, optimally amplifying the signal-to-noise ratio of a common rhythm. We evaluate the performance of these methods for two particular sets of data: EEG data recorded with closed eyes and EEG data recorded while observing a screen flickering at 15 Hz. We found an improvement in the signal-to-noise ratio of the collective signal for the KHT over the PCA, particularly when random temporal shifts are added to the channels.

Classroom drama therapy program for immigrant and refugee adolescents: a pilot study.

This evaluative study assesses the effects of a school drama therapy program for immigrant and refugee adolescents designed to prevent emotional and behavioral problems and to enhance school performance. The 9-week program involved 136 newcomers, aged 12 to 18, attending integration classes in a multiethnic school. Pretest and posttest data were collected from the students and their teachers. The self-report and teacher's forms of the Strengths and Difficulties Questionnaire were used to assess emotional and behavioral symptoms. At the end of the program, although there were no reported improvement in self-esteem or emotional and behavioral symptoms, the adolescents in the experimental group reported lower mean levels of impairment by symptoms than those in the control group, when baseline data were controlled for. Their performance in mathematics also increased significantly compared to that of their control peers. The findings suggest that the workshops may have an impact on social adjustment of recently arrived immigrants and refugees. This drama therapy program appears to be a promising way of working preventively and in a nonstigmatizing manner with adolescents who have been exposed to diverse forms of adversity, among which are war and violence.

[Resection with end-to-end anastomosis for postintubation tracheal stenosis]. / Resección con anastomosis término-terminal en la estenosis traqueal tras intubación.

OBJECTIVE: To study results of resection and end-to-end anastomosis in tracheal stenosis (TS). PATIENTS AND METHOD: Retrospective review of 14 patients with previous long-term intubation and residual tracheal stenosis, all operated on with resection and end-to-end anastomosis. We studied the percentage of surgical success, decannulation index, use of Montgomery T tube, and complications. RESULTS: We performed a total of 42 interventions (mean, 2.93) and 19 T-Montgomery tubes were used. We achieved surgical success in 85.12 % of patients, with a decannulation index of 71.42 %. Two patients developed granulomas in the suture field that required treatment with endoscopic laser and cryotherapy. One patient died intraoperatively. CONCLUSIONS: Surgical resection with end-to-end anastomosis and insertion of a T-Montgomery tube is a useful technique in post-intubation tracheal stenosis despite involving multiple interventions in a large percentage of patients.

[Playing with identities, transforming shared realities: school theatre workshop for immigrant and refugee adolescents]. / Du jeu des identités à la transformation de réalités partagées: un programme d'ateliers d'expression théâtrale pour adolescents immigrants et réfugiés.

Migration during adolescence represents a challenge for the youth who need to simultaneously work through the multiple losses associated with the migratory journey and adapt to a young adult status. The drama workshop program described here was designed to facilitate the adjustment of newly arrived immigrant teens. The aim of the program is to make it easier for adolescents to adjust to their new environment through creative group work around identity issues. The program also seeks to improve intergroup relations in multiethnic schools. The workshops are inspired both from playback theater and from Boal's form theater which emphasizes the collective transformation of the singular experience. The qualitative assessment of the program effects on the adolescents suggests that the workshops constitute a safe space of expression, in which the team and the ritual nature of the play hold the participants. The workshops facilitate the representation of the multiplicity of values in the adolescent world and invite them to reconsider the way in which they interact, with their environment, without splitting between "us" and "them," but rather creating solidarities around issues of social justice. The workshops also address the life transformation associated both with adolescence and migration and help the elaboration of the losses linked to the migratory journey and the construction of a hybrid identity.

Effects of myxoma virus and rabbit hemorrhagic disease virus on the physiological condition of wild European rabbits: Is blood biochemistry a useful monitoring tool?

Myxomatosis and rabbit hemorrhagic disease (RHD) are the major viral diseases that affect the wild European rabbit (Oryctolagus cuniculus). These diseases arrived in Europe within the last decades and have caused wild rabbit populations to decline dramatically. Both viruses are currently considered to be endemic in the Iberian Peninsula; periodic outbreaks that strongly impact wild populations regularly occur. Myxoma virus (MV) and rabbit hemorrhagic disease virus (RHDV) alter the physiology of infected rabbits, resulting in physical deterioration. Consequently, the persistence and viability of natural populations are affected. The main goal of our study was to determine if blood biochemistry is correlated with serostatus in wild European rabbits. We carried out seven live-trapping sessions in three wild rabbit populations over a two-year period. Blood samples were collected to measure anti-MV and anti-RHDV antibody concentrations and to measure biochemical parameters related to organ function, protein metabolism, and nutritional status. Overall, we found no significant relationships between rabbit serostatus and biochemistry. Our main result was that rabbits that were seropositive for both MV and RHDV had low gamma glutamyltransferase concentrations. Given the robustness of our analyses, the lack of significant relationships may indicate that the biochemical parameters measured are poor proxies for serostatus. Another explanation is that wild rabbits might be producing attenuated physiological responses to these viruses because the latter are now enzootic in the study area.

Coccidian and nematode infections influence prevalence of antibody to myxoma and rabbit hemorrhagic disease viruses in European rabbits.

The interaction among several parasites in European rabbits (Oryctolagus cuniculus) is crucial to host fitness and to the epidemiology of myxomatosis and rabbit hemorrhagic disease. These diseases have caused significant reductions in rabbit populations on the Iberian Peninsula. Most studies have focused on the epidemiology and pathogenesis of these viruses individually, and little is known about interactions between these viruses and other parasites. Taking advantage of an experimental restocking program in Spain, the effects of coccidian and nematode infections on the probability of having detectable antibody to myxoma and rabbit hemorrhagic disease viruses were tested in European wild rabbits. For 14 mo, we monitored rabbit abundance and parasite loads (coccidia and nematodes) in three reintroduced rabbit populations. While coccidian and nematode loads explained seasonal antibody prevalences to myxoma virus, the pattern was less clear for rabbit hemorrhagic disease. Contrary to expectations, prevalence of antibody to myxoma virus was inversely proportional to coccidian load, while nematode load seemed to play a minor role. These results have implications for viral disease epidemiology and for disease management intended to increase rabbit populations in areas where they are important for ecosystem conservation.