Reassortment and evolutionary dynamics of tilapia lake virus genomic segments.

The tilapia lake virus (TiLV), a highly infectious negative-sense single-stranded segmented RNA virus, has caused several outbreaks worldwide since its first report from Israel in 2014, and continues to pose a major threat to the global tilapia industry. Despite its economic importance, little is known about the underlying mechanisms in the genomic evolution of this highly infectious viral pathogen. Using phylogenomic approaches to the genome sequences of TiLV isolates from various geographic regions, we report on the pervasive role of reassortment, selection, and mutation in TiLV evolution. Our findings provided the evidence of genome-wide reassortment in this newly discovered RNA virus. The rate of non-synonymous (dN) to synonymous (dS) substitutions was less than one (dN/dS = 0.076 to 0.692), indicating that each genomic segment has been subjected to purifying selection. Concurrently, the rate of nucleotide substitution for each genomic segment was in the order of 1-3 × 10-3 nucleotide substitutions per site per year, which is comparable to the rate of other RNA viruses. Collectively, in line with the results of the previous studies, our results demonstrated that reassortment is the dominant force in the evolution and emergence of this highly infectious segmented RNA virus.

Impacts of epizootic ulcerative syndrome on subsistence fisheries and wildlife.

Epizootic ulcerative syndrome (EUS), caused by the water mould (Oomycota) Aphanomyces invadans, has spread throughout the world's major continents over the last 50 years, with the apparent exception of South and Central America. With over 160 susceptible fish species representing 54 families and 16 orders recorded to date, EUS is of international concern and infection with A. invadans is a World Organisation for Animal Health (OIE) listed disease. This paper examines what little has been reported on the impacts of EUS on subsistence fisheries and wildlife, or what can be deduced about those impacts, and concludes that there is a need for systematic data collection on the size and socio-economic importance of subsistence fisheries. Such fisheries are often relied upon by the poorest communities, thus food and nutrition security impacts can be significant. Similarly, impacts on wildlife are poorly documented, emphasising the lack of, and the need for, research on and modelling of the ecosystem-level impacts of EUS and other aquatic animal diseases. The history of EUS and several other aquatic animal diseases also brings into question the effectiveness of current measures for controlling the international spread of aquatic animal diseases and calls for a re-think on how best to meet this ongoing challenge.

En l'espace d'un demi-siècle, le syndrome ulcératif épizootique dû à l'oomycète Aphanomyces invadans s'est propagé dans toutes les régions du monde, à l'exception, semble-t-il, de l'Amérique du Sud et Centrale. Avec plus de 160 espèces de poissons répertoriées comme sensibles, réparties en 54 familles et 16 ordres, le syndrome ulcératif épizootique est une maladie préoccupante à l'échelle internationale et figure parmi les maladies listées par l'Organisation mondiale de la santé animale (OIE) sous le nom d'infection à A. invadans. Les auteurs font état des très rares signalements concernant l'impact du syndrome ulcératif épizootique sur la pêche de subsistance et sur la faune sauvage et tentent d'en tirer quelques conclusions, en insistant sur la nécessité de procéder à une collecte systématique de données afin de déterminer l'envergure et l'importance socioéconomique de la pêche de subsistance. Les communautés les plus pauvres étant souvent celles qui dépendent le plus de cette activité, la maladie a sans doute un impact majeur sur la sécurité alimentaire et nutritionnelle de ces populations. De même, l'impact sur la faune sauvage n'a pas vraiment été étudié jusqu'à présent, d'où la nécessité de conduire des travaux de recherche et de modélisation sur l'impact du syndrome ulcératif épizootique (et d'autres maladies des animaux aquatiques) à l'échelle des écosystèmes. L'histoire du syndrome ulcératif épizootique et d'autres maladies des animaux aquatiques pose également la question de l'efficacité des mesures appliquées actuellement pour maîtriser la propagation internationale de ces maladies et invite à repenser la réponse à apporter à ce défi toujours présent.

En los últimos 50 años, el síndrome ulcerante epizoótico, causado por el hongo acuático (oomiceto) Aphanomyces invadans, se ha diseminado por casi todos los continentes del planeta, con la aparente salvedad de Sudamérica y Centroamérica. Se trata de una enfermedad de importancia internacional que, hasta donde consta a día de hoy, afecta a más de 160 especies piscícolas de 54 familias y 16 órdenes. De ahí que la infección por A. invadans sea una patología inscrita en la lista de la Organización Mundial de Sanidad Animal (OIE). Los autores, tras exponer lo poco que hasta ahora se ha descrito de los efectos de la enfermedad sobre la pesca de subsistencia y la fauna silvestre o lo que es posible inferir acerca de esos efectos, llegan a la conclusión de que se requiere una labor sistemática de obtención de datos sobre la magnitud e importancia socioeconómica de la actividad pesquera de subsistencia, de la que dependen a menudo las comunidades más pobres, por lo que las consecuencias para la seguridad nutricional y alimentaria pueden ser de calado. Tampoco están bien descritas las repercusiones de la enfermedad en los animales silvestres, lo que pone de relieve la ausencia, y por ende la necesidad, de investigaciones y de modelos sobre los efectos ecosistémicos del síndrome ulcerante epizoótico y otras varias enfermedades de los animales acuáticos. La historia de estas patologías también arroja dudas sobre la eficacia de las medidas aplicadas actualmente para controlar la propagación internacional de las enfermedades de los animales acuáticos y exige replantearse cuál es la respuesta idónea a este problema que no cesa.

Vulnerabilities in aquatic animal production.

The role of aquatic animals in global food and nutrition security is increasingly recognised. The global demand for fish is increasing, leading to a need to significantly increase its supply. Securing future fish supplies through sustainable production is a challenge as major resources such as fresh water and land are becoming limited worldwide. Aquaculture and capture fisheries face various threats from both human-mediated and natural environmental change, including climate change. Aquaculture systems and practices are vulnerable to such changes. Moreover, aquatic animal diseases are currently considered one of the most important constraints to sustainable global fish production. The need to increase global production, combined with climate change, may increase losses due to diseases. This paper examines key vulnerabilities, their impacts and management to achieve increased and sustainable global fish production. The authors focus on the need to apply international standards, and to develop biosecurity and capacity in aquatic animal health to improve global fish health. Research needed to underpin the development of improved detection and control of fish diseases is also discussed.

L'importance des animaux aquatiques pour la sécurité alimentaire et nutritionnelle mondiale est désormais reconnue. La demande mondiale en aliments issus d'animaux aquatiques ne cessant d'augmenter, il est devenu impératif de renforcer significativement l'offre du secteur. La sécurisation future de cette offre grâce à la mise en place d'une production durable constitue un défi de taille en raison de la raréfaction de certaines ressources cruciales, dont l'eau douce et les terres. L'aquaculture et la pêche de capture font face à plusieurs menaces induites par les transformations tant naturelles qu'anthropiques subies par l'environnement, y compris le changement climatique. Les systèmes et les pratiques de l'aquaculture présentent des vulnérabilités à ces changements. De plus, on considère aujourd'hui que les maladies des animaux aquatiques constituent l'une des principales entraves à une production aquacole durable au niveau mondial. Les pertes dues aux maladies vont probablement augmenter par l'effet conjoint du changement climatique et de la nécessité d'accroître les quantités produites dans le monde. Les auteurs examinent les principales vulnérabilités à l'œuvre ainsi que leur impact et les manières d'y faire face en vue d'une production aquacole mondiale accrue et durable. Ils mettent l'accent sur la nécessité de se conformer aux normes internationales et de renforcer la biosécurité et les capacités du secteur de la santé des animaux aquatiques afin d'améliorer le statut sanitaire de ces animaux à l'échelle mondiale. Ils font également le point sur les travaux de recherche qu'il convient de mener afin de mettre au point de meilleures méthodes de détection et de contrôle des maladies des animaux aquatiques.

Cada vez está más clara la función de los animales acuáticos en relación con la seguridad alimentaria y nutricional del mundo. La demanda planetaria de alimentos derivados de animales acuáticos va en aumento, lo que obliga a incrementar sustancialmente el suministro. El objetivo de asegurar el abastecimiento de animales acuáticos en el futuro gracias a una producción sostenible plantea no pocas dificultades, en la medida en que recursos importantes, como el agua dulce o las tierras, empiezan a escasear en todo el mundo. La acuicultura y la pesca de captura afrontan una serie de amenazas derivadas de los cambios ambientales, ya sean de origen natural o antrópico, en particular el cambio climático. Las praxis y los sistemas acuícolas son vulnerables a esos cambios. Están además las enfermedades de los animales acuáticos, consideradas actualmente uno de los principales frenos a la producción sostenible del sector en el mundo. La necesidad de elevar la producción mundial, combinada con el cambio climático, puede acrecentar el volumen de pérdidas debidas a enfermedades. Los autores examinan las principales fragilidades del sistema, sus consecuencias y la forma de gestionarlas para lograr una producción acuícola mundial más cuantiosa y sostenible, centrándose en la necesidad de aplicar normas internacionales y de desarrollar tanto la seguridad biológica como la capacidad en materia de sanidad de los animales acuáticos para mejorar el estado de salud de estos animales a escala mundial. También se refieren a las investigaciones necesarias para fundamentar sistemas más eficaces de detección y control de las enfermedades de los animales acuáticos.

Transcoccygeal neurolytic ganglion impar block for perineal pain: A case series.

BACKGROUND AND AIMS: Chronic perineal pain (CPP) is a poorly localized pain. Its etiology may be benign or malignant. The ganglion impar is a solitary retroperitoneal structure at sacrococcygeal junction. It provides the nociceptive and sympathetic supply to the perineal structures. CPP has been effectively managed by ganglion impar block. Here, we describe a case series of neurolytic ganglion impar block by transcoccygeal approach, analyzing its safety and efficacy. MATERIAL AND METHODS: In this study, five consecutive patients who were given ganglion impar block for CPP using a transcoccygeal approach were followed up for 2 months. The visual analog scale (VAS) score for pain at presentation, time required for the pain to reduce by 50% after the block, VAS during a 2-month follow-up, time required to perform the procedure, number of attempts, and any complications were noted. RESULTS: All the five patients had an excellent pain relief. The mean duration for decrease in VAS by 50% was 14.8 ± 3.1 min. The mean duration to perform the procedure was 10.2 ± 1.5 min. There were no complications. All the patients had clinically significant pain relief with VAS score of 2 till 2-month follow-up. CONCLUSION: Transcoccygeal ganglion impar block may offer a safe and effective treatment option for CPP as compared to opioids. This approach for neurolysis of the ganglion impar may be recommended in view of the direct course, appreciable end point, and smaller volume of neurolytic requirement.

Prevalence of human papillomavirus16 DNA and p16INK4a protein in oral squamous cell carcinoma: A systematic review and meta-analysis.

BACKGROUND AND AIM: Indian patients with oral squamous cell carcinoma (OSCC) are etiologically associated with the use of tobacco and alcohol; yet, a proportion of tumors that may harbor human papillomavirus (HPV) infections cannot be neglected. The following meta-analysis was conducted to address the association of p16INK4a and HPV DNA with OSCC. In addition, the study also provides the updated prevalence of HPV-induced OSCC. MATERIALS AND METHODS: Literature survey was performed using databases such as PubMed with the help of the following keywords - "HPV infection," "oral squamous cell carcinoma," "p16INK4a," "HPV DNA," "E6," "E7," "L1," "L2" and "LCR." Proportion method was performed to derive the forest plot using MedCalc statistical software version 16.4.3. RESULTS: Among 145 research articles, 33 articles were selected for further analysis, in which 13 articles were related to HPV DNA detection in tissues, 11 articles detected the overexpression of p16INK4a and nine articles reported the detection of both HPV DNA and p16INK4a expression. Meta-analysis revealed significant heterogeneity (P < 0.0001) among the articles. Overall, the study consisted of 3339 patients with OSCC, among which 559 patients were diagnosed with the presence of HPV16 DNA with a random proportion of 20.1% at 95% confidence interval (CI) (13.9-27.1, P < 0.0001). Overexpression of p16INK4a protein was observed in 709 patients with a random proportion of 25.4% at 95% CI (14.3-38.3, P < 0.0001). CONCLUSION: HPV DNA and expression of p16INK4a was suggested as gold standard for the detection of HPV infection in many cases of cancers. Frequency of HPV infection is significantly higher in patients with OSCC as identified through the detection of HPV DNA and p16INK4a expression. Even though the association of HPV infection has been established in head and neck cancer, this review could further the establishment of molecular level interaction of HPV in patients with oral cancer.

Oral autopsy: A simple, faster procedure for total visualization of oral cavity.

Identification of humans, especially in mass disaster is a challenging aspect for team members of the disaster victim identification (DVI) unit. Identification is necessary for humanitarian and emotional reasons and for many legal issues, particularly for family members. In the modern day, all possible methods have been applied for establishing the identification of deceased individuals. The DVI team comprises specialists from different disciplines. The forensic dentist plays a major role in the identification of victims in disaster. To establish a simple, faster and time saving procedure for Postmortem dental identification in mass disaster. In this article, we present a simpler and faster method, which helps in gaining access into the oral cavity that helps in the recording of postmortem oral findings where required.

A prospective review of the labor analgesia programme in a teaching hospital.

BACKGROUND: The structured labor analgesia programme in our tertiary care hospital has been in place for the past few years. We undertook this study to analyze the programme and to draw conclusions to further improve the outcomes. METHODS: A prospective analysis of the data pertaining to 200 patients participating in an ongoing labor analgesia programme in a tertiary care hospital from Nov 2008 to Aug 2009 was performed. RESULTS: Mean visual analog score (VAS) before epidural block was 8.34 ± 0.79. Post procedure the average VAS score was 2.20 ± 0.79. One hundred and fifty six (78%) parturients delivered vaginally, 18 (9%) required instrumentation with vacuum including 1 forceps delivery in a multiparous parturient. In 17parturients (8.7%) fetal distress led to a decision to perform LSCS for delivery. Multiparous patients were significantly more satisfied as compared to nulliparous patients (p = 0.010). CONCLUSION: The study demonstrated excellent pain relief and patient satisfaction with minimal complications. The safety and efficacy of epidural bupivacaine in concentrations less than 0.625% combined with 25 mcg of fentanyl demonstrated in our study should be considered are commendation for the widespread adoption of the procedure in tertiary care hospitals.

The spread of pathogens through trade in aquatic animals and their products.

It is well known that the transboundary spread of infectious diseases is aided by trade in live animals and the consequences can be severe if, as a result, a pathogen broadens its host range to new species. Trade in aquatic animal species is increasing, and aquaculture is also expanding to meet the growing human population's demands for animal protein. Moreover, it is clear that aquaculture has created potential new pathways by which pathogens and diseases may be introduced or spread to new areas. The risk of pathogen transfer is generally considered greater for the movement of live aquatic animals than for the movement of processed and dead products. The currently available health standards support the concept of minimising the risk of disease and pathogen incursion while, at the same time, avoiding unjustifiable or unnecessary impediments to trade. Nevertheless, the international spread of diseases through the movement of animals still occurs, despite these standards. Consequently, this paper considers the evidence linking international trade in aquatic animals and aquatic animal-derived products with the transmission and spread of diseases. The authors provide examples of pathogen transfer leading to disease spread and considerthe situation of emerging diseases, as well as the need for a holistic approach to deal with risk-based threats at their source.

Detection of Laem-Singh virus in cultured Penaeus monodon shrimp from several sites in the Indo-Pacific region.

Laem-Singh virus (LSNV) is a positive-sense single-stranded RNA (ssRNA) virus that was recently identified in Penaeus monodon shrimp in Thailand displaying signs of slow growth syndrome. A total of 326 shrimp collected between 1998 and 2007 from countries in the Indo-Pacific region were tested by RT-PCR for evidence of LSNV infection. The samples comprised batches of whole postlarvae, and lymphoid organ, gill, muscle or pleopod tissue of juvenile, subadult and adult shrimp. LSNV was not detected in 96 P. monodon, P. japonicus or P. merguiensis from Australia or 16 P. monodon from Fiji, Philippines, Sri Lanka and Mozambique. There was no evidence of LSNV infection in 73 healthy juvenile P. vannamei collected during 2006 from ponds at 9 locations in Thailand. However, LNSV was detected in each of 6 healthy P. monodon tested from Malaysia and Indonesia, 2 of 6 healthy P. monodon tested from Vietnam and 39 of 40 P. monodon collected from slow-growth ponds in Thailand. A survey of 81 P. monodon collected in 2007 from Andhra Pradesh, India, indicated 56.8% prevalence of LSNV infection but no clear association with disease or slow growth. Phylogenetic analysis of PCR amplicons obtained from samples from India, Vietnam, Malaysia and Thailand indicated that nucleotide sequence variation was very low (>98% identity) and there was no clustering of viruses according to site of isolation or the health status of the shrimp. The data suggests that LSNV exists as a single genetic lineage and occurs commonly in healthy P. monodon in parts of Asia.

Viral disease emergence in shrimp aquaculture: origins, impact and the effectiveness of health management strategies.

Shrimp aquaculture has grown rapidly over several decades to become a major global industry that serves the increasing consumer demand for seafood and has contributed significantly to socio-economic development in many poor coastal communities. However, the ecological disturbances and changes in patterns of trade associated with the development of shrimp farming have presented many of the pre-conditions for the emergence and spread of disease. Shrimp are displaced from their natural environments, provided artificial or alternative feeds, stocked in high density, exposed to stress through changes in water quality and are transported nationally and internationally, either live or as frozen product. These practices have provided opportunities for increased pathogenicity of existing infections, exposure to new pathogens, and the rapid transmission and transboundary spread of disease. Not surprisingly, a succession of new viral diseases has devastated the production and livelihoods of farmers and their sustaining communities. This review examines the major viral pathogens of farmed shrimp, the likely reasons for their emergence and spread, and the consequences for the structure and operation of the shrimp farming industry. In addition, this review discusses the health management strategies that have been introduced to combat the major pathogens and the reasons that disease continues to have an impact, particularly on poor, small-holder farmers in Asia.

Perspectives on aquatic animal disease contingency planning in the Asia-Pacific region.

The movement of live aquatic animals is one of the principal reasons for the rising number of disease emergencies in Asia and the Pacific. Contingency planning is crucial in the effective management of such emergencies. Within Asia, the Asia Regional Technical Guidelines on Health Management and the Responsible Movement of Live Aquatic Animals provide the basic framework for national and regional efforts to reduce the risk of introducing disease across borders. However, in following these guidelines, the progress made by countries on contingency planning has, to date, been rather limited. In this paper, the authors broadly examine the implementation of health management programmes, highlight some regional initiatives that support contingency planning and describe the present status of contingency planning in the Asia-Pacific region.

Farm-level plans and husbandry measures for aquatic animal disease emergencies.

Disease is one of the gravest threats to the sustainability of the aquaculture industry. A good understanding of biosecurity and disease causation is essential for developing and implementing farm-level plans and husbandry measures to respond to disease emergencies. Using epidemiological approaches, it is possible to identify pond- and farm-level risk factors for disease outbreaks and develop intervention strategies. Better management practices (BMPs) should be simple, science-based, cost-effective and appropriate to their context if farmers are to adopt and implement them. As part of a regional initiative by the Network of Aquaculture Centres in Asia-Pacific (NACA) to control aquatic animal diseases, effective extension approaches to promote the widespread adoption of BMPs have been developed in India, Indonesia, Vietnam and Thailand, and have proved their worth. A highly successful programme, which addresses rising concerns about the effect of disease on the sustainability of shrimp farming in India, is now in its seventh year. In this paper, the authors present a brief insight into the details of the programme, its outcomes and impact, the lessons learned and the way forward.

Evaluation of an immunodot test to manage white spot syndrome virus (WSSV) during cultivation of the giant tiger shrimp Penaeus monodon.

A monoclonal antibody-based immunodot test was compared to a polymerase chain reaction (PCR) assay for managing white spot syndrome virus (WSSV) on shrimp farms at Kundapur and Kumta situated in Udupi and Uttar Kannada Districts, respectively, of Karnataka on the west coast of India. Of 12 grow-out farms in Kundapur, 6 (F1 to F6) yielded shrimp samples that were negative for WSSV by both immunodot test and 1-step PCR from stocking to successful harvest. Samples from the other 6 farms (F7 to F12) were positive for WSSV by both immunodot test and 1-step PCR at various times post stocking, and their crops failed. In the 2 farms at Kumta (F13, F14), immunodot and 1-step PCR results were both negative, and harvests were successful. In contrast to 1-step PCR results, farms F5, F6, F13, and F14 gave positive results for WSSV by 2-step PCR, and they were successfully harvested at 105 d post stocking. Our results indicate that an inexpensive immunodot assay can be used to replace the more expensive 1-step PCR assay for disease monitoring.

Contribution of science to farm-level aquatic animal health management.

The contribution of science to farm level disease management is a story of two worlds. The development of effective vaccines has allowed for the control of important salmonid diseases such as furunculosis, yersiniosis and vibriosis and has significantly reduced farmers' reliance on antibiotics. Control of diseases for which cost-effective vaccines have yet to be developed has been achieved through the development of increasingly targeted antibiotics and chemotherapeutants. Increasingly, accurate and rapid diagnostic and water quality tests have allowed farmers to improve farm-level aquatic animal health management. In developed countries, these achievements have been possible thanks to the strong link between science and farm management. This link has been assisted by the presence of strong farmer organizations capable of coordinating research projects and hosting meetings at which scientific information is discussed and disseminated. Although Asia is responsible for the production of about 90% of aquaculture products, it presents a rather different picture from the above. Science has indeed made significant progress in health management but the links with farm management are still weak. Management practices capable of preventing important health problems in shrimp and fish farming are still poorly adopted by farmers. This is largely due to constraints in the dissemination of information to the large number of producers involved, the limited resources of both producers and their countries and the lack of effective farmer organizations capable of liaising with the scientific world. Recently, the Asian region has witnessed some successful examples of aquatic animal health management through the adoption of simple Better Management Practices. Efforts so far have been largely focused on shrimp farming, although activities have been initiated to adopt a similar approach to other commodities. The need for both observational and experimental epidemiological studies to identify simple and affordable farm practices for the control of aquatic animal diseases is highlighted.

Communication and networking in a regional organisation.

Access to accurate information and technical expertise is a pre-requisite for informed decision making. The Network of Aquaculture Centres in Asia-Pacific (NACA), an intergovernmental organization of 17 governments in Asia-Pacific, works on the principle of cooperation and collaboration with the intention of sharing regional resources amongst the stakeholders within the network: governments, institutions and individuals. Networking, communication and project implementation coordinated by NACA in collaboration with partner organizations and donor agencies has been instrumental in facilitating the flow of science and provision of technical assistance to relevant stakeholders in Member Countries. Development and adoption of the FAO/NACA's Asia regional technical guidelines (TG) for the responsible movement of live aquatic animals by 21 Asia-Pacific governments is a major outcome of networking and communication that had been facilitated by the NACA, from 1999 to 2001. Since then, the implementation of key elements of the TG has remained the focus of NACA's regional aquatic animal health programme. The present paper provides some examples of past and ongoing activities that highlight the role of networking and communication in a regional organization in strengthening aquatic animal health capacity and biosecurity in the Asia-Pacific region.

Antigen expression in biofilm cells of Aeromonas hydrophila employed in oral vaccination of fish.

Total protein, S-layer protein and lipopolysaccharides (LPS) of biofilm cells of Aeromonas hydrophila were analysed by SDS-PAGE and compared with that of planktonic cells. In the whole cell lysate of biofilm cells, about 15 proteins were repressed while three new proteins were expressed compared to that in planktonic cells. Interestingly, in biofilm cells the S-layer proteins were lost and LPS showed an additional high molecular weight band compared to that in planktonic cells. We propose that the change in LPS profile must have contributed to the loss of S-layer. Also, the high molecular weight band of LPS might play a role in the better performance of biofilm oral vaccine by eliciting a protective immune response.

Evaluation of biofilm of Aeromonas hydrophila for oral vaccination of Clarias batrachus--a carnivore model.

Biofilm of Aeromonas hydrophila was evaluated for oral vaccination of walking catfish (Clarias batrachus L.). Fish were fed with fish paste incorporating biofilm (BF) or free cells (FC) of A. hydrophila for 20 days and monitored for serum antibody production up to 60 days post-vaccination. Serum agglutinating antibody titre and relative percent survival (RPS) following challenge were found to be significantly higher in catfish fed with BF vaccine compared to that with FC.