Natural Outbreaks Research Articles

Preparation and Application of Egg Yolk Antibodies Against Chinese Sacbrood Virus Infection.

Chinese sacbrood virus (CSBV) infects Apis cerana larvae, resulting in the inability of the larvae to pupate and their consequent death, which may pose a serious threat to entire colonies. As there is no effective medical treatment for CSBV infections, further studies are necessary. In this study, an effective treatment for CSBV is described, based on a specific immunoglobulin Y (IgY) from egg yolk against CSBV. The inactivated vaccine was produced by ultracentrifugation and formalin treatment, using CSBV purified from a natural outbreak. The specific IgY was produced by immunization of white leghorn hens with the vaccine. An enzyme-linked immunosorbent assay using purified CSBV as the coating antigen revealed that the anti-CSBV IgY titer began increasing in the egg yolk on the 14th day post-immunization, reaching a peak on day 42, and anti-CSBV IgY remained at a high level until day 91. IgY isolated from the combinations of egg yolk collected between days 42–91 was purified by PEG and ammonium sulfate precipitation. In three repeated protection experiments using A. cerana larvae inoculated with CSBV, the survival rate of larvae was more than 80%, and the titer of anti-CSBV IgY was more than 25 and 24 when the larvae were fed IgY 24 h after and before inoculation with CSBV, respectively. Therefore, 400 colonies infected with CSBV were treated by feeding sugar containing IgY solutions with an antibody titer of 25, and the cure rate was 95–100%. Three hundred susceptible colonies were protected by feeding the larvae with sugar containing IgY solutions with an antibody titer of 24, and the protection rate was 97%. The results clearly suggest that a specific IgY was obtained from hens immunized with an inactivated-CSBV vaccine; this may be a novel method for controlling CSBV infection.

Detection and phylogenetic analysis of Orf virus in Kashmir Himalayas.

Orf virus (ORFV) is a zoonotic pathogen that primarily infects sheep and goats, and is responsible for significant economic losses. ORFV is endemic in all the major sheep and goat rearing areas of the world including Indian subcontinent. However, the nature of ORFV circulating among sheep and goat in Kashmir Himalayas has not yet been characterized. In the present study, we describe natural outbreaks of ORFV in sheep and goats of Kashmir Himalayas. We detected the presence of ORFV in the scab lesion by PCR amplification of the major envelope protein (B2L) gene. We sequenced the virus interferon resistance (VIR) gene and determined their phylogenetic relationship with that of the published reference sequences. Phylogenetic analysis based on VIR gene revealed that the ORFV isolates from Kashmir Himalayas separated into main two clusters. The sheep isolates showed genetic homology with the sheep strains reported from Greece and Italy, whereas the goat-specific strain show homology with the goat strains reported from China. This study demonstrates the presence of ORFV infection in sheep and goats, and report first phylogenetic analysis of the ORFV strains prevalent in the Kashmir Himalayas.

Whole genome sequencing and identification of Bacillus endophyticus and B. anthracis isolated from anthrax outbreaks in South Africa

BackgroundBacillus endophyticus is a soil plant-endophytic bacterium, while B. anthracis is the causative agent of anthrax. The virulence factors of B. anthracis are the plasmid encoded tripartite toxins (pXO1) and poly-γ-glutamic acid (PGA) capsule (pXO2). B. endophyticus isolated alongside B. anthracis from animals that died of anthrax in Northern Cape Province (NCP), South Africa, harbored polyglutamate genes. The study compared the characteristics of B. anthracis and B. endophyticus with other Bacillus species with a focus on the presence of the PGA capsule or/and unbound PGA. The morphology and whole genome sequence analysis of B. endophyticus strains and B. anthracis were compared.ResultsIn conventional microbiology, B. endophyticus showed gram-positive round-shaped rods in single/short chains, which were endospore-forming, non-motile, non-haemolytic with white and dry colonies, and γ-phage resistant. B. anthracis was differentiated from B. endophyticus based on the latter’s box-shaped rods in pairs/long chains, white-grey and slimy colonies, encapsulated and γ-phage susceptible. The study identified a PGA polyglutamate synthase operon that consisted of pgsBCA, γ-glutamyltranspeptidase (ggt) and pgsE in B. endophyticus genomes.ConclusionsPGA regions of B. anthracis contain capBCADE genes located in the pXO2 required for capsulation formation, while B. endophyticus contain the pgsBCAE genes in the chromosome. Whole genome and microbiology analysis identified B. endophyticus, as a non-capsuled endospore-forming bacterium that consists of PGA required for biosynthesis. B. endophyticus strains do not synthesize surface associated PGA, therefore capsule visualization of B. anthracis is a key diagnostic characteristic. The study highlights the significance of using whole genome shotgun sequencing to identify virulence and other important genes that might be present amongst unknown samples from natural outbreaks. None of the B. anthracis related plasmids or virulence genes were found in the B. endophyticus genomes.

Detecção do vírus da diarreia viral bovina em carrapatos Rhipicephalus (Boophilus) microplus alimentados e, bovino persistentemente infectado

Background: Bovine viral diarrhea virus (BVDV) is one of the main agents that cause economical losses in cattle worldwide. Congenitally infected calves that are born persistently infected (PI) to BVDV are the main sources of infection to susceptible cattle. Direct contact is the most important form of transmission, but indirect contact can also spread BVDV, not only inside herds, but also between them. Transmission of BVDV by haematophagous insects has been proven experimentally, but the role of ticks in the transmission of BVDV has never been investigated. Ticks can heavily infest cattle raised in tropical areas and Rhipicephalus (Boophilus) microplus is the most important among them. The present experiment was carried out to investigate the role of R. microplus ticks in the transmission of BVDV, experimentally infecting PI calf with ticks. Material, Methods and Results: Three calves were used in the experiment: one PI calf was identified from a natural outbreak; a second animal was infested with the progeny of a tick fed on the PI calf and the third was kept as a negative control, infested with negative ticks. Viral RNA investigation was performed by reverse transcription followed by polymerase chain reaction (RT-PCR) from the sera of the calves and from ticks (adult females, eggs and larvae that were the progeny of the experimentally contaminated adult females and from the control animal). BVDV RNA was detected in tick adult females fed on the PI calf, but not in the control animal. Experimental infestation of a second cattle with larvae derived from adult females infected with BVDV was not able to produce infection. These data suggest that the virus is able to pass to ticks during feeding on the infected PI animal, but that there is no transmission by transovarial route, as viral RNA was not detected in eggs and larvae from adult females infected with BVDV. Discussion: Bovine tick is the most important ectoparasite in domestic animals in tropical and subtropical areas. However, its role in transmission of viral agents, particularly BVDV, has not been previously studied. The results of our experiment suggested that adult females of R. microplus were not able to transmit the infection to susceptible cattle. However, a macerate of a pool of tick females fed on the PI calf was positive to BVDV. A further validation using a larger number of infested bovines would help to confirm this new finding. R. microplus ticks are monoxenic, but it must be considered that the males, different from females, make a non-continual process of blood sucking and may move between bovines to reproduce. Additionally, in conditions of close contact between animals, besides tick males, larvae may change hosts in the early stages of development. These facts do not permit to exclude the risk of direct spread of viral infection in the herd by a same specimen of R. microplus. On the other hand, the presence of virus inside females represents an environmental reservoir of BVDV, which may infect through epithelial abrasions if ingested. These considerations may be reinforced by the fact that in field conditions it has been observed that high animal density favors the fast spread of BVDV in cattle herds. Collectively, these evidences suggest that ticks would represent an additional factor to be allowed for in BVDV transmission. As a conclusion, the present study demonstrates that R. microplus can be contaminated with BVDV during blood feeding, strengthening the idea that haematophagous vectors can be involved in the spread of the disease. In spite of the fact that BVDV was not transmited by the progeny of the ticks, it is not possible to discard such form of transmission under natural conditions.

Identification of swinepox virus from natural outbreaks in pig population of Assam.

Outbreaks of swinepox [caused by a swinepox virus (SWPV)] in pigs were investigated in 3 districts of Assam, a north eastern state of India. Diagnosis of the disease was carried out employing both standard virological as well as molecular methods. Three representative isolates from different places were selected for inoculation into confluent monolayers of Porcine Kidney-15 (PK-15) cell line. The cytopathic effects were characterized by cell rounding, nuclear vacuolation, cell fusion, granulation of cells and finally detachment from third blind passage onwards. The three genes viz., SPV18-20 and P42 of SWPV was targeted for confirmation of the virus. Swinepox virus was successfully adapted to the PK-15 cell line from seventh passage onwards. The isolated viruses were characterized by sequencing and phylogenetic analysis of P42 gene (extracellular envelope protein), a homologue of vaccinia virus F13L gene. In India, studies on swine pox are very limited. This is the first report on successful isolation of swinepox virus from north eastern region of India. Assam and the other north-eastern states of India being a hub for pig husbandry, isolation of swinepox virus will help in developing and formulating control strategies against the disease.

Diets containing shrimp protein hydrolysates provided protection to European sea bass (Dicentrarchus labrax) affected by a Vibrio pelagius natural infection outbreak

This study was conducted to investigate the effects of the dietary supplementation of shrimp protein hydrolysate (SPH) on somatic growth performance, innate immune response in juvenile European sea bass (Dicentrarchus labrax) and their differential cumulative mortality when affected by a Vibrio pelagius natural infection outbreak. A diet containing 20% fish meal (FM) was used as a control, whereas three other diets differing in the level of FM inclusion (75 and 25% FM replacement by plant protein sources) and the inclusion of the additive (5% FM, 5% FM + 5% SPH and 15% FM + 5% SPH) were tested. After 110 days, there were no statistically significant differences in somatic growth parameters nor proximate composition in fish fed different experimental diets (P > 0.05), while the humoral non-specific immune responses (lysozyme, bacteriolytic and complement activities) were significantly enhanced by the inclusion of SPH in diets (P < 0.05). Additionally, an outbreak of the pathogenic bacteria V. pelagius, a bacterial species previously described as producer of the virulence factor hemolysin, occurred in all experimental tanks (4 replicates per diet) due to crowding and repeated handling stress for fish sorting. Survival rates among different experimental groups ten days after the bacterial epizootic differed depending on the diets, with groups containing SPH showing the best results (P < 0.05). In particular, fish fed the 15% FM + 5% SPH diet showed the highest survival rate (96.4 ± 5.0%), followed by those fed the 5% FM5 + 5% SPH5 (61.8 ± 16.3%). In contrast, survival rates in fish fed diets deprived of the additive (20% FM and 5% FM5 diets) were the lowest ones (32.0 ± 6.7% and 38.2 ± 13.5%, respectively). The present study showed that SPH can be incorporated in aquafeeds with high levels of FM substitution by PP sources without detrimental impact on the somatic growth performance of fish. In addition, the non-specific humoral immunity in seabass and their survival when affected by an epizootic outbreak of V. pelagius were positively affected, which showed the immunomodulatory benefits of shrimp protein hydrolysate to promote health and prevent diseases in fish.

Photosensitization in Cattle Caused by Spontaneous and Experimentally Ingestion of Stryphnodendron fissuratum

Background: Stryphnodendron fissuratum is a tree from the Brazilian Cerrado. Its fruit is toxic to cattle and can cause clinical digestive signs, hepatogenous photosensitization, and abortion. Cases of poisoning in cattle, goats and guinea pigs have been experimentally reproduced; however, photosensitization could not be reproduced. The aim of this work was to describe an outbreak of natural poisoning and experimental reproduction in cattle, both with hepatogenous photosensitization.Materials, Methods &amp; Results: Its described and natural outbreak and an experimental poisoning. In the outbreak, three bovines in the acute phase and three in the chronic phase were examined. Blood samples were collected from all of these animals in order to measure serum levels of aspartate aminotransferase (AST), gamma-glutamyl transferase (GGT), urea, and creatinine. The first three animals underwent necropsy and histopathological evaluation. The experiment was conducted with two nine-month-old calves that received an oral paste made with crushed S. fissuratum fruits mixed with water. These fruits were collected at a farm at which cattle poisoning cases had occurred. Blood samples were collected in order to measure serum levels of AST, GGT, urea, and creatinine, before plant administration and then daily during the experimental period. Skin biopsies were taken before plant administration and new one after the first signs of skin lesions. The natural outbreak affected 52 of 160 bovine (31 calves and 21 cows) in the lot. Two calves and 14 cows died. Clinical signs consisted of depression, ataxia, incoordination, behavioral changes, decubitus, and death. One animal that died and 36 others that recovered had photodermatitis. Necropsy findings in the animals consisted of bad corporal condition, pale kidneys, evidence of liver lobular pattern, dry rumen contents, and full bladder. In two animals, fruit seeds were found in the rumen, and one animal had ulcers and transmural edema in the abomasum. Microscopically, mild to moderate renal tubular distension, accumulation of proteinaceous material in lumen with mild to moderate swelling, and epithelial necrosis. In the liver, swelling of hepatocytes and moderate bile stasis was detected. Enzymes values in all evaluated bovines were higher than those considered normal for the species. Experimentally, both calves became ill and one died. The clinical signs were apathy, inappetence, wobbling, weight loss, and goosebumps. One of them had jaundice, tearing, photophobia, ear skin detachment, and ulcers at the muzzle, nostrils and ventral face of the tongue. This animal was euthanized in extremis, and the necropsy findings showed generalized jaundice, evidence of increased liver lobular pattern, thick bile, pale kidneys, and esophageal, tongue, and epiglottal ulcers. Microscopically, the lesions were similar to those described during the natural outbreak. The skin biopsy from the calf that recovered showed perivascular edema and mild eosinophilia.Discussion: The diagnosis was made based on clinical signs, necropsy findings, histopathological lesions, and epidemiological analysis. Experimentally, the plant was toxic at the administered doses. Photosensitization was the most common clinical sign during the natural outbreak and until now, has never been experimentally reproduced. Based on histopathological lesions observed in this study, we can consider that is from hepatogenous origin. The results showed that the kidney lesions have an important role during the pathogenesis caused by this poisoning and during disease evolution.

Comparative sequence and structural analysis of Indian orf viruses based on major envelope immuno-dominant protein (F1L), an homologue of pox viral p35/H3 protein

Orf virus (ORFV), a member of the genus Parapoxvirus in the family Poxviridae, is the cause of orf, a highly contagious zoonotic viral disease that affects mainly sheep and goats. In the present study, the sequence and phylogenetic analysis of Indian ORFV isolates (n = 15) from natural outbreaks in sheep and goats belonging to different geographical regions were analysed on the basis of F1L gene along with homology modelling of F1L protein. Multiple sequence alignments revealed highly conserved C-terminus and heterogeneity of N-terminus region of F1L among all orf viruses studied. Further, a comparative sequence alignment indicated conservation of various motifs such as glycosaminoglycan (GAG), Asp/Glu–any residue–Asp (D/ExD) and a Cx3C chemokine like motif among all poxviruses and unique motifs (proline rich region [PRR] and Lys-Gly-Asp [KGD]), in parapoxviruses including ORFV isolates irrespective of geography and host species. Phylogenetically, two major clusters were noticed which included Indian orf isolates along with foreign isolates. Structurally, ORFV F1L resembled the topology as exhibited by its homologue vaccinia virus H3 protein with mixed β/α folds and ligand binding specificity in docking models. We noted that despite differences in host cell specificity and pathogencity, poxvirus proteins especially ORFV F1L protein and its homologues presumed to share similarities as they are highly conserved irrespective of species and countries of origin. Further, the study also indicated the possibilities of differentiation of ORFV strains based on N-terminal heterogeneity despite highly conserved C-terminal region with conserved motifs.

Efficacy of a bivalent inactivated vaccine against red seabream iridovirus and Streptococcus iniae in red seabream, Pagrus major

The red seabream (Pagrus major) is an economically important marine fish species that is cultured in Japan. Natural outbreaks of red seabream iridovirus (RSIV) and/or Streptococcus iniae can cause massive mortalities and severe economic losses in red seabream production. No effective single-injection vaccine for protecting red seabream against both diseases has yet become commercially available. Here, we evaluated the efficacy of a bivalent formalin-killed vaccine (PISCIVAC™ Irido Si) against RSIV and S. iniae infections in red seabream. In laboratory trials, intraperitoneally vaccinated fish reared at 25 °C were protected against challenges with RSIV and S. iniae as early as 3 days post vaccination (dpv), with a relative percent survival (RPS) of 69% and 90%, respectively. The protection was also observed in fish reared at 15 °C, with a RPS of 88% and 89% after challenging the fish with RSIV and S. iniae at 10 dpv and 14 dpv, respectively. Furthermore, intramuscular vaccination effectively protected fish against RSIV (RPS of 100% and 65–96% at 10 and 20 dpv, respectively) and S. iniae (RPS of 92–100% at 14 dpv). The vaccine conferred protection against RSIV infection for at least 2 months and against S. iniae infection for at least 6 months in the field trial. These results indicate that PISCIVAC™ Irido Si is effective for protecting red seabream against RSIV and S. iniae infections.

Environmental impact monitoring of household vinegar-injections to cull crown-of-thorns starfish, Acanthaster spp.

Large-scale population outbreaks of the crown-of-thorns starfish (COTS, Acanthaster spp.) have occurred in every nation with substantial coral reefs in the Indo-Pacific during the past few decades. While a multitude of control efforts have been trialed to combat the outbreaks, an efficient solution has remained elusive. Recent developments have however introduced single-shot injection methods using bovine derivatives (bile salts) and household products (vinegar) that have proven effective at culling COTS. In this study we use a Multiple-Before-After-Control-Impact (MBACI) experimental design to conduct an assessment of the environmental impact of using household vinegar as a chemical for culling COTS. During our six-week assessment we found no changes in coral cover or coral disease. Furthermore, while video recordings documented a number of fish species consuming decaying COTS, we found no evidence of changes in fish abundance or the presence of fish disease, despite densities of injected COTS far exceeding those recorded during natural outbreaks. The efficiency of scavenging fish ensured that few traces of decaying COTS were visible 72 h post-injection. The lack of any observed environmental impact supports our conclusion that vinegar is a low-risk chemical for use in COTS control. Because vinegar is highly accessible, low in cost, and effective at killing COTS without harm to non-target organisms, it has the potential to become a powerful new tool to defend the reef against COTS outbreaks.

Yellow, red, dead: the nutritional consequences for Cardiaspina densitexta (Hemiptera: Aphalaridae) nymphs of inducing senescence in old Eucalyptus fasciculosa leaves

AbstractMany psyllids are manipulative herbivores that alter their hosts to provide shelter and ameliorate nutritional quality. Among eucalypt‐feeding psyllids, Cardiaspina have specialised to manipulate natural processes of foliar senescence and thereby host nutritional quality but not foliar morphology. Using a natural outbreak, we assessed the effects of feeding by nymphs of Cardiaspina densitexta Taylor, ultraviolet exposure and temperature on changes in nutritional quality and leaf abscission. Over 6 months, we followed the responses of tagged Eucalyptus fasciculosa F.Muell. leaves that, at the beginning of the study, were at one of three different stages of utilisation by psyllids (no psyllids, only eggs present, or leaves with late instar nymphs and red lesions). We measured foliar pigments, free amino acids and polyphenols every second month to characterise foliar nutritional quality. Psyllid feeding was briefly associated with chlorosis but lesions rapidly turned red (anthocyanic) and died after nymphs had matured. Red leaves had shortened longevities and their risk of abscission was positively correlated with the UV‐index rating of the preceding fortnight but not with psyllid abundance or area necrotic. Hence, psyllids altered the balance of chlorophylls and anthocyanin‐equivalents of green leaves and presumably therefore their ability to fully utilise incoming light energy. Green leaves had distinct free amino acids and polyphenol compositions compared to red leaves. In green leaves, changes in anthocyanin‐equivalents were negatively correlated with methionine while in red leaves psyllids were positively correlated with threonine and negatively correlated with leucine. Feeding by Cardiaspina densitexta nymphs is associated with the visible symptoms of photodamage which are associated with pronounced changes in nutritional quality. These changes are not analogous to foliar hypersensitive responses because they are expressed by old leaves, necrotic tissues are not abscised, they occur late in the development of nymphs and do not directly affect their survival. Specialisation of Cardiaspina on old eucalypt leaves may appear maladaptive if these modules are considered to be low in amino nitrogen and high in polyphenols. This perspective needs refining given the influence of photodamage on nutrient availability and because condensed tannins (weak pro‐oxidants) are more abundant than hydrolysable tannins in old leaves.

Humanitarian health computing using artificial intelligence and social media: A narrative literature review

IntroductionAccording to the World Health Organization (WHO), over 130 million people are in constant need of humanitarian assistance due to natural disasters, disease outbreaks, and conflicts, among other factors. These health crises can compromise the resilience of healthcare systems, which are essential for achieving the health objectives of the sustainable development goals (SDGs) of the United Nations (UN). During a humanitarian health crisis, rapid and informed decision making is required. This is often challenging due to information scarcity, limited resources, and strict time constraints. Moreover, the traditional approach to digital health development, which involves a substantial requirement analysis, a feasibility study, and deployment of technology, is ill-suited for many crisis contexts. The emergence of Web 2.0 technologies and social media platforms in the past decade, such as Twitter, has created a new paradigm of massive information and misinformation, in which new technologies need to be developed to aid rapid decision making during humanitarian health crises. ObjectiveHumanitarian health crises increasingly require the analysis of massive amounts of information produced by different sources, such as social media content, and, hence, they are a prime case for the use of artificial intelligence (AI) techniques to help identify relevant information and make it actionable. To identify challenges and opportunities for using AI in humanitarian health crises, we reviewed the literature on the use of AI techniques to process social media. MethodologyWe performed a narrative literature review aimed at identifying examples of the use of AI in humanitarian health crises. Our search strategy was designed to get a broad overview of the different applications of AI in a humanitarian health crisis and their challenges. A total of 1459 articles were screened, and 24 articles were included in the final analysis. ResultsSuccessful case studies of AI applications in a humanitarian health crisis have been reported, such as for outbreak detection. A commonly shared concern in the reviewed literature is the technical challenge of analyzing large amounts of data in real time. Data interoperability, which is essential to data sharing, is also a barrier with regard to the integration of online and traditional data sources.Human and organizational aspects that might be key factors for the adoption of AI and social media remain understudied. There is also a publication bias toward high-income countries, as we identified few examples in low-income countries. Further, we did not identify any examples of certain types of major crisis, such armed conflicts, in which misinformation might be more common. ConclusionsThe feasibility of using AI to extract valuable information during a humanitarian health crisis is proven in many cases. There is a lack of research on how to integrate the use of AI into the work-flow and large-scale deployments of humanitarian aid during a health crisis.

Efficacy and effectiveness of water, sanitation, and hygiene interventions in emergencies in low- and middle-income countries: a systematic review

There are increasing numbers of people affected by natural disasters, disease outbreaks, and conflict. Water, sanitation, and hygiene (WASH) interventions are used in nearly all emergency responses to help reduce disease risk. However, there is a lack of summarized evidence on the efficacy and effectiveness of these interventions. We conducted a systematic review of the published and grey literature on the efficacy and effectiveness of short-term WASH interventions in emergency response in low- and middle-income countries, including: developing theory of change models; setting inclusion criteria; conducting the search; selecting evaluations for inclusion; assessing the quality of the evidence; and analysing the included evaluations. Overall, 15,026 documents were identified and 106 studies describing 114 evaluations met inclusion criteria. Interventions from 39 countries were included. Most included evaluations (77 per cent) had high risk of bias and half were from grey literature (50 per cent). For the m...

Does Perceived Travel Risk Influence Tourists Revisit Intention?

The tourism industry of any country is strongly impacted by domestic as well as external events or issues, such as natural calamity, diplomatic relations, political conflicts, disease outbreaks, environmental issues, and economic crisis. In developing countries where tourism is one of the major sources of national income, these events or issues can seriously affect the industry. Despite the significance of perceived travel risk, few studies addressed its influence on revisit intentions of tourists. The present study offers new insights by investigating the effects of perceived travel risks on revisiting intentions of the 374 tourists visiting Uttarakhand, India. This study was conducted during July 2013 to September 2013, just after Kedarnath incident - a major natural disaster. Data were gathered from tourists through a survey instrument. Following analysis of data, multiple risk dimensions seriously affecting revisit intentions of tourists were identified. Important managerial implications concerning the management of risk perceptions were discussed.

Decreased Clinical Severity of Strangles in Weanlings Associated with Restricted Seroconversion to Optimized Streptococcus equi ssp equi Assays.

Background Streptococcus equi ssp. equi causes characteristic clinical signs that are most severe in young horses, including fever, purulent nasal discharge, and lymph node abscessation in the head region.Hypothesis/ObjectivesClinical, serologic, and microbiologic factors related to unexpectedly mild disease severity in a natural outbreak of strangles in immunologically naïve weanlings were investigated.AnimalsOne‐hundred and twelve warmblood weanlings.MethodsProspective longitudinal observational study of a natural outbreak of strangles. The entire cohort was examined at the peak of the outbreak by deep nasal swabs for culture and quantitative PCR (qPCR) for the presence of S. equi and clinically and serologically in a sequential manner by an optimized ELISA from the index case throughout the outbreak until resolution. Descriptive statistics were calculated and comparisons made using a nondirectional Wilcoxon signed‐rank test.ResultsOutbreak morbidity was 53%, with 9 of 14 horses culture positive and 26 of 53 horses qPCR positive for S. equi lacking clinical signs characteristic of strangles. By resolution, 91 of 112 had seroconverted to Antigen A by ELISA but seroconversion to antigen C (part of the SeM protein) was minimal. Sequencing of the isolates detected no alterations in the SeM protein, but identified a 61 bp deletion in the gene SEQ_0402.Conclusions and Clinical ImportanceAbsence of clinical signs alone in naïve horses may be an insufficient criterion to release horses from strangles quarantine measures. Restricted seroconversion to antigen C may have been associated with decreased clinical severity. The role of a minor gene deletion in SEQ_0402 in the virulence of S. equi warrants further investigation.

A cross sectional study on constraints in broiler farming at Perambalur district of TamilNadu

The poultry farming plays an important role in the rural economy of India. Broiler farming is faced with many challenges including diseases, predators and inadequate feed. The study was conducted in 30 respondents (30 Poultry farmers) with preformed questionnaire to analysis the constraints faced by the farmers in broiler farming using the Garrett ranking method. In the present study found that constraints in terms of marketing of chicks, non-remunerative price was the main constraints followed by transportation problem, Disease attacked time rumor regarding price fluctuation and late payment. A constraint faced by the farmers in production of chicken water scarcity is the main problem followed by high temperature, mortality problem, availability of labour and feed. Among the Social and natural problems outbreaks of disease was the main problem followed by predator animal likes cats, dog, and pollution of environment. The broiler farming is a profitable venture and has a bright future in the study area of Perambalur district of Tamil Nadu for reducing the constraints faced by the poultry farming community.

Warming, shading and a moth outbreak reduce tundra carbon sink strength dramatically by changing plant cover and soil microbial activity

Future increases in temperature and cloud cover will alter plant growth and decomposition of the large carbon pools stored in Arctic soils. A better understanding of interactions between above- and belowground processes and communities of plants and microorganisms is essential for predicting Arctic ecosystem responses to climate change. We measured ecosystem CO2 fluxes during the growing season for seven years in a dwarf-shrub tundra in West Greenland manipulated with warming and shading and experiencing a natural larvae outbreak. Vegetation composition, soil fungal community composition, microbial activity, and nutrient availability were analyzed after six years of treatment. Warming and shading altered the plant community, reduced plant CO2 uptake, and changed fungal community composition. Ecosystem carbon accumulation decreased during the growing season by 61% in shaded plots and 51% in warmed plots. Also, plant recovery was reduced in both manipulations following the larvae outbreak during the fifth treatment year. The reduced plant recovery in manipulated plots following the larvae outbreak suggests that climate change may increase tundra ecosystem sensitivity to disturbances. Also, plant community changes mediated via reduced light and reduced water availability due to increased temperature can strongly lower the carbon sink strength of tundra ecosystems.

Strengthening the Cost Effectiveness of Medical Countermeasure Development Against Rare Biological Threats: The Ebola Outbreak

Some chemical, biological, radiological, and nuclear agents, whether naturally, accidentally, or intentionally released, can be very damaging and pose a high risk to national security, owing to their potential for economic and social disruption. Efficacious pharmaceutical research and development could protect populations against such agents via new prophylactic drugs and vaccines or post-exposure treatment with antidotes and antimicrobials. However, because of the unpredictable nature of when, if ever, the health risks of specific chemical, biological, radiological, and nuclear agents might be realized, the development of medical countermeasures against these agents carries less promise of free market rewards to entice investment, and thus this development necessitates public funding or incentives. In terms of defining the level and targets of such public funding, the potential economic impact of any realized threat must be determined. This article first examines the specific components of market failure—research and development efforts vs. market rewards—associated with medical countermeasures against chemical, biological, radiological, and nuclear agents. Then, the latest natural outbreak of the Ebola virus disease is used as a case study to illustrate the risks that such biological agents can pose to social and economic structures. Rather than addressing risks associated with exposure from terrorist events, this case study highlights the potential to strengthen the case to fund relevant medical countermeasures for naturally occurring diseases with epidemic potential that could also impact Western countries owing to the consequences on their armed forces operating in the area of the outbreak, on trade, or even travelers who may disseminate the disease. To that end, causal factors that led to a lack of medical countermeasures prior to the 2014 outbreak are identified, then opportunities that could have triggered a re-evaluation as a threat worthy of high actionable concern are probed.

Construction of an infectious Macrobrachium rosenbergii nodavirus from cDNA clones in Sf9 cells and improved recovery of viral RNA with AZT treatment

Macrobrachium rosenbergii nodavirus (MrNV) is usually accompanied by extra small virus (XSV) in natural outbreaks of white tail disease (WTD) in the giant river prawn Macrobrachium rosenbergii. Testing the virulence of MrNV alone has been problematic due to the difficulty in completely separating XSV from MrNV by viral purification steps from naturally infected shrimp. However, based on reports of natural M. rosenbergii specimens from WTD outbreak ponds that were positive for MrNV but negative for XSV led us to hypothesize that MrNV alone might cause WTD. To test this hypothesis, we prepared the two, complete genomic RNA fragments (RNA1 and RNA2) of MrNV from cDNA clones and used these to transfect Sf9 cells that subsequently showed cellular changes, including cell swelling, syncytial cell formation, and development of cytoplasmic inclusions within 72h post-transfection. Replication of RNA1 and RNA2 increased in the transfected cells and transmission electron microscopy of the cell lysates revealed the presence of icosahedral viral-like particles that were 40–50nm in diameter. When naïve Sf9 cells were inoculated with the cell lysate, the newly infected cells showed cellular changes and produced strong immunoreactivity against MrNV capsid protein indicating the infectious nature of the cell lysate. When the lysates were injected into the whiteleg shrimp Penaeus vannamei, MrNV RNA replication in the shrimp was followed by morality accompanied by typical MrNV lesions that gave possible positive immunohistochemical reactions for the MrNV capsid protein. Treatment of the Sf9 cells with azidothymidine triphosphate (AZT) prior to transfection significantly increased viral RNA synthesis and pathogenicity when compared with untreated, transfected cells. Using this model to produce infectious MrNV without XSV contamination proves that MrNV alone can be lethal to shrimp and it opens the way to further investigate the molecular basis of MrNV pathogenesis, and to develop antiviral strategy to control white tail disease.

Fowl aviadenovirus serotype 1 confirmed as the aetiological agent of gizzard erosions in replacement pullets and layer flocks in Great Britain by laboratory and in vivo studies

ABSTRACTAn investigation into the aetiology and pathogenesis of adenoviral gizzard erosion has been conducted following three natural outbreaks affecting one flock of 6-week-old replacement pullets and two consecutive placements of free range layers at the age of 21 and 23 weeks. Affected flocks showed increased mortality (0.12–0.30% per week), and gizzard lesions were consistent with fowl aviadenovirus (FAdV) involvement. To substantiate the initial findings, a selection of archived formalin-fixed paraffin-embedded gizzard samples from another 12 pullet and layer flocks, for which macroscopic and histopathological diagnosis of the disease were recorded in Great Britain during the period 2009–2016, were also investigated. In situ hybridization (ISH), virology and/or PCR confirmed the presence of FAdV species-A, serotype-1 (FAdV-A, FAdV-1) DNA in gizzard samples of all 15 cases investigated. Co-infections with additional FAdV serotypes including FAdV-8a were detected by serology and/or virology in two of the pullet flocks. However, species-specific in situ hybridization revealed that pathological changes of affected gizzards were only associated with the detection of FAdV-A. A subsequent in vivo study infecting 21-day-old SPF pullets with FAdV-1 or FAdV-8a strains isolated from the 6-week-old replacement pullets revealed characteristic pathomorphological changes only in the gizzards from birds infected with FAdV-1. While infection with FAdV-8a was confirmed by virology and serology, infected SPF birds did not develop pathomorphological changes. Therefore, the aetiological involvement of the isolated FAdV-8a in the development of adenoviral gizzard erosion in commercial pullets has been ruled out.