European outbreak of atypical myopathy in the autumn 2009

Background – Atypical myopathy is an acute, severe rhabdomyolysis occurring in grazing horses. In the beginning of October 2009, a new outbreak occurred in several European countries. Geographic, demographic and clinical data of the reported cases in the month October 2009 are described. Key Findings – The survival rate in this outbreak was 25%. The most frequently observed clinical signs were congested mucous membranes, dyspnea, tachycardia, depression, weakness, stiffness, recumbency, trembling, sweating, and myoglobinuria. Nonsurvivors were significantly more likely to be recumbent than survivors. Prognostic factors, symptomatic treatment, and preventive measures are discussed. Significance – Differences were encountered during the described outbreak of atypical myopathy in October 2009 compared with previous outbreaks reported. Equine practitioners should be aware that previous epidemiological studies have shown that after a high prevalence in the autumn, new cases are likely to occur in the following spring.     

A comparison of methods for combining maps in pest risk assessment: application to Diabrotica virgifera virgifera

Host area, potential pest impact and probability of pest presence are frequently displayed on maps by pest risk assessors. These variables can be mapped separately, but it is also important to map combinations of these variables in order to define the area of potential establishment and the endangered area to assist decision‐making processes. This paper presents different methods for combining maps, and discusses their advantages and disadvantages. Different methods are shown that can be used to combine maps depending on whether the individual maps were derived from continuous quantitative variables or from discrete variables. The authors suggest combining maps derived from continuous variables using simple mathematical equations in order to compute expected invaded areas and expected potential impacts. Maps derived from discrete variables (e.g. scores) can be combined using a risk matrix, but the results may be highly dependent on the chosen matrix. The practical interest of these methods is illustrated in a case study on Diabrotica virgifera virgifera. The authors recommend combining the original continuous variables when such variables are available. The combination of categories defined from continuous variables led to a loss of information and may decrease the values of the maps. Risk matrices should be used only if the individual variables are discrete and if the underlying continuous variables are not available.     

A decision‐support scheme for mapping endangered areas in pest risk analysis*

This paper describes a decision‐support scheme (DSS) for mapping the area where economically important loss is likely to occur (the endangered area). It has been designed by the PRATIQUE project to help pest risk analysts address the numerous risk mapping challenges and decide on the most suitable methods to follow. The introduction to the DSS indicates the time and expertise that is needed, the data requirements and the situations when mapping the endangered areas is most useful. The DSS itself has four stages. In stage 1, the key factors that influence the endangered area are identified, the data are assembled and, where appropriate, maps of the key factors are produced listing any significant assumptions. In stage 2, methods for combining these maps to identify the area of potential establishment and the area at highest risk from pest impacts are described, documenting any assumptions and combination rules utilised. When possible and appropriate, Stage 3 can then be followed to show whether economic loss will occur in the area at highest risk and to identify the endangered area. As required, Stage 4, described elsewhere, provides techniques for producing a dynamic picture of the invasion process using a suite of spread models. To illustrate how the DSS functions, a maize pest, Diabrotica virgifera virgifera, and a freshwater invasive alien plant, Eichhornia crassipes, have been used as examples.     

Consistency in pest risk analysis – how can it be achieved and what are the benefits?*

This paper describes the efforts in the PRATIQUE EU project to increase consistency that were integrated into the revised EPPO Decision‐support scheme (DSS) for Pest Risk Analysis (PRA). The establishment section is used here to illustrate the changes and improvements of the DSS, as it has undergone the most comprehensive changes with reformulation and restructuring of many questions and detailed rating guidance. When revising the establishment section of the EPPO DSS for PRA, there were three principal objectives that influenced the revision: (i) to focus the assessment on the most relevant factors influencing establishment; (ii) to identify the area where establishment is possible before assessing the suitability of that area, and (iii) to enhance the consistency of the establishment section by providing rating guidance with sub‐questions and examples. To simplify the process, some questions were rephrased as closed questions (answer is either yes or no). Clearer notes were provided to explain what information is needed to answer the questions. Furthermore, consistency has been enhanced by developing tools to help assessors when deciding on an appropriate overall risk rating and uncertainty score by providing a visual summary of the risk ratings and uncertainty scores (‘Visualizer’) and a method for integrating all the responses to the questions to provide a summary score for each major section and an overall assessment of risk (‘Rule based matrix model’).     

Pathway analysis: aquatic plants imported in 10 EPPO countries

Pathway analyses are regarded by National Plant Protection Organizations as a very efficient way to address the risks posed by invasive alien species. Data on import of aquatic plants was obtained from 10 EPPO countries (Austria, Czech Republic, Estonia, France, Germany, Hungary, the Netherlands, Latvia, Switzerland and Turkey) and aggregated in order to consider whether invasive or potentially invasive alien plants could be introduced in the EPPO region through this pathway. This study highlights that this pathway mainly consists of the import of tropical plants for use in aquaria, and which do not represent a risk due to their climatic requirements. However, a few species require thorough attention owing to the threats they cause. Of the 247 species recorded as imported, only 10 are currently considered to be a threat, representing 4% of the total number of plants imported. These 10 invasive or potentially invasive species continue to be traded in huge quantities in spite of the fact that Crassula helmsii and Eichhornia crassipes are recommended for regulation by EPPO, Azolla filiculoides, Egeria densa, Elodea nuttalli, Lagarosiphon major, Ludwigia grandiflora and Myriophyllum aquaticum should have their entry and spread prevented by countries and Hydrilla verticillata and Pistia stratiotes are recorded on the EPPO Alert List. Six additional species have been identified as representing a moderate to high potential risk: Alternanthera sessilis, Adiantum raddianum, Gymnocoronis spilanthoides, Hygrophila polysperma, Limnophila sessiliflora and Syngonium podophyllum. These species could be subject to further investigation, possibly a pest risk analysis, to evaluate the risk they may represent.     

The EPPO prioritization process for invasive alien plants

Although invasive alien plants are gaining increased attention within EPPO countries, there is no existing widely agreed method to identify those alien plants that are considered invasive and represent the highest priority for pest risk analysis. In the framework of the ad hoc Panel on Invasive Alien Species, EPPO proposes a prioritization process for invasive alien plants designed (i) to produce a list of invasive alien plants that are established or could potentially establish in the EPPO region and (ii) to determine which of these have the highest priority for an EPPO pest risk analysis. The process consists of compiling available information on alien plants according to pre‐determined criteria, and can be run at the EPPO region level, or at a country or local area level. These criteria examine whether the species is alien in the area under study, and whether it is established or not. The criteria used primarily rely on observations in the EPPO region but, if the species is not established, the invasive behaviour of the species in other countries should be investigated, as well as the suitability of the ecoclimatic conditions in the area under consideration. The spread potential, the potential negative impacts on native species, habitats and ecosystems, as well as on agriculture, horticulture or forestry are considered. If the species qualifies as an invasive alien plant of major concern through this first set of questions, the process then investigates the efficiency of international measures (to be justified through a pest risk analysis) to prevent the entry and spread of the species. The second set of questions are designed to determine whether the species is internationally traded or enters new countries through international pathways for which the risk of introduction is superior to natural spread, and whether the species still has a significant suitable area for further spread. If used by several EPPO countries, this prioritization process represents an opportunity to provide consistent country lists of invasive alien plant species, as well as a tool for dialogue and exchange of information.     

The suppressive effects of composts used as growth media against <Emphasis Type="Italic">Botrytis cinerea</Emphasis> in cucumber plants

The incidence/severity of soil-borne plant diseases is often reduced when composts are used as growth media. However, much less information is available about the effects of composts on the development of foliar diseases. Here we studied the suppressive capacity of five composts (from olive marc-cotton gin trash, grape marc, cork, spent mushroom and municipal organic and yard wastes) as growth media against Botrytis cinerea disease in cucumber plants. We also examined the putative correlations of several biotic and abiotic factors involved in disease suppression. The suppressive capacity of the growth media was studied by comparing disease incidence/severity in plants grown in composts with that occurring in plants grown in commercial peats, which are conducive to most soilborne diseases. Correlations were made between the occurrence of disease and leaf nutrient status, as well as electrical conductivity (EC) and microbial activity (measured as β-glucosidase activity) in the growth media. Cucumber plants grown in the peats showed greater severity of B. cinerea during the bioassay than those grown in composts. Mo, Ca and Si content in leaves showed negative correlations with this disease. A negative correlation with disease severity was observed for EC and microbial activity in the growth media. The noticeable reduction in B. cinerea in plants grown in composts was related to the supply of specific chemical elements, a certain degree of salt stress, and the high microbial activity of composts.     

AORTO-CARDIAC FISTULAS IN SEVEN HORSES

This report describes the history, clinical, electrocardiographic and echocardiographic findings, treatment, outcome, and post-mortem findings in seven horses with aorto-cardiac fistula. Affected horses included 5 stallions, one gelding and one mare; 2 each of the Thoroughbred, Arabian and Standardbred breeds and one Thoroughbred-cross with a mean ± s.d. age of 12 ± 4 years, range 6–18 years. The presenting sings were acute distress (four horses), exercise intolerance (two horses) and the lesion was detected during a routine examination in one horse. Five horses had monomorphic ventricular tachycardia on admission and one other had a history of this arrhythmia. Five horses had a characteristic continuous murmur loudes in the right fourth intercostal space. Echocardiography (six horuses) and/or post-mortem examination (four horses) revealed the horses had aorto-cardiac fistulas arising from the right aortic sinus in all five horses in which the site was recorded. Two horses had ruptured aneurysmall dilatations of the aortic wall at this site. Fistulas extended into the right ventricle in four horses; the right atrium in two horses, the left ventricle in one horse, and five horses had dissecting tracts in the septal myocardium. Horses survived for periods ranging from 24th to 4 years. Aorto-cardiac fistula should be considered in the differential diagnosis for horses presenting with acute distress, bounding arterial pulse, a right-sided continuous murmur and/or monomorphic ventricular tachycardia, particularly in middle-aged or older stallions. Echocardiography is the technique of choice for confirming the diagnosis and demonstrating accompanying cardiac changes.