38 research outputs found

    Disease suppression of potting mixes amended with composted biowaste

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    Peat mining destroys valuable nature areas and contributes to the greenhouse effect. This warrants the search for alternatives for peat in potting mixes. Composted biowaste could provide such an alternative. An additional advantage of (partially) replacing peat by compost is the increased disease suppressiveness. In this study, nine commercial composted biowastes were tested for disease suppressiveness using the pathosystems Pythium ultimum-cucumber, Phytophthora cinnamomi-lupin and Rhizoctonia solani-carrot. Increased disease suppression was found in compost-amended potting mixes for all three pathosystems. The level of disease suppression ranged from slight stimulation of disease to strong suppression. Suppressiveness against one disease was not well correlated with that against the other diseases. The CO2 production, a measure of general microbial activity, was the parameter most strongly correlated with the level of disease suppression. Wetsieving the biowaste with tap water over a 4-mm sieve prior to composting yielded a compost with an 2.4-fold increase in organic matter and a twofold decrease in EC and Cl--concentration of the compost. The latter reductions allow for an increase of the amount of peat that can be replaced by compost. A linear relation was found between the amount of compost added to the potting mix and the level of disease suppression indicating the potential for increasing disease suppressiveness of potting mixes by replacing peat by high-quality composted biowastes

    Target product profiles:leprosy diagnostics

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    The World Health Organization (WHO) aims to reduce new leprosy cases by 70% by 2030, necessitating advancements in leprosy diagnostics. Here we discuss the development of two WHO's target product profiles for such diagnostics. These profiles define criteria for product use, design, performance, configuration and distribution, with a focus on accessibility and affordability. The first target product profile outlines requirements for tests to confirm diagnosis of leprosy in individuals with clinical signs and symptoms, to guide multidrug treatment initiation. The second target product profile outlines requirements for tests to detect Mycobacterium leprae or M. lepromatosis infection among asymptomatic contacts of leprosy patients, aiding prophylactic interventions and prevention. Statistical modelling was used to assess sensitivity and specificity requirements for these diagnostic tests. The paper highlights challenges in achieving high specificity, given the varying endemicity of M. leprae, and identifying target analytes with robust performance across leprosy phenotypes. We conclude that diagnostics with appropriate product design and performance characteristics are crucial for early detection and preventive intervention, advocating for the transition from leprosy management to prevention.</p

    Target product profiles:leprosy diagnostics

    Get PDF
    The World Health Organization (WHO) aims to reduce new leprosy cases by 70% by 2030, necessitating advancements in leprosy diagnostics. Here we discuss the development of two WHO's target product profiles for such diagnostics. These profiles define criteria for product use, design, performance, configuration and distribution, with a focus on accessibility and affordability. The first target product profile outlines requirements for tests to confirm diagnosis of leprosy in individuals with clinical signs and symptoms, to guide multidrug treatment initiation. The second target product profile outlines requirements for tests to detect Mycobacterium leprae or M. lepromatosis infection among asymptomatic contacts of leprosy patients, aiding prophylactic interventions and prevention. Statistical modelling was used to assess sensitivity and specificity requirements for these diagnostic tests. The paper highlights challenges in achieving high specificity, given the varying endemicity of M. leprae, and identifying target analytes with robust performance across leprosy phenotypes. We conclude that diagnostics with appropriate product design and performance characteristics are crucial for early detection and preventive intervention, advocating for the transition from leprosy management to prevention.</p

    An Overview of Phytosanitary Risk Aspects of Composting by Organic Farmers

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    Usage of compost in agriculture always brings about the risk of introducing plant pathogens. By proper composting, resulting in high temperatures during the thermophilic phase, compost can be applied safely. Organic farmers often prefer to compost organic residues themselves. The advantage of such an approach is that no material of foreign origin is introduced, but a drawback is the smaller scale of composting, which brings about greater phytosanitary risks. These risks can be dealt with by increasing the composting duration and by proper turning of the compost heap. If only organic residues from farms are composted, this usually results in low-quality composts because of the low lignin contents. Therefore, addition of materials that are high in lignin, such as wood chips, is advisable. In conclusion, on-farm composting is well possible from a phytosanitary point of view, but the farmer has to be aware of the factors that affect the phytosanitation of organic waste and the quality of the compost

    Identification of measures for prevention of black spots in organically produced stored carrots

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    In the Netherlands winter carrot for the fresh market is a cash crop for many organic growers of field vegetables. In the last few years blackish spots have been observed during storage of carrot roots. An inventory was carried out in 2001/2002 and 2002/2003 including in total 42 carrot lots from 22 growers. Statistical analysis was performed by multiple regression analysis to identify factors and variables that best explained the occurrence of black spots on stored carrots. Rhexocercosporidium carotae was the dominating pathogen in black spots of carrots harvested in 2001. From carrots harvested in 2002, Alternaria radicina was isolated most frequently, followed by A. dauci and R. carotae. Multiple regression analysis indicated that the occurrence of R. carotae was associated with wild umbelliferous plants or carrot production during the previous year in the neighbourhood of the investigated carrot fields. A high occurrence of the symptoms of black spots was associated with increasing damage caused during harvest or with higher temperatures during harvest

    Number of people requiring post-exposure prophylaxis to end leprosy: A modeling study.

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    BackgroundWorldwide, around 210,000 new cases of leprosy are detected annually. To end leprosy, i.e. zero new leprosy cases, preventive interventions such as contact tracing and post-exposure prophylaxis (PEP) are required. This study aims to estimate the number of people requiring PEP to reduce leprosy new case detection (NCD) at national and global level by 50% and 90%.Methodology/principal findingsThe individual-based model SIMCOLEP was fitted to seven leprosy settings defined by NCD and MB proportion. Using data of all 110 countries with known leprosy patients in 2016, we assigned each country to one of these settings. We predicted the impact of administering PEP to about 25 contacts of leprosy patients on the annual NCD for 25 years and estimated the number of contacts requiring PEP per country for each year. The NCD trends show an increase in NCD in the first year (i.e. backlog cases) followed by a significant decrease thereafter. A reduction of 50% and 90% of new cases would be achieved in most countries in 5 and 22 years if 20.6 and 40.2 million people are treated with PEP over that period, respectively. For India, Brazil, and Indonesia together, a total of 32.9 million people requiring PEP to achieve a 90% reduction in 22 years.Conclusion/significanceThe leprosy problem is far greater than the 210,000 new cases reported annually. Our model estimates of the number of people requiring PEP to achieve significant reduction of new leprosy cases can be used by policymakers and program managers to develop long-term strategies to end leprosy

    Fate of Escherichia coli O157:H7 in manure and amended soil: effects of cattle feeding, manure type and dairy management

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    In the present study, we studied the effect of cattle diet on the survival of E. coli O157:H7 in manure from dairy cattle subjected to 6 different feeding regimes consisting of 3 different roughage types and 2 levels of crude protein concentrates. In addition, the rate of survival of E. coli O157:H7 in manure-amended soil as a function of manure type (manure vs. slurry) and dairy farm management (organic vs. conventional) was determined. The roughage type affected significantly the decline rate of E. coli O157:H7: decline was faster in manures with relative higher pH and fiber content. Decline was faster in slurry compared to manure and in organic slurry compared to conventional slurry
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