An integrated strategy for managing Grapevine leafroll-associated virus 3 in red berry cultivars in New Zealand vineyards

<p>To sustain growth and revenue projections, the New Zealand wine sector aims to produce premium quality wine to supply lucrative export markets. In grapevines, however, the presence of virus and virus-like diseases can negatively influence qualitative parameters of wine production. Where such risks are identified, sustainable remediation protocols should be developed. One risk factor is Grapevine leafroll-associated virus 3 (GLRaV-3), an economically important virus of Vitis. In this thesis, I develop components of an integrated management plan with the aim of reducing and sustaining GLRaV-3 incidence at <1%. In Hawke’s Bay vineyard study blocks, three aspects related to GLRaV-3 management were explored between 2008 and 2013: Firstly, herbicide-treated vines and/or land left fallow after removing infected vines may mitigate the effects of GLRaV-3. Historically though, vine root removal was not well implemented, meaning persistent roots may be long term reservoirs for GLRaV-3. I tested the virus reservoir hypothesis in vineyard blocks where virus incidence of ≥95% necessitated removing all vines. Enzyme-linked immunosorbent assay (ELISA) and/or real-time polymerase chain reaction (real-time PCR) detected GLRaV-3 in most remnant root samples tested, independent of the herbicide active ingredient applied (glyphosate, triclopyr, or metsulfuron) or the fallow duration (6 months to 4 years). On some virus-positive root samples, the GLRaV-3 mealybug vector, Pseudococcus calceolariae, was found, and after real-time PCR testing, virus was detected in some mealybugs. Thus, without effective vine removal, unmanaged sources of virus inoculum and viruliferous vectors could pose a risk to the health of replacement vines. Secondly, in most red berry cultivars, GLRaV-3 is characterised by dark red downward curling leaves with green veins. With visual diagnostics predicted to be a reliable identifier of GLRaV-3-symptomatic red berry vines, early identification could support a cost-effective and sustainable virus management plan. In blocks planted in Merlot, Cabernet Sauvignon, Syrah, and Malbec vines, the reliability of visual symptom identification was compared with ELISA. In terms of sensitivity (binomial generalised linear model, 0.966) and specificity (0.998), late-season visual diagnostics reliably predicted virus infection. Moreover, accuracy appeared unaffected by the genetically divergent GLRaV-3 populations detected in Hawke’s Bay. Thirdly, by acting to visually identify and remove (rogue) symptomatic vines when GLRaV-3 incidence is low (<20%), an epidemic may be averted. In this ongoing study, an integrated approach to virus management was adopted in 13 well established Hawke’s Bay vineyard study blocks. All were planted in vines from one of five red berry cultivars. When monitoring commenced in 2009, all symptomatic vines visually identified (n=2,544 or 12%) were rogued. Thereafter, integrating visual diagnostics with roguing reduced virus incidence so that by 2013, just 434 (2.0%) vines were identified with virus symptoms. Annual monitoring revealed within-row vines immediately either side of an infected vine were most at risk of vector mediated virus transmission, although by 2013, just 4% of these vines had virus symptoms. Hence, roguing symptomatic vines only was recommended. In individual study blocks in 2013, virus management was tracking positively in four blocks; while in another four, results were inconclusive. In the remaining five blocks, contrasting but definitive results were evident. In three of those blocks, mean virus incidence of 10% in 2009 was sustained at ≤0.3% within 2-3 years of roguing commencing; in the other two blocks, mean incidence was 12% but cumulative vine losses of 37% (2011) and 46% (2013) culminated in roguing being replaced with whole block removal. In all five blocks, roguing protocols were standardised but in those with effective virus control, mealybug numbers were significantly lower in all years (mean: <0.2 per vine leaf; p≤0.036) relative to those where all vines were removed (mean: 0.4-2.3 per vine leaf). Overall, the results of this research suggest that rather than adopting a single management tactic in isolation, effective GLRaV-3 control instead requires an integrated plan to be implemented annually.</p>

An integrated strategy for managing Grapevine leafroll-associated virus 3 in red berry cultivars in New Zealand vineyards

<p>To sustain growth and revenue projections, the New Zealand wine sector aims to produce premium quality wine to supply lucrative export markets. In grapevines, however, the presence of virus and virus-like diseases can negatively influence qualitative parameters of wine production. Where such risks are identified, sustainable remediation protocols should be developed. One risk factor is Grapevine leafroll-associated virus 3 (GLRaV-3), an economically important virus of Vitis. In this thesis, I develop components of an integrated management plan with the aim of reducing and sustaining GLRaV-3 incidence at <1%. In Hawke’s Bay vineyard study blocks, three aspects related to GLRaV-3 management were explored between 2008 and 2013: Firstly, herbicide-treated vines and/or land left fallow after removing infected vines may mitigate the effects of GLRaV-3. Historically though, vine root removal was not well implemented, meaning persistent roots may be long term reservoirs for GLRaV-3. I tested the virus reservoir hypothesis in vineyard blocks where virus incidence of ≥95% necessitated removing all vines. Enzyme-linked immunosorbent assay (ELISA) and/or real-time polymerase chain reaction (real-time PCR) detected GLRaV-3 in most remnant root samples tested, independent of the herbicide active ingredient applied (glyphosate, triclopyr, or metsulfuron) or the fallow duration (6 months to 4 years). On some virus-positive root samples, the GLRaV-3 mealybug vector, Pseudococcus calceolariae, was found, and after real-time PCR testing, virus was detected in some mealybugs. Thus, without effective vine removal, unmanaged sources of virus inoculum and viruliferous vectors could pose a risk to the health of replacement vines. Secondly, in most red berry cultivars, GLRaV-3 is characterised by dark red downward curling leaves with green veins. With visual diagnostics predicted to be a reliable identifier of GLRaV-3-symptomatic red berry vines, early identification could support a cost-effective and sustainable virus management plan. In blocks planted in Merlot, Cabernet Sauvignon, Syrah, and Malbec vines, the reliability of visual symptom identification was compared with ELISA. In terms of sensitivity (binomial generalised linear model, 0.966) and specificity (0.998), late-season visual diagnostics reliably predicted virus infection. Moreover, accuracy appeared unaffected by the genetically divergent GLRaV-3 populations detected in Hawke’s Bay. Thirdly, by acting to visually identify and remove (rogue) symptomatic vines when GLRaV-3 incidence is low (<20%), an epidemic may be averted. In this ongoing study, an integrated approach to virus management was adopted in 13 well established Hawke’s Bay vineyard study blocks. All were planted in vines from one of five red berry cultivars. When monitoring commenced in 2009, all symptomatic vines visually identified (n=2,544 or 12%) were rogued. Thereafter, integrating visual diagnostics with roguing reduced virus incidence so that by 2013, just 434 (2.0%) vines were identified with virus symptoms. Annual monitoring revealed within-row vines immediately either side of an infected vine were most at risk of vector mediated virus transmission, although by 2013, just 4% of these vines had virus symptoms. Hence, roguing symptomatic vines only was recommended. In individual study blocks in 2013, virus management was tracking positively in four blocks; while in another four, results were inconclusive. In the remaining five blocks, contrasting but definitive results were evident. In three of those blocks, mean virus incidence of 10% in 2009 was sustained at ≤0.3% within 2-3 years of roguing commencing; in the other two blocks, mean incidence was 12% but cumulative vine losses of 37% (2011) and 46% (2013) culminated in roguing being replaced with whole block removal. In all five blocks, roguing protocols were standardised but in those with effective virus control, mealybug numbers were significantly lower in all years (mean: <0.2 per vine leaf; p≤0.036) relative to those where all vines were removed (mean: 0.4-2.3 per vine leaf). Overall, the results of this research suggest that rather than adopting a single management tactic in isolation, effective GLRaV-3 control instead requires an integrated plan to be implemented annually.</p>

Electronic surveillance system for COVID-19 virus management in Palestine- an observational study

This research investigated the performance of the electronic surveillance system of COVID 19 and assessed its key attributes. The research results for the overall system performance were good (82.81%). The highest attribute score was 100% for representativeness and data completeness and the lowest score was 75.30% for acceptability. The COVID-19 surveillance system is generally simple and accepted by users, although the instability of electricity and the Internet, the benefit from the training on the system, and the lack of willingness to participate in the system at the health facility level had the greatest impact on simplicity and acceptability scores. The quality and completeness of the data enabled stakeholders to carry out the most effective prevention and control activities. System developers indicated that the system has achieved the desired benefit, due to the flexibility and stability of the system and comprehensiveness of geographical coverage.

COVID-19 mitigation strategies for reduced transmission in U.S. prisons

During the global COVID-19 pandemic, prisons have been the center of numerous outbreaks. Current efforts in virus containment have largely failed, due to a lack of standardized guidelines and reporting of key data regarding testing, cases, and deaths within state prisons. This article addresses challenges associated with pandemic management in prisons and policy options to reduce risk to inmates, prison staff, and the communities surrounding prisons. A comprehensive framework for evaluating a state prison’s virus management can facilitate improved responses, in particular amongst the rise of more virulent strains and ongoing cases. Such a framework may also serve as guidance in other situations of a similar nature.

A nurse-led, telehealth-driven hepatitis C management initiative in regional Victoria: Cascade of care from referral to cure

Introduction Elimination of hepatitis C virus stands as an unresolved World Health Organization target, and is associated with complications including cirrhosis and hepatocellular carcinoma. Hepatitis C virus management has been revolutionised following the widespread availability of direct-acting antiviral agents in Australia since 2016; however, large proportions of the population remain untreated. Telehealth-based service delivery is an accessible and effective alternative, and we aimed to assess qualitative and clinical outcomes in a clinical nurse consultant-led regional telehealth model. Methods A prospective cohort analysis of all patients referred to a Victorian regional hospital’s hepatitis C virus telehealth clinic between 1 April 2017 and 10 June 2020 was conducted. Data were collated from outpatient and electronic medical records. Results Fifty-five out of 71 referred patients were booked, with 44 patients (80%) attending at least one appointment. A history of alcohol use disorder and psychiatric comorbidity was seen in 25 (54%) and 24 (52%) patients, respectively. Twenty-one out of 24 (88%) eligible patients had direct-acting antiviral agent treatment and 14 out of 21 (67%) successfully completed the treatment. An average of 46.5 km, 54.6 min and $AUD30.70 was saved per patient for each visit. Observed benefits included: increased medical engagement, adherence to and completion of HCV treatment and cirrhosis monitoring. Telehealth-driven hepatocellular carcinoma surveillance was successful in the cirrhotic subgroup. Conclusion Clinical nurse consultant-led hepatitis C virus management via telehealth allows access to marginalised regional populations. Clinical outcomes were comparable to other cohorts with additional cost-benefit, efficiency gains and carbon footprint reduction amongst a previously unreported regional Victorian hepatitis C virus population.

Viral Infections in Pregnancy – Part 2: Viral Influenza, Mononucleosis, Mumps, Parvovirus, Rubella, Rubeola, Varicella-Zoster Virus, and Zika Virus

A number of viral infections contribute to morbidity and mortality in pregnancy and the postpartum period [Table 1]. Here we discuss some of the major viral infections that occur in pregnancy. This particular review focuses on viral influenza, mononucleosis, mumps, parvovirus, rubella, rubeola, varicella-zoster virus, and Zika virus; other viral etiologies are discussed separately. It is imperative to understand the risk factors, clinical course, diagnostic methodology, and management of these illnesses in order to optimize perinatal outcome. This review contains 4 figures, 12 tables, and 76 references. Keywords: viral infection, pregnancy, prenatal, perinatal, influenza, mumps, parvovirus, rubella, rubeola, measles, varicella-zoster virus, Zika virus, management