Re-evaluation of Seed Transmission of Clavibacter michiganensis subsp. nebraskensis in Zea mays.

The spread of Goss's bacterial wilt and leaf blight of corn (Zea mays), caused by Clavibacter michiganensis subsp. nebraskensis, to a wider geographic range in the early 2000s compared with the late 1960s has generated concern about the possible role of seed transmission in long-distance spread. The objectives of this research were: (1) to determine the percentage of seed infection found in seed harvested from inoculated and noninoculated plants of hybrids that varied in resistance to Goss's wilt; and (2) to estimate the seed transmission rate from these infected seed lots. The greatest percent seed infection was detected in seed from inoculated plants of the most susceptible hybrid and the least in seed from the most resistant hybrid. Seed lots with seed infection that ranged from 3.6 to 37.0% were planted in three field and three greenhouse trials. A total of 12 seed transmission events (Goss's wilt symptomatic seedlings) were identified among 241,850 plants examined, for a seed transmission rate of 0.005%. When the seed transmission rate was recalculated to consider only the infected seed portion of each seed lot, the rate increased to 0.040% (12 events from 30,088 potentially infected plants). Based on the low seed transmission rate observed and previous research on disease spread from a point source, it seems unlikely that seed transmission could introduce enough inoculum to create a serious disease outbreak in a single growing season. However, risk of seed transmission is relevant for phytosanitary restrictions and preventing the introduction of the pathogen to new areas. To date, Goss's wilt has not been detected outside North America, and while the risk of seed transmission is very low, the risk is not zero. Fortunately, the presence of C. michiganensis subsp. nebraskensis in corn seed is readily detectable by established seed health testing methods.

Impact of coronavirus disease 2019 on patients with primary adrenal insufficiency: a cross-sectional study.

Objective: Patients with primary adrenal insufficiency (PAI) are thought to be particularly vulnerable to coronavirus disease 2019 (COVID-19); however, little is known about its true impact on this group. We assessed morbidity and health promotion attitudes during the pandemic amongst a large cohort of patients with PAI. Design: Cross-sectional, single-centre study. Methods: In May 2020, COVID-19 advice on social distancing and sick-day rules was distributed to all patients with PAI registered with a large secondary/tertiary care centre. A semi-structured questionnaire was used to survey patients in early 2021. Results: Of 207 contacted patients, 162 responded (82/111 with Addison's disease, AD; 80/96 with congenital adrenal hyperplasia, CAH). Patients with AD were older than those with CAH (median age 51 vs 39 years; P < 0.001) and had more comorbidities (Charlson comorbidity index ≥2 47.6% vs 10.0%; P< 0.001). By the time of the survey, 47 patients (29.0%) had been diagnosed with COVID-19, the second commonest cause of sick-day dosing during the study and the leading trigger of adrenal crises (4/18 cases). Patients with CAH had a higher risk of COVID-19 compared to AD (adjusted odds ratio 2.53 (95% CI 1.07-6.16), P= 0.036), were less inclined to have the COVID-19 vaccine (80.0% vs 96.3%; P = 0.001), and were less likely to have undergone hydrocortisone self-injection training (80.0% vs 91.5%; P = 0.044) or wear medical alert jewellery (36.3% vs 64.6%; P = 0.001). Conclusions: COVID-19 was a principal trigger for adrenal crises and sick-day dosing in patients with PAI. Despite a higher risk of COVID-19, patients with CAH showed less engagement with self-protective attitudes. Significance statement: We conducted a cross-sectional study on a large and well-characterised group of patients with PAI and demonstrated that COVID-19 was a leading cause of morbidity during the early phases of the pandemic. Patients with AD were older and had a greater burden of comorbidity than those with CAH, including non-adrenal autoimmune disorders. However, patients with CAH were more likely to develop COVID-19 and demonstrated reduced engagement with healthcare services and health promotion strategies.

Interventions for the prevention of adrenal crisis in adults with primary adrenal insufficiency: a systematic review.

Objective: The incidence of adrenal crisis (AC) remains high, particularly for people with primary adrenal insufficiency, despite the introduction of behavioural interventions. The present study aimed to identify and evaluate available evidence of interventions aiming to prevent AC in primary adrenal insufficiency. Design: This study is a systematic review of the literature and theoretical mapping. Methods: MEDLINE, MEDLINE in Process, EMBASE, ERIC, Cochrane CENTRAL, CINAHL, PsycINFO, the Health Management Information Consortium and trial registries were searched from inception to November 2021. Three reviewers independently selected studies and extracted data. Two reviewers appraised the studies for the risk of bias. Results: Seven observational or mixed methods studies were identified where interventions were designed to prevent AC in adrenal insufficiency. Patient education was the focus of all interventions and utilised the same two behaviour change techniques, 'instruction on how to perform a behaviour' and 'pharmacological support'. Barrier and facilitator themes aiding or hindering the intervention included knowledge, behaviour, emotions, skills, social influences and environmental context and resources. Most studies did not measure effectiveness, and assessment of knowledge varied across studies. The study quality was moderate. Conclusion: This is an emerging field with limited studies available. Further research is required in relation to the development and assessment of different behaviour change interventions to prevent AC.