Quantitative DNA metabarcoding reveals species composition of a macrocyclic lactone and pyrantel resistant cyathostomin population in the UK.
Journal: International journal for parasitology. Drugs and drug resistance
Year: August 14, 2024
Cyathostomins are the most abundant equid endoparasites globally. There are approximately fifty cyathostomin species and, whilst they occupy distinct niches within the large intestine, they are generally considered to share similar characteristics in terms of pathogenicity and response to drug treatment. There are three classes of anthelmintic licensed in the UK to treat cyathostomins (benzimidazoles, tetrahydropyrimidines and macrocyclic lactones) and cases of resistance have been documented for all classes. Previously, faecal egg count reduction tests (FECRT) on four UK Thoroughbred studs revealed multidrug resistant cyathostomins on one stud (A), with evidence of resistance to the macrocyclic lactones (MLs) ivermectin (IVM) and moxidectin (MOX), and to pyrantel (PYR). The remaining three studs (B-D) lacked resistance to IVM and MOX but had a shortened egg reappearance period post treatment. To determine whether specific species could be associated with the observed resistance and shortened egg reappearance period, strongyle eggs collected from between six and 15 individual horses per stud were copro-cultured to third larval stage (L3), before and after anthelmintic treatment, over a three-year timeframe (2021-2023). Quantitative DNA metabarcoding of the ITS-2 region was carried out on all samples. On stud A, single but differing species were found to be responsible for ML and pyrantel resistance in yearlings, Cyathostomum catinatum and Cylicocyclus nassatus, respectively. On studs B-D, with shortened egg reappearance periods, species composition remained largely unchanged post treatment. This study is the first to quantitatively profile cyathostomin species composition pre- and post-treatment in a multidrug resistant population in the UK, revealing that resistance in cyathostomins was species specific. This raises the question of whether these species may be responsible for ML and PYR resistance more widely and indicates that anthelmintic resistance in cyathostomins may not be a multi-species phenomenon.
Prevalence and Determinants of Food Allergy in the Era of Early Allergen Introduction: The EarlyNuts Population-Based Study.
Journal: The Journal Of Allergy And Clinical Immunology. In Practice
Year: May 03, 2024
Background: Infant feeding guidelines in Australia changed in 2016 to recommend introducing common allergy-causing foods by age 1 year to prevent food allergy. Although most Australian infants now eat peanut and egg by age 6 months, some still develop food allergy despite the early introduction of allergens.
Objective: To describe the prevalence of food allergy in a cohort recruited after introducing the nationwide allergy prevention recommendations; identify characteristics of infants who developed allergy despite early introduction of allergens; and estimate the causal effect of modifiable exposures on food allergy prevalence and whether this differed between infants who were introduced to allergens before or after age 6 months.
Methods: We recruited a population-based sample of 12-month-old infants in Melbourne, Australia. Infants had skin prick tests to four foods and parents completed questionnaires. Infants with evidence of sensitization were offered oral food challenges. Prevalence estimates were adjusted using inverse probability weighting.
Results: In a cohort of infants (n = 1,420) in which nearly all infants had been introduced to common allergens such as egg, milk, and peanut by age 1 year, the prevalence of food allergy remained high at 11.3% (95% CI, 9.6-13.4). Infants who developed food allergy despite introduction of the allergen by age 6 months were more likely to have Asian-born parents. Early-onset moderate or severe eczema was associated with an increased odds of food allergy irrespective of whether allergens were introduced before or after age 6 months. Among infants who were introduced to peanut at age 6 months or earlier, antibiotic use by age 6 months was associated with an increased odds of peanut allergy (adjusted odds ratio = 6.03; 95% CI, 1.15-31.60).
Conclusions: In a cohort in which early allergen introduction was common, the prevalence of food allergy remained high. Infants who developed food allergy despite introduction of the respective allergen by age 6 months were more likely to have had Asian parents and early-onset eczema. New interventions are needed for infants with a phenotype of food allergy that is not amenable to early allergen introduction.
Population Screening for Hereditary Haemochromatosis-Should It Be Carried Out, and If So, How?
Journal: Genes
Year: April 28, 2024
The Human Genome Project, completed in 2003, heralded a new era in precision medicine. Somewhat tempering the excitement of the elucidation of the human genome is the emerging recognition that there are fewer single gene disorders than first anticipated, with most diseases predicted to be polygenic or at least gene-environment modified. Hereditary haemochromatosis (HH) is an inherited iron overload disorder, for which the vast majority of affected individuals (>90%) have homozygosity for a single pathogenic variant in the HFE gene, resulting in p.Cys282Tyr. Further, there is significant benefit to an individual in identifying the genetic risk of HH, since the condition evolves over decades, and the opportunity to intervene and prevent disease is both simple and highly effective through regular venesection. Add to that the immediate benefit to society of an increased pool of ready blood donors (blood obtained from HH venesections can generally be used for donation), and the case for population screening to identify those genetically at risk for HH becomes more cogent. Concerns about genetic discrimination, creating a cohort of "worried well", antipathy to acting on medical advice to undertake preventive venesection or simply not understanding the genetic risk of the condition adequately have all been allayed by a number of investigations. So why then has HH population genetic screening not been routinely implemented anywhere in the world? The answer is complex, but in this article we explore the pros and cons of screening for HH and the different views regarding whether it should be phenotypic (screening for iron overload by serum ferritin and/or transferrin saturation) or genotypic (testing for HFE p.Cys282Tyr). We argue that now is the time to give this poster child for population genetic screening the due consideration required to benefit the millions of individuals at risk of HFE-related iron overload.
Neonatal BCG Vaccination for Prevention of Allergy in Infants: The MIS BAIR Randomised Controlled Trial.
Journal: Clinical And Experimental Allergy : Journal Of The British Society For Allergy And Clinical Immunology
Year: March 26, 2024
Background: The beneficial off-target effects of Bacille Calmette-Guérin (BCG) vaccination potentially include protection against allergy.
Objective: In the MIS BAIR trial, we aimed to determine whether neonatal BCG vaccination reduces atopic sensitisation and clinical food allergy in infants.
Methods: In this randomised controlled trial, 1272 neonates were allocated to BCG-Denmark vaccine (0.05 mL intradermal dose) or no BCG at birth. Randomisation was stratified by recruitment site, mode of delivery and plurality of birth. The primary outcome was the incidence of atopic sensitisation determined by skin prick test at 1 year of age. Food allergy was determined by 3-monthly online questionnaires and oral food challenges. Data were analysed by intention-to-treat using binary regression.
Results: gov (NCT01906853). Results: Atopic sensitisation during the first year of life was 22.9% among infants in the BCG group and 18.9% in the control group (adjusted risk difference (aRD) 3.8% (95% CI -1.5 to 9.1) after multiple imputation). Clinical food allergy was similar between infants in the BCG and control groups (9.8% vs. 9.6%; aRD 0.2, 95% CI -3.4 to 3.8). An interaction was observed between the primary outcome and maternal history of BCG vaccination. No interaction was observed for the additional prespecified potential effect modifiers tested (sex, delivery mode, family history of any allergy, season of birth, hepatitis B vaccination at randomisation, BCG scar and age at BCG administration).
Conclusions: Neonatal BCG-Denmark vaccination does not protect against atopic sensitisation or clinical food allergy in the first year of life.
Still a 'boys' club': a qualitative analysis of how gender affects a career in anaesthesia in Australia and Aotearoa New Zealand.
Journal: Anaesthesia
Year: February 28, 2024
Gender inequity remains an issue in anaesthesia despite increasing numbers of women training and achieving fellowship in the speciality. Women are under-represented in all areas of anaesthetic research, academia and leadership. The Gender Equity Subcommittee of the Australian and New Zealand College of Anaesthetists recently conducted a survey asking "Does gender still matter in the pursuit of a career in anaesthesia in 2022?". The survey was distributed to a randomly selected sample of 1225 anaesthetic consultants and completed by 470 respondents (38% response rate) with 793 free-text comments provided. Three overarching themes were identified: gender effects on the career and family interface; women do not fit the mould; and gender equity changes the status quo. Women respondents described a need to make a choice between career and family, which was not described by men, as well as stigmatisation of part-time work, a lack of access to challenging work and negative impacts of parental leave. Women respondents also described a sense of marginalisation within anaesthesia due to a 'boys' club' mentality, a lack of professional respect and insufficient structural supports for women in leadership. This was compounded for women from ethnically and culturally diverse backgrounds. A need for specific strategies to support anaesthetic careers for women was described as well as normalisation of flexibility in workplaces, combined with a broadening of our definition of success to allow people of all genders to experience fulfilment both at home and at work. This study is the first published qualitative data on factors affecting gender equity for anaesthetists in Australia and Aotearoa New Zealand. It highlights the need for further exploration, as well providing a foundation for changes in attitude and structural changes towards advancing gender equity.