Genetic typing of bovine viral diarrhoea virus in cattle on Irish farms

Bovine viral diarrhoea (BVD) is a pestivirus infection of cattle and other domesticated and free living animals. Two genotypes, bovine viral diarrhoea virus type 1 (BVDV-1) and bovine viral diarrhoea virus type 2 (BVDV-2) are recognised with 17 subgroups of BVDV 1 and 3 subgroups of BVDV 2. However, little is known about the genotypes of BVDV circulating in Irish cattle herds and the aim of this project was to characterise the BVD virus types archived at the Irish Equine Centre. A database of all BVDV positive diagnostic samples archived at the Irish Equine Centre was compiled. This consisted of information relating to in excess of one thousand blood and milk samples submitted for analysis between 2011 and 2014. A randomized panel of 375 virus positive samples representative of location, type (beef or dairy), gender, age, breed, year and month of detection was selected for genotyping. Total nucleic acid was extracted from all samples and the RNA concentration was measured using a biophotometer. Forward and reverse primers were synthesised to target two regions consistently conserved among all pestiviruses, a highly conserved 288bp portion of the 5’ untranslated region (UTR) and a more variable 428bp segment of the N-terminal autoprotease (Npro) gene. A one-step reverse transcriptase polymerase chain reaction (RT-PCR) method was specifically optimized to amplify both targets. Amplified products were gel purified, sequenced and aligned with 5’UTR and Npro gene sequences representative of all known BVDV genotypes and sub-genotypes. The genotype and subgenotype was established for 325 field viruses and one commercial vaccine viral strain based on the analysis of at least one genomic region. BVDV-1a was the prominent subgenotype (n=317) with BVDV-1b (n=6), BVDV-1d (n=1) and BVDV-1e (n=1) also observed. A number of nucleotide sequence alignments and phylogenetic trees were constructed to represent the relationship between Irish field viruses and reference strains representative of all known BVDV genotypes and subgenotypes. Evidence of both herd specific clustering and circulation of multiple strains within herds was observed; however no evidence of county specific clustering was observed. A number of completely conserved nucleotide regions were observed and the 5’UTR was found to be more conserved than the Npro fragment analysed. The results of this study provide a detailed and comprehensive insight into the genetic diversity of BVDV in circulation within Irish cattle herds and will act as a baseline reference for future BVDV genotyping studies

Prevalence of treatment-resistant hypertension after considering pseudo-resistance and morbidity: a cross-sectional study in Irish primary care

Background To confirm treatment-resistant hypertension (TRH), ambulatory blood pressure measurement (ABPM) must exclude white-coat hypertension (WCH), three or more medications should be prescribed at the optimal doses tolerated, and non-adherence and lifestyle should be examined. Most previous studies have not adequately considered pseudo-resistance and merely provide an apparent TRH (aTRH) prevalence figure. Aim To conduct a cross-sectional study of the prevalence of aTRH in general practice, and then consider pseudo-resistance and morbidity. Design and setting With support, 16 practices ran an anatomical therapeutic chemical (ATC) drug search, identifying patients on any possible hypertensive medications, and then a search of individual patients' electronic records took place. Method ABPM was used to rule out WCH. The World Health Organization-defined daily dosing guidelines determined adequate dosing. Adherence was defined as whether patients requested nine or more repeat monthly prescriptions within the past year. Results Sixteen practices participated (n = 50 172), and 646 patients had aTRH. Dosing was adequate in 19% of patients, 84% were adherent to medications, as defined by prescription refill, and 43% had ever had an ABPM. Using a BP cut-off of 140/90 mmHg, the prevalence of aTRH was 9% (95% confidence interval [CI] = 9.0 to 10.0). Consideration of pseudo-resistance further reduced prevalence rates to 3% (95% CI = 3.0 to 4.0). Conclusion Reviewing individual patient records results in a lower estimate of prevalence of TRH than has been previously reported. Further consideration for individual patients of pseudo-resistance additionally lowers these estimates, and may be all that is required for management in the vast majority of cases

Measuring adherence to therapy in apparent treatment-resistant hypertension: a feasibility study in Irish primary care

BACKGROUND: Apparent treatment-resistant hypertension (aTRH) is defined as uncontrolled blood pressure (BP) in patients taking three or more antihypertensive medications. Some patients will have true treatment-resistant hypertension, some undiagnosed secondary hypertension, while others have pseudo-resistance. Pseudo-resistance occurs when non-adherence to medication, white-coat hypertension (WCH), lifestyle, and inadequate drug dosing are responsible for the poorly controlled BP. AIM: To examine the feasibility of establishing non-adherence to medication, for the first time in primary care, using mass spectrometry urine analysis. Operationalisation would be established by at least 50% of patients participating and 95% of samples being suitable for analysis. Clinical importance would be confirmed by >10% of patients being non-adherent. DESIGN AND SETTING: Eligible patients with aTRH (n = 453) in 15 university research-affiliated Irish general practices were invited to participate. METHOD: Participants underwent mass spectrometry urine analysis to test adherence and ambulatory BP monitoring (ABPM) to examine WCH. RESULTS: Of the eligible patients invited, 52% (n = 235) participated. All 235 urine samples (100%) were suitable for analysis: 174 (74%) patients were fully adherent, 56 (24%) partially adherent, and five (2%) fully non-adherent to therapy. A total of 206 patients also had ABPM, and in total 92 (45%) were categorised as pseudo-resistant. No significant associations were found between adherence status and patient characteristics or drug class. CONCLUSION: In patients with aTRH, the authors have established that it is feasible to examine non-adherence to medications using mass spectrometry urine analysis. One in four patients were found to be partially or fully non-adherent. Further research on how to incorporate this approach into individual patient consultations and its associated cost-effectiveness is now appropriate