Difference in differences analysis evaluates the effects of the badger control policy on bovine tuberculosis in England.

Persistent tuberculosis (TB) in cattle populations in England has been associated with an exchange of infection with badgers (Meles meles). A badger control policy (BCP) commenced in 2013. Its aim was to decrease TB incidence in cattle by reducing the badger population available to provide a wildlife reservoir for bovine TB. Monitoring data from 52 BCP intervention areas 200-1600 km2 in size, starting over several years, were used to estimate the change in TB incidence rate in cattle herds, which was associated with time since the start of the BCP in each area. A difference in differences analysis addressed the non-random selection and starting sequence of the areas. The herd incidence rate of TB reduced by 56% (95% Confidence Interval 41-69%) up to the fourth year of BCP interventions, with the largest drops in the second and third years. There was insufficient evidence to judge whether the incidence rate reduced further beyond 4 years. These estimates are the most precise for the timing of declines in cattle TB associated with interventions primarily targeting badgers. They are within the range of previous estimates from England and Ireland. This analysis indicates the importance of reducing transmission from badgers to reduce the incidence of TB in cattle, noting that vaccination of badgers, fertility control and on farm biosecurity may also achieve this effect.

Introduction of a Maternal-Fetal Medicine Tele-Ultrasound Program in Rural Alberta.

OBJECTIVES: We established a program of Maternal-Fetal Medicine (MFM) telemedicine that is safe and acceptable. Since December 2019, a multi-disciplinary team has been planning this quality improvement project. METHODS: We performed a pilot study to investigate the feasibility of using telemedicine and tele-ultrasound to enable prompt MFM consultations for patients in remote locations. We began with the training of sonographers followed by implementation in a small pilot. Interim analysis of the acceptability and feasibility of the program was done through patient surveys, images audit, and review of neonatal outcomes. RESULTS: Our background epidemiologic data showed that in Alberta, between 2017 and 2022, 460 patients travelled >6 hours, and 5038 travelled >2 hours from home to reach their site of birth. Patients were appropriately triaged to delivery/consultation at the tertiary level center based on diagnosis/suspicion of anomalies, such as abnormally invasive placenta, intrauterine growth restriction, hydrops, and partial agenesis of the corpus callosum, all of which were confirmed postdelivery. There was no neonatal mortality, and the single stillbirth was related to an unpreventable peri-viable co-twin demise. The patient survey demonstrated that for >85% of respondents the program reduced costs and stress. Ultrasound image audit found improvement and consistency in image quality after 3 months of training combined with supervision. CONCLUSION: MFM telemedicine is feasible and can be safe with adequate supervision. Additional support and resources are needed to scale and spread this quality improvement initiative.

Simulating partial vaccine protection: BCG in badgers.

In wildlife disease management there are few diseases for which vaccination is a viable option. The human vaccine BCG has been used for the control of bovine tuberculosis in badgers since 2010 and is expected to increase. Understanding the long-term effects of repeated vaccination campaigns on disease prevalence is vital, but modelling thus far has generally assumed that a vaccine provides perfect protection to a proportion of the population, and that animals exposed to a repeated vaccination have a second independent chance of becoming protected. We held a workshop with experts in the field to obtain consensus over the main pathways for partial protection in the badger, and then simulated these using an established model. The available data supported the possibility that some individuals receive no benefit from the BCG vaccine, others may result in a delayed disease progression and in the remaining animals, vaccine protected the individual from any onward transmission. Simulating these pathways using different levels of overall efficacy demonstrated that partial protection leads to a reduced effect of vaccination, but in all of the identified scenarios it was still possible to eradicate disease in an isolated population with no disease introduction. We also identify those potential vaccination failures that require further investigation to determine which of our proposed pathways is the more likely.

Impact of birth tourism on health care systems in Calgary, Alberta.

BACKGROUND: Birth tourism refers to non-resident women giving birth in a country outside of their own in order to obtain citizenship and/or healthcare for their newborns. We undertook a study to determine the extent of birth tourism in Calgary, the characteristics and rationale of this population, and the financial impact on the healthcare system. METHODS: A retrospective analysis of 102 women identified through a Central Triage system as birth tourists who delivered in Calgary between July 2019 and November 2020 was performed. Primary outcome measures were mode of delivery, length of hospital stay, complications or readmissions within 6 weeks for mother or baby, and NICU stay for baby. RESULTS: Birth Tourists were most commonly from Nigeria (24.5%). 77% of Birth Tourists stated that their primary reason to deliver their baby in Canada was for newborn Canadian citizenship. The average time from arrival in Calgary to the EDD was 87 days. Nine babies required stay in the neonatal intensive care unit (NICU) and 3 required admission to a non NICU hospital ward in first 6 weeks of life, including 2 sets of twins. The overall amount owed to Alberta Health Services for hospital fees for this time period is approximately $694 000.00. CONCLUSION: Birth Tourists remain a complex and poorly studied group. The process of Central Triage did help support providers in standardizing process and documentation while ensuring that communication was consistent. These findings provide preliminary data to guide targeted public health and policy interventions for this population.

A combined measure of tuberculous lesions for assessing the efficacy of vaccination against tuberculosis (Mycobacterium bovis) in European badgers (Meles meles) supports the 3Rs principle of reduction.

BACKGROUND: An oral vaccine is a potential tool to tackle the reservoir of Mycobacterium bovis in European badgers (Meles meles), which contributes to tuberculosis of cattle in the British Isles. Inferences about vaccine protection against experimental challenge with M. bovis depend on the measurement of tuberculosis. Assessment of tuberculosis in larger species, such as badgers, is typically based on the tuberculous lesions visible at post-mortem examination and histopathology. We have developed a robust scoring system for tuberculous lesions by combining several parallel measures, which we call the "disease burden score" (DBS). METHODS: Alternative scoring systems were compared within a regression analysis applied to observations from a total of 168 badgers from eight studies, including 107 badgers subjected to vaccination treatment and 61 non-vaccinated controls. The analysis included incidental observations that were recorded from each badger as potential covariate factors explaining some of the variation among animals sourced from the wild. RESULTS: DBS was found to be the most accurate and reliable of the scoring systems compared. By taking account of significant covariates affecting disease, application of the DBS reduced residual variance by 22.9%. A previously used measure, based on assessment of visible lesions, was suboptimal due to non-uniform variance that increased with expected value, although square root transformation addressed this issue. The covariate model fitted to DBS included sex (males had higher DBS), weight (negatively associated with DBS) and immunological evidence of prior exposure to Mycobacterium avium (positively associated with DBS). CONCLUSIONS: We identified improved measures of tuberculous disease derived from data already collected. We also demonstrated that the proper scaling of measurements of disease in such models is necessary and can be determined empirically. The covariates which were most strongly associated with the severity of disease are important in experimental studies involving outbred animals with variable background.

Optimisation of Mycobacterium bovis BCG Fermentation and Storage Survival.

Mycobacterium bovis Bacillus Calmette-Guérin (M. bovis BCG) was generated over a century ago for protection against Mycobacterium tuberculosis (Mtb) and is one the oldest vaccines still in use. The BCG vaccine is currently produced using a pellicle growth method, which is a complex and lengthy process that has been challenging to standardise. Fermentation for BCG vaccine production would reduce the complexity associated with pellicle growth and increase batch to batch reproducibility. This more standardised growth lends itself to quantification of the total number of bacilli in the BCG vaccine by alternative approaches, such as flow cytometry, which can also provide information about the metabolic status of the bacterial population. The aim of the work reported here was to determine which batch fermentation conditions and storage conditions give the most favourable outcomes in terms of the yield and stability of live M. bovis BCG Danish bacilli. We compared different media and assessed growth over time in culture, using total viable counts, total bacterial counts, and turbidity throughout culture. We applied fluorescent viability dyes and flow cytometry to measure real-time within-culture viability. Culture samples were stored in different cryoprotectants at different temperatures to assess the effect of these combined conditions on bacterial titres. Roisin's minimal medium and Middlebrook 7H9 medium gave comparable, high titres in fermenters. Flow cytometry proved to be a useful tool for enumeration of total bacterial counts and in the assessment of within-culture cell viability and cell death. Of the cryoprotectants evaluated, 5% (v/v) DMSO showed the most significant positive effect on survival and reduced the negative effects of low temperature storage on M. bovis BCG Danish viability. In conclusion, we have shown a reproducible, more standardised approach for the production, evaluation, and storage of high titre, viable, BCG vaccine.

Two Intraoperative Techniques for Midurethral Sling Tensioning: A Randomized Controlled Trial.

OBJECTIVE: To evaluate whether the use of a Mayo Scissor as a suburethral spacer compared with a Babcock clamp holding a loop of tape under the urethra results in different rates of abnormal bladder outcomes 12 months after retropubic midurethral sling surgery. METHODS: The MUST (Mid-Urethral Sling Tensioning) trial was a block-randomized, double-blind, multicenter clinical trial that allocated women to have their retropubic midurethral slings tensioned by Scissor or Babcock technique. The primary outcome (abnormal bladder) was a composite of persistent stress urinary incontinence (SUI), overactive bladder, and urinary retention. Secondary outcomes included outcomes of the composite, postoperative catheterization, incontinence-related questionnaires, repeat incontinence treatment, and uroflowmetry. Sample size of 159 in each arm (N=318) was planned for a superiority trial, hypothesizing a 10% difference in primary outcome. RESULTS: From September 2015 to December 2017, 506 women were screened and 318 were randomized. Baseline characteristics were similar in each arm. At 12 months, 253 (79.6%) women provided information on primary outcome: 40 of 128 (31.3%) patients with midurethral slings tensioned by Scissor experienced abnormal bladder, compared with 23 of 125 (18.4%) of those with midurethral slings tensioned by Babcock (P=.018, relative difference 12.9%). Secondary analyses favored Babcock for median duration of catheterization and the proportions of women experiencing urinary retention requiring sling lysis. Uroflowmetry parameters suggest the Scissor technique is more restrictive. Rates of mesh erosion were lower for the Scissor arm. No differences occurred in proportions of women experiencing patient reported persistent SUI after surgery. CONCLUSION: Abnormal bladder outcomes were 12.9% less frequent for women with midurethral slings tensioned by Babcock. Both techniques provided a comparable patient reported cure for SUI at 12 months. Women with midurethral slings tensioned by Scissors experienced more intervention for obstruction, whereas those with midurethral slings tensioned by Babcock experienced higher rates of mesh erosion. This information about how the postoperative courses differ allows surgeons to better counsel patients preoperatively or tailor their choice of technique. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, NCT02480231. FUNDING SOURCE: Boston Scientific.

Bioreactor-Grown Bacillus of Calmette and Guérin (BCG) Vaccine Protects Badgers against Virulent Mycobacterium bovis When Administered Orally: Identifying Limitations in Baited Vaccine Delivery.

Bovine tuberculosis (TB) in Great Britain adversely affects animal health and welfare and is a cause of considerable economic loss. The situation is exacerbated by European badgers (Meles meles) acting as a wildlife source of recurrent Mycobacterium bovis infection to cattle. Vaccination of badgers against TB is a possible means to reduce and control bovine TB. The delivery of vaccine in oral bait holds the best prospect for vaccinating badgers over a wide geographical area. There are practical limitations over the volume and concentration of Bacillus of Calmette and Guérin (BCG) that can be prepared for inclusion in bait. The production of BCG in a bioreactor may overcome these issues. We evaluated the efficacy of oral, bioreactor-grown BCG against experimental TB in badgers. We demonstrated repeatable protection through the direct administration of at least 2.0 × 108 colony forming units of BCG to the oral cavity, whereas vaccination via voluntary consumption of bait containing the same preparation of BCG did not result in demonstrable protection at the group-level, although a minority of badgers consuming bait showed immunological responses and protection after challenge equivalent to badgers receiving oral vaccine by direct administration. The need to deliver oral BCG in the context of a palatable and environmentally robust bait appears to introduce such variation in BCG delivery to sites of immune induction in the badger as to render experimental studies variable and inconsistent.

The effect of BCG vaccination on macrophage phenotype in a mouse model of intranasal Mycobacterium bovis challenge.

In order to develop improved vaccinations against tuberculosis, it is essential to understand the effect of vaccination on the immune response, and to overcome the mechanisms by which mycobacteria regulate this immune response. In this study, we examine the effect of intradermal vaccination with Mycobacterium bovis bacille Calmette-Guèrin on macrophage phenotype following intranasal challenge with virulent Mycobacterium bovis. Preserved lung tissues used in the present study were obtained from a previous vaccination trial in BALB/c mice. Vaccinated mice showed less extensive pulmonary lesions along with a significant decrease in bacterial lung burden when compared to control mice. Immunohistochemical markers of classically activated macrophages (iNOS) and alternatively activated macrophages (Arg1, FIZZ1) were applied to lung sections. Vaccination led to a statistically significant decrease in the number of Arg1+ macrophages. The presence of macrophages that expressed Arginase 1 in pulmonary lesions was much smaller than the presence of macrophages expressing iNOS. The low presence of Arg1+ macrophages induced by vaccination may be caused by Th1 polarization and may reduce alternative activation of macrophages, with an overall more effective intracellular killing of bacteria.

No. 383-Screening, Diagnosis, and Management of Placenta Accreta Spectrum Disorders.

BACKGROUND: Placenta accreta spectrum (PAS) disorders are a potentially life-threatening complication of pregnancy that demand coordinated interdisciplinary care to achieve safer outcomes. The rising incidence of this disease is due to a growing number of uterine surgical procedures, including the rising incidence of pregnancy following Caesarean section. OBJECTIVE: To provide current evidence-based guidelines on the optimal methods used to effectively screen, diagnose, and manage PAS disorders. METHODS: Members of the guideline committee were selected on the basis of their ongoing expertise in managing this condition across Canada and by practice setting. The committee reviewed all available evidence in the English medical literature, including published guidelines, and evaluated diagnostic tests, surgical procedures, and clinical outcomes. EVIDENCE: Published literature, including clinical practice guidelines, was retrieved through searches of Medline and The Cochrane Library to March 2018 using appropriate controlled vocabulary and key words. Results were restricted to systematic reviews, randomized controlled trials, and observational studies written in English. Searches were updated on a regular basis and incorporated in the guideline to July 2018. VALUES: The quality of evidence in this document was graded using the criteria described in the Report of the Canadian Task Force on Preventive Health Care. RESULTS: This document reviews the evidence regarding the available diagnostic and surgical techniques used for optimal management of women with suspected PAS disorders, including anaesthesia and practical considerations for interdisciplinary care. BENEFITS, HARMS, AND COSTS: Implementation of the guideline recommendations will improve awareness of this disease and increase the proportion of affected women receiving interdisciplinary care in regional centres. CONCLUSIONS: Interdisciplinary team-based care providing accurate diagnostic services, coordinated planning, and safer surgery deliver effective care with improved clinical outcomes in comparison with alternative management. SUMMARY STATEMENTS: RECOMMENDATIONS.

In vitro and in vivo evaluation of a single chain antibody fragment generated in planta with potent rabies neutralisation activity.

Rabies causes more than 60,000 human deaths annually in areas where the virus is endemic. Importantly, rabies is one of the few pathogens for which there is no treatment following the onset of clinical disease with the outcome of infection being death in almost 100% of cases. Whilst vaccination, and the combination of vaccine and rabies immunoglobulin treatment for post-exposure administration are available, no tools have been identified that can reduce or prevent rabies virus replication once clinical disease has initiated. The search for effective antiviral molecules to treat those that have already developed clinical disease associated with rabies virus infection is considered one of the most important goals in rabies research. The current study assesses a single chain antibody molecule (ScFv) based on a monoclonal antibody that potently neutralises rabies in vitro as a potential therapeutic candidate. The recombinant ScFv was generated in Nicotiana benthamiana by transient expression, and was chemically conjugated (ScFv/RVG) to a 29 amino acid peptide, specific for nicotinic acetylcholine receptor (nAchR) binding in the CNS. This conjugated molecule was able to bind nAchR in vitro and enter neuronal cells more efficiently than ScFv. The ability of the ScFv/RVG to neutralise virus in vivo was assessed using a staggered administration where the molecule was inoculated either four hours before, two days after or four days after infection. The ScFv/RVG conjugate was evaluated in direct comparison with HRIG and a potential antiviral molecule, Favipiravir (also known as T-705) to indicate whether there was greater bioavailability of the ScFv in the brains of treated mice. The study indicated that the approach taken with the ScFv/RVG conjugate may have utility in the design and implementation of novel tools targetting rabies virus infection in the brain.

Re-evaluating the effect of Favipiravir treatment on rabies virus infection.

There is no antiviral treatment available once clinical disease following rabies virus infection has initiated. Considered a neglected tropical disease, >60,000 human rabies deaths are estimated each year despite the availability of pre- and post-exposure prophylaxis for pre-immunisation or administration following a potential exposure before the onset of clinical disease. Such post-exposure treatments include administration of rabies immunoglobulin (RIG) and vaccination at a distant site to prime a humoral immune response. However, current therapeutic options are limited. Regardless there is a need for molecules that target virus infection following the onset of clinical disease where the outcome of infection is invariably fatal. Numerous molecules have been assessed as potential antivirals against rabies virus (RABV) but with little promise. Favipiravir (T-705) is a broad-spectrum RNA polymerase inhibitor, which has been shown to have antiviral activity against a range of RNA viruses including some against RABV. In the present study, the utility of T-705 has been reassessed in vitro as well as in vivo in a murine model using intraperitoneal administration to investigate any immune protective effect of the molecule. In vitro T-705 effectively reduces RABV replication. However, in vivo, following assessment of various applications of the molecule in both pre- and post-exposure scenarios, the effect was limited. T-705 treatment delayed the onset of clinical signs when virus was delivered intramuscularly at a higher dose (106.8 TCID50/ml) and reduced the number of mice that developed clinical signs when virus was delivered at a lower dose (105.8 TCID50/ml) during the observation period. The day at which treatment commenced did not appear to have a statistically significant effect on the results in either experiment. The use of T-705 as a single biological entity may be limited, however, further work is required to assess the synergistic effect of T-705 as a component of a multi-drug therapy for treating human rabies infections.

Uterosacral vault suspension (USLS) at the time of hysterectomy: laparoscopic versus vaginal approach.

INTRODUCTION AND HYPOTHESIS: To compare laparoscopic and vaginal approaches to uterosacral ligament vault suspension (USLS) by perioperative data, short-term complications, rates of successful concomitant adnexal surgery and procedural efficacy. METHODS: Retrospective cohort of USLS procedures performed at the time of hysterectomy at a tertiary care center over a 3-year period. Patient demographics, surgical data, concomitant adnexal procedures and complications were abstracted from a surgical database and compared using parametric or non-parametric tests as appropriate. Validated questionnaires (POPDI-6, UDI-6, PROMIS) were used to collect information on recurrence and long-term complications. Patients were analyzed according to both intention-to-treat analysis based on the intended approach and the completed route of surgery to deal with intraoperative conversions. RESULTS: Two hundred six patients met the criteria for inclusion; 152 underwent vaginal USLS (V-USLS) and 54 laparoscopic USLS (L-USLS). No statistically significant differences in mean case time, postoperative length of stay or perioperative infection were found. While no ureteric obstructions occurred in the L-USLS group, in the V-USLS group 14 (9%) obstructions occurred (p = 0.023). Postoperative urinary retention was higher with V-USLS (31% vs. 15%, p = 0.024). Rates of successfully completed adnexal surgery differed (56% vs. 98%, p < 0.001) in favor of L-USLS. Patient-reported symptomatic recurrence of prolapse was higher in the V-USLS group (41% vs. 24%, p = 0.046); despite this, re-treatment did not differ between the groups (0% vs. 7%, p = 0.113). CONCLUSIONS: Perioperative case time and complications did not differ between approaches. However, rates of completed adnexal surgery were significantly higher in the laparoscopic group, which could influence surgical decisions concerning approaches to prolapse surgery.

A new bovine tuberculosis model for England and Wales (BoTMEW) to simulate epidemiology, surveillance and control.

BACKGROUND: Bovine tuberculosis (bTB) is a zoonotic disease of cattle caused by Mycobacterium bovis, widespread in England and Wales. It has high incidence towards the South West of England and Wales, with much lower incidence to the East and North. A stochastic simulation model was developed to simulate M. bovis transmission among cattle, transfer by cattle movements and transmission from environmental reservoirs (often wildlife and especially badgers). It distinguishes five surveillance streams, including herd tests, pre-movement testing and slaughter surveillance. The model thereby simulates interventions in bTB surveillance and control, and generates outputs directly comparable to detailed disease records. An anonymized version of the executable model with its input data has been released. The model was fitted to cattle bTB records for 2008-2010 in a cross-sectional comparison, and its projection was compared with records from 2010 to 2016 for validation. RESULTS: The fitted model explained over 99% of the variation among numbers of breakdowns in four defined regions and surveillance streams in 2010. It classified 7800 (95% confidence interval c. 5500 - 14,000) holdings within high incidence regions as exposed to infectious environmental reservoirs, out of over 31,000 cattle holdings identified as potentially exposed to such sources. The model was consistent with previous estimates of low M. bovis transmission rate among cattle, but cattle to cattle transmission was clearly required to generate the number of cattle cases observed. When projected to 2016, the model as fitted to 2010 continued to match the distribution of bTB among counties, although it was notable that the actual distribution of bTB in 2010 was itself a close match for its distribution in 2016. CONCLUSIONS: The close model fit demonstrated that cattle movements could generate breakdowns as observed in low incidence regions, if persistent environmental reservoirs such as wildlife maintained infection levels in the high incidence regions. The model suggests that environmental reservoirs may be a challenge for control, because, although many holdings are exposed to infection from wildlife or the environment, they are a minority of holdings. Large impacts on disease in wildlife will be required to avoid each individual transmission event to cattle.

Early voiding dysfunction after midurethral sling surgery: comparison of two management approaches.

INTRODUCTION AND HYPOTHESIS: Early voiding dysfunction (EVD) with urinary retention (UR) is a complication of midurethral sling (MUS) surgery. Management is not standardized. Our objective was to characterize management approaches at our center, and report outcomes including resolution of UR, persistent voiding dysfunction, and recurrent stress urinary incontinence (SUI). METHODS: All women requiring catheterization for ≥7 days after MUS surgery during the period March 2014 to 2016 were eligible for inclusion in this prospective study. The management plan for each patient was decided jointly by the surgeon and the patient. Questionnaires regarding urinary symptoms were administered at enrollment, and 3 and 6 months after surgery. The timing and type of any surgical intervention were recorded. RESULTS: During the 2-year period, 31 women experienced EVD for ≥7 days after MUS surgery. At 6 months, complete data were available for 30 women (97%). Two management approaches were identified: "early mobilization" to loosen the MUS intact (in 10 patients), and continued catheterization with delayed sling lysis as needed (in 21 patients). In eight of the ten women in the early mobilization group, UR resolved after one intervention. Two required a second mobilization. For all women in this group, UR resolved after one or two procedures. In 11 of the 21 women in the continued catheterization group UR resolved without intervention. The other ten women in the continued catheterization group opted for sling lysis ≤6 months after MUS surgery. None of the women in the mobilization group reported SUI at 6 months in contrast to 9 of 20 (45%) in the planned continued catheterization group (p = 0.029). Seven of the nine women experiencing recurrent SUI had undergone sling lysis. CONCLUSIONS: Patients experiencing EVD after MUS surgery can be informed that UR will resolve in 50% with continued catheterization. Mobilization should be an option for those not comfortable with prolonged catheterization. Early intervention by mobilization may be associated with a lower risk of recurrent SUI, compared to continued catheterization and delayed sling lysis.