Horse populations are severely underestimated in a region at risk of Hendra virus spillover.

OBJECTIVE: To identify the size and distribution of the horse population in the Northern Rivers Region of NSW, including changes from 2007 to 2021, to better understand populations at risk of Hendra virus transmission. METHODS: Census data from the 2007 Equine Influenza (EI) outbreak were compared with data collected annually by New South Wales Local Land Services (LLS) (2011-2021), and with field observations via road line transects (2021). RESULTS: The horse populations reported to LLS in 2011 (3000 horses; 0.77 horses/km2) was 145% larger than that reported during the EI outbreak in 2007 (1225 horses; 0.32 horses/km2). This was inconsistent with the 6% increase in horses recorded from 2011 to 2020 within the longitudinal LLS dataset. Linear modelling suggested the true horse population of this region in 2007 was at least double that reported at the time. Distance sampling in 2021 estimated the region's population at 10,185 horses (3.89 per km2; 95% CI = 4854-21,372). Field sampling and modelling identified higher horse densities in rural cropland, with the percentage of conservation land, modified grazing, and rural residential land identified as the best predictors of horse densities. CONCLUSIONS: Data from the 2007 EI outbreak no longer correlates to the current horse population in size or distribution and was likely not a true representation at the time. Current LLS data also likely underestimates horse populations. Ongoing efforts to further quantify and map horse populations in Australia are important for estimating and managing the risk of equine zoonoses.

Dataset of 18O and 2H in streamflow across Canada: A national resource for tracing water sources, water balance and predictive modelling.

Oxygen-18 and deuterium were measured in streamflow samples collected from 331 gauging stations across Canada during 2013 to 2019. This dataset includes 9206 isotopic analyses made on 4603 individual water samples, and an additional 1259 analysis repeats for quality assurance/quality control. We also include arithmetic and flow-weighted averages, and other basic statistics for stations where adequate data were available. Station data are provided including station code, name, province, latitude, longitude and drainage area. Flow data were extracted from the historical database of the Water Survey of Canada. Details on the preliminary application of these data are provided in "18O and 2H in streamflow across Canada" [1]. Overall, these data are expected to be useful when combined with precipitation datasets and analytical or numerical models for water resource management and planning, including tracing streamflow source, water balance, evapotranspiration partitioning, residence time analysis, and early detection of climate and land use changes in Canada.

Hendra in the Hunter Valley.

In June 2019 the first equine case of Hendra virus in the Hunter Valley, New South Wales, Australia was detected. An urgent human and animal health response took place, involving biosecurity measures, contact tracing, promotion of equine vaccinations and investigation of flying fox activity in the area. No human or additional animal cases occurred. Equine vaccination uptake increased by over 30-fold in the surrounding region in the three months following the case. Black flying fox and grey-headed flying fox species were detected in the Valley. The incident prompted review of Hendra virus resources at local and national levels. This event near the "horse capital of Australia", is the southernmost known equine Hendra case. Management of the event was facilitated by interagency collaboration involving human and animal health experts. Ongoing One Health partnerships are essential for successful responses to future zoonotic events.

Suitability of selected free-gas and dissolved-gas sampling containers for carbon isotopic analysis.

RATIONALE: Storage trials were conducted for 2 to 3 months using a hydrocarbon and carbon dioxide gas mixture with known carbon isotopic composition to simulate typical hold times for gas samples prior to isotopic analysis. A range of containers (both pierced and unpierced) was periodically sampled to test for δ(13)C isotopic fractionation. METHODS: Seventeen containers were tested for free-gas storage (20°C, 1 atm pressure) and 7 containers were tested for dissolved-gas storage, the latter prepared by bubbling free gas through tap water until saturated (20°C, 1 atm) and then preserved to avoid biological activity by acidifying to pH 2 with phosphoric acid and stored in the dark at 5°C. Samples were extracted using valves or by piercing septa, and then introduced into an isotope ratio mass spectrometer for compound-specific δ(13)C measurements. RESULTS: For free gas, stainless steel canisters and crimp-top glass serum bottles with butyl septa were most effective at preventing isotopic fractionation (pierced and unpierced), whereas silicone and PTFE-butyl septa allowed significant isotopic fractionation. FlexFoil and Tedlar bags were found to be effective only for storage of up to 1 month. For dissolved gas, crimp-top glass serum bottles with butyl septa were again effective, whereas silicone and PTFE-butyl were not. FlexFoil bags were reliable for up to 2 months. CONCLUSIONS: Our results suggest a range of preferred containers as well as several that did not perform very well for isotopic analysis. Overall, the results help establish better QA/QC procedures to avoid isotopic fractionation when storing environmental gas samples. Recommended containers for air transportation include steel canisters and glass serum bottles with butyl septa (pierced and unpierced).

Pre- and post-employment median nerve latency in pork processing employees.

There is some controversy regarding the relationship between development of median nerve dysfunction and employment activities. We performed nerve conduction studies of median nerve function on individuals before and after starting employment in the pork processing industry. After working an average of 64 days, employees (n = 45) showed significant prolongation of median motor and sensory nerve latency when comparing initial and final testing results in both dominant and non-dominant hands (P = < 0.01 to 0.03). A similar trend was found when testing a smaller group of employees (n = 17) who were already working (mean of 3 days), though this did not generally reach statistical significance. This study supports the conclusion that prolongation of median motor and sensory nerve latency can occur within as little as 2 months after beginning employment in the pork processing industry.

Inside-out vein graft repair compared with nerve grafting for nerve regeneration in rats.

The inside-out vein graft is a vein conduit pulled through itself to invert the normal orientation and place the adventitial layer within the lumen of the conduit. Our study compares regeneration of peripheral nerves in the rat through two conduits: inside-out graft of the jugular vein and autogenous nerve graft. In 10 rats, the right jugular vein was harvested, turned inside out, and used to bridge a 10 mm defect created in the right sciatic nerve. The 10 mm nerve segment from the right was then used as a standard nerve graft to bridge a 10 mm gap created in the left sciatic nerve. Rats were sacrificed at 8 and 12 weeks. Regeneration on the inside-out vein graft side showed superior functional results (faster conduction velocities) and improved histological results (greater axon counts) compared with the nerve grafted side. We feel the adventitial surface of the wall of the vein promotes nerve regeneration by providing an environment rich with collagen, laminin, and Schwann cells and promotes increased vascularization of the new nerve.

CO2 laser-assisted repair of esophageal lacerations.

This study was designed to evaluate the feasibility of CO2 laser-assisted repair of esophageal injuries. Nine-millimeter longitudinal incisions were made in the cervical esophagus of 40 Sprague-Dawley rats. The rats were divided into two groups. Twenty rats in Group 1 had their incisions closed in two layers (mucosa and muscularis) with the I.L. Med Unilase microsurgical CO2 laser (LAREL), using 80 mW of power with a spot size of 200 mu (power density = 255). Twenty rats in Group 2 had their incisions closed in two layers using 8-0 Vicryl conventional suture technique (CST). Postoperatively, an intraluminal methylene blue injection evaluated patency and leakage. Histologic analysis was performed at 3 days, 2 weeks, 1 month, and 6 months. Patency rates of LAREL and CST were comparable. No fistulas or strictures were found with either technique. Laser-assisted repair of esophageal lacerations (LAREL) was found to be faster and easier than CST. The question arises whether small esophageal tears can be safely repaired through the endoscope. This study demonstrates the feasibility of tissue welding the esophagus. Further research is mandatory to study the applicability of this technique in the clinical setting.