Seroprevalence and exposure to risk factors for leptospirosis among veterinary students at Massey University.

AIMS: To determine the seroprevalence and quantify putative risk factors for exposure to leptospirosis both within and outside the veterinary curriculum among undergraduate veterinary students at Massey University, New Zealand. METHODS: A cross-sectional study was conducted from September 2010 to November 2011. In total, 302 students were blood sampled, with serum tested by microscopic agglutination test (MAT) for antibodies to Leptospira borgpetersenii serovars Hardjobovis, Leptospira interrogans Pomona and Leptospira borgpetersenii Ballum. Information on demographic characteristics, potential exposure within and outside the veterinary curriculum in the previous 18 months, and previous leptospirosis-like clinical history were recorded using an online questionnaire. RESULTS: All students were MAT negative for each serovar, using a cut-point of ≥1:48. Potential exposure to animal urine within and outside the veterinary curriculum was reported by 259/302 (85.8%) and 150/302 (49.7%) of the students, respectively. The median number of potential exposures to animal urine by each student within the veterinary curriculum in the previous 18 months was 63 (min 1, max 155). The other potential exposures among respondents included home slaughter (63/302; 20.9%), hunting (43/302; 14.2%) and outdoor activities involving exposure to fresh water (241/302; 79.8%). CONCLUSIONS: This study demonstrated that these veterinary students were at low risk of contracting leptospirosis, despite frequent exposure to potential sources of infection. The findings in this study contribute to a broader understanding of the occupational risk of leptospirosis. Data describe the level of animal exposure in veterinary students, which can support other zoonotic disease studies in this group.

Longitudinal serological survey and herd-level risk factors for Leptospira spp. serovars Hardjo-bovis and Pomona on deer farms with sheep and/or beef cattle.

AIM: To investigate the seroprevalence of Leptospira spp. serovars Hardjo-bovis and Pomona on deer and mixed deer, sheep and/or beef cattle farms in the lower North Island of New Zealand and to examine associations between putative risk factors for seropositive deer herds. METHODS: Serological screening was conducted on 19 commercial deer farms, 16 with sheep and/or beef cattle, between August and October each year between 2006 and 2008. No leptospiral vaccination had been conducted on the farms. On each farm every year, serum samples were collected from a random sample of 20 or more rising 2-year-old replacement animals from each species. The microscopic agglutination test (MAT) was used to detect leptospiral antibodies against Leptospira borgpetersenii serovar Hardjo-bovis and Leptospira interrogans serovar Pomona. For both serovars, a titre of ≥1:48 was considered positive and a herd was considered seropositive if >3 of 20 serum samples were positive. Information on potential herd-level risk factors for deer herds being seropositive was obtained from a questionnaire completed by the farm owner or manager. RESULTS: The mean percentage of deer, cattle and sheep herds seropositive for Hardjo-bovis alone over 3 years was 42%, 53% and 54%, respectively, and for serovar Pomona was 7%, 5% and 0%, respectively. Antibodies to both serovars were found in 23%, 16% and 10% of deer, cattle and sheep herds, respectively. At the individual animal level, 228/1,107 (21%) deer, 308/767 (40%) cattle and 369/1,244 (30%) sheep were seropositive for Hardjo-bovis, 102 (9%) deer, 51 (7%) cattle and 23 (2%) sheep were seropositive for Pomona, and 49 (4%) deer, 28 (4%) cattle and 18 (1%) sheep were seropositive for both serovars. Deer herds were more likely to be seropositive for Hardjo-bovis in 2006 than 2008 (p=0.008), when seropositive in the preceding year (p=0.016) and on hilly compared with flat topography (p<0.001). Deer herds were more likely to be seropositive for Pomona when seropositive in the preceding year (p=0.016), when co-grazing with sheep flocks that were seropositive for Pomona (p<0.001), and when herds had a closed- compared with open-herd replacement policy (p<0.001). CONCLUSIONS: Exposure to Leptospira spp. was widely distributed in deer, sheep and beef cattle in the lower North Island of New Zealand. Co-grazing of deer with sheep that were seropositive was a potential risk factor for deer herds to be seropositive.

Complex Regional Pain Syndrome-Reflex Sympathetic Dystrophy.

Complex regional pain syndrome-reflex sympathetic dystrophy (CRPS/RSD) is a complex pain-dysfunction syndrome of unknown cause that typically affects a single extremity. Changes are usually more marked peripherally. There are no generally accepted clinical diagnostic criteria or laboratory studies for CRPS/RSD; our current state of knowledge allows the diagnosis to be made only on clinical grounds. Clinical suspicion should be raised if pain and disability are greater than would usually be expected as a result of the original incident, if recovery is slower than expected, and if autonomic changes are prominent in the affected extremity. The pain associated with the condition may be sympathetically maintained, sympathetically independent, or both. No evidence-based treatment regimens for CRPS/RSD are available. Treatment of the individual patient is empiric and uses symptomatic techniques that seem logical or that have been proven to be effective in other conditions. The sympathetic nervous system makes an unknown contribution to CRPS/RSD, but it is not known whether this is a cause or an effect of the pain. Psychological and psychiatric changes are probably secondary rather than etiologic. Treatment should be immediate, aggressive, and directed toward restoration of full function of the extremity. Various analgesic techniques may be necessary to permit the patient to comply with the rehabilitation program. This program is best carried out in a comprehensive interdisciplinary setting, with a primary emphasis on functional restoration.

Semicrystalline Polymers via Ring-Opening Polymerization: Preparation and Polymerization of Alkylene Phthalate Cyclic Oligomers.

Preparation of cyclic oligomeric alkylene phthalates via pseudo-high dilution condensation of alkylene diols with iso- and terephthaloyl chlorides and conversion to high molecular weight polyesters via ring-opening polymerization is described. Sterically unhindered amines such as quinuclidine or 1,4-diazabicyclo[2.2.2]octane (DABCO) catalyze the condensation significantly faster than other tertiary amines and are useful for carrying out this conversion in high yield, in the first direct reaction of diol and diacid chloride to form cyclic polyesters. The mixtures of oligomeric cyclics melt at 150-200 degrees C, providing liquids of low viscosity. Ring-opening polymerization using tin or titanate catalysts affords high molecular weight polymers within minutes. Complete polymerization of PBT oligomeric cyclics can be achieved at 180-200 degreesC, significantly below the polymer's melting point of 225 degreesC, and with molecular weights as high as 445 x 10(3). Polymers formed via such a process are more crystalline than conventionally prepared polyesters.

Differential Rotation and Dynamics of the Solar Interior

Splitting of the sun's global oscillation frequencies by large-scale flows can be used to investigate how rotation varies with radius and latitude within the solar interior. The nearly uninterrupted observations by the Global Oscillation Network Group (GONG) yield oscillation power spectra with high duty cycles and high signal-to-noise ratios. Frequency splittings derived from GONG observations confirm that the variation of rotation rate with latitude seen at the surface carries through much of the convection zone, at the base of which is an adjustment layer leading to latitudinally independent rotation at greater depths. A distinctive shear layer just below the surface is discernible at low to mid-latitudes.