Characterization of newcastle disease viruses in wild and domestic birds in Luxembourg from 2006 to 2008.

Newcastle disease virus (NDV) is one of the most important viral diseases of birds. Wild birds constitute a natural reservoir of low-virulence viruses, while poultry are the main reservoir of virulent strains. Exchange of virus between these reservoirs represents a risk for both bird populations. Samples from wild and domestic birds collected between 2006 and 2010 in Luxembourg were analyzed for NDV. Three similar avirulent genotype I strains were found in ducks during consecutive years, suggesting that the virus may have survived and spread locally. However, separate introductions cannot be excluded, because no recent complete F gene sequences of genotype I from other European countries are available. Detection of vaccine-like strains in wild waterbirds suggested the spread of vaccine strains, despite the nonvaccination policy in Luxembourg. Among domestic birds, only one chicken was positive for a genotype II strain differing from the LaSota vaccine and exhibiting a so-far-unrecognized fusion protein cleavage site of predicted low virulence. Three genotype VI strains from pigeons were the only virulent strains found. The circulation of NDV in wild and free-ranging domestic birds warrants continuous surveillance because of increased concern that low-virulence wild-bird viruses could become more virulent in domestic populations.

Effects of vascular risk factors on balance assessed by computerized posturography in the elderly.

AIMS: The purpose of this study was to evaluate the effects of vascular risk factors, isolated or in association, on balance, as assessed by posturographic platform. METHODS: One hundred and seven elderly subjects (mean age 73.8+/-5.8), with no cognitive impairment (MMSE>24), able to perform self-care activities and to walk independently for at least 400 meters, free from major diseases. Subjective complaints were assessed by means of the Sickness Impact Profile Questionnaire. The following cardiovascular risk factors were considered: hypercholesterolemia, smoking, hypertension, glucose intolerance, and obesity. Balance tests were performed in three standardized positions (side-by-side, semi-tandem, tandem) on a vertical force platform, from which center of foot pressure positions and displacements were recorded. RESULTS: A large percentage of enrolled subjects (35.5%) complained of unsteadiness, dizziness or vertigo, but only a few (24=22.4%) reported at least one fall in the 6 months before enrolment in the study. Among the cardiovascular risk factors taken into account, only glucose intolerance and, to a lesser extent, obesity, were associated with worse performance in stabilometric tests, independent of age and sex. Subjects with 3 or more risk factors, compared with those with 2 or less showed worse performance in medio-lateral sway (p=0.001), track length (p=0.05) and elliptical area (p=0.005), in tandem position. CONCLUSIONS: The cumulative presence of cardiovascular risk factors may contribute to impairment of balance in the elderly. This effect may be due to subclinical damage of that part of the nervous system controlling balance.

Effects of hypertension on balance assessed by computerized posturography in the elderly.

Unsteadiness, dizziness and vertigo occur more frequently in hypertensive subjects, compared to the normal ones. This study evaluated the influence of hypertension on balance tests, performed on posturographic platform. The study pool consisted of 112 persons aged 65 and older (65 hypertensives), their mean age was 72.9+/-0.5, scored on the Mini Mental State Examination (MMSE) greater than 24, were able to perform self-care activities, to walk independently for at least 400 m and were free from major diseases. Subjective dizziness and vertigo were assessed by means of Sickness-Impact-Profile-Questionnaire (SIPQ). The static posturographic tests were performed on a vertical force platform, from which the center of foot pressure (COP) positions and displacements were recorded. In balance tests three standardized positions were utilized: feet 30 degrees apart, semitandem and tandem. Subjects with hypertension complained more frequently dizziness and vertigo (41.5% vs. 21.3%). The track-length and COP-velocity were associated with age in all the balance tests. In semitandem and tandem positions, the medio-lateral sway distance significantly increased in elderly subjects compared to young controls. No difference, however, was found in balance tests between normotensive and hypertensive subjects. Those with uncomplicated hypertension compared with normo-tensive subjects, although complaining more frequently symptoms of postural instability, did not show worse performances in static posturographic tests.