Institutional tuberculosis transmission : controlled trial of upper room ultraviolet air disinfection : a basis for new dosing guidelines

RATIONALE : Transmission is driving the global tuberculosis epidemic, especially in congregate settings. Worldwide, natural ventilation is the most common means of air disinfection, but it is inherently unreliable and of limited use in cold climates. Upper room germicidal ultraviolet (UV) air disinfection with air mixing has been shown to be highly effective, but improved evidence-based dosing guidelines are needed. OBJECTIVES : To test the efficacy of upper room germicidal air disinfection with air mixing to reduce tuberculosis transmission under real hospital conditions, and to define the application parameters responsible as a basis for proposed new dosing guidelines. METHODS : Over an exposure period of 7 months, 90 guinea pigs breathed only untreated exhaust ward air, and another 90 guinea pigs breathed only air from the same six-bed tuberculosis ward on alternate days when upper room germicidal air disinfection was turned on throughout the ward. MEASUREMENTS AND MAIN RESULTS : The tuberculin skin test conversion rates (.6 mm) of the two chambers were compared. The hazard ratio for guinea pigs in the control chamber converting their skin test to positive was 4.9 (95% confidence interval, 2.8–8.6), with an efficacy of approximately 80%. CONCLUSIONS : Upper room germicidal UV air disinfection with air mixing was highly effective in reducing tuberculosis transmission under hospital conditions. These data support using either a total fixture output (rather than electrical or UV lamp wattage) of 15–20 mW/m3 total room volume, or an average whole-room UV irradiance (fluence rate) of 5–7 mW/cm2, calculated by a lighting computer-assisted design program modified for UV use.http://www.atsjournals.org/journal/ajrccm2016-08-31hb201

Work-life balance, management practices and productivity

Do “Anglo-Saxon” management practices generate higher productivity only at the expense of lousy work-life balance (WLB) for workers? Many critics of “neo-libéralisme sauvage” have argued that increased competition from globalisation is damaging employees’ quality of life. Others have argued the opposite that improving work-life balance is actually a competitive tool that companies can use to raise productivity. We try to shed some empirical light on these issues using an innovative survey tool to collect new data on management and work-life balance practices from 732 medium sized manufacturing firms in the US, France, Germany and the UK. First, we show that our measure of work-life balance is a useful summary of a range of policies in the firm – family-friendly policies, flexible working, shorter hours, more holidays, subsidised childcare, etc. We show that this worklife balance measure is significantly associated with better management. Firms in environments that are more competitive and/or who are more productive, however, do not have significantly worse work-life balance for their workers. These findings are inconsistent with the view that competition, globalisation and “Anglo-Saxon” management practices are intrinsically bad for the work-life balance of workers. On the other hand, neither are these findings supportive of the optimistic “winwin” view that work-life balance improves productivity in its own right. Rather we find support for a “hybrid” theory that work-life balance is a choice for managers that is compatible with low or high productivity