Expansion of the Lyme Disease Vector Ixodes Scapularis in Canada Inferred from CMIP5 Climate Projections.

BACKGROUND: A number of studies have assessed possible climate change impacts on the Lyme disease vector, Ixodes scapularis. However, most have used surface air temperature from only one climate model simulation and/or one emission scenario, representing only one possible climate future. OBJECTIVES: We quantified effects of different Representative Concentration Pathway (RCP) and climate model outputs on the projected future changes in the basic reproduction number (R0) of I. scapularis to explore uncertainties in future R0 estimates. METHODS: We used surface air temperature generated by a complete set of General Circulation Models from the Coupled Model Intercomparison Project Phase 5 (CMIP5) to hindcast historical (1971-2000), and to forecast future effects of climate change on the R0 of I. scapularis for the periods 2011-2040 and 2041-2070. RESULTS: Increases in the multimodel mean values estimated for both future periods, relative to 1971-2000, were statistically significant under all RCP scenarios for all of Nova Scotia, areas of New Brunswick and Quebec, Ontario south of 47°N, and Manitoba south of 52°N. When comparing RCP scenarios, only the estimated R0 mean values between RCP6.0 and RCP8.5 showed statistically significant differences for any future time period. CONCLUSION: Our results highlight the potential for climate change to have an effect on future Lyme disease risk in Canada even if the Paris Agreement's goal to keep global warming below 2°C is achieved, although mitigation reducing emissions from RCP8.5 levels to those of RCP6.0 or less would be expected to slow tick invasion after the 2030s. https://doi.org/10.1289/EHP57.

Home mechanical ventilation through mask: monitoring leakage and nocturnal oxygenation at home.

BACKGROUND: Leakage is common in patients receiving home mechanical ventilation (HMV) via a face mask. Although pressure ventilators have partial compensatory capacity, excessive leakage can compromise the effectiveness of treatment. Home ventilators are equipped with built-in software which provides information on leakage. However, the values of leakage and their effects in routine clinical practice are currently little known. OBJECTIVE: To measure leakage in stable patients on nocturnal HMV and its impact on treatment effectiveness. METHODS: Consecutive outpatients on HMV were recruited. Nocturnal pulse oximetry was performed at home and leakage was measured using the ventilator's built-in software. We measured: mean SpO(2), percentage of time with SpO(2) <90% (T90), mean leakage (meanL), maximum leakage (maxL), and minimum leakage (minL) during the ventilation session. We estimated ventilator capacity to compensate for leakage according to inspiratory positive airway pressure and divided the patients into two groups: those with leak compensation and those without. RESULTS: The study included 41 patients [mean age, 64 years (SD 11.9); 23 (56%) women]. Nocturnal pulse oximetry showed an SpO(2) of 94% (±2.9) and a T90 of 10% (±21.7). Leakage (in l/min) was: meanL, 32.2 (±15.3); maxL, 64.8 (±28.5), and minL, 18.8 (±10.6). Seven cases (17%) had leakage greater than the ventilator compensatory capacity, but no significant difference in SpO(2) or T90 was observed between patients with or without leak compensation. CONCLUSIONS: A wide variation between maxL and minL was observed in our series; 17% of cases had higher leakage values than the compensatory capacity of the ventilator, but this did not affect nocturnal oxygenation.