Varicella-zoster virus: pathogenesis, incidence patterns and vaccination programs.

Varicella or chickenpox is a common and highly contagious exanthematic disease caused by the varicella-zoster virus (VZV) that during primary infection has the ability to establish latency. VZV reactivation, even decades after primary infection, causes herpes zoster. In healthy immunocompetent subjects, children in particular, varicella results in mild to moderate illness and for this reason, regardless its high morbidity, it is not considered a public health priority. Varicella still represents the most widespread vaccine preventable childhood infectious disease in industrialized countries; due to its relevant burden on healthcare resources several countries has introduced varicella vaccination into the recommended routine childhood national immunization schedule. Nowadays, live attenuated monovalent and combined MMRV vaccines are licensed worldwide. The use of several millions of doses has demonstrated the excellent safety and efficacy level of varicella vaccines as well as of combined MMRV vaccines. Universal vaccination adopted in many countries with a two-dose strategy has allowed to significantly reducing morbidity and mortality of this infectious disease. Anyway, an ample international debate is ongoing on the time range to be used between the two doses, and on the safety issues related to the use as first-dose of MMRV vaccine. Taking into account the availability of a zoster vaccine in subjects older than 50 years of age, it will be relevant to clarify if an impact on exogenous boosters and on the epidemiology of herpes zoster can occur after the adoption of extensive varicella immunization.

Inspiratory-Expiratory Muscle Training Improved Respiratory Muscle Strength in Dialysis Patients: A Pilot Randomised Trial.

End-stage kidney disease (ESKD) exposes patients to progressive physical deconditioning involving the respiratory muscles. The aim of this pilot randomized controlled trial was to determine the feasibility and effectiveness of low-intensity respiratory muscle training (RMT) learned at the hospital and performed at home. A group of ESKD patients (n = 22) were randomized into RMT or usual care (control group, CON) in a 1:1 ratio. The respiratory training was performed at home with an inspiratory-expiratory system for a total of 5 min of breathing exercises in a precise rhythm (8 breaths per minute) interspersed with 1 min of rest, two times per day on nondialysis days for a total of 4 weeks, with the air resistance progressively increasing. Outcome measures were carried out every 4 weeks for 3 consecutive months, with the training executed from the 5th to the 8th week. Primary outcomes were maximal inspiratory and expiratory pressure (MIP, MEP), while secondary outcomes were lung capacity (FEV1, FVC, MVV). Nineteen patients without baseline between-group differences completed the trial (T: n = 10; Age: 63 ± 10; Males: n = 12). Both MIP and MEP significantly improved at the end of training in the T group only, with a significant difference of MEP of 23 cmH2O in favor of the RMT group (p = 0.008). No significant variations were obtained for FVC, FEV1 or MVV in either group, but there was a greater decreasing trend over time for the CON group, particularly for FVC (t = -2.00; p = 0.046). Low-fatiguing home-based RMT, with a simple device involving both inspiratory and expiratory muscles, may significantly increase respiratory muscle strength.

Impact of Improvement in Walking Speed on Hospitalization and Mortality in Females with Cardiovascular Disease.

Cardiovascular disease (CVD) is the principal cause of death in women. Walking speed (WS) is strongly related with mortality and CVD. The rate of all-cause hospitalization or death was assessed in 290 female outpatients with CVD after participation in a cardiac rehabilitation/secondary prevention program (CR/SP) and associated with the WS maintained during a moderate 1 km treadmill-walk. Three-year mortality rates were 57%, 44%, and 29% for the slow (2.1 ± 0.4 km/h), moderate (3.1 ± 0.3 km/h), and fast (4.3 ± 0.6 km/h) walkers, respectively, with adjusted hazard ratios (HRs) of 0.78 (p = 0.24) and 0.55 (p = 0.03) for moderate and fast walkers compared to the slow walkers. In addition, hospitalization or death was examined four to six years after enrollment as a function of the change in the WS of 176 patients re-assessed during the third year after baseline. The rates of hospitalization or death were higher across tertiles of reduced WS, with 35%, 50%, and 53% for the high (1.5 ± 0.3 km/h), intermediate (0.7 ± 0.2 km/h), and low tertiles (0.2 ± 0.2 km/h). Adjusted HRs were 0.79 (p = 0.38) for the intermediate and 0.47 (p = 0.02) for the high tertile compared to the low improvement tertile. Improved walking speed was associated with a graded decrease in hospitalization or death from any cause in women undergoing CR/SP.

A moderate 200-m walk test estimates peak oxygen uptake in elderly outpatients with cardiovascular disease.

BACKGROUND: A moderate 1-km treadmill walk test (1k-TWT) has been demonstrated to be a valid tool for estimating peak oxygen uptake (VO2peak) in outpatients with cardiovascular disease (CVD). The results obtained by the 1k-TWT predict survival and hospitalization in men and women with CVD. We aimed to examine whether shorter versions of the full 1k-TWT equally assess VO2peak in outpatients with CVD. METHODS: One hundred eighteen outpatients with CVD, aged 70±9 years, referred to an exercise-based secondary prevention program, performed a moderate and perceptually-regulated (11-13/20 on the Borg Scale) 1k-TWT. Age, height, weight, heart rate, time to walk 100-m, 200-m, 300-m, and 400-m, and the full 1000-m, were entered into equations to estimate VO2peak. RESULTS: The minimal distance providing similar VO2peak results of the full 1k-TWT was 200-m: 23.0±5.3 mL/kg/min and 23.0±5.5 mL/kg/min, respectively. The concordance correlation coefficient between the two was 0.97 (95%CI 0.96 to 0.98, P<0.0001). The slope and the intercept of the relationship between the values obtained by the 200-m and the full 1k-TWT were not different from the line of identity. Bland-Altman analysis did not show systematic or proportional error. CONCLUSIONS: A moderate 200-m treadmill-walk is a reliable method for estimating VO2peak in elderly outpatients with CVD. A 200-m walk enables quick and easy cardiorespiratory fitness assessment, with low costs and low burden for health professionals and patients. These findings have practical implications for the transition of patients from clinically-based programs to fitness facilities or self-guided exercise programs.