Mother‐to‐Child Transmission of HIV in China and the USA: A Comparative Analysis

This paper analyzes and compares the existing policies and programs for the prevention of mother‐to‐child transmission of HIV existing in China and in the USA. The implementation of these is still imperfect and there needs to be improvements in the education (the spreading of information) and in the general health care system of China. Particular attention will be drawn to the existing barriers to the effective implementation of prevention of mother‐to‐child‐transmission. The recommendations aim to solve similar barriers in both countries and some specifically dealing with problems in China. Since HIV infection in children is caused almost entirely by prenatal transmission, it is important that the governments, in partnership with civic society organizations, make all the necessary efforts to save the lives of their newborn citizens.     

中国股市与世界其他股市之间的大风险溢出效应

目的/意义以我国金融业各个部门为研究对象,从动态关联性角度出发研究各部门间的金融风险传染效应。设计/方法首先运用广义方差分解方法构建静态关联度矩阵,确定各个部门关联度的方向及强度,随后通过滚动窗口预测方法测算金融市场各个部门的动态关联度,刻画各部门的风险传染网络。结论/发现研究发现：1. 我国金融部门之间有显著的关联性;2. 极端事件的发生能够加强我国金融部门间的联动性;3. 金融部门之间的风险传染网络具有动态关联性。     

Effects of air pollution and weather on the initial COVID-19 outbreaks in United States,Italy, Spain,and China: A comparative study

Contrasting effects have been identified in association of weather (temperature and humidity) and pollutant gases with COVID-19 infection, which could be derived from the influence of lockdowns and season change. The influence of pollutant gases and climate during the initial phases of the pandemic, before the closures and the change of season in the northern hemisphere, is unknown. Here, we used a spatial-temporal Bayesian zero-inflated-Poisson model to test for short-term associations of weather and pollutant gases with the relative risk of COVID-19 disease in China (first outbreak) and the countries with more cases during the initial pandemic (the United States, Spain and Italy), considering also the effects of season and lockdown. We found contrasting association between pollutant gases and COVID-19 risk in the United States, Italy, and Spain, while in China it was negatively associated (except for SO₂). COVID-19 risk was positively associated with specific humidity in all countries, while temperature presented a negative effect. Our findings showed that short-term associations of air pollutants with COVID-19 infection vary strongly between countries, while generalized effects of temperature (negative) and humidity (positive) with COVID-19 was found. Our results show novel information about the influence of pollution and weather on the initial outbreaks, which contribute to unravel the mechanisms during the beginning of the pandemic.     

Culture-based versus risk-based screening for the prevention of group B streptococcal disease in newborns: A review of national guidelines

BackgroundMaternal colonisation with group B streptococcus (GBS) is recognised as the most frequent cause of severe early onset infection in newborns. National and international guidelines outline two approaches to the prevention of early onset disease in the neonate: risk based management and antenatal culture-based screening. We undertook an analysis of existing national and international guidelines in relation to GBS in pregnancy using a standardised and validated instrument to highlight the different recommended approaches to care.MethodsEnglish language guidelines on the screening and management of GBS colonisation in pregnant women and the prevention of early-onset group B streptococcal disease in newborns were sought.ResultsFour guidelines met the inclusion criteria, one from the United States of America (USA), the United Kingdom (UK), Canada and New Zealand. All four were appraised as at a high standard in terms of development using the AGREE II tool. Both approaches were recommended in the guidelines with different regions of the world advocating different approaches often based on the same evidence. Guidelines from the USA recommend an antenatal culture-based approach while the UK guidelines recommend risk-based management.ConclusionBased on an AGREE II analysis, the standard of the guidelines was high despite having disparate recommendations. Both approaches to the prevention of early onset GBS infection in neonates are recommended with the split being geographically-based.     

Testing Heterogeneity for Frailty Distribution in Shared Frailty Model

Abstract

The frailties, representing extra variations due to unobserved measurements, are often assumed to be iid in shared frailty models. In medical applications, however, a speculation can arise that a data set might violate the iid assumption. In this paper we investigate this conjecture through an analysis of the kidney infection data in McGilchrist and Aisbett (McGilchrist, C. A., Aisbett, C. W. (1991). Regression with frailty in survival analysis. Biometrics 47:461–466). As a test procedure, we consider the cusum of squares test which is frequently used for monitoring a variance change in statistical models. Our result strongly sustains the heterogeneity of the frailty distribution.     

猪生殖—呼吸综合征合并感染猪传染性胸膜肺炎的临床病理学研究

对自然感染并经血清学和病原学定性为猪生殖—呼吸综合征（ＰＲＲＳ） 合并感染猪传染性胸膜肺炎的１０ 头仔猪进行了临床病理学研究,结果表明,其临床表现为高热稽留,呼吸困难;病理表现为纤维素性胸膜肺炎,非化脓性脑炎,急性出血性淋巴结炎及脾炎,广泛性淤血及出血性素质。猪合并感染上述两种病的临床症状和病理损伤远较单一发病严重且死亡率极高     

老年肺部感染患者的呼吸道管理

目的探讨呼吸道管理对治疗老年肺部感染患者的有效性。方法对120~J老年肺部感染患者，由责任护士负责，对患者进行评估、湿化呼吸道、胸部物理疗法等综合措施。结果采取合理的呼吸道管理后，能有效地清除呼吸道分泌物，促进有效的呼吸，同时患者的自我护理能力有所提高。结论做好呼吸道的管理是治疗老年患者肺部感染的重要措施。     

An Analytical Framework for Relating Dose, Risk, and Incidence: An Application to Occupational Tuberculosis Infection

An adverse health impact is often treated as a binary variable (response vs. no response), in which case the risk of response is defined as a monotonically increasing function R of the dose received D. For a population of size N , specifying the forms of R(D) and of the probability density function (pdf) for D allows determination of the pdf for risk, and computation of the mean and variance of the distribution of incidence, where the latter parameters are denoted E[S _N] and Var[ S _N], respectively. The distribution of S _N describes uncertainty in the future incidence value. Given variability in dose (and risk) among population members, the distribution of incidence is Poisson-binomial. However, depending on the value of E[S _N], the distribution of incidence is adequately approximated by a Poisson distribution with parameter μ= E[S _N], or by a normal distribution with mean and variance equal to E[S _N] and Var[ S _N]. The general analytical framework is applied to occupational infection by Mycobacterium tuberculosis (M. tb). Tuberculosis is transmitted by inhalation of 1–5 μm particles carrying viable M. tb bacilli. Infection risk has traditionally been modeled by the expression: R(D) = 1 – exp(– D ), where D is the expected number of bacilli that deposit in the pulmonary region. This model assumes that the infectious dose is one bacillus. The beta pdf and the gamma pdf are shown to be reasonable and especially convenient forms for modeling the distribution of the expected cumulative dose across a large healthcare worker cohort. Use of the the analytical framework is illustrated by estimating the efficacy of different respiratory protective devices in reducing healthcare worker infection risk.     

Issues in the design and analysis of therapeutic trials in human immunodeficiency virus infection

The first randomized trial of antiviral therapy in human immunodeficiency virus (HIV) disease included 282 patients with acquired immune deficiency syndrome (AIDS) or AIDS-related complex and was stopped in 1986 after an average follow-up of 4 months because of a substantial reduction in mortality in the group who received zidovudine (AZT). The era of anti-HIV treatment had begun. This paper discusses some of the difficulties which have emerged over the subsequent 10 years as new anti-HIV drugs have been developed requiring evaluation in clinical trials. The trials in which the British Medical Research Council has played a major role (the Concorde, Alpha and Delta trials) and some of the key trials conducted by the AIDS Clinical Trials Group (ACTG) (the ACTG 019 and ACTG 175 trials) and the Community Programs for Clinical Research on AIDS (CPCRA) (the CPCRA 007 trial) in the US will be used to illustrate some of the issues faced by clinical trialists and governmental regulatory agencies in the evaluation of therapies for a disease which, in spite of advances in therapy, still has a high mortality.     

Self-Consistency Estimation of Distributions Based on Truncated and Doubly Censored Survival Data with Applications to AIDS Cohort Studies

Gomez and Lagakos (1994) propose a nonparametric method for estimating the distribution of a survival time when the origin and end points defining the survival time suffer interval-censoring and right-censoring, respectively. In some situations, the end point also suffers interval-censoring as well as truncation. In this paper, we consider this general situation and propose a two-step estimation procedure for the estimation of the distribution of a survival time based on doubly interval-censored and truncated data. The proposed method generalizes the methods proposed by DeGruttola and Lagakos (1989) and Sun (1995) and is more efficient than that given in Gomez and Lagakos (1994). The approach is based on self-consistency equations. The method is illustrated by an analysis of an AIDS cohort study.