抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

Background Global and regional projections of mortality and burden of disease by cause for the years 2000, 2010, and 2030 were published by Murray and Lopez in 1996 as part of the Global Burden of Disease project. These projections, which are based on 1990 data, continue to be widely quoted, although they are substantially outdated; in particular, they substantially underestimated the spread of HIV/AIDS. To address the widespread demand for information on likely future trends in global health, and thereby to support international health policy and priority setting, we have prepared new projections of mortality and burden of disease to 2030 starting from World Health Organization estimates of mortality and burden of disease for 2002. This paper describes the methods, assumptions, input data, and results. Methods and Findings Relatively simple models were used to project future health trends under three scenarios—baseline, optimistic, and pessimistic—based largely on projections of economic and social development, and using the historically observed relationships of these with cause-specific mortality rates. Data inputs have been updated to take account of the greater availability of death registration data and the latest available projections for HIV/AIDS, income, human capital, tobacco smoking, body mass index, and other inputs. In all three scenarios there is a dramatic shift in the distribution of deaths from younger to older ages and from communicable, maternal, perinatal, and nutritional causes to noncommunicable disease causes. The risk of death for children younger than 5 y is projected to fall by nearly 50% in the baseline scenario between 2002 and 2030. The proportion of deaths due to noncommunicable disease is projected to rise from 59% in 2002 to 69% in 2030. Global HIV/AIDS deaths are projected to rise from 2.8 million in 2002 to 6.5 million in 2030 under the baseline scenario, which assumes coverage with antiretroviral drugs reaches 80% by 2012. Under the optimistic scenario, which also assumes increased prevention activity, HIV/AIDS deaths are projected to drop to 3.7 million in 2030. Total tobacco-attributable deaths are projected to rise from 5.4 million in 2005 to 6.4 million in 2015 and 8.3 million in 2030 under our baseline scenario. Tobacco is projected to kill 50% more people in 2015 than HIV/AIDS, and to be responsible for 10% of all deaths globally. The three leading causes of burden of disease in 2030 are projected to include HIV/AIDS, unipolar depressive disorders, and ischaemic heart disease in the baseline and pessimistic scenarios. Road traffic accidents are the fourth leading cause in the baseline scenario, and the third leading cause ahead of ischaemic heart disease in the optimistic scenario. Under the baseline scenario, HIV/AIDS becomes the leading cause of burden of disease in middle- and low-income countries by 2015. Conclusions These projections represent a set of three visions of the future for population health, based on certain explicit assumptions. Despite the wide uncertainty ranges around future projections, they enable us to appreciate better the implications for health and health policy of currently observed trends, and the likely impact of fairly certain future trends, such as the ageing of the population, the continued spread of HIV/AIDS in many regions, and the continuation of the epidemiological transition in developing countries. The results depend strongly on the assumption that future mortality trends in poor countries will have a relationship to economic and social development similar to those that have occurred in the higher-income countries.

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Projections of Global Mortality and Burden of Disease from 2002 to 2030

http://diposit.ub.edu/dspace/bitstream/2445/122776/1/gbd2016riskfactorscollaborators2017_3028.pdf

Global, regional, and national comparative risk assessment of 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks in 188 countries, 1990-2013: A systematic analysis for the Global Burden of Disease Study 2013

Food in the Anthropocene: the EAT–Lancet Commission on healthy diets from sustainable food systems

Estimates and 25-year trends of the global burden of disease attributable to ambient air pollution: an analysis of data from the Global Burden of Diseases Study 2015

This study quantifies the cost savings from the Acid Rain Program (ARP) compared with a command-and-control alternative and also examines the impact of trading under the ARP on health damages. To quantify cost savings, we compare compliance costs for non-NSPS (New Source Performance Standards) coal-fired Electricity Generating Units (EGUs) under the ARP with compliance costs under a uniform performance standard that achieves the same aggregate emissions. We do this for the year 2002, the third year of Phase II of the program. We find annual cost savings of approximately $250 million (1995$). To examine the health effects of trading, we compute the health damages associated with observed sulfur dioxide (SO2) emissions from all units regulated under the ARP in 2002?approximately 10.2 million tons?and compare them with damages from a No-Trade counterfactual in which each unit emits SO2 at a rate equal to its allocation of permits for the year 2002, plus any drawdown of its allowance bank. Damages under the No-Trade scenario are $2.4 billion (2000$) higher than under the ARP. This reflects the transfer of allowances from EGUs west of the Mississippi River to units in the eastern US with higher exposed populations.

/pdf/the-net-benefits-of-the-acid-rain-program-what-can-we-learn-5f514emi6z.pdf

The Net Benefits of the Acid Rain Program: What Can We Learn from the Grand Policy Experiment?

This paper examines positive externalities and complementarities between countries in the use of antiviral pharmaceuticals to mitigate pandemic influenza. It demonstrates the presence of treatment externalities in simple SIR (susceptible-infectious-recovered) models and simulations of a Global Epidemiological Model. In these simulations, the pandemic spreads from city to city through the international airline network and from cities to rural areas through ground transport. While most treatment benefits are private, spillovers suggest that it is in the self-interest of high-income countries to pay for some antiviral treatment in low-income countries. The most cost-effective policy is to donate doses to the country where the outbreak originates; however, donating doses to low-income countries in proportion to their populations may also be cost-effective. These results depend on the transmissibility of the flu strain, its start date, the efficacy of antivirals in reducing transmissibility, and the proportion of infectious people who can be identified and treated.

Policy Response to Pandemic Influenza: The Value of Collective Action

Except for two relatively minor statutes, U.S. environmental laws do not permit the balancing of costs and benefits in setting environmental standards. The Clean Air Act, for example, prohibits the Environmental Protection Agency (EPA) from considering costs in setting ambient air quality standards. Similarly, the Clean Water Act does not allow consideration of benefits in setting effluent standards. When the EPA is allowed to balance benefits against costs, it has considerable discretion in defining"balancing."The authors ask two questions: Whether allowed to or not, has the EPA balanced costs and benefits in setting environmental standards? Where has the EPA drawn the line in deciding how much to spend to save a statistical life? Their answers are based on data about the costs and benefits of regulations involving three classes of pollutants: cancer-causing pesticides usedon food crops (1975-89); carcinogenic air pollutants (1975-90); and all uses of asbestos regulated under the Toxic Substances Control Act. The following are their findings. The EPA behaved as though it were balancing costs and benefits in its regulation of pesticides under Federal Insecticide, Fungicide and Rodenticide Act (FIFRA) and of asbestos under Toxic Substance Control Act (TSCA), the two so-called balancing statutes. The higher the cost of the ban, the less likely the EPA was to ban the use of these products. The greater the number of lives saved, the more likely the EPA was to ban their use. But the amount the EPA was (implicitly) willing to spend to save a life was high: $52 million to prevent cancer among pesticide applicators, and $49 million to avoid cancer through exposure to asbestos. The value the EPA attached to saving a life was higher for workers than for consumers. The value attached to avoiding a case of cancer through exposure to pesticide resides on food was less than $100,000, in contrast with the $52 million value of preventing cancer among pesticide applicators - perhaps because workers are exposed to higher levels of pollution than consumers. After 1987, when the Natural Resources Defense Council sued the EPA for considering costs in setting emissions standards for vinyl chloride, the EPA considered costs in setting emissions standards only after an acceptable level of risk was achieved. Ironically, before the vinyl chloride decision, the value per cancer case avoided was only $15 million. The amount the EPA was willing to spend to save a life was thus less under the Clean Air Act than under the balancing statutes. But after this decision, the EPA did not consider costs at all if the risk of cancer to the maximally exposed individual was above one in 10,000.

When is a life too costly to save? : evidence from U.S. environmental regulations

Under the Paris Agreement, India has pledged that 40 percent of its electricity generating capacity will come from non-fossil-fuel sources by the year 2030; however, this pledge does not limit total coal-fired generating capacity. As of 2019, planned increases in coal-fired capacity totaled 95 gigawatts—46 percent of installed coal-fired capacity in 2018. In this paper, we estimate the carbon dioxide benefits and health co-benefits of not building these plants. We also estimate the mortality impacts of the 2018 stock of coal-fired power plants and use it to calculate the tax on electricity generation from coal that would internalize these damages.

The Health Impacts of Coal-Fired Power Plants in India and the Co-benefits of Greenhouse Gas Reductions

The value of mortality risk reduction is an important component of the benefits of environmental policies. In recent years, the number, scope, and quality of valuation studies have increased dramatically. Revealed preference studies of wage compensation for occupational risks, on which analysts have primarily relied, have benefited from improved data and statistical methods. Stated preference research has improved methodologically and expanded dramatically. Studies are now available for several health conditions associated with environmental causes, and researchers have explored many issues concerning the validity of the estimates. With the growing numbers of both types of studies, several meta-analyses have become available that provide insight into the results of both methods. Challenges remain, including better understanding of the persistently smaller estimates from stated preference than from wage differential studies and of how valuation depends on the individual’s age, health status, and characteristics of the illnesses most frequently associated with environmental causes.

Maureen L. Cropper

Papers

The Net Benefits of the Acid Rain Program: What Can We Learn from the Grand Policy Experiment?

Policy Response to Pandemic Influenza: The Value of Collective Action

When is a life too costly to save? : evidence from U.S. environmental regulations

The Health Impacts of Coal-Fired Power Plants in India and the Co-benefits of Greenhouse Gas Reductions

Valuing Mortality Risk Reductions: Progress and Challenges