The Epidemiology of Infectious Diseases

The Epidemiology of Infectious Diseases Infectious diseases have always existed and have had a major impact on human development. It is widely believed that our immune systems and genetic makeup have evolved over many years under the selective pressure of potentially fatal diseases, such as malaria (Haldane 1948; Weatherall 1996). In addition, epidemics of infectious diseases have decimated entire communities, and have sometimes changed the course of history. Examples In Europe in the 14th Century, there were about 25 million deaths from bubonic plague out of a population of approximately 100 million. In 1520 the Aztecs lost about half of their population of 3.5 million from smallpox, introduced by the more immune invading Spaniards. This has been proposed as an important feature in the defeat of the Aztecs by the Spanish invaders. In 1919, after the First World War, the global epidemics of influenza killed an estimated 20 million people during one year more than died as a result of the war. During the 20th century, important advances in the prevention and control of many infectious diseases were achieved with the development of vaccines and antibiotic drugs. This has sometimes created the impression that infectious diseases are no longer a major threat to public health. However, this is far from being the case. The following is a quote from Dr Gro Harlem Brundtland, the Director-General of the World Health Organization: Illness and death from infectious diseases can be, in most cases, avoided at an affordable cost. It is in everyones interest that these obstacles to development be removed. Because of drug resistance, increased travel and the emergence of new diseases, we may only have a limited time in which to make rapid progress. In the following, you will see some of the reasons why infectious diseases are still an important challenge to public health at the beginning of the 21st century. Mortality Infectious diseases are a leading cause of global mortality, causing more than 13 million deaths a year. They are still the main cause of death among children under 5 and the main single cause of premature death in persons under the age of 45. Morbidity Infectious diseases are also a major cause of global morbidity. They are responsible for a huge amount of disability and suffering in the world as measured in DALYs. DALY Disability Adjusted Life Years, a measure of disease burden. It includes years of life lost due to premature death, and years of healthy life lost due disability or illness. Recurring episodes of illness and long-term disability have a major economic impact on the developing countries most affected by infectious diseases. Role in chronic disease Infectious diseases are increasingly being implicated in the pathogenesis of many important diseases that were previously thought to have a non-infectious origin. Cervical cancer is now known to be associated with human papillomavirus infection. Cervical cancer is the sixth most common cancer worldwide and the most common cancer in women in many developing countries. In the past two decades, evidence has grown on the role of Helicobacter pylori infection in gastritis, duodenal ulcer, gastric ulcer, gastric cancer and gastric-mucosa-associated lymphoid tissue (MALT) lymphoma. Chronic infection with hepatitis B or C can cause primary hepatocellular carcinoma (HCC). HCC is among the most common cancers in many parts of Africa and Asia. Potential for epidemic spread A specific feature of infectious diseases is their ability to be transmitted between individuals. This can result in the occurrence of large outbreaks. Between 1997-2000 there were more than 600 outbreaks of disease considered by the WHO to be of international importance. Outbreak The term used to describe a localised epidemic, e.g. in a village, town or city. The term large outbreak is increasingly being used instead of epidemic, as it is less emotive. With increasing urbanisation and international travel, the world is becoming a smaller place, and the routes for transmission of infection are increasing. Aeroplane journeys enable individuals to travel within the incubation period of most infectious diseases. This allows infections to spread to distant places within very short periods of time. An example of this is the annual global dispersal of meningococcal meningitis by pilgrims returning from the Haj Muslim religious festival (Saudi Arabia). Newly emerging diseases Over the past three decades, over 30 new infectious diseases and pathogens have been identified for the first time in humans. These include diseases with a very high case-fatality rate, such as new variant Creutzfeldt-Jacob disease (nvCJD) and Ebola haemorrhagic fever. Some of these new infections are highly prevalent, for example Hepatitis C and rotavirus. Other infections, such as HIV, have rapidly spread around the world. New variant Creutzfeldt-Jacob disease (nvCJD) A new variant of Creutzfeldt-Jakob disease was described in the United Kingdom in 1996. The agent is considered to be the same as that causing bovine spongiform encephalopathy, a disease that emerged in the 1980s and affected thousands of cattle in the United Kingdom and other, mainly European countries. Ebola The first outbreaks of Ebola haemorrhagic fever occurred in 1976 and the discovery of the virus was reported in 1977. Cases reported to WHO up to June 1997 indicated a case-fatality rate of over 70%. A major outbreak in Uganda in 2000 was thought to be associated with spread of the virus by soldiers moving across the country. Hepatitis C This virus was identified in 1989, and is now known to be the most common cause of post-transfusion hepatitis worldwide. So far, up to 3% of the world population are estimated to be infected, among whom 170 million are chronic carriers at risk of developing liver cirrhosis and/or liver cancer. Rotavirus First recognised in 1973, rotavirus is the most common cause of childhood diarrhoea worldwide. 20% of all diarrhoeal deaths and 5% of all deaths in under-5 year olds are due to rotavirus. HIV Although the Acquired Immune Deficiency Syndrome (AIDS) was recognised in 1981, the causal virus, HIV, was first isolated in 1983. It is estimated that, since the start of the epidemic, 30.6 million people worldwide have become HIV-infected and nearly 12 million have died from AIDS or AIDS-related diseases. Re-emerging diseases In addition to the emergence of new infectious diseases, many old diseases that had previously been under control are starting to appear in increased numbers or in previously unaffected populations. Resurgence of infectious diseases can occur because of any of the following reasons: changes in social or environmental conditions, failure to maintain immunisation programmes, increased drug resistance Drug resistance is currently an increasing problem for a number of diseases worldwide, and we are often in a race to develop new treatments faster than the pathogens can develop resistance. Example Since the mid-1980s there has been a major resurgence of diphtheria in several countries of Eastern Europe, which had previously been progressing towards elimination of the disease. In 1993, 15,211 diphtheria cases were reported in Russia and 2,987 cases in Ukraine. The main reason for the return of diphtheria in these countries was a decreased immunisation coverage due to an irregular supply of vaccines and large-scale population movements (Galazka et al 1995). Example Mortality and morbidity rates from tuberculosis (TB) in industrialised countries declined during most of the 20th century. However, from the mid-1980s onwards, many of these countries have seen an important increase in the incidence of TB. This is mainly due to a decline in TB control programmes, the increased incidence of multi-drug resistance TB and the effect of the HIV epidemic (Grange 1998). Potential for prevention and control The mechanisms involved in many infectious diseases are well understood, from the molecular aspects of the infectious agent to the demographic characteristics of host populations. This level of understanding has enabled potentially very effective prevention and control measures to be developed for some infectious diseases. With efficient intervention strategies and the advent of national public health agencies, elimination of specific infectious diseases has become feasible. In some cases, there has even been the possibility (or reality) of global eradication. Following the successful WHO programme for the global eradication of smallpox through vaccination, the last naturally acquired case of this disease occurred in October 1977 in Somalia. The countries of the Western Hemisphere have set a target for the elimination of measles by the end of the year 2005. Polio and guineaworm are now also on the verge of eradication, after intensive, globally co-ordinated programmes. Strategies to immunise millions of children on the same day have resulted in few countries now reporting cases due to wild poliovirus. Infectious disease epidemiology In epidemiology, we are interested in describing and explaining the distribution of diseases in populations. The distribution of an infectious disease depends on the transmission of the infectious agent within the host population. This is a dynamic process, which is influenced by characteristics of the specific infectious agent, characteristics of the host population and characteristics of the relationship between the infectious agent and the host.

Rational models and self evaluation Essay -- essays research papers

My supervisor requested a self-evaluation in connection with an upcoming annual performance review, the self evaluation was meant to answer questions regarding A certain customer service decision and accommodations made by me that went beyond company standard operating procedure and protocols. Conio-caca Graphics Imaging Corporation ordered my team to perform a systems installation for a small publishing company in North Miami. The installation was to be performed according to company standards; first the hardware which included an image setter and then a â€Å"Mac Server† running OS 10 (Operating system version 10) followed by installing specialized software to interface with a desktop publishing application. Upon completing the installation of the software and hardware, the team and the customer found the software was not functioning which effectively meant the customer at that point was, â€Å"Out of Business†. PROBLEM DEFINITION The on-site Team defined the problem (Bazerman, Max H. Judgment in Managerial Decision Making, 5th edition. New York: John Wiley & Sons. 2002), resolving; Apple Computer Corp. had shipped a machine to the customer with the very latest operating system on it which did not work with a standard desktop publishing application; it required a missing upgrade patch having a zipped (compressed) volume of about 80MB’s. Alternative1: After careful communication with my supervisor, I was ordered to tell the customer to order the upgrade patch on a CD direct fr...

Aspartame and Holland Sweetener Co.

27-Feb Bitter Competition: The Holland Sweetener Co. vs. NutraSweet (A) (HBS 9-794-079) 1. How should Vermijs expect NutraSweet to respond to the Holland Sweetener Company’s entry into the European and Canadian aspartame markets? Ans: 1. NutraSweet had a very high Cost of Goods Sold in producing the Aspartame. So it was not a wise move for NutraSweet goes for Price war with Holland Sweetener Company, which might possibly results in a negative gain on the product. . Even though price war is not expected, NutraSweet possibly might use his advantage as the first one introducing the market to continue dominated the market. NutraSweet might also increase its advertisement expense to reintroduce and redirect consumers’ interest back to NutraSweet. 3. In response to Holland’s sue against the company; NutraSweet might probably try their best to fight against it, since they wanted to continuously dominate the soft drink industry.However, even though NutraSweet succeed to defend its anti-competitive, if Holland Sweetener Company or other sweeteners offered a rather better price, similar quality, and comparable distribution offer, in a long run, the drink industry might go to the use of multi-sweetener to lower the suppliers’ control power and to follow government’s suggestion. 4. Since the market shares for NutraSweet will drop with the entry of Holland Sweetener and other Sweetener companies, NutraSweet may expect a sales decrease. Thus, NutraSweet will continue to improve their operation to make it more profitable. . Specifically, how should Vermijs assess the relative likelihood of the two scenarios—price war and normal competition—he has in mind? Price war Anw: Vermijs can use game theory to assess the relative likelihood (N -0. 7, H-0. 3) Holland Enter the Market Normal (N 0. 6, H 0. 4) Nutra Holland did not enter the Market (Nutra 1, Holland 0) When Vermijs think about the likelihood of the two scenarios, he needs to stand in NutraSweet’s shoes to think what Holland will do. If Holland did not enter the market, then Holland will get nothing.But if Holland enter the Market, there’s 50% chance Holland will get some revenue. So Holland will enter the market. When Holland enter the market, Nutra had price war, then they both lost revenue, but if Nutra just normally compete with Holland, then at least Nutra still have positive revenue gain. So Nutra will not start a price war. 3 Other Notes: NutraSweet once reached 711 million for Aspartame business from 1965 to 1987 (patents’ expiration in European and Canadian market); 1986, Holland Sweetener Company prepare to enter this market.NutraSweet’s decision: Normal competition & Price war. NutraSweet has limited production capacity, which hinders the growth of sales and limited their profit; so either NutraSweet increase more capacity to expand their market shares, or after the expiration of exclusivity, let other company get in. Extensive advertising led to wide use of Aspartame by food/beverage manufacturer. Huge price discount first to raise awareness and then put its foot onto soft drink and powdered drink industry.

Jeremy Bentham And Utilitarianism Theory - Free Essay Example

Sample details Pages: 1 Words: 342 Downloads: 1 Date added: 2019/08/08 Category Ethics Essay Level High school Tags: Utilitarianism Essay Did you like this example? The most significant philosopher in Utilitarianism is Jeremy Bentham Jeremy is considered as the founder of Utilitarianism. He was impact by the thinking of human nature of Hobbes and Humes account of social utility. Bentham was born in a family of Conservative lawyers in Spitalfields in East London. He is considered a child prodigy, because he was a beginner walking child who had read the vast history of England at his fathers desk and began to learn Latin at the age of three. After graduating from Westminster High School, Bentham entered Queens College of Oxford in 1760 and received his bachelors and masters degrees in 1763 and 1766. He studied law and was qualified as a lawyer in 1769, but he quickly became tired of the lack of a rational foundation in British law. He believes that British law is a matter of fact and subjective. He hopes that the guiding principles of law can draw on nutrition from science, rather than being dominated by pure privilege, selfishness, and superstition as in the 18th century. After obtaining the permission and help of his father, Bentham began to study the law and handwritten the book. However, the early struggle of the Brigade alone did not affect much. It was not until the early 19th century that he devoted himself to social policy and the specific practical work of the government. Don’t waste time! Our writers will create an original "Jeremy Bentham And Utilitarianism Theory" essay for you Create order Benthams great dream is to establish a perfect and comprehensive legal system, a Pannomion. Trying to make the universal and perfect legal eye into every corner of social life, and to clarify the universal inaccuracy and disorder in English law. The core of Benthams clarification of English law is to demystify the common law. He vigorously lashes between natural law and common law, because in his eyes, many logical fictions of natural law and common law are just myths. Only through thorough legal reform can we build a truly rational legal order. But Bentham not only proposed a lot of legal and social reforms, but also clarified the potential ethical principles on which these laws are based.