DOCSLIB.ORG

7 Microbial Aspects

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
7 Microbial Aspects 77 MicrobialMicrobial aspectsaspects A conceptual framework for Introduction implementing the Guidelines (Chapter 1) (Chapter 2) hehe greatestgreatest riskrisk toto FRAMEWORK FOR SAFE DRINKING-WATER SUPPORTING TTpublicpublic healthhealth fromfrom INFORMATION microbesmicrobes in in water water is is asso-asso- Health-based targets Public health context Microbial aspects ciatedciated with with consumptionconsumption (Chapter 3) and health outcome (Chapters 7 and 11) ofof drinking-waterdrinking-water thatthat isis Water safety plans Chemical aspects (Chapter 4) (Chapters 8 and 12) contaminatedcontaminated withwith hu-hu- System Management and Radiological Monitoring manman andand animalanimal excreta,excreta, assessment communication aspects althoughalthough otherother sourcessources (Chapter 9) Acceptability and routes of exposure Surveillance and routes of exposure aspects (Chapter 5) maymay also also be be signifi significant. cant. (Chapter 10) ThisWaterborne chapter focusesout- onbreaks organisms have beenfor which asso- Application of the Guidelines in specific circumstances thereciated is withevidence, inadequate from (Chapter 6) outbreak studies or from treatment of water sup- Climate change, Emergencies, prospectiveplies and unsatisfactorystudies in Rainwater harvesting, Desalination systems, Travellers, Planes and non-outbreakmanagement of situations, drinking- ships, etc. ofwater diseases distribution. being caused For byexample, ingestion in distributionof drinking-water, systems, inhalation such outbreaks of water have droplets been linked or dermal to cross-connections, contact with drinking-watercontamination andduring their storage, prevention low andwater control. pressure For and the purposeintermittent of the supply. Guidelines, Water - theseborne routes outbreaks are considered are preventable waterborne. if an integrated risk management framework based on aChapter multiple-barrier 11 (Microbial approach fact fromsheets) catchment provides to additional consumer detailed is applied. information Implementing on individualan integrated waterborne risk management pathogens, framework as well as onto keepindicator the water microorganisms. safe from contamination in distribution systems includes the protection of water sources, the proper selection 7.1and Microbialoperation of hazards drinking-water associated treatment with processes, drinking-water and the correct management Infectiousof risks within diseases the caused distribution by pathogenic systems (forbacteria, further viruses information, and parasites see the (e.g. supporting proto- zoadocument and helminths) Water safety are the in distributionmost common systems and ;widespread Annex 1). health risk associated with drinking-water.This chapter The focuses public healthon organisms burden is for determined which there by theis evidence,severity and from incidence outbreak ofstudies the illnesses or from associated prospective with pathogens,studies in theirnon-outbreak infectivity andsituations, the population of diseases exposed. being Incaused vulnerable by ingestion subpopulations, of drinking-water, disease outcome inhalation may of be water more droplets severe. or dermal contact 117117 with drinking-water and their prevention and control. For the purpose of the Guide- lines, these routes are considered waterborne. Chapter 11 (Microbial fact sheets) provides additional detailed information on individual waterborne pathogens, as well as on indicator microorganisms. 7.1 Microbial hazards associated with drinking-water Infectious diseases caused by pathogenic bacteria, viruses and parasites (e.g. proto- zoa and helminths) are the most common and widespread health risk associated with drinking-water. The public health burden is determined by the severity and incidence of the illnesses associated with pathogens, their infectivity and the population exposed. In vulnerable subpopulations, disease outcome may be more severe. 117 117a GUIDELINES FOR DRINKING-WATER QUALITY 7. MICROBIAL ASPECTS Breakdown in water supply safety (source, treatment and distribution) may lead to large-scale contamination and potentially to detectable disease outbreaks. In some Infectious diseases caused by pathogenic cases, low-level, potentially repeated con- bacteria, viruses, protozoa and helminths tamination may lead to significant spor- are the most common and widespread adic disease, but public health surveillance health risk associated with drinking‑water. is unlikely to identify contaminated drink- ing-water as the source. Waterborne pathogens have several properties that distinguish them from other drinking-water contaminants: • Pathogens can cause acute and also chronic health effects. • Some pathogens can grow in the environment. • Pathogens are discrete. • Pathogens are often aggregated or adherent to suspended solids in water, and pathogen concentrations vary in time, so that the likelihood of acquiring an in- fective dose cannot be predicted from their average concentration in water. • Exposure to a pathogen resulting in disease depends upon the dose, invasiveness and virulence of the pathogen, as well as the immune status of the individual. • If infection is established, pathogens multiply in their host. • Certain waterborne pathogens are also able to multiply in food, beverages or warm water systems, perpetuating or even increasing the likelihood of infection. • Unlike many chemical agents, pathogens do not exhibit a cumulative effect. Quantitative microbial risk assessment (QMRA), a mathematical framework for evaluating infectious risks from human pathogens, can assist in understanding and managing waterborne microbial hazards, especially those associated with sporadic disease. 7.1.1 Waterborne infections The pathogens that may be transmitted through contaminated drinking-water are diverse in characteristics, behaviour and resistance. Table 7.1 provides general infor- mation on pathogens that are of relevance for drinking-water supply management. Waterborne transmission of the pathogens listed has been confirmed by epidemio- logical studies and case histories. Part of the demonstration of pathogenicity involves reproducing the disease in suitable hosts. Experimental studies in which healthy adult volunteers are exposed to known numbers of pathogens provide information, but these data are applicable to only a part of the exposed population; extrapolation to more vulnerable subpopulations is an issue that remains to be studied in more detail. Table 7.2 provides information on organisms that have been suggested as possible causes of waterborne disease but where evidence is inconclusive or lacking. The spectrum of pathogens may change as a result of host, pathogen and environmental changes such as fluctuations in human and animal populations, reuse of wastewater, changes in lifestyles and medical interventions, population movement and travel, selective pressures for new pathogens and mutants or recombinations of existing pathogens. The immunity of individuals also varies considerably, whether acquired 118 GUIDELINES FOR DRINKING-WATER QUALITY GUIDELINES FORDRINKING-WATER 118 Table 7.1 Pathogens transmitted through drinking-watera Type species/ Health Persistence in Resistance to Relative Important Pathogen genus/groupb significancec water suppliesd chlorinee infectivityf animal source Bacteria Burkholderia B. pseudomallei High May multiply Low Low No Campylobacter C. coli High Moderate Low Moderate Yes C. jejuni Escherichia coli – High Moderate Low Low Yes Diarrhoeagenicg E. coli – E. coli O157 High Moderate Low High Yes Enterohaemorrhagic Francisella F. tularensis High Long Moderate High Yes 7. MICROBIALASPECTS Legionella L. pneumophila High May multiply Low Moderate No Mycobacteria (non‑ Mycobacterium avium Low May multiply High Low No tuberculous) complex 119 Salmonella typhi High Moderate Low Low No Other salmonellae S. enterica High May multiply Low Low Yes S. bongori Shigella S. dysenteriae High Short Low High No Vibrio V. cholerae O1 and High Short to longh Low Low No O139 Viruses Adenoviridae Adenoviruses Moderate Long Moderate High No Astroviridae Astroviruses Moderate Long Moderate High No Caliciviridae Noroviruses, High Long Moderate High Potentially Sapoviruses Hepeviridae Hepatitis E virus High Long Moderate High Potentially Picornaviridae Enteroviruses, High Long Moderate High No Parechoviruses, Hepatitis A virus Reoviridae Rotaviruses High Long Moderate High No 7. MICROBIALASPECTS 7. MICROBIALASPECTS 119 Table 7.1 (continued) Type species/ Health Persistence in Resistance to Relative Important Pathogen genus/groupb significancec water suppliesd chlorinee infectivityf animal source Protozoa Acanthamoeba A. culbertsoni High May multiply High High No Cryptosporidium C. hominis/parvum High Long High High Yes Cyclospora C. cayetanensis High Long High High No Entamoeba E. histolytica High Moderate High High No Giardia G. intestinalis High Moderate High High Yes Naegleria N. fowleri High May multiply Low Moderate No Helminths Dracunculus D. medinensis High Moderate Moderate High No 7. MICROBIALASPECTS a This table contains pathogens for which there is some evidence of health significance related to their occurrence in drinking‑water supplies. More information on these and other pathogens is presented in chapter 11. 119a b The type species listed (e.g. L. pneumophila) are those most commonly linked to waterborne transmission but other species may also cause disease. c Health significance relates to the incidence and severity of disease, including association
Load more

Recommended publications
  • Medicine in 18Th and 19Th Century Britain, 1700-1900
    Medicine in 18th and 19th century Britain, 1700‐1900 The breakthroughs th 1798: Edward Jenner – The development of How had society changed to make medical What was behind the 19 C breakthroughs? Changing ideas of causes breakthroughs possible? vaccinations Jenner trained by leading surgeon who taught The first major breakthrough came with Louis Pasteur’s germ theory which he published in 1861. His later students to observe carefully and carry out own Proved vaccination prevented people catching smallpox, experiments proved that bacteria (also known as microbes or germs) cause diseases. However, this did not put an end The changes described in the Renaissance were experiments instead of relying on knowledge in one of the great killer diseases. Based on observation and to all earlier ideas. Belief that bad air was to blame continued, which is not surprising given the conditions in many the result of rapid changes in society, but they did books – Jenner followed these methods. scientific experiment. However, did not understand what industrial towns. In addition, Pasteur’s theory was a very general one until scientists begun to identify the individual also build on changes and ideas from earlier caused smallpox all how vaccination worked. At first dad bacteria which cause particular diseases. So, while this was one of the two most important breakthroughs in ideas centuries. The flushing toilet important late 19th C invention wants opposition to making vaccination compulsory by law about what causes disease and illness it did not revolutionise medicine immediately. Scientists and doctors where the 1500s Renaissance – flushing system sent waste instantly down into – overtime saved many people’s lives and wiped‐out first to be convinced of this theory, but it took time for most people to understand it.
    [Show full text]
  • Bradford Hill Criteria for Causal Inference Based on a Presentation at the 2015 ANZEA Conference
    Bradford Hill Criteria for Causal Inference Based on a presentation at the 2015 ANZEA Conference Julian​ King Director,​ Julian King & Associates – a member of the Kinnect Group www.julianking.co.nz​ | www.kinnect.co.nz 2015 We think we’re good at determining causality, but we suck at it One​ of the great At​ one level, this is an Unfortunately,​ though, the challenges in evaluation is everyday, common sense way we are wired does not determining whether the task. As a species we’ve predispose us to logical results we’re seeing are been making judgments thinking. We are inclined because of the program about causation for a to be led astray by all sorts we’re evaluating, some million years or so. of biases and heuristics. other influences out there in the big world, or random chance. The​ Kinnect Group www.kinnect.co.nz 2 Along came logic Eventually,​ after a very long time, we evolved into philosophers who invented formal logic. Thanks to scientific method, our species has recently triumphed to the extent that we now have cars that drive themselves and flying drones that deliver pizza (don’t confuse this with progress – we still suck at ethics but that’s a story for another day). 3 But we’re still not great at causation Over​ time, the rocket But​ deep down we’re still Such​ a rigid view is not science for dealing with biased, heuristical beings much use in the real causation has become and not very good at world, where there are all more sophisticated – a thinking things through.
    [Show full text]
  • Medical Bacteriology
    LECTURE NOTES Degree and Diploma Programs For Environmental Health Students Medical Bacteriology Abilo Tadesse, Meseret Alem University of Gondar In collaboration with the Ethiopia Public Health Training Initiative, The Carter Center, the Ethiopia Ministry of Health, and the Ethiopia Ministry of Education September 2006 Funded under USAID Cooperative Agreement No. 663-A-00-00-0358-00. Produced in collaboration with the Ethiopia Public Health Training Initiative, The Carter Center, the Ethiopia Ministry of Health, and the Ethiopia Ministry of Education. Important Guidelines for Printing and Photocopying Limited permission is granted free of charge to print or photocopy all pages of this publication for educational, not-for-profit use by health care workers, students or faculty. All copies must retain all author credits and copyright notices included in the original document. Under no circumstances is it permissible to sell or distribute on a commercial basis, or to claim authorship of, copies of material reproduced from this publication. ©2006 by Abilo Tadesse, Meseret Alem All rights reserved. Except as expressly provided above, no part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage and retrieval system, without written permission of the author or authors. This material is intended for educational use only by practicing health care workers or students and faculty in a health care field. PREFACE Text book on Medical Bacteriology for Medical Laboratory Technology students are not available as need, so this lecture note will alleviate the acute shortage of text books and reference materials on medical bacteriology.
    [Show full text]
  • Molecular Pathological Epidemiology in Diabetes Mellitus and Risk of Hepatocellular Carcinoma
    Submit a Manuscript: http://www.wjgnet.com/esps/ World J Hepatol 2016 September 28; 8(27): 1119-1127 Help Desk: http://www.wjgnet.com/esps/helpdesk.aspx ISSN 1948-5182 (online) DOI: 10.4254/wjh.v8.i27.1119 © 2016 Baishideng Publishing Group Inc. All rights reserved. REVIEW Molecular pathological epidemiology in diabetes mellitus and risk of hepatocellular carcinoma Chun Gao Chun Gao, Department of Gastroenterology, China-Japan logy and epidemiology, and investigates the relationship Friendship Hospital, Ministry of Health, Beijing 100029, China between exogenous and endogenous exposure factors, tumor molecular signatures, and tumor initiation, progres- Author contributions: Gao C conceived the topic, performed sion, and response to treatment. Molecular epidemiology research, retrieved concerned literatures and wrote the paper. broadly encompasses MPE and conventional-type mole- cular epidemiology. Hepatocellular carcinoma (HCC) Supported by Beijing NOVA Programme of Beijing Municipal is the third most common cause of cancer-associated Science and Technology Commission, No. Z13110.7000413067. death worldwide and remains as a major public health Conflict-of-interest statement: No conflict of interest. challenge. Over the past few decades, a number of epidemiological studies have demonstrated that diabetes Open-Access: This article is an open-access article which was mellitus (DM) is an established independent risk factor selected by an in-house editor and fully peer-reviewed by external for HCC. However, how DM affects the occurrence and
    [Show full text]
  • Foundations of Epidemiology
    66221_CH01_5398.qxd 6/19/09 11:16 AM Page 1 © Jones and Bartlett Publishers, LLC. NOT FOR SALE OR DISTRIBUTION CHAPTER 1 Foundations of Epidemiology OBJECTIVES After completing this chapter, you will be able to: ■ Define epidemiology. ■ Define descriptive epidemiology. ■ Define analytic epidemiology. ■ Identify some activities performed in epidemiology. ■ Explain the role of epidemiology in public health practice and individual decision making. ■ Define epidemic, endemic, and pandemic. ■ Describe common source, propagated, and mixed epidemics. ■ Describe why a standard case definition and adequate levels of reporting are important in epidemiologic investigations. ■ Describe the epidemiology triangle for infectious disease. ■ Describe the advanced epidemiology triangle for chronic diseases and behavioral disorders. ■ Define the three levels of prevention used in public health and epidemiology. ■ Understand the basic vocabulary used in epidemiology. 66221_CH01_5398.qxd 6/19/09 11:16 AM Page 2 © Jones and Bartlett Publishers, LLC. NOT FOR SALE OR DISTRIBUTION 2 CHAPTER 1 ■ Foundations of Epidemiology In recent years, the important role of epidemiology has become increasingly recognized. Epidemiology is a core subject required in public health and health education programs; it is a study that provides information about public health problems and the causes of those problems. This information is then used to improve the health and social conditions of people. Epidemiology has a population focus in that epidemiologic investigations are concerned with the collective health of the people in a community or population under study. In contrast, a clinician is concerned for the health of an individual. The clinician focuses on treating and caring for the patient, whereas the epidemiologist focuses on iden- tifying the source or exposure of disease, disability or death, the number of persons exposed, and the potential for further spread.
    [Show full text]
  • Molecular Pathological Epidemiology Gives Clues to Paradoxical Findings
    Molecular Pathological Epidemiology Gives Clues to Paradoxical Findings The Harvard community has made this article openly available. Please share how this access benefits you. Your story matters Citation Nishihara, Reiko, Tyler J. VanderWeele, Kenji Shibuya, Murray A. Mittleman, Molin Wang, Alison E. Field, Edward Giovannucci, Paul Lochhead, and Shuji Ogino. 2015. “Molecular Pathological Epidemiology Gives Clues to Paradoxical Findings.” European Journal of Epidemiology 30 (10): 1129–35. https://doi.org/10.1007/ s10654-015-0088-4. Citable link http://nrs.harvard.edu/urn-3:HUL.InstRepos:41392032 Terms of Use This article was downloaded from Harvard University’s DASH repository, and is made available under the terms and conditions applicable to Open Access Policy Articles, as set forth at http:// nrs.harvard.edu/urn-3:HUL.InstRepos:dash.current.terms-of- use#OAP HHS Public Access Author manuscript Author Manuscript Author ManuscriptEur J Epidemiol Author Manuscript. Author Author Manuscript manuscript; available in PMC 2016 October 07. Published in final edited form as: Eur J Epidemiol. 2015 October ; 30(10): 1129–1135. doi:10.1007/s10654-015-0088-4. Molecular Pathological Epidemiology Gives Clues to Paradoxical Findings Reiko Nishiharaa,b,c, Tyler J. VanderWeeled,e, Kenji Shibuyac, Murray A. Mittlemand,f, Molin Wangd,e,g, Alison E. Fieldd,g,h,i, Edward Giovannuccia,d,g, Paul Lochheadi,j, and Shuji Oginob,d,k aDepartment of Nutrition, Harvard T.H. Chan School of Public Health, 655 Huntington Ave., Boston, Massachusetts 02115 USA bDepartment of Medical Oncology, Dana-Farber Cancer Institute and Harvard Medical School, 450 Brookline Ave., Boston, Massachusetts 02215 USA cDepartment of Global Health Policy, Graduate School of Medicine, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, Japan dDepartment of Epidemiology, Harvard T.H.
    [Show full text]
  • HIV and AIDS: a Module for Cnas and Hhas
    HIV AND AIDS: A Module for CNAs AND HHAs INTRODUCTION The human immunodeficiency virus (HIV) is a virus that is transmitted through sexual contact or contact with infected blood. HIV causes an illness called acquired immune deficiency syndrome - AIDS. AIDS was first diagnosed in New York City and San Francisco in 1981. However, there is evidence that HIV has actually been infecting people for many, many years before it was recognized and isolated cases of AIDS had occurred many years before the epidemic started. The cause of AIDS, HIV, was finally isolated in 1983. There are now over 33 million people in the world who are infected with HIV. A large number of them will develop AIDS, and AIDS is an enormous public health problem in the United States and worldwide. Modern medications have now allowed many people infected with HIV to avoid developing AIDS. However, there is no cure for HIV infection - the virus cannot be eliminated or eradicated - and there is still no vaccine available that can prevent the spread of HIV. Learning Break: Many people use the terms HIV and AIDS interchangeably, but it is important to remember that they are two different things. HIV is the virus that causes AIDS. AIDS is the disease - or group of diseases - that are caused by infection with HIV. Someone can be infected with HIV but not have AIDS. OBJECTIVES When the student has finished this module, he/she will be able to: 1. Identify a definition of HIV. 2. Identify a definition of AIDS. 3. Identify the basic defense mechanism the body uses against infections.
    [Show full text]
  • Colonization V. Infection
    Colonization vs Infection Colonization • The presence of microorganisms in or on a host with growth and multiplication but without tissue invasion or damage • Understanding this concept is essential in the planning and implantation of epidemiological studies in a healthcare infection prevention and control program Infection v. Colonization • Confusing colonization with infection can lead to spurious associations that may lead to expensive, ineffective, and time‐ consuming interventions Multi Drug‐Resistant Organisms Management in Long Term Care • Colonization may become infection when changes in the host Facilities Workshop occur Louisiana Office of Public Health Healthcare‐Associated Infections Program Objectives Colonization: Definition By the end of the presentation, attendees will be able to: • Colonization: presence of a microorganism on/in a host, with • Define colonization growth and multiplication of the organism, but without • Differentiate colonization from infections interaction between host and organism (no clinical expression, no immune response). • Apply appropriate laboratory test by common LTC infectious • agents Carrier: individual which is colonized + more • • Understand the necessity of communicating infectious status Subclinical or unapparent infection: presence of upon patient transfer microorganism and interaction between host and microorganism (sub clinical response, immune response). Often the term colonization is applied for relationship host‐ agent in which the immune response is difficult to elicit. • Contamination: Presence of a microorganism on a body surface or an inanimate object. 1 Colonization vs Infection Spectrum: No Exposure ‐ Exposure ‐ Colonization ‐ Carrier Infection ‐ Disease A carrier is an individual that harbors a specific microorganism Host + Infectious agent What is “Exposed” ? in the absence of discernible clinical disease and serve as a No foothold: Exposed Means of transmission: potential source of infection.
    [Show full text]
  • Epidemiological Causation Criteria
    Slide 1 © 2003 By Default! EpidemiologicalEpidemiological CausationCausation CriteriaCriteria James R. Coughlin, Ph.D. Coughlin & Associates Laguna Niguel, California [email protected] www.jrcoughlin-associates.com Meat Industry Research Conference Chicago, IL October 23, 2007 A Free sample background from www.awesomebackgrounds.com Slide 2 © 2003 By Default! DiscussionDiscussion TopicsTopics 1. Types of epidemiologic studies 2. Epidemiologic science and the media 3. Bradford Hill’s “Causation Criteria” 4. Statistical considerations 5.5. QuestionsQuestions toto askask whenwhen reviewingreviewing anan epidemiologicepidemiologic studystudy A Free sample background from www.awesomebackgrounds.com Slide 3 © 2003 By Default! Epidemiology Defined • Epi (upon) = demos (people) + ology (study of) • Historical - the study of epidemics of infectious disease • Modern - the study of the distribution and determinants of health and disease frequency in human populations • Epidemiology looks for patterns of disease (time, place, personal characteristics) A Free sample background from www.awesomebackgrounds.com Slide 4 © 2003 By Default! A Free sample background from www.awesomebackgrounds.com Slide 5 © 2003 By Default! A Free sample background from www.awesomebackgrounds.com Slide 6 © 2003 By Default! A Free sample background from www.awesomebackgrounds.com Slide 7 © 2003 By Default! A Free sample background from www.awesomebackgrounds.com Slide 8 © 2003 By Default! A Free sample background from www.awesomebackgrounds.com Slide 9 © 2003 By Default! Epidemiologic Science and the Media • Dramatically increased interest in health over the past decade • What we eat…or don’t eat…is always being linked to various diseases, especially obesity and cancer • Anxiety-provoking media headlines – • “Carcinogen-of-the-month” being the most scary to consumers • Dietary epi studies always seem to be contradicting each other • Lots of nutrition nonsense and “food faddism” out there • U.S.
    [Show full text]
  • Koch's Postulates Koch's Postulates Are Four Criteria Designed to Establish a Causative Relationship Between a Microbe and a Disease
    Koch's postulates Koch's postulates are four criteria designed to establish a causative relationship between a microbe and a disease. The postulates were formulated by Robert Koch and Friedrich Loeffler in 1884, based on earlier concepts described by Jakob Henle, and refined and published by Koch in 1890. Koch applied the postulates to describe the etiology of cholera and tuberculosis, but they have been controversially generalized to other diseases. These postulates were generated prior to understanding of modern concepts in microbial pathogenesis that cannot be examined using Koch's postulates, including viruses (which are obligate cellular parasites) or asymptomatic carriers. They have largely been supplanted by other criteria such as the Bradford Hill criteria for infectious disease causality in modern public health. The postulates Koch's postulates of disease. Koch's postulates are the following: 1. The microorganism must be found in abundance in all organisms suffering from the disease, but should not be found in healthy organisms. 2. The microorganism must be isolated from a diseased organism and grown in pure culture. 3. The cultured microorganism should cause disease when introduced into a healthy organism. 4. The microorganism must be reisolated from the inoculated, diseased experimental host and identified as being identical to the original specific causative agent. However, Koch abandoned the universalist requirement of the first postulate altogether when he discovered asymptomatic carriers of cholera and, later, of typhoid fever. Asymptomatic or subclinical infection carriers are now known to be a common feature of many infectious diseases, especially viruses such as polio, herpes simplex, HIV, and hepatitis C.
    [Show full text]
  • Elements of Causal Inference
    Elements of Causal Inference Foundations and Learning Algorithms Adaptive Computation and Machine Learning Francis Bach, Editor Christopher Bishop, David Heckerman, Michael Jordan, and Michael Kearns, As- sociate Editors A complete list of books published in The Adaptive Computation and Machine Learning series appears at the back of this book. Elements of Causal Inference Foundations and Learning Algorithms Jonas Peters, Dominik Janzing, and Bernhard Scholkopf¨ The MIT Press Cambridge, Massachusetts London, England c 2017 Massachusetts Institute of Technology This work is licensed to the public under a Creative Commons Attribution- Non- Commercial-NoDerivatives 4.0 license (international): http://creativecommons.org/licenses/by-nc-nd/4.0/ All rights reserved except as licensed pursuant to the Creative Commons license identified above. Any reproduction or other use not licensed as above, by any electronic or mechanical means (including but not limited to photocopying, public distribution, online display, and digital information storage and retrieval) requires permission in writing from the publisher. This book was set in LaTeX by the authors. Printed and bound in the United States of America. Library of Congress Cataloging-in-Publication Data Names: Peters, Jonas. j Janzing, Dominik. j Scholkopf,¨ Bernhard. Title: Elements of causal inference : foundations and learning algorithms / Jonas Peters, Dominik Janzing, and Bernhard Scholkopf.¨ Description: Cambridge, MA : MIT Press, 2017. j Series: Adaptive computation and machine learning series
    [Show full text]
  • Introduction to Medical Microbiology Medical Microbiology: Is a Science of Studying Micro-Organisms That Are Associated with Human Disease
    Introduction to medical microbiology Medical Microbiology: is a science of studying micro-organisms that are associated with human disease. FIELDS OF Microbiology : 1- Medical microbiology: This field focuses on pathogens, diseases, and body defenses. Immunology, Virology, Bacteriology, Mycology, and Parasitology. 2- Industrial microbiology: This field focuses on the production of alcohol, enzymes, vitamins, and antibiotic. 3- Agricultural microbiology: This filed is concerned with Soil fertilization, nitrogen, carbon, sulfur, and phosphorous cycles, as well as plant disease. 4- Food microbiology: This field focuses on food poisoning, toxicity and spoilage. 5- Molecular microbiology: deals with molecular mechanisms and physiological processes of microbes and utilization in production of biotechnology products such as vaccines, and antibodies. 6- Sanitary microbiology: is a science based on the detection of risks associated with the production, manufacture and consumption of foods and water. It has been established that environment facts determine the survival, growing and inactivation of the microorganisms. 7- environmental microbiology: is the study of the composition and physiology of microbial communities in the environment. ** There are four classes of organisms that can cause disease: 1- Viruses: Their size < 0.3 microns in diameter, they are totally dependent on infected cells for replication. They cause intracellular infection. 2- Bacteria: Usually measure about one micron or more, multiply by binary fission, and they can cause intercellular or extracellular infection. 3- Fungi, these can be of two varieties: a- Yeasts are unicellular organisms measuring (2-20) microns. b- Molds are large multicellular organisms. 4- Parasites: these can be of two classes: a- Protozoa, these are unicellular organisms that vary in size, some are very small (about 3 microns) and can cause intercellular infection.
    [Show full text]