Chapter 1 - Principles of asepsis. Our bodies are amazing structures that defend us against infections under normal circumstances. As you read this chapter you will learn about disease-causing microorganisms, how the body defends itself against infections, and ways that infections might occur.
CHAPTER Principles of Asepsis © 2011 The McGraw-Hill Companies, Inc All rights reserved 12 Learning Outcomes 1.1 Explain the historical background of infectious disease prevention 1.2 Identify the types of microorganisms that cause disease 1.3 List some infectious diseases, and identify their signs and symptoms 1.4 Discuss the importance of preventing antibiotic resistance in a health-care setting 1.5 Describe ways you can help prevent antibiotic resistance in health-care settings © 2011 The McGraw-Hill Companies, Inc All rights reserved 13 Learning Outcomes (cont.) 1.6 Explain the disease process 1.7 Explain how the body’s defenses protect against infection 1.8 Describe the cycle of infection 1.9 Identify and describe the various methods of disease transmission 1.10 Explain how you can help break the cycle of infection © 2011 The McGraw-Hill Companies, Inc All rights reserved 14 Introduction Our bodies are amazing structures that defend us against infections under normal circumstances You will learn about: – Disease-causing microorganisms – How the body fights disease – Ways infections occur – Antibiotic-resistant organisms – Importance of patient education on the proper use of antibiotics © 2011 The McGraw-Hill Companies, Inc All rights reserved 15 History of Infectious Disease Prevention • Throughout history people have attempted to discover – Causes of infection – How to prevent infections – How to treat infections © 2011 The McGraw-Hill Companies, Inc All rights reserved History of Infectious Disease Prevention 16 (cont.) Scientist Contribution Edward Jenner (1749–1823) • Developed first effective vaccine • Used cowpox to vaccinate against smallpox Ignaz Semmelweis (1818–1865) and Oliver Wendell Holmes (1809– 1894) • Promoted handwashing as a means of reducing the spread of puerperal fever to women in childbirth © 2011 The McGraw-Hill Companies, Inc All rights reserved History of Infectious Disease Prevention 17 (cont.) Scientist Contribution Louis Pasteur (1822–1895) • Helped develop the germ theory of infectious disease, stating that disease is caused by microorganisms Joseph Lister (1827–1912) • • Helped develop germ theory Introduced aseptic techniques through the use of antiseptics on wounds, surgical sites, and surgical instruments © 2011 The McGraw-Hill Companies, Inc All rights reserved History of Infectious Disease Prevention 18 (cont.) Scientist Contribution Robert Koch (1843–1910) • Developed a set of proofs, known as Koch’s postulates, claiming that microbes cause disease Sir Alexander Fleming (18811955) Discovered penicillin â 2011 The McGraw-Hill Companies, Inc All rights reserved History of Infectious Disease Prevention 19 (cont.) • Remarkable advances in the past century • Threat of infection still present – New infectious diseases • AIDS • Ebola – Resistant diseases • MRSA • VRSA • Multidrug-resistant TB © 2011 The McGraw-Hill Companies, Inc All rights reserved 110 Apply Your Knowledge Why is the threat of infection still present even though great advances have been made in controlling infections over the past century? ANSWER: The threat of infection is still present because of new diseases and diseases that have become resistant to treatments © 2011 The McGraw-Hill Companies, Inc All rights reserved 155 Apply Your Knowledge What is the difference between active and passive immunity? ANSWER: Active immunity is long-term immunity in which the body produces its own antibodies Passive immunity results when antibodies produced outside the body enter the body Both can be natural or artificial Impressive! © 2011 The McGraw-Hill Companies, Inc All rights reserved 156 Cycle of Infection • A reservoir host – animal, insect, or human body capable of sustaining pathogen growth – Carrier – unaware of presence of pathogen – Subclinical case – unnoticeable infection – Endogenous infection – normally harmless microorganisms become pathogenic – Exogenous infection – pathogen introduced into the body Click for Cycle of Infection © 2011 The McGraw-Hill Companies, Inc All rights reserved 157 Cycle of Infection (cont.) • Means of exit – how the pathogen leaves the host – Nose, mouth, eyes, or ears – Feces or urine – Semen, vaginal fluid, or other reproductive discharge – Blood or blood products Click for Cycle of Infection © 2011 The McGraw-Hill Companies, Inc All rights reserved 158 Cycle of Infection (cont.) • Means of transmission – how a pathogen spreads to a host – – – – – – Touching Airborne • Direct Blood-borne • Indirect through During pregnancy or birth fomites Foodborne – Inanimate reservoir of pathogens Vector-borne • Living organism that carries microorganisms to another person – Drinking glass, door knob, etc Click for Cycle of Infection © 2011 The McGraw-Hill Companies, Inc All rights reserved 159 Cycle of Infection (cont.) • Means of entrance – Enter through any cavity lined with mucous membrane • Mouth, nose, vagina, rectum • Ears, eyes, intestinal tract, urinary tract, reproductive tract, breaks in the skin Click for Cycle of Infection © 2011 The McGraw-Hill Companies, Inc All rights reserved 160 Cycle of Infection (cont.) Susceptible host Individual with little or no immunity to infection by a pathogen Host factors influencing susceptibility Age Genetic predisposition Nutritional status Other disease processes Stress levels Hygiene habits General health – Pathogen factors • Number and concentration • Virulence • Point of entry Click for Cycle of Infection © 2011 The McGraw-Hill Companies, Inc All rights reserved 161 Cycle of Infection (cont.) Back © 2011 The McGraw-Hill Companies, Inc All rights reserved 162 Cycle of Infection (cont.) • Environmental factors – Dense populations – Animals – unpasteurized milk – Insects – Economic and political factors – Availability of transportation – Population growth rates – Sexual behavior © 2011 The McGraw-Hill Companies, Inc All rights reserved 163 Breaking the Cycle • Asepsis – condition in which pathogens are absent or controlled Maintain strict housekeeping standards Adhere to government guidelines to protect against disease Educate patients in hygiene, health promotion, and disease prevention © 2011 The McGraw-Hill Companies, Inc All rights reserved 164 Apply Your Knowledge What are fomites? ANSWER: Fomites are inanimate objects such as clothing, water, and food that serve as a means of transportation for microorganisms Nice Job! © 2011 The McGraw-Hill Companies, Inc All rights reserved 165 In Summary 1.1 Infection control has been a problem throughout history Though there have been many advances, controlling infection continues to be a challenge for doctors 1.2 There is great variety in the types of pathogenic organisms Types of potentially infectious microorganisms include prions, viruses, bacteria, protozoans, fungi, and helminths © 2011 The McGraw-Hill Companies, Inc All rights reserved 166 In Summary (cont.) 1.3 It is important to be familiar with the diseases that infect people so that you can protect your patients, coworkers, and yourself These diseases include but are not limited to chickenpox, croup, diphtheria, hepatitis, influenza, measles, mumps, and polio 1.4 Antibiotic resistance of microbial pathogens is a growing problem The number of infections for which there is little or no treatment is increasing It is the responsibility of health-care workers to use antibiotics wisely © 2011 The McGraw-Hill Companies, Inc All rights reserved 167 In Summary (cont.) 1.5 The CDC began a campaign to prevent antimicrobial resistance There are four strategies outlined in the campaign: 1) prevent infection; 2) diagnose and treat infection appropriately; 3) use antibiotics carefully; and 4) prevent transmission of infections 1.6 There are numerous human pathogens These pathogens cause disease by damaging the body in a number of ways including depleting nutrients needed by cells, reproducing themselves within body cells, making body cells the targets of the body’s own defenses, and producing toxins that damage cells and tissues © 2011 The McGraw-Hill Companies, Inc All rights reserved 168 In Summary (cont.) 1.7 The body is able to protect itself from disease through the use of several lines of defense These lines of defense may be nonspecific or specific 1.8 In order for an infection to occur, five elements must be in place There must be a reservoir host, a means of exit, a means of transmission, a means of entrance, and a susceptible host 1.9 Direct disease transmission occurs when the pathogen moves immediately from one host to another Indirect transmission is possible only if the pathogen is able to survive outside the host for some period of time © 2011 The McGraw-Hill Companies, Inc All rights reserved 169 End of Chapter In today's world, new infections and diseases can spread across the country and even across the world in a matter of days, or even hours, making early detection critical. ~ John Linder Member of the U.S. House of Representatives, Georgia © 2011 The McGraw-Hill Companies, Inc All rights reserved ... Ignaz Semmelweis (18 18 18 65) and Oliver Wendell Holmes (18 0 9– 18 94) • Promoted handwashing as a means of reducing the spread of puerperal fever to women in childbirth © 2 011 The McGraw-Hill Companies,... Prevention 1 7 (cont.) Scientist Contribution Louis Pasteur (18 22 18 95) • Helped develop the germ theory of infectious disease, stating that disease is caused by microorganisms Joseph Lister (18 27 19 12)... spread – – – • Use tissues when coughing or sneezing Wash hands frequently Use disposable dishware, if possible Incubation – to days © 2 011 The McGraw-Hill Companies, Inc All rights reserved 1 19