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Human Diseases A Systemic Approach Sixth Edition Mary Lou Mulvihill Mark Zelman Paul Holdaway Elaine Tompary Jill Raymond Chapter 3 Infectious Diseases Mulvihill, Zelman, Holdaway, Tompary, and Raymond Human Diseases: A Systemic Approach, 6e Copyright ©2006 by Prentice-Hall, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Chapter 3 Infectious Diseases Multimedia Asset Directory Slide 12 Slide 27 Slide 34 Slide 35 Pneumonia Penicillin Specimen Collection Sanitation, Disinfection, and Sterilization Mulvihill, Zelman, Holdaway, Tompary, and Raymond Human Diseases: A Systemic Approach, 6e Copyright ©2006 by Prentice-Hall, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Bacteria Small size, no nucleus or membranous organelles Cell wall – – – – Cocci Bacilli Spirilla Vibrios Gram-positive Gram-negative Mulvihill, Zelman, Holdaway, Tompary, and Raymond Human Diseases: A Systemic Approach, 6e Copyright ©2006 by Prentice-Hall, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Infectious Disease Contagious Communicable – transmitted from human to human Noncommunicable – not transmitted directly from humans Mulvihill, Zelman, Holdaway, Tompary, and Raymond Human Diseases: A Systemic Approach, 6e Copyright ©2006 by Prentice-Hall, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Figure 3-1: Types of pathogenic organisms include bacteria (A), viruses (B), protozoa ( C ), and helminths, or worms (D). Mulvihill, Zelman, Holdaway, Tompary, and Raymond Human Diseases: A Systemic Approach, 6e Copyright ©2006 by Prentice-Hall, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Bacterial Reproduction – Illness Binary fission Endospores – genetic material resistant to dessication Endotoxin – causes life-threatening shock Bacteria are able to adapt and survive in a number of different environments. Mulvihill, Zelman, Holdaway, Tompary, and Raymond Human Diseases: A Systemic Approach, 6e Copyright ©2006 by Prentice-Hall, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Figure 3-2A: Gram-stained bacteria on microscope slide. Pink rod-shaped cells are Escherichia coli. (Courtesy of the CDC, 1979.) Mulvihill, Zelman, Holdaway, Tompary, and Raymond Human Diseases: A Systemic Approach, 6e Copyright ©2006 by Prentice-Hall, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Figure 3-2B: Purple cocci are Staphylococus aureus. (© SIU BioMed/Custom Medical Stock Photo.) Mulvihill, Zelman, Holdaway, Tompary, and Raymond Human Diseases: A Systemic Approach, 6e Copyright ©2006 by Prentice-Hall, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Table 3-1: Common Bacterial Pathogens and Associated Diseases. Mulvihill, Zelman, Holdaway, Tompary, and Raymond Human Diseases: A Systemic Approach, 6e Copyright ©2006 by Prentice-Hall, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Normal chest x-ray of clear lungs. (Courtesy of the CDC.) Mulvihill, Zelman, Holdaway, Tompary, and Raymond Human Diseases: A Systemic Approach, 6e Copyright ©2006 by Prentice-Hall, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Lung with bacterial pneumonia in lower right lobe. Bacterial infection has caused the air space to fill with pus and fluid. (Courtesy of the CDC.) Mulvihill, Zelman, Holdaway, Tompary, and Raymond Human Diseases: A Systemic Approach, 6e Copyright ©2006 by Prentice-Hall, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Click on the screenshot to view a video on the topic of pneumonia. Mulvihill, Zelman, Holdaway, Tompary, and Raymond Human Diseases: A Systemic Approach, 6e Return to Directory Copyright ©2006 by Prentice-Hall, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Virus Core genetic material (RNA or DNA) enclosed in a capsid Does not independently grow, metabolize or reproduce Carries out life processes by entering cells and directing energy, materials and organelles or by causing cells to lyse Responsible for acute, and latent infections Mulvihill, Zelman, Holdaway, Tompary, and Raymond Human Diseases: A Systemic Approach, 6e Copyright ©2006 by Prentice-Hall, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Figure 3-3: Structure of an enveloped virus. Mulvihill, Zelman, Holdaway, Tompary, and Raymond Human Diseases: A Systemic Approach, 6e Copyright ©2006 by Prentice-Hall, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Table 3-2: Viral Pathogens and their Diseases. Mulvihill, Zelman, Holdaway, Tompary, and Raymond Human Diseases: A Systemic Approach, 6e Copyright ©2006 by Prentice-Hall, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Protozoa Eukaryotic microorganisms Larger than bacteria with complex internal structures Classified as amoeboids, flagellates, cilates, and sporozoans Mulvihill, Zelman, Holdaway, Tompary, and Raymond Human Diseases: A Systemic Approach, 6e Copyright ©2006 by Prentice-Hall, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Figure 3-4: The human hookworm lifecycle. Mulvihill, Zelman, Holdaway, Tompary, and Raymond Human Diseases: A Systemic Approach, 6e Copyright ©2006 by Prentice-Hall, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Fungi Multicelled organisms Contain polysaccharide – Chitin Reproductive structures – spores Cause disease by interfering with normal organ structure and function or by inflammation or allergy Mulvihill, Zelman, Holdaway, Tompary, and Raymond Human Diseases: A Systemic Approach, 6e Copyright ©2006 by Prentice-Hall, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Helminths Roundworms, flatworms Well developed reproductive systems Complex lifecycle Infections are called infestations Mulvihill, Zelman, Holdaway, Tompary, and Raymond Human Diseases: A Systemic Approach, 6e Copyright ©2006 by Prentice-Hall, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Roundworms Round in cross section Include: filarial (infect lymphatics), large (infect the intestines) Examples: Ascaris, Enerobius Mulvihill, Zelman, Holdaway, Tompary, and Raymond Human Diseases: A Systemic Approach, 6e Copyright ©2006 by Prentice-Hall, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Flatworms Flattened bodies examples: Schistosoma Taenia Cause disease by using host nutrients or by feeding on host blood causing anemia and severe inflammatory responses Mulvihill, Zelman, Holdaway, Tompary, and Raymond Human Diseases: A Systemic Approach, 6e Copyright ©2006 by Prentice-Hall, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Arthropod Vectors Ticks, mites, lice, flies, mosquitoes, and fleas Transmit pathogenic microorganisms to humans Example: plasmodium Animals act as reservoirs – source of the pathogen; example: rabies Mulvihill, Zelman, Holdaway, Tompary, and Raymond Human Diseases: A Systemic Approach, 6e Copyright ©2006 by Prentice-Hall, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Epidemiology and Transmission Epidemiology – study of transmission, occurrence, distribution, and control of disease Horizontal transmission – infected human to susceptible human Vertical transmission – infection from one generation to the next Mulvihill, Zelman, Holdaway, Tompary, and Raymond Human Diseases: A Systemic Approach, 6e Copyright ©2006 by Prentice-Hall, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Distribution and Frequency Incidence – number of new cases Prevalence – number of existing cases Endemic – exists in low levels Pandemic – infection spreads to large numbers Outbreak – sudden occurrence in unexpected numbers within a limited area Mulvihill, Zelman, Holdaway, Tompary, and Raymond Human Diseases: A Systemic Approach, 6e Copyright ©2006 by Prentice-Hall, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Treatment Antibacterials Antivirals Antifungals Supportive care for inflammation, pain, and fever Treatment must be targeted and specific to avoid antimicrobial resistance Mulvihill, Zelman, Holdaway, Tompary, and Raymond Human Diseases: A Systemic Approach, 6e Copyright ©2006 by Prentice-Hall, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Antibiotics – Mechanism of Action Target bacterial cell wall Target cell membrane Inhibit protein synthesis targets in bacterial machinery Interfere with bacterial metabolism, DNA, and RNA synthesis Mulvihill, Zelman, Holdaway, Tompary, and Raymond Human Diseases: A Systemic Approach, 6e Copyright ©2006 by Prentice-Hall, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Click on the screenshot to view an animation showing penicillin. Mulvihill, Zelman, Holdaway, Tompary, and Raymond Human Diseases: A Systemic Approach, 6e Return to Directory Copyright ©2006 by Prentice-Hall, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Antivirals Nucleic acid analogues mimic correct DNA or RNA bases. Interfere with assembly of new virus particles within the cell or interfere with the attachment of viruses to host cells Reduces the number of viruses reproduced Mulvihill, Zelman, Holdaway, Tompary, and Raymond Human Diseases: A Systemic Approach, 6e Copyright ©2006 by Prentice-Hall, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Antifungals Target cell walls and membranes Affect human cells, therefore may be toxic Mulvihill, Zelman, Holdaway, Tompary, and Raymond Human Diseases: A Systemic Approach, 6e Copyright ©2006 by Prentice-Hall, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Antiprotozoals Interfere with protein synthesis and metabolism Sensitive to medications that paralyze protozoal muscles or interfere with carbohydrate metabolism Resistant microorganisms evolve, rendering existing treatments useless Mulvihill, Zelman, Holdaway, Tompary, and Raymond Human Diseases: A Systemic Approach, 6e Copyright ©2006 by Prentice-Hall, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Vaccination The presentation of antigens from a microorganism to provoke an immune response Contain dead bacterial, extracted antigens, inactivated toxins, viral particles, or genetically engineered proteins Have been used to eliminate disease Mulvihill, Zelman, Holdaway, Tompary, and Raymond Human Diseases: A Systemic Approach, 6e Copyright ©2006 by Prentice-Hall, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Table 3-3 Universally recommended vaccinations Mulvihill, Zelman, Holdaway, Tompary, and Raymond Human Diseases: A Systemic Approach, 6e Copyright ©2006 by Prentice-Hall, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Emerging Infectious Disease Tuberculosis Antibiotic resistance Changes in climate, urbanization, crowding, increased incidence of chronic disease, fast world travel, disruption of social government structure Mulvihill, Zelman, Holdaway, Tompary, and Raymond Human Diseases: A Systemic Approach, 6e Copyright ©2006 by Prentice-Hall, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Click on the screenshot to view a video showing how to collect specimens. Mulvihill, Zelman, Holdaway, Tompary, and Raymond Human Diseases: A Systemic Approach, 6e Return to Directory Copyright ©2006 by Prentice-Hall, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Click on the screenshot to view a video on the topic of sanitation, disinfection, and sterilization. Mulvihill, Zelman, Holdaway, Tompary, and Raymond Human Diseases: A Systemic Approach, 6e Return to Directory Copyright ©2006 by Prentice-Hall, Inc. Upper Saddle River, New Jersey 07458 All rights reserved.