The document discusses communicable diseases and infection transmission. It covers principles of infection occurrence, the epidemiological triad of agent, host, and environment. It also discusses the spectrum of infection and disease, stages of infection, and methods of breaking the chain of transmission. The document outlines Healthy People 2020 objectives for infectious diseases, defines infectious versus communicable disease, and reviews legal responsibility for disease control in the United States.

1. Chapter 25 Communicable Diseases
Chapter 25 Communicable Diseases ON Chapter 25 Communicable DiseasesRead chapter
25 of the the attached PowerPoint presentation; once done answer the following
questions.Mention and discuss the principles related to the occurrence and transmission of
infection and infectious diseases.Describe and discuss the three focus areas in Healthy
People 2020 objectives that apply to infectious diseases.Define and discuss the definition of
infectious and communicable disease and give and explain at least 2 examples of each one of
them.Describe and discuss the legal responsibility for control of the communicable diseases
in the United States.Please present the assignment in an APA format word document, Arial
12 font, A minimum of 2 references (excluding the class textbook) & A minimum of 700
words is required.Chapter 25 Communicable Diseasesattachment_1Unformatted
Attachment PreviewChapter 25 Communicable Disease Copyright © 2015, 2011, 2007,
2001, 1997, 1993 by Saunders, an imprint of Elsevier Inc. Principles of Infection and
Infectious Disease Occurrence ? Biological and epidemiological principles ? Multicausation ?
Spectrum of Infection ? Stages of Infection ? Spectrum of disease occurrence Copyright ©
2015, 2011, 2007, 2001, 1997, 1993 by Saunders, an imprint of Elsevier Inc. 2
Multicausation Disease etiology is complex and multicausal. An infectious agent alone is not
sufficient to cause disease; the agent must be transmitted within a conducive environment
to a susceptible host. Host Environment Agent Epidemiological Triad Copyright © 2015,
2011, 2007, 2001, 1997, 1993 by Saunders, an imprint of Elsevier Inc. 3 Spectrum of
Infection ? Not all contact with an infectious agent leads to infection, and not all infection
leads to an infectious disease. ? ? ? ? Subclinical infection: no overt symptomatic disease
(unapparent or asymptomatic) Infections: entry and multiplication of infectious agent in
host Infectious disease and communicable disease: pathophysiological responses of the host
to the infectious agent, manifesting as an illness (considered a case) Carriers: people who
continue to shed infectious agent without any symptoms of disease Copyright © 2015,
2011, 2007, 2001, 1997, 1993 by Saunders, an imprint of Elsevier Inc. 4 Stages of Infection ?
Latent period ? ? ? Communicable period ? ? Chapter 25 Communicable Diseases? Infectious
agent has invaded a host and found conditions hospitable to replicate Replication before
shedding Follows latency Begins with shedding of agent Incubation period ? ? Time from
invasion to time when disease symptoms first appear May overlap with communicable
period Copyright © 2015, 2011, 2007, 2001, 1997, 1993 by Saunders, an imprint of Elsevier
Inc. 5 Stages of Infection (Cont.) Figure 25-1 From Grimes DE: Infectious diseases, St Louis,
1991, Mosby. Copyright © 2015, 2011, 2007, 2001, 1997, 1993 by Saunders, an imprint of

2. Elsevier Inc. 6 Spectrum of Disease Occurrence ? ? ? ? ? Incidence—new cases in a
population Endemic—diseases that occur at a consistent, expected level in a geographic
area Outbreak—an unexpected occurrence of an infectious disease in a limited geographic
area during a limited period of time Epidemic—an unexpected increase of an infectious
disease in a geographic area over an extended period of time Pandemic—steady occurrence
of a disease over a large geographic area or worldwide Copyright © 2015, 2011, 2007,
2001, 1997, 1993 by Saunders, an imprint of Elsevier Inc. 7 Chain of Transmission ? ? ? ?
Infectious agents Reservoirs Portals of exit and entry Modes of transmission ? Direct ?
Indirect • Fomites or vectors ? Fecal-oral, airborne ? Host susceptibility Copyright © 2015,
2011, 2007, 2001, 1997, 1993 by Saunders, an imprint of Elsevier Inc. 8 Chain of
Transmission (Cont.) Figure 25-2 Copyright © 2015, 2011, 2007, 2001, 1997, 1993 by
Saunders, an imprint of Elsevier Inc. 9 Chain of Transmission: Part 1 Links of the Chain
Definition Factors Infectious agent An organism (virus, rickettsia, bacteria, fungus,
protozoan, helminth, or prion) capable of producing infection or infectious disease
Properties of the agent: morphology, chemical composition, growth requirements, and
viability. Interaction with the host: mode of action, infectivity, pathogenicity, virulence,
toxigenicity, antigenicity, and ability to adapt to the host Reservoirs The environment in
which a pathogen lives and multiplies Humans, animals, arthropods, plants, soil, or any
other organic substance Portal of exit Means by which an infectious agent is transported
from the host Respiratory secretions, vaginal secretions, semen, saliva, lesion exudates,
blood, and feces Table 25-1 Copyright © 2015, 2011, 2007, 2001, 1997, 1993 by Saunders,
an imprint of Elsevier Inc. 10 Chain of Transmission: Part 2 Links of the Chain Definition
Factors Mode of transmission Method whereby the infectious agent is transmitted from one
host (or reservoir) to another host Direct: person to person Indirect: implies a vehicle of
transmission (biological or mechanical vector, common vehicles or fomite) Airborne
droplets Portal of entry Means by which an infectious agent enters a new host Respiratory
passages, mucous membranes, skin, percutaneous injection, ingestion, and through the
placenta Host susceptibility The presence or lack of sufficient resistance to an infectious
agent to avoid or prevent contracting an infection or acquiring an infectious disease
Biological and personal characteristics (e.g., gender, age, genetics), general health status,
personal behaviors, anatomical and physiological lines of defense, immunity Table 25-1
Copyright © 2015, 2011, 2007, 2001, 1997, 1993 by Saunders, an imprint of Elsevier Inc. 11
Breaking the Chain of Transmission ? ? ? Controlling the agent Eradicating the nonhuman
reservoir Controlling the human reservoir ? Chapter 25 Communicable Diseases?
Controlling the portals of exit and entry ? ? ? Quarantine—during incubation period
Isolation of sick persons Universal precautions Improving host resistance and immunity
Copyright © 2015, 2011, 2007, 2001, 1997, 1993 by Saunders, an imprint of Elsevier Inc. 12
Types of Immunity ? ? Natural immunity: an innate resistance to a specific antigen or toxin
Acquired immunity: derived from actual exposure to specific infectious agent, toxin, or
appropriate vaccine ? ? ? ? Active acquired: body produces its own antibodies Passive
acquired: temporary resistance that has been donated to the host Primary vaccine failure:
failure of vaccine to stimulate any immune response Secondary vaccine failure: waning of
immunity following an initial immune response Copyright © 2015, 2011, 2007, 2001, 1997,

3. 1993 by Saunders, an imprint of Elsevier Inc. 13 Types of Acquired Immunity Type Natural
How Acquired Length of Resistance Active Natural contact and infection with the antigen
May be temporary or permanent Passive Natural contact with antibody transplacentally or
through colostrum and breast milk Temporary Active Inoculation of antigen May be
temporary or permanent Passive Inoculation of antibody or antitoxin Temporary Artificial
Table 25-2 Copyright © 2015, 2011, 2007, 2001, 1997, 1993 by Saunders, an imprint of
Elsevier Inc. 14 Types of Immunity ? Herd immunity: a state in which those not immune to
an infectious agent will be protected if a certain proportion (generally considered to be
80%) of the population has been vaccinated or is otherwise immune Figure 25-3 Copyright
© 2015, 2011, 2007, 2001, 1997, 1993 by Saunders, an imprint of Elsevier Inc. 15 Public
Health Control of Infectious Diseases ? Control ? ? The reduction of incidence (new cases) or
prevalence (existing cases) of a given disease to a locally acceptable level as a result of
deliberate efforts Elimination ? Controlling a disease within a specified geographic area and
reducing the prevalence and incidence to near zero ? The result of deliberate efforts, but
continued intervention measures are required ? Eradication ? Reducing the worldwide
incidence of a disease to zero as a function of deliberate efforts (e.g., smallpox in 1977) ? No
need for further control measures ? Only possible under certain conditions Copyright ©
2015, 2011, 2007, 2001, 1997, 1993 by Saunders, an imprint of Elsevier Inc. 16 Criteria for
Disease Eradication ? ? ? ? ? ? ? ? ? ? Human host only; no host in nature Easy diagnosis;
obvious clinical manifestations Limited duration and intensity of infection Natural lifelong
immunity after infection Highly seasonal transmission Availability of vaccine, curative
treatment, or both Substantial global morbidity and mortality rates Cost effectiveness of
campaign and eradication Integration of eradication with additional public health variables
Eradication imperative over control measures – CDC (1993) Copyright © 2015, 2011, 2007,
2001, 1997, 1993 by Saunders, an imprint of Elsevier Inc. 17 Notifiable Infectious Diseases
in the United States ? ? ? HCP MUST report to local or regional health departments ? state
health dept. ?CDC Reported weekly in the MMWR Go to CDC website for latest listing of
diseases: http://www.cdc.gov Note: State health departments have the responsibility for
monitoring and controlling communicable diseases within their respective states; they
determine which diseases will be reported within their jurisdiction. Those lists might be
longer than the CDC’s list. Copyright © 2015, 2011, 2007, 2001, 1997, 1993 by Saunders, an
imprint of Elsevier Inc. 18 Vaccines and Infectious Disease Prevention ? Immunization is a
broad term used to describe a process by which active or passive immunity to an infectious
disease is induced or amplified. ? Chapter 25 Communicable Diseases? Immunizing agents
can include vaccines as well as immune globulins or antitoxins. Vaccination is a narrower
term referring to the administration of a vaccine or toxoid to confer active immunity by
stimulating the body to produce its own antibodies. Copyright © 2015, 2011, 2007, 2001,
1997, 1993 by Saunders, an imprint of Elsevier Inc. 19 Recommended Immunization
Schedules ? ? ? ? Recommendations for international immunization practices determined by
WHO In the United States, AAP and ACIP Current U.S. recommendations found on CDC
website: http://www.cdc.gov/vaccines Schedules, footnotes, and educational fact sheets
provide guidelines for practice Copyright © 2015, 2011, 2007, 2001, 1997, 1993 by
Saunders, an imprint of Elsevier Inc. 20 Vaccines: Words of Caution ? ? Information and

4. recommendations on immunizations and vaccine usage change regularly Vaccine
Information Statements (VISs) that explain the bene?ts and risks must be given out before
vaccine is administered— a federal law!!
(http://www.cdc.gov/vaccines/hcp/vis/index.html) Copyright © 2015, 2011, 2007, 2001,
1997, 1993 by Saunders, an imprint of Elsevier Inc. 21 Available Vaccines by Type Live
attenuated vaccines (See Textbook Table 25-3) ? Viral: measles, mumps, rubella, oral polio,
vaccinia, yellow fever, varicella ? Bacterial: BCG (Bacille Calmette-Guérin) ? Recombinant:
oral typhoid Copyright © 2015, 2011, 2007, 2001, 1997, 1993 by Saunders, an imprint of
Elsevier Inc. 22 Available Vaccines by Type (Cont.) Inactivated vaccines (See Textbook Table
25-3) ? Viral: influenza, polio, rabies, and hepatitis A ? Bacterial: typhoid, cholera, and
plague ? Subunit (fractional): influenza, acellular pertussis, typhoid Vi and Lyme disease ?
Toxoid: diphtheria and tetanus ? Recombinant: hepatitis B ? Conjugate polysaccharide:
Haemophilus influenzae type B and pneumococcal 7-valent ? Pure polysaccharide:
Pneumococcal 23-valent, meningococcal, and Haemophilus influenzae type b Copyright ©
2015, 2011, 2007, 2001, 1997, 1993 by Saunders, an imprint of Elsevier Inc. 23
Recommended Vaccine Schedules (Textbook Box 25-6) ? ? ? ? ? ? ? Children/adolescents ?
http://www.cdc.gov/vaccines/schedules/hcp/child-adolescent.html Adults ? Chapter 25
Communicable DiseasesChapter 25 Communicable
Diseaseshttp://www.cdc.gov/vaccines/schedules/hcp/adult.html Travelers ?
http://wwwnc.cdc.gov/travel/destinations/list Pregnant women ?
www.cdc.gov/vaccines/pubs/preg-guide.htm Health care workers ?
www.cdc.gov/vaccines/spec-grps/hcw.htm Specific health conditions ?
www.cdc.gov/vaccines/spec-grps/conditions.htm Other special groups ?
www.cdc.gov/vaccines/spec-grps/default.htm Copyright © 2015, 2011, 2007, 2001, 1997,
1993 by Saunders, an imprint of Elsevier Inc. 24 Vaccine Storage, Transport, and Handling ?
? ? ? ? ? ? Cold chain Routes of administration, dosage, and sites Proper timing and spacing
Hypersensitivity and contraindications Documentation Vaccine safety and reporting of
adverse events and vaccine-related injuries (VAERS) Vaccine needs for special groups
Copyright © 2015, 2011, 2007, 2001, 1997, 1993 by Saunders, an imprint of Elsevier Inc. 25
Prevention of Communicable Diseases ? Primary prevention ? ? Secondary prevention ? ? To
prevent transmission of an infectious agent and to prevent pathology in the person exposed
to an infection Activities to detect early and effectively treat persons who are infected
Tertiary prevention ? Caring for persons with an infectious disease to ensure that they are
cured or that their quality of life is maintained Copyright © 2015, 2011, 2007, 2001, 1997,
1993 by Saunders, an imprint of Elsevier Inc. 26 …Chapter 25 Communicable Diseases