Download Communicable Disease Control: Introduction

Communicable Disease Control
Prepared by Suhail Al Humoud
Communicable Disease
Control
Communicable Disease Control: Objective
Prepared by Suhail Al Humoud
Upon mastery of this chapter, you should be able to:
● Discuss the global and national trends and issues in
communicable disease control.
● Describe the three modes of transmission for
communicable diseases.
● Explain the strategies used for the three levels of
prevention in communicable disease control.
● Explain the significance of immunization as a
communicable disease control measure.
● Describe major issues that affect the control and
elimination of tuberculosis.
Communicable Disease Control: Objective
Prepared by Suhail Al Humoud
● Differentiate between human immunodeficiency virus
(HIV) infection and acquired immunodeficiency syndrome
(AIDS).
● Discuss specific ways to prevent sexually transmitted
diseases, including HIV/AIDS.
● Identify six globally emerging communicable diseases.
● Discuss the consequences of biologic terrorism with
weapons such as anthrax and smallpox.
● Describe the nurse’s role in communicable disease
control.
● Discuss ethical issues affecting communicable disease
and infection control
Communicable Disease Control: Introduction
Prepared by Suhail Al Humoud
What is the communicable disease
A communicable disease is one that can be transmitted
from one person to another.
It is caused by an agent that is infectious (capable of
producing infection) and is transmitted from a source, or
reservoir, to a susceptible host.
A communicable disease: A disease or illness in a
susceptible host, caused by a potentially harmful
infectious organism or its toxic byproduct.
Communicable disease spreads due to contact between
an infectious agent and a susceptible host
Communicable Disease Control: Introduction
What is the communicable disease ……… cont
Host: a person or other living being that can be infected
by an organism
Infectious agent: an organism that causes infectious
disease. Agents can be:
1. Bactria
2. Fungi
3. Viruses
4. Metazoa
5. Protozoa
Agent: something that must be present in the
environment for a disease to occur in a susceptible host
Communicable Disease Control: Introduction
What is the communicable disease ……… cont
Endemic: when an infectious agent or disease has a
constant presence within a defined geographic area
Epidemic: occurrences of infectious agent or disease
that clearly exceed the usual expected frequency of the
disease in a particular population
Pandemic when an epidemic outbreak occurs worldwide
Communicable Disease Control: Introduction
Knowledge of communicable diseases is fundamental to
the practice of community health nursing because:
1. these diseases typically spread through communities of
people.
2. Understanding of the basic concepts of communicable
disease control, as well as the numerous issues arising in
this area, helps a community health nurse work
effectively to prevent and control communicable
disease in populations and groups.
3. It also helps nurses teach important and effective
preventive measures to community members, advocate
for those affected, and protect the well-being of
uninfected persons (including the nurses themselves).
Communicable Disease Control: Introduction
Several issues and circumstances have
emerged during the last quarter-century
that are important areas of concern to
community health nurses:
Communicable Disease Control: Introduction
• Despite significant declines in mortality, communicable
diseases are responsible for persistently high morbidity
among various age and population groups.
• Rates of some communicable diseases, especially
tuberculosis (TB) and sexually transmitted diseases
(STDs), remain disproportionately high in selected
population groups (in some cases, shockingly high), a fact
often masked when statistics are aggregated.
• Diseases that were once little-known in the United
States, such as West Nile virus, are making an appearance.
Communicable Disease Control: Introduction
• The development of resistant (MDR) strains of bacteria
and viruses poses a significant occupational health
challenge as well as a practice issue for health workers.
• Current research reveals that infectious agents may be
responsible for a number of the chronic diseases, including
some forms of cancer, that have occupied the interest of
health care providers in the last few decades
Communicable Disease Control: Introduction
Evolution of Communicable Disease Control
Communicable diseases have challenged health care providers for
centuries.
They have led to the development of countless nursing and medical
preventive measures, from simple procedures such as hand-washing,
sanitation, and proper ventilation to the research and development of
vaccines and antibiotics.
 Communicable diseases, particularly those of epidemic and pandemic
proportions, such as TB and acquired immunodeficiency syndrome
(AIDS), continue to cost millions of lives and billions of dollars to the
global human society every year.
Communicable Disease Control: Introduction
Global Trends
During the last several decades, substantial progress has
been made in controlling some major infectious diseases
around the world, although other diseases have not been
managed as well. The following are some of the major
accomplishments:
1995, more than 80% of the world’s children had been
immunized against diphtheria, tetanus, whooping cough,
poliomyelitis, measles, and TB, compared with fewer than
5% in 1974
Global eradication of smallpox was achieved in 1980
Because of improved sanitation and hygiene, outbreaks of
relapsing fever, transmitted by lice, are rare today.
Communicable Disease Control: Introduction
Reported cases worldwide of poliomyelitis have
declined by 99% since the campaign began, with
only 537 new cases in the world in 2001.
Malaria remains a major threat, even though the
mortality rate has improved in the last 25 years.
In 1954, there were 2.5 million deaths annually and
250 million cases of malaria worldwide; in 2002,
there were an estimated 1.5 to 2.7 million deaths
and 300 to 500 million cases.
Communicable Disease Control: Introduction
New, Emerging, and Resurging Diseases
Pathogens that are considered to be under control because
they respond well to current treatment can mutate and
produce new, virulent strains; diseases that have been
almost eliminated can emerge again if public health efforts
slacken; and diseases that are eradicated in the United
States can revisit this country on any one of the hundreds
of international flights arriving each day.
Communicable Disease Control: Introduction
Emerging diseases are diseases rarely or never before
seen one country. These diseases may also be new to
public health officials in other countries.
Emerging diseases
occurring in the United States include the hantavirus, seen
in the southwestern United States in 1993; dengue fever,
acquired from travel outside the United States and first
seen among people in Texas in the 1980s; and typhoid, seen
in a native Nigerian in New York City in 1994.
Communicable Disease Control: Introduction
Resurging diseases are those communicable diseases
that have been endemic in some parts of the world but are now
endemic in more countries and are increasing to epidemic
proportions in others.
Often, the resurgence is caused by the emergence of new, drugresistant strains of a familiar organism, such as the MDR TB
bacillus. Staphylococcus aureus infections have some strains so
powerful that they are not responding to vancomycin any longer;
they still respond to two new antibiotics, but those could also lose
effectiveness.
Communicable Disease Control: Introduction
Healthy People:
Many objectives still focus on infectious diseases and
immunizations, aiming to decrease morbidity and mortality from
infectious diseases and to increase the number of children and
adults immunized.
Communicable Disease Control: Introduction
Modes of Transmission
the reservoir of infection can be a person, animal, insect,
or inanimate material in which the infectious agent lives
and multiplies and which serves as a source of infection to
others. Transmission of a communicable disease can occur
by direct or indirect methods..
Communicable Disease Control:
Direct Transmission
Direct transmission occurs by immediate transfer of
infectious agents from a reservoir to a new host. It
requires direct contact with the source, through touching,
biting, kissing, or sexual intercourse, or by the direct
projection of droplet spray onto the conjunctiva or onto
the mucous membranes of the eye, nose, or mouth during
sneezing, coughing, spitting, laughing, singing, or talking.
Direct transmission is limited to a distance of 1 meter or
less.
Communicable Disease Control: Introduction
Indirect Transmission
Indirect transmission occurs when the infectious agent is
transported within contaminated inanimate materials such
as air, water, or food. It is also commonly referred to as
vehicleborne transmission.
Communicable Disease Control: Introduction
Airborne Transmission
Airborne transmission occurs through droplet nuclei—the
small residues that result from evaporation of fluid from
droplets emitted by an infected host. They may also be created
purposely by atomizing devices or accidentally in microbiology
laboratories. Because of their small size and weight, they can remain
suspended in the air for long periods before they are inhaled into
the respiratory system of a host.
Airborne transmission can also occur in dust. Small particles
of dust from soil containing fungus spores may cling to clothing,
bedding, or floors. Alternatively, the spores may become separated
from dry soil by the wind and then be inhaled by the host..
Communicable Disease Control: Introduction
PRIMARY PREVENTION
In the context of communicable disease control, two
approaches are useful in achieving primary prevention:
(1) education using mass media and targeting health
messages to aggregates
(2) immunization.
Communicable Disease Control: Introduction
Education
Health education in primary prevention is directed both at
helping at-risk individuals understand their risk status and
at promoting behaviors that decrease exposure or
susceptibility.
Communicable Disease Control: Introduction
Use of Mass Media for Health Education
All people need to be informed about the risks of
communicable diseases. Often, use of the mass media is
the most effective way to reach the largest number of
people. Additionally, many target groups, such as lowincome and racially and ethnically diverse communities at
high risk for communicable diseases, are very hard to
reach one on one. One way to reach them is through the
media. To disseminate public health information to large
numbers of people, there are four major roles of mass
media:
Communicable Disease Control:
Use the media as a primary change agent
1. Programs can successfully increase knowledge about
communicable diseases and preventive measures.
2. Use the media as a complement to other disease prevention
efforts; the media can effectively model preventive behaviors,
such as condom use and drug abstinence.
3. Use the media as a promoter of communicable disease
control programs; the media can help to increase participation
of community members in primary prevention services.
4. Use the media to promote disease prevention messages;
the media can contribute to the creation of a social environment
that promotes health (eg, increasing acceptance of regular
condom use in the prevention of STDs).
Communicable Disease Control: Introduction
Immunization
Immunization is the process of introducing
some form of disease-causing organism into a person’s system
to cause the development of antibodies that will resist that disease.
A vaccine is a preparation made from killed, living
attenuated, or living fully virulent organisms that is administered
to produce or artificially increase immunity to a particular
disease.
Before the introduction of pertussis vaccine in the
1940s, more than 200,000 cases were diagnosed yearly in the
United States, with 5000 to 10,000 deaths each year. Today,
pertussis (whooping cough) claims 10 to 15 lives per year.
Communicable Disease Control: Introduction
Passive immunity is short-term resistance to a specific
diseasecausing organism; it may be acquired naturally (as with
newborns through maternal antibody transfer) or
artificially through inoculation with a vaccine that gives
temporary resistance.
Such immunizations must be repeated periodically
to sustain immunity levels. An example is the influenza
vaccination.
Active immunity is long-term (sometimes lifelong)
resistance to a specific disease-causing organism; it
also can be acquired naturally or artificially. Naturally
acquired active immunity occurs when a person contracts a
disease and develops long-lasting antibodies that provide
immunity against future exposure
Communicable Disease Control: Introduction
Vaccine-Preventable Diseases
Vaccine-preventable diseases (VPD), such as hepatitis B,
H. influenzae type b, measles, polio, diphtheria, pertussis,
and chickenpox, are diseases that can be prevented
through immunization. Immunity may be either passive or
active.
Communicable Disease Control: Introduction
Herd Immunity
Herd immunity is central to understanding immunization
as a means of protecting community health. it is the
immunity level present in a particular population of people .
If there are few immune persons within a community,
there is low herd immunity and the spread of disease is
more likely. Vaccination of more individuals in the
community, so that a high proportion have acquired
resistance to the infectious agent, contributes to high
herd immunity. High herd immunity reduces the probability
that the few unimmunized persons will come in contact with
one another, making spread of the disease less likely.
Communicable Disease Control: Introduction
Barriers to Immunization Coverage
(1) Religious Barriers.
(2) Financial Barriers
(3) Social Barriers
(4) Cultural Barriers
(5) Philosophical Objections
(6) Provider Limitations
Communicable Disease Control: Introduction
SECONDARY PREVENTION
There are two approaches to secondary prevention of
communicable disease:
(1) screening
(2) contact investigation, partner notification, and casefinding
Communicable Disease Control: Introduction
Screening
The term screening is used in community health and
disease prevention to describe programs that deliver a
testing mechanism to detect disease in groups of
asymptomatic, apparently healthy individuals.
Communicable Disease Control: Introduction
Criteria for Screening Tests
Validity and Reliability. The screening test must be
valid and reliable. Validity refers to the test’s ability to accurately
identify those with the disease. Reliability refers to the test’s
ability to give consistent results when administered on different
occasions by different technicians.
Predictive Value and Yield. The predictive value of a screening
test is important for determining whether the screening
intervention is justified. Yield refers to the number of positive
results found per number tested. The predictive value and the
yield of screening tests become important in planning screening
programs for communicable disease detection and prevention
because they can help planners locate screening efforts in areas
or within population groups that are known to be at high risk for
the disease. The predictive value of screening tests increases as
the prevalence of the disease increases.
Communicable Disease Control: Introduction
Epidemiologic criteria for screening interventions for
the detection of health problems are as follows:
1. Is the disease an important public health problem?
2. Is there a valid and reliable test?
3. Is there an effective and tolerable treatment that favorably
influences the early stages of the disease?
4. Are facilities for diagnosis and treatment after a positive
screening result available and accessible?
5. Is there a recognizable early asymptomatic or latent stage
in the disease?
6. Do clear guidelines for referral and treatment exist?
7. Is the total cost of the screening justifiable compared with
the costs of treating the disease if left undiscovered?
8. Is the screening test itself acceptable?
9. Will screening be ongoing?
Communicable Disease Control: Introduction
Contact Investigation, Partner Notification, and Case-Finding
In this approach, the community health nurse seeks to
discover and notify those who have had contact with a
person diagnosed with a communicable disease such as with
TB and to notify partners in the case of STDs. The
objective of contact investigation and partner notification
is specifically to reach contacts of the index case
(diagnosed person) before the contacts, in turn, become
infectious (CDC, 2002c). Therefore, the rapidity with
which contact investigation can be accomplished
is a concern.
Communicable Disease Control: Introduction
Tertiary Prevention
The approaches to tertiary prevention of communicable
disease include isolation and quarantine of the infected
person and safe handling and control of infectious wastes.
Communicable Disease Control: Introduction
Isolation and Quarantine
Communicable disease control includes two methods for
keeping infected persons and noninfected persons apart to
prevent the spread of a disease. Isolation refers to
separation of the infected persons (or animals) from
others for the period of communicability to limit the
transmission of the infectious agent to susceptible
persons. Quarantine refers to restrictions placed on
healthy contacts of an infectious case for the duration of
the incubation period to prevent disease transmission if
infection should develop (Chin, 1999).
Communicable Disease Control: Introduction
SELECTED COMMUNICABLE DISEASES
There are several communicable diseases that community
health nurses encounter in their practice. They are
frequently diagnosed and treated in the community.
Tuberculosis (TB) Chlamydia, genital herpes, hepatitis,
HIV/AIDS, influenza, pneumonia, syphilis, and viral warts
and other
Communicable Disease Control: Introduction
Tuberculosis (TB)
Incidence and Prevalence
Roughly one third of the world’s population is infected with
Mycobacterium tuberculosis. These 2 billion people have
the potential for developing active TB at some point in
time. Each year, 8 million people worldwide develop active
TB and 1.8 million people die. Approximately 80% of TB
cases are found in 23 countries; the highest incidence
rates are in Africa and southeast Asia
Communicable Disease Control: Introduction
Tuberculosis (TB)
Population at risk
TB disease cases occur predominantly among the following groups:
foreignborn persons (46%), the elderly (23%), homeless people
(5%), and individuals infected with HIV (8%).
Higher incidences of TB are found among low-income people,
persons with alcohol or drug abuse problems, the underserved, the
malnourished, people in correctional facilities, people with other
medical conditions, and individuals working where people at risk for
TB are grouped together (eg, homeless shelters, drug treatment
centers, health care facilities). TB rates are highest among
refugees and immigrants, and noncompliance with treatment in all
groups is a major factor in continued transmission of the disease
and development of MDR organisms.
Children, persons with HIV infection , persons in congregate
living such as prisons shelters, long term facilities
Communicable Disease Control: Introduction
Tuberculosis (TB)
Prevention and Intervention
Tuberculin testing, the standard method for evaluating TB
infection, is a simple skin test that measures by visible
reaction whether the body has had immunologic experience
with M. tuberculosis (Table 9–5). From there, evaluation
procedures determine the classification status of the
disease, ranging from 0 to 5. The two most used terms are
infected without current disease (classification 2) and with
current TB disease (classification 3) (Table 9–6). The skin
test itself is not diagnostic of disease.
Treatment: multidrug regimen with direct observation
therapy to ensure compliance
Communicable Disease Control: Introduction
Hepatitis
Community health nurses have the key role in TB
prevention and treatment. they can:
a. Identify people at risk
b. Initiate testing programs
c. Do follow-up for compliance
d. Provide education
Communicable Disease Control: Introduction
Hepatitis
Five viral hepatitis infections are A, B, C, D, and E
Each constitutes a serious liver disease caused by a
different hepatitis virus. Progress is being made to develop
immunizations against various types of hepatitis.
Nevertheless, the number of people being infected
with hepatitis is globally epidemic.
Communicable Disease Control: Introduction
Hepatitis A:
venerable population : person exposed to unsanitary
condition, poor hygiene, sexual contact with infected
person, exposed to contaminated food and water
Prevention: a vaccine for those at risk for exposure
Hepatitis A:
venerable population : person who have contact with
blood or body fluid of infected person, sexual contact with
infected person, people who share needles, newborn
infected during birth
Primary Prevention: a vaccination, children, health worker
Secondary Prevention: screening
 Tertiary prevention: minimizing effects of the disease
Communicable Disease Control: Introduction
Hepatitis C:
venerable population : intravenous drug users, frequent
blood transfusion, sexual contact with infected person,
Prevention: education and screening
Hepatitis D:
venerable population : same as hepatitis B
Primary Prevention: a vaccination,
Hepatitis E:
Usually spread through contaminated water or by fecaloral contamination
There is no diagnosis test
Has high mortality rate
Communicable Disease Control: Introduction
Influenza
Viral illness characterized by sever muscle aches, fever,
headache, sore throat, and cough
Influenza derives its importance from the rapidity with
which epidemics evolve, the widespread morbidity, and the
seriousness of complications, namely pneumonia
Influenza infections occur primarily in the winter
months, affecting individuals in all age groups and causing
approximately 20,000 deaths and 110,000 hospitalizations
annually in the United States
Primary Prevention: yearly vaccination for vulnerable
population, health worker
Secondary Prevention: early diagnosis , and treatment
Communicable Disease Control
Hantavirus
Respiratory disease caused by a virus that is carried and
spread by rodents. Person to person transmission may also
possible
 symptoms: fever, interstitial edema, severe shortness of
breath, joint pain, nausea and vomiting
Venerable populations: people exposed to rodent feces
and urine contaminated materials and people bitten by
rodents
Primary Prevention: rodent control in endemic areas,
precautions for decontaminating suspected infectious
areas and using protective clothing
Secondary Prevention: testing for hantavirus antibodies
 treatment: there is no cure, mortality rate 45%,
supportive care such as controlling fever, provide
respirtory supports or controlling hemorrhage
Communicable Disease Control
Ebola
Caused by a virus that is can be spread from person to
person, or through direct contact with infected blood,
semen and secretions
 symptoms: bleeding in the mucosa abdomen pericardium
and vagina and death
Venerable populations: people living in an area of
outbreak , contact with infected person , laboratory
worker
Primary Prevention: interrupting of spread of the virus
from person to person
Secondary Prevention: testing for Ebola antibodies
 treatment: there is no cure, mortality rate 90%,
Communicable Disease Control
Lyme disease
Lyme disease bacterium is transmitted when an
infected deer tick bites a person, a bull's-eye rash may
appear at the site of tick bite, early symptom like flue
Venerable populations: people living in areas with
infected ticks
Primary Prevention:
- Education – avoiding tick endemic areas – inspection for
ticks and using insecticide and proper light colored clothing
outside doors
Secondary Prevention:
-Procedures for properly removed the ticks
-Follow-up testing and early diagnosis
 treatment: antibiotics
Communicable Disease Control
Pediculosis
 is infestation of lice, tiny insects that feed on human
blood
 there are many type of Pediculosis divided by the body
parts
Itching is the symptom
Venerable populations: children, and or people with poor
hygiene
Prevention: screening and teaching
treatment: removal of lice by especial shampoo
Communicable Disease Control
Scabies
 a skin disease caused by a tiny parasite that burrows
under the skin
Characteristic welts are usually found
-between fingers – on the buttocks – in the axillae
- On the inside of the wrists – along the beltline
Symptom: Itching at night
Venerable populations: any one who has contacted with
infected person
Prevention: education and good hygiene
treatment: insecticide lotions
Communicable Disease Control
Rabies
 viral illness occurring in mammals that may spread to
humans through contact with an infected animals
Symptom: fever, headache, malaise, itching
Difficulty swallowing, paralysis , agitation and coma
Venerable populations: contact with animals infected
Primary Prevention: education
Vaccination of pets
Animals controls
Avoiding wild animals
Not feeding wild animals
Pre exposure vaccination