Download Theme 3 Communicable Disease

TOPIC 5
Communicable Diseases
Date: 13th February 2017
Presenter : D. NAIDU
Department of Primary Health Care
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COMMUNICABLE DISEASES
D.NAIDU -Community Population Centered
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Objectives:
1. Understand the prevalence and Incidence of
Common Communicable diseases in Fiji and
the region.
2. Discuss the etiology of the common
communicable diseases occurring in Fiji and
the Pacific.
3. Discuss nursing strategies for prevention of
common communicable diseases.
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Communicable Disease
An illness due to an
infectious agent or its toxic
products which is
transmitted directly or
indirectly to a person from an infected
person or animal through the agency of
an intermediate animal, host or vector,
or through the inanimate environment.
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Legal Aspects
• Reporting of cases
• Isolation and
disinfection
• Contact tracing
• Disease investigation
• Sanitation Policy
• Building Policy Dorms ,
Kitchen
• Animals – Chickens ,
cows , horses out of the
village
• Discrimination ,
counselling , testing,
reporting and
confidentiality
• Litter Decree
• Demolition order
• Health and safety at
workplace
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WHAT ARE COMMUNICABLE DISEASE
Diseases that are spread from one person to the next
Diseases that are “catching”
Diseases that are caused by germs or pathogens
Examples of pathogens include:
viruses, bacteria, protozoa, parasitic worms and fungi.
Examples of common communicable diseases…
Cold
Flu Hepatitis Leptospirosis Dengue fever
STD’s HIV/AIDS TB typhoid
athogens include: viruses, bacteria, protozoa, parasitic worms and fungi
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WHAT ARE COMMUNICABLE DISEASE
Diseases are grouped according to;
• Mode of transmission
• Means of prevention
• Rather than by individual organism.
– An illness that is transmitted by contact with body
fluids
• directly transmitted
• acquired from a person or vector (ticks,
mosquitoes, or other animal)
– indirectly transmitted
• by contact with contaminated objects.
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WHAT ARE COMMUNICABLE DISEASE
The topic of infectious diseases includes a wide
variety of organisms
pathology they may cause, diagnosis, treatment,
prevention and control.
Diseases are grouped according to;
• Mode of transmission
• Means of prevention
• Rather than by individual organism.
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History Of Communicable Disease And
Public Health Nursing
• Share a long history- with the growth of urban
areas in the early part of the 19th century,
epidemics swept through communities
• Hospitals were unsanitary hot beds of
infection –and often considered places where
people went to die
• In 1900, epidemics of communicable diseases
were the leading cause of death throughout
the world
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History of Communicable Disease and Public
Health Nursing
• Share a long history- with the growth of urban
areas in the early part of the 19th century,
epidemics swept through communities
• Hospitals were unsanitary hot beds of
infection –and often considered places where
people went to die
• In 1900, epidemics of communicable diseases
were the leading cause of death throughout
the world
• Fleas and rats spread the bubonic plague in
1348. 1/3 Europe died!
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Some Infectious Diseases In The Pacific
• Respiratory Infections
• Influenza ,Tuberculosis, Acute Rheumatic
Fever
• STI
• HIV/ AIDS, Syphilis, Gonorrhoea, Hepatitis
• FECO-ORAL DISEASES
• Cholera, Typhoid, Hepatitis A &E,
Gastroenteritis, Shigellosis, amoebiasis
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Epidemics , Endemics and Pandemics
Epidemics
Is defined as rates of disease
significantly higher than the
usual frequency. Epidemic is
confined to a localized area.
Can be referred to as an
outbreak
Endemic
The usual frequency , endemic
refers to the on-going , usual ,or
constant presence of a disease
in a community or among a
group of people.
For example influenza follows
a seasonal trend with the
highest number of cases in
the winter months , it is
considered endemic if the
pattern is consistent from
year to year.
Pandemics
Include large areas of the world
A pandemic is an epidemic
affecting or attacking the
population of an extensive
region , country or continent.
Example : HIV / AIDs spread
from one region to many
other regions of the world.
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Epidemics , Endemics and Pandemics
Endemic: a disease that exists
permanently in a particular region
or population. Malaria is a constant
worry in parts of Africa.
Epidemic: An outbreak of disease
that attacks many peoples at about
the same time and may spread through
one or several communities.
Pandemic: When an epidemic spreads
throughout the world.
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Factors contributing to emergence of CD
Human behaviors- high risk e g. drug use,
unhealthy diet creates susceptible host
International travel, migration
Urbanization
Widespread use of antibiotics-leading to drug
resistance
Food production
Environmental changes
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Infectious Disease Mode of Transmission
As discussed earlier infections CD are based
on mode of transmission :
INSECT BORNE DISEASES
E.g.: Dengue, Malaria
WATER- WASHED DISEASES
E.g.: Scabies, lice, fungal infections, Trachoma,
Conjunctivitis, Tropical ulcers
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Infectious Disease Mode of Transmission
INFECTIOUS SKIN RASH
E.g.: Chickenpox
FOOD BORNE DISEASES
Food poisoning, staph, clostridium(Gram positive
anaerobic spore forming rod like bacteria
commonly found in soil and in the intestinal tract)
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Infectious Disease Mode of Transmission
DOMESTIC ZOONOSES
E.g.: Leptospirosis, Brucellosis, Filariasis
• Leptospirosis is a zoonosis that lurks in water, soil
and foods contaminated by urine of infected
animals, especially cattle, rats and pigs.
• The disease can become especially problematic
after heavy floods. In
• The past, this was what happened in parts of, Cuba
and Nicaragua where many cases of leptospirosis
occurred after floods.
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Mode of Transmission
• Horizontal transmission- is the transport of infectious
agents from person to person.
• Vertical transmission – is the passing of the infection from
parent to offspring via sperm , placenta , milk , or contact
in the vaginal canal transmission of HIV and syphilis.
• The transport of infectious agents between hosts can be
accomplished in a number of ways like Direct contact ,
indirect contact , common vehicle , airborne, or vector
born. Most sexually transmitted infections are spread by
direct sexual contact.
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Modes of transmission cont.
• Direct transmission- is the immediate transfer
of disease from the infected host to the
susceptible host ,transmission of STI ,needle
stick injury.
• Indirect transmission- occurs when the human
host comes in contact with vehicles or vectors
that support and transport the infectious agent
e.g.. fleas transporting bubonic plague from
infected rats to human hosts.
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Modes of transmission cont.
• Airborne transmission- happens when
microorganisms are suspended in the air and
spread to a suitable port of entry
• Occurs primarily through droplet nuclei or
aerosols
• Droplets containing measles virus are contained
in the spray from sneezing-find conjunctiva or
mucus membrane for portal of entry
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Modes of transmission cont.
• Fecal oral transmission- occurs directly when the
hands or other objects are contaminated with
organisms from human or animal feces and then
placed in the mouth. Example : Typhoid
• Can also occur indirectly- ingestion of water or
food that has been contaminated with fecal
particles-E. coli and Hepatitis A
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Transmission of Communicable Disease
The transmission of communicable disease
depends on the successful interaction of the
infectious agent , the host and the
environment.
These three factors make the: Epidemiologic
Triangle
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How are Communicable disease Spread
Direct Contact: Exposure to infected body fluids such as blood
or saliva.
Vectors/Reservoirs: Germs are spread by an animal or insect,
usually through a bite
Airborne: Germs are spread through the air, for example
when someone coughs or sneezes.
Food and Water: Food and water can become
contaminated with germs and people can get sick when
they eat or drink them.
Indirect contact: Pathogens remain on surfaces that were
in contact with
an infected person.
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Epidemiological Triangle
The epidemiological triangle
recognises three major factors in
pathogenesis
• Agent
• Host
• Environment
This model is well suited to an
explanation of the aetiology of
infections disease.
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Epidemiological Triangle
• The agent is the cause of the disease ; whose absence
or presence causes a disease.
• the host is an organism , usually a human or an
animal that harbors the disease;
• the environment includes those surroundings and
conditions external to the human or animal that
cause or allow disease transmission and time
accounts for incubation periods , life expectancy of
the host or the pathogen , and duration of the course
of the illness or condition.
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Agent Factors
Four (4) major categories of agents cause most
infections and infectious disease:
• Bacteria ( Salmonella and E.coli)
• Fungi (Aspergillus and Candida)
• Parasites (Helminthes and Protozoa)
• Viruses ( Hepatitis A and B and HIV)
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Seven Characteristics of an Infectious Agent
1.Infectivity: The ability of the agent to enter a host
and multiply to an infectious dose, thereby
producing the infection or disease.
2.Pathogenicity: The ability of the agent to cause
disease in an infected host.
3.Virulence: This term refers to the severity of the
infection. A highly virulent strain of a disease agent
will most always produce severe cases or death.
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Seven Characteristics of an Infectious Agent
4.Toxigenicity: This term refers to the ability of the agent to
produce a toxin. The resulting illness or disease is from the
toxin produced by the organism/agent and not the
microorganism itself.
5.Resistance: This term refers to the ability of the agent to
survive under adverse environmental conditions. It is also a
measure of the agent's fragility.
6.Antigenicity: This term refers to the ability of the agent to
induce antibody production in the host.
7. Invasiveness : The ability to penetrate and spread
throughout a tissue
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Six Types of Agent
• Physical Agent: Mechanical forces or friction that may cause injury
or temperature or excessive radiation.
• Chemical Agent: Dusts , gases , vapours , fumes , liquids , toxins and
poisons.
• Nutrient Agents : basic dietary components that we need to
survive.
• Biological Agents: Insects , worms , protozoa , fungi , bacteria ,
viruses ( infection)
• Genetic Agents : Parent to child through genes.
• Psychological agent : stressful circumstances in the environment.
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Host Factors
A human or animal host can harbour an infectious agent.
The characteristics of the host that may influence the
spread of disease are
 Host resistance
 Immunity
 Herd immunity and
 Infectiousness of the host.
An agent must be present for an infectious disease to
develop
Agent must be capable of infecting a host
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Host Factors
The host after exposure to
an infection progresses
through a chain of events.
From subclinical infection
to active disease
The end result may be
complete recovery
permanent disability ,
disfigurement , or death.
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Host Factors
• Resistance – is the ability of the host to withstand
infection , and it may involve Natural or Acquired
immunity.
• Natural Immunity – refers to species- determined
innate resistance to an infectious agent.
Example: People who had recovered from the plague would
never get it again—they had acquired immunity.
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Host Factors
• Acquired Immunity is the resistance acquired by
a host as a result of previous natural exposure to
an infectious agent. Acquired immunity may be
induced by active or passive immunization.
• Example: Having measles once protects against
future infection. Acquired immunity may be
induced by active or passive immunity.
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Natural and Acquired Immunity
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Active and Passive Immunization
Two types of Acquired Immunity
Active Immunization : Refers to the immunization of an
individual by administration of an antigen (infectious agent
or vaccine) and is usually characterised by the presence of
an antibody produced by the individual host. E.g.:
Immunization / Vaccination
Passive Immunization : Refers to immunization through
the transfer of a specific antibody from an immunized
individual to a non-immunized individual , such as the
transfer of antibody –containing preparation E.g.: passing
antibodies from mother
to foetus.
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Two type of Acquired Immunity
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Host Factors
Ability to cause infection is determined by a
number of factors some are properties of host:
An important determinant is the hosts ability to
fight off the infectious agent
Ability to fight has 2 main categories
1. Nonspecific defence mechanism
2. Disease specific defence mechanism
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Non-Specific Defence Mechanism
The human body is equipped with a number of means
to reduce the likelihood that an agent will penetrate
and cause disease
Most environmental agents are unable to enter the
body because of the protection by our
• Skin
• Mucosal Surface
• Tears and Saliva
• High pH of our gastric juice is lethal to marry agents.
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Non-Specific Defence Mechanism
• Several other factors influence host response
to infectious agent.
• E.g. As we age immunity decrease , through
reduced immune function
• Nutritional status of the host also critical ,
genetic factors.
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Disease Specific Defence Mechanism
• Includes immunity against a particular agent
• Immunity refers to the resistance of the host
to a disease agent.
• Immunity to a disease may be either natural
or artificial active or passive
• Active immunity: body produces it own
resistance through mild cases or vaccination.
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Herd Immunity
 Refers to the immunity of a group or community.
 It is resistance of a group of people to invasion and spread of an
infectious agent.
 Based on the resistance of a high proportion of individual
members of a group to infection.
 It is the basis for increasing immunization coverage for vaccinepreventable disease.
 Example immunization greater than 90% of specified group of
people.
 The higher the immunization coverage the greater the herd
immunity.
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Environmental Factor
• The environment refers to everything that is
external to the human host , including physical ,
biological , social , and cultural factors.
• These environmental factors facilitate the
transmission of an infectious agent from an
infected host to other susceptible hosts
• Reduction in communicable disease risk can be
achieved by altering these environmental factors.
• Example: Using mosquito nets and repellents to
avoid bug bites , installing sewage system to
prevent faecal contamination of water supplies.
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Environmental Factor
Physical , Socio-Economic and Biological Environments.
Physical
Environment
Geographical Structure , availability of resources , water
and plants weather , climate. Seasons influence these
factors.
Socio-Economic
Environment
Environmental sanitation , pasteurization of milk ,
disposal of rubbish , availability of medical facilities
immunization and medical care.
Biological
Environment
Environmental factors that are necessary to maintain
the agent or allow for its transmission.
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Example of a Epi-Triad
For TB: In this model the agent is the TB bacterium; host factors
include non-immune, weakened resistance, poor nutrition; and
environmental factors include crowded conditions, poor ventilation,
and bad sanitation.
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Community health nurses role relevant to
communicable disease control
• Community health nurses must arm
themselves with information about new
emerging infectious diseases
• Recognizing infectious disease conditions is a
challenge and responsibility of nurses working
to protect the health of communities
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Roles of CHN
• Community health nurses should be well
aware of the epidemiological principles so
that they can use this knowledge to break the
chain of infection
• Strengthening the host through immunization
and education, controlling the environment
through protection of food and water supplies
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Roles of CHN
• Educating consumers about basic sanitation,
principles related to food preparation as well
as the importance of hand washing with
proper soap
• Water supplies protected from contamination,
appropriate waste control, knowledgeable
food growers and handlers, proper hand
washing and safe sex practices
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Nurses role in control of communicable
diseases
• Primary prevention- CHNs can be active
participants in the education of individuals,
families and communities
• Informing individuals of disease risk and ways
to prevent disease occurrence
• Strengthening the host by immunization
interrupts the spread of infection and
supports primary prevention
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Role of CHN cont.
• Secondary prevention- minimizing effect of
agent on host and environment
• Nurses should be leaders in early recognition
and treatment of infection to minimize the
potential long term effects of these diseases
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Role of CHN cont.
• Tertiary prevention- nurses should be aware
of agencies and other resources that can assist
clients in the management of disease
• Effective case management can help to
eliminate the debilitating effects of disease
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Prevalence and Incidence of Common
Communicable diseases in Fiji.
• Communicable diseases along with maternal, perinatal and
nutritional conditions in Fiji accounted for an estimated 18
per cent of all mortality in 2008.
• In 2012, Fiji’s HIV prevalence stood at 0.2 per cent; the figure
had remained consistent at 0.1 per cent in the period 19902009.
• The country is free from malaria. Estimated incidences of
tuberculosis (TB) fell by nearly three-quarters in the period
1990-2012 and estimated mortality (when mortality data
excludes cases co-morbid with HIV) also reduced significantly
in that time.
• There were two reported cases of leprosy in 2010, as well as
one reported case of measles and one reported case of
rubella in 2009.
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Reporting of Communicable Disease
The following are priority notifiable diseases:
•
•
•
•
•
•
•
Cholera
Dengue Fever
Influenza
Leptospirosis
Measles
Rubella
Typhoid Fever
AKA Disease Surveillance
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1.
Leptospirosis
2.
Typhoid
3.
Dengue fever
4.
Filiarasis
5.
Tuberculosis
6.
Hepatitis B
Divide into Six Groups and research on the above diseases try and
collect information before coming for tutorial. Write the following things
about the disease . Can use PPP. 15 minutes per presentation.
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For the above Diseases. Discuss the
Following.
1.
Draw a Epidemiological Triangle (Agent , Host and Environment )
2.
Prevalence in Fiji ( age , gender , ethnicity ) Burden Cost
3.
Mode of transmission
4.
Incubation Period
5.
Management of case
6.
Complications
7.
Control measures
8.
Preventative actions
9.
What’s important about this condition (summary)
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