Communicable Diseases
Presented by: DR /Amira Yahia
Introduction
• Communicable Diseases are the major
causes of morbidity and mortality.
• Main causes of morbidity and mortality in
emergencies are diarrheal diseases, acute
respiratory infections, measles, and in
areas where it is endemic malaria.
7/1/2016
Introduction
• Every disease has certain weak points
susceptible to attack and the basic
approach in controlling diseases is to
identify these weak points and break the
weakest links in the chain of transmission.
• This requires sound epidemiological
knowledge of the disease (FrequencyDistribution in place, person and timecausation )
Introduction
• There are many methods to control
transmission
of
communicable
diseases. The choice of method will
depend
upon
many
factors;
availability of proper tools, and
technique.
Definitions
• Communicable Disease is one that can
transmitted from one person to another
and it is caused by an infectious agent that
is transmitted from a source or reservoir to
a susceptible host directly or indirectly.
• Infectious diseases is one that caused by
infectious agent.
Transmission of Infectious
Agents
Transmission refers to any mechanism by
which an infectious agent is spread from a
source or reservoir to a person:
1. Chain of transmission:
– Reservoir.
– Mode of transmission.
– Susceptible host.
Transmission of Infectious
Agents
2. Epidemiological trait:
- Agent
- Environment
- Host
Six Factors furthering the
process
•
•
•
•
Agent
Reservoir
Portal of exit
Mode of
transmission
• Portal of entry
• Susceptible host
Cont….
Host •
person/animal that affords subsistence to
an infectious agent under natural
conditions
Carrier •
person/animal that harbors a specific
infectious agent in the absence of
discernible clinical disease and serves as
a potential source of infection.
Cont…
• Fomite
Contaminated substance (not necessarily
a reservoir) serving as an intermediate
means of transport for an infectious agent
• Reservoir
Anything (living or inert) in which an
infectious agent lives and multiplies in
such a manner that it can be transmitted to
a susceptible host
Cont…
• Vector is invertebrate animal
capable of transmitting an
infectious agent to vertebrates.
• Virulence is the ability of an
infectious agent to cause severe
or fatal infections.
Chain of Transmission
Susceptible
host
Routes of
Transmission
Reservoir
Reservoir
Man
1=Case:-case can be prevented and controlled by
1-Identification:-
--presentation:This involves signs and symptoms of this disease.
--Lab finding :Diagnostic test, or physical examination
--complications
That may arise due to this disease.
Man
Case
2-Treatment
3-Isolation:- (type of isolation required)
this needs to determine period of communicability
4-Health education:About
-S&S of complication
-treatment compliance.
Man
carrier
2=carrier:1-Types of carrier
-by type
.healthy carrier
.incubatory carrier
.convalescence carrier
-by portal of exit
.respiratory carrier
.GIT carrier
. GUT carrier
2-active detection
.Household surveillance for early detection of disease
Reservoir
3-health education
concerning special hygiene and avoid risk
factors
4-Quarantine :-
this needs to know Incubation period of
the disease.
Animal(Reservoir)
•
-
Case
Identification
Treatment
Isolation
Extermination
• Carrier
- Type
- Active detection
- Quarantine
- Extermination
Soil
(Reservoir)
• Disinfection
Mode of transmission
-Direct :-1. Direct contact
2. Vertical transmission
3. Droplet infection
4. Animal bite transmission
5. Contact with soil
Indirect
1.
2.
3.
4.
5.
Air-borne
Vehicle borne
Vector-borne transmission
Fomite –borne
Hand –borne
Susceptible host
Man
1- The individual at risk
Systemic diseases
Surgical patients
Immunocompromised individuals
Genetic based
Organ transplant
Chemotherapy
Radiotherapy
HIV infection
Cont….
2-health education :about vaccination and preventive measures
3-immunization :if available.
4-prophylaxis :5-special protective measures :6-legislation :-
Susceptible host
Animals
1- At
risk
2- Prophylaxis
3- Special protective measures
Emerging Infectious Diseases
Emerging infectious diseases are
diseases that have appeared for the first
time or that have occurred before
appeared in populations where they have
not previously been reported.
Reemerging Infectious
Diseases
Reemerging infectious diseases are
familiar diseases caused by wellunderstood organisms that were once
under control or declining but now are
resistant to common drugs or gaining
new footholds in the population and
increasing in incidence.
Fundamental principles of Control of
Communicable Diseases
•
•
•
•
•
Rapid Assessment
Prevention
Surveillance
Outbreak Control
Disease Management
Modern Conditions that Favor
the Spread of Infectious
Diseases
1. Global travel
2. Globalization of food supply and
centralization of food processing
3. Population growth, increased
urbanization and overcrowding
4. Migration due to wars, famines, and
natural disasters
Modern Conditions that Favor
the Spread of Infectious
Diseases
5. Irrigation, deforestation, and
reforestation projects that alter habitats
6. Human behaviors, such as IV drug use
and risky sexual behavior
7. Increased use of antimicrobial agents
and pesticides
8. Increased human contact with
wilderness habitats
Primary Prevention
• Increasing the resistance of the host
• Inactivating the agent
• Interrupt the chain of infection
• Restricting spread of infection
–
isolation
– quarantine
– segregation
– personal surveillance
Secondary Prevention
• Activities targeted at detecting disease
at earliest possible time to:
– begin treatment
– stop progression
– protect others in the community
Tertiary Prevention
• Limits the
progression of
disability
• Treatment of
symptoms and
rehabilitation vary
with each specific
disease
Surveillance
• Surveillance is the ongoing systematic
collection, analysis and interpretation of
data in order to plan, implement and
evaluate public health intervention.
Surveillance system should be simple,
flexible, acceptable.
Outbreak Control
• An outbreak is occurrence of a number of
cases of a disease that is unusually large or
unexpected for a given place and time.
 Outbreaks and epidemics refer to the one
and same thing.
 Outbreaks in emergency situations can
spread rapidly giving rise to high morbidity
and mortality rates.
 Aim should be to detect and control the
outbreak as early as possible.
Steps in the management of a
communicable disease outbreak
•
Preparation
•
Detection
•
Response
•
Evaluation
Preparation for the outbreak
• Health coordination meetings
• Strong surveillance system
• Outbreak response plan for each
disease
• Stocks of iv fluids, antibiotics and
vaccines
• Plans for isolation wards
• Laboratory support
Steps in the management of a
communicable disease outbreak
•
Preparation
•
Detection
•
Response
•
Evaluation
Detection of outbreak
• Surveillance system with early warning
system for epidemic prone diseases.
• Inform ministry of health and WHO in
case of outbreaks of specific diseases.
• Take appropriate specimens (stool,
CSF or serum) for laboratory
confirmation.
• Include case in the weekly report.
Steps in the management of a
communicable disease outbreak
•
Preparation
•
Detection
•
Response
•
Evaluation
Response to the outbreak
• Confirm the outbreak
• Activate the outbreak control team
• Investigate the outbreak
• Control the outbreak
Steps in the management of a
communicable disease outbreak
•
Preparation
•
Detection
•
Response
•
Evaluation
Evaluation
• Assess appropriateness and
effectiveness of containment measures.
• Assess timelines of outbreak detection
and response.
• Change public health policy if indicated.
• Write and disseminate outbreak report.
Global Disease Eradication
Efforts
Methods to accomplish the goal of
eradication of diseases include:
– immunization and vaccination
– drug therapy
– community training
– health education
– national disease surveillance efforts
Nurses’ Role
Community health nurses play an important role
with regarded to all population at risk for
communicable diseases
Nurses concerned with control of communicable
diseases must
• Recognize who at risk.
• Where the reservoirs and source of infectious
disease agents are located.
• What environmental factors promote the spread.
• What comprise the characteristic of
vulnerability of community member and
groups-particularly those subject to
intervention
• Community health nurses must work
collaboratively with other public health
professional to establish immunization and
educational programs , to improve
community infection control policies , and
to develop abroad range of services to
population at risk
References
1. Clement.I.2009, Basic Concepts of Community Health
Nursing, Second edition, Bengalru: Jaypee Borther.
2. Spradley.B.W. 1996Community Health Nursing
concepts and practice, 4th edition. USA:library of
congress catologing.
3. Stone.S.C.1998, Comperhensive Community Health
Nursing, 5th edition, USA:Nancy. L.coon.
4. Karem.H.C. Communicable diseases
prevention,accessed on www.google.com
5. Kamalam.S.2005, Essentials in Community Health
Nursing Practice, First edition, New Delhi: Jaypee
Borther.
6. Omara.m.2007.Community Medicine.7th edition,
A.R.E.