A communicable disease can be transmitted from one person to another in several ways, such as contact with blood or body fluids, inhalation of an airborne virus, or insect bites.

1. Communicable And Non-
communicable Diseases
Lecturer 1

2. • This module is composed of three units namely:
• Unit One: Concepts of Communicable and Non-Communicable
Diseases.
• Unit Two: Types of Communicable Diseases.
• Unit Three: Types of Non-Communicable Diseases.
Introduction

3. • By the end of this module, you will be able to:
• Discuss different concepts of communicable and non-communicable diseases
• Discuss types of communicable diseases
• Discuss types of non-communicable diseases
Module Objectives

4. • Welcome to the first unit of this module. In this unit you will define
key terms used in communicable and non-communicable diseases
and also differentiate between communicable and non-
communicable diseases.
Unit One: Concepts of Communicable and Non-
Communicable Diseases

5. • By the end of this unit, you will be able to:
• Define terms commonly used in communicable and non-
communicable diseases
• Classify communicable and non-communicable diseases
Unit Objectives

6. Importance of Communicable Disease in Developing
Countries
• Communicable Diseases Remain Very Important In Developing Countries
Because:
• Many of them are Very Common
• Some of them are Serious and Cause Death and Disability
• Some of them Cause Widespread Out Breaks of Disease or Epidemics
• Most of them are Preventable y Fairly Simple Means.

7. Conti…
• Poor socio-economic status of the individuals makes them
• vulnerable to a variety of diseases
• Low educational status
• Lack of access to modern health care service

8. • You will start by defining the key terms used in communicable and non-communicable
diseases. These terms include the following:
• Communicable.
• Non-communicable diseases.
• Etiology.
• Incubation.
• Manifestation.
• Control of diseases.
Definition of Key Terms

9. • Prevention of diseases.
• Primary prevention, secondary prevention and tertiary prevention.
• Emerging diseases.
• Re-emerging diseases.
• Vector.
• Reservoir.
• Fomite.
• Host.
Conti…

10. • Communicable diseases are diseases that are transmitted through direct contact with an infected
individual or indirectly through a vector.
• Communicable disease can also be referred as contagious disease. Examples include the
following:
• Malaria is transmitted from an infected ‘person to another person through a vector known as a
mosquito’.
• Scabies is a skin condition that is transmitted from an infected person to another person through
contact.
Communicable Diseases

11. • Non-communicable diseases (NCDs) are also known as chronic diseases. These diseases
are not passed from person to person and tend to be of long duration with slow in
progression.
• Examples include the following:
• Hypertension is an example of a non-communicable disease. It is not transmitted from
one person to another. It is also a chronic disease, that is, patients tend to have the
disease for a long time.
• Cancer is another NCD which cannot be transmitted from person to person.
conti….

12. •Etiology: Etiology is a branch of medical science concerned with the
causes and origins of diseases. For example:
• The etiology of malaria is the protozoan plasmodium
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13. • Incubation: This is the development of an infection from the time the
pathogen enters the body until signs or symptoms first appear. For
example, the incubation period for malaria is 14-21 days from the
time one is bitten by a mosquito to the onset of signs and symptoms
of malaria.
Conti….

14. • Control of Diseases
• This refers to a reduction in the incidence, prevalence, morbidity or
mortality of an infectious disease to a locally acceptable level. For
example, the reduction of the number of people infected with a
disease from a high number such as 20000 infections to a tolerable
level, for example 1000 infections.
Conti…

15. Manifestation
This is an obvious indication or specific evidence that a disease is
present. It is also known as a symptom. For example a high fever is an
early manifestation of malaria.
Conti….

16. • Control of Diseases
This refers to a reduction in the incidence, prevalence, morbidity or
mortality of an infectious disease to a locally acceptable level.
• For example, the reduction of the number of people infected with a
disease from a high number such as 20000 infections to a tolerable level,
for example 1000 infections.
Conti…

17. • Prevention of Diseases
• Disease prevention covers measures not only to prevent the
occurrence of disease, such as risk factor reduction, but also to arrest
its progress and reduce its consequences once established.
Conti….

18. • Primary Prevention
• Primary prevention refers to preventive measures that stop the onset
of illness or injury. This practice focuses on the identification of
potential risk factors for disease or disability in healthy individuals, for
example, wearing seatbelts and immunisation.
Conti…

19. • Secondary Prevention
• These are measures aimed toward the early detection of underlying disease when obvious clinical symptoms
are not yet apparent.
The goal is to slow progression of a disease or in the case of an injury, limiting long-term disability or
preventing re-injury. Examples include the following:
• Screening and detection of cancer, such as pap-smear and initiation of early treatment.
• Mother attending maternal child health clinics to be screened for syphilis, if found to be positive the clinician
will initiate appropriate treatment.
Conti…

20. • Tertiary Prevention
• Tertiary prevention is when treatment is implemented after the disease becomes symptomatic. Focus is
helping people manage chronic health problems and preventing further deterioration of disease or
disability.
• Examples are the following:
• Surgery to treat lung cancer, rehabilitation after a stroke, and cardiac rehabilitation post-myocardial
infarction.
• Patients with diabetes mellitus should be given insulin to maintain low blood sugar to avoid renal failure.
Conti….

21. • Emerging Diseases
• An emerging disease is one that has appeared in a population for the first time, or
that may have existed previously but is rapidly increasing in incidence or
geographic range (WHO, 2015).
• Examples of emerging diseases in Africa include Ebola, avian flu, small pox and
anthrax.
Conti…

22. • Re-emerging Diseases
• This is any condition usually an infection that reappears after it had
been eradicated or brought under control. For example, cholera,
dengue, diphtheria and tuberculosis
Conti…

23. • Host
• A host is a person or animal that gives subsistence to an infectious
agent under natural conditions.
• For example; the host of plague is a rat and the host of leishmaniasis
is mainly canines and rodents.
Conti…

24. • Vector
• Vector is an invertebrate or an animal capable of transmitting an
infectious agent to vertebrates. For example the following:
• A flea is a vector of plague
• Mosquitos are vectors of malaria
Conti…

25. • Reservoir
• Reservoir is anything whether living or inert, in which an infectious agent lives
and multiples in such a manner that it can be transmitted to a susceptible host.
• Examples include the following:
• The reservoir host for trypanosomiasis is wild herbivore
• The reservoir host for yellow fever is wild monkeys
Conti..

26. • Fomites
• Fomites are non-living things which harbour and transmit infectious agents to a
susceptible host. Examples are patient’s cloths and contaminated food (Nordberg,
2005).
• By now, you should know the meaning of some of the common terms you will be using
in this course. Next you will look at the classification of communicable and non-
communicable diseases.
Conti…