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Yasmin Essam Khalil
Prof Dr. Mona Aboserea
General Epidemiology of communicable
and non communicable diseases
It is medical science that involves the study of the incidence and
distribution of diseases in large populations and the conditions
influencing the spread and severity of disease.
Epidemiology is the study of the distribution and determinants of
health-related states or events (including disease), and the
application of this study to the control of diseases and other
EPIDEMIOLOGY OF COMMUNICABLE
Communicable diseases are diseases transmitted from one
case to another. There is a cycle for transmission of infection
from one host to another.
What is the aim of studying epidemiology of
communicable diseases ?
To put preventive and control measures, limit their spread in the
community and limit their complications in cases.
Disease is the result of forces within a dynamic system
which is called an epidemiologic triad
1- Agent • Protozoa, unicellular parasites e.g. amoebae
• Metazoa, multicellular parasites e.g ascaris and ancylostoma
• Fungi e.g tinea captis
• Bacteria e.g. gram (+), gram (-) bacilli, coccus e.g Enteric fever,
• Rickettsia e.g rocky mountain fever, typhus
• Viruses e.g hepatitis
Exposure to an agent does not always cause clinical
symptomsThere are some factors:
1- Natural characteristic of the agent e.g. reproduction, metabolism,
motility, and production of toxin.
2- Characteristic of the agent related to infection in human:-
Infectivity The ability of an organism to invade and infect a host.
Pathogenicity Ability to cause disease.
Virulence Ability to cause serious complications and or death
Antigenicity Ability to stimulate host production of antibody
The starting point for the occurrence of a communicable disease is the
existence of a reservoir or source of infection.
The source of infection "is the immediate person or object fro
m which the infectious agent passes to the host.
Reservoir: The natural habitat, in which an agent lives, grows and
2-Source and reservoir
N.B: The source of infection may be a part of the reservoir or
not e.g. food poisoning (the reservoir is the carrier who contami
nate the food, while the source of infection is the food itself).
I- Human Reservoir
A- Cases :
are those individuals who are suffering from the disease.
They may be
• Typical cases showing the typical manifestation of the disease and
their level of severity may range from being mild to moderate to
severe, or they may be
• Atypical i.e. does not show the typical manifestation of diseases
• Subclinical or in apparent which can pass undiagnosed.
B- Carriers a person who is harboring the organism
(allows its multiplication inside his body) without showing signs
and symptoms. And is capable of transmitting the disease to other
N.B the carriers are considered to be the most dangerous source
of infection followed by the subclinical or in apparent infection
then the atypical cases and finally the typical cases
Types of Carriers
1. Incubatory carriers who shed the infectious agent during the
incubation period of disease before they become symptomatic.
2. Convalescent carriers who continue to shed the infectious
agent during the period of convalescence.
3. Contact carriers during care for case.
4. Chronic carriers who continue to harbor an agent for indefinite
II- Animals reservoir
Diseases that can be transmitted under natural conditions
from vertebrate animals to humans are called zoonosis
(e.g. rabies, yellow fever, plague, anthrax, brucellosis).
The famous animal reservoirs are cat, dog, horse, cattle,
poultry and rodents
III- Reservoir in non-living things
Soil can also act as reservoir of infection (e.g. soil may harbor agents
that cause tetanus and anthrax).
3- Portal of exit
Path by which an agent leaves its human or animal source host. e.g.
1- Respiratory tract e.g. influenza virus
2- Genitourinary tract e.g. sexually transmittal diseases
3- Alimentary tract e.g. hepatitis A virus (HAV)
4- Blood e.g. hepatitis B virus (HBV)
5- In-utro transmission e.g. rubella, cytomegalovirus.
4- Modes of transmission
Droplet or air borne method: either directly from reservoir to host
via droplets during kissing, sneezing, cough, spitting (short distance
transmission). Or indirectly through droplet nuclei (suspended air
particles or dust that transmit agents to far places) or through conta
minated articles as cups, spoon, fomites.
Food borne method: either directly from host feces to mouth via w
ater, hands, food or indirectly through flies, cockroach, dust.
Contact method (by skin and mucous membrane): direct contact be
tween case and new host, contact with infected animal. Or indirect t
hrough clothes, fomites, dust, water pool. Infection by contaminated
syringes occurs through skin penetration. Therefore it can be consid
ered as one of the contact routes of transmission.
the way in which the agent is transferred to a
Arthropod borne method: either biological transmission i.e mul
tiplication or development of new stages of the organism occur inside
the vector as in malaria, filarial. No infection occurs without this
biological transformation. The other method is mechanical i.e the vec
tor just carry the organism from the case to new host as flies carrying
typhoid bacilli from patient's feces to food.
From mother to infant during pregnancy: intrauterine infection
as German measles, malaria, syphilis, AIDS.
5-Portal of Entry
the route the agent uses to get into the new host. In general, the portal
of entry is similar to the portal of exit e.g.
the intrinsic factors that influence an individual's exposure,
susceptibility, or response to a causative agent.
There is a balance between immunity of host and virulence of
organism. For infection to occur, the virulence must exceed
host immunity. If the individual has high immunity he can
defend any infection
Factors affecting host immunity:
1- Age: extremes of age have low immunity.
2- Sex: some diseases affect females more as poliomyelitis.
3- Pregnancy: more severe manifestations of infection occur in preg
nant than non-pregnant of the same age.
4- Nutrition: malnutrition is associated with increased infection.
5- Trauma and fatigue or stress increase the incidence and severity
6- Occupation: certain occupations are more prone to infection as
medical staff and laboratory workers.
7- Environmental conditions: unsanitary water and waste
disposal, presence of vectors and rodents, ill ventilation, increased
temperature enhances growth of certain organisms.
8- Education and culture of people affecting their sanitary habits,
health consciousness and practice towards infection.
9- Socio-economic standard that affects sanitary housing
conditions, good nutrition.
10-Vaccination, subclinical / clinical infections provide level
of immunity may be lifelong
(Immunity of the community)
Describes the immunity level that is present in a population group
Herd immunity provides an immunological barrier to the spread
of diseases in the community.
The higher the herd immunity is the higher the power to
defense of an epidemic occurrence in the community.
Herd immunity may be acquired after frequent mass vaccinations.
Types of immunity
1. Non-specific: mechanisms that prevent entrance of agents
to the body: - e.g.
a) Intact skin
b) Cough, sneezing reflexes
c) Gastric juices
d) Normal bacterial flora
e) Secretions as saliva, tears.
2. Specific: The immune system consists of cell-mediated immunity
and circulating antibodies.
a) Cell-mediated immunity is responsible for delayed hypersensitivity
and the regulation of anti-body production, e.g. patients with acquired i
mmune deficiency syndrome (AIDS) have abnormalities in the T-cell su
b populations and, consequently, are infected by common organisms tha
t typically do not cause disease in healthy people.
b) Humeral immunity:
• Circulating antibodies are proteins that inactivate specific antigens
or organisms and prevent replication in the body.
• Antibodies are disease–specific (e.g. the measles antibody only
protects against measles).
• They are either naturally acquired or artificially acquired.
I. Naturally Acquired Immunity:
I- Natural active immunity
After infection (manifest disease or subclinical infections), the body for
ms antibodies against that infection. Some infections give solid immunit
y as measles, chicken pox and others give short time immunity as influe
II- Natural passive immunity (maternal immunity) antibodies fr
om mothers during pregnancy are transmitted to infant. It depends on th
e diseases the mother had exposed to before pregnancy to form antibodi
es. No cellular immunity is transmitted because of placental barriers. An
tibodies also are present in colostrum breast milk secreted on the first da
ys after labor.
II. Artificially acquired immunity
1. Artificial acquired active immunity:
Immunity is induced by immunization by vaccine which stimulates t
he body to form immunoglobulin. Duration of immunity depends on
the type of vaccine.
a) Live vaccine (as small pox) and live attenuated vaccine (as MM
R and measles) give lifelong immunity.
b) Killed vaccine (contains killed agents but still retain their antigeni
city) as typhoid, pertussis give short time or low level of immun
c) Vaccine may be prepared from
The whole organism: as polio and measles
The capsule of organism: polysaccharide vaccine as meningitis
Surface antigen of virus as hepatitis B vaccine
Toxin secreted by the organism : as diphtheria and tetanus
Causes of failure of Active Immunization:
spoiled vaccine due to change in its optimal temperature (most va
ccines need cold chain in transportation and storage )
Vaccination during the first 6 months of life when maternal immu
nity is still present and interferes with action of vaccine.
2. Artificial acquired passive immunity
Seroprophylaxis ready-made immunoglobulin given for rapid
protection after exposure to infection. The body has no role in immunity
It is given either for prevention or attenuation of disease severity.
It usually gives short duration of immunity.
Immunoglobulins or Antitoxins are either of animal origin as tetanus, di
phtheria and gas gangrene antitoxins or of human origin prepared from
plasma of actively immunized persons as rabies serum.
Chemoprophylaxis: administration of antimicrobial drug before
exposure or just after exposure to prevent occurrence of disease (not for
treatment). Penicillin is used for prevention of rheumatic fever,
tetracyclines for cholera, INH for tuberculosis, rifampicin for meningitis
Chemoprophylaxis has disadvantages: expensive, side effects of drug,
not used for long period, short immunity (immunity is present while dru
g is taken only). Drug resistance after its community use for long
7- Incubation period (I.P)
The time interval between contact with an agent and the first clinical
evidence of the disease.
It depends on:
Portal of entry (defense mechanism).
The ability of multiplication (infectivity).
Number of agents.
Level of antibody in the host.
Importance of IP:
Tracing the source of infection and contact
Period of surveillance
Identification of point source or propagated epidemics
Prognosis e.g. in rabies, and tetanus, the shorter the IP is,
the worse the prognosis of disease.
The incubation period varies individually according to:
Defense mechanism: the ability to react against agent invasion in the
body. It consist of :-
a) The external defense mechanism (Cough, Sneeze reflex, Gastric
acid, Vomit reflex, Skin, Tears).
b) The internal defense mechanism: cellular and humeral immunity.
If the external defense mechanism cannot eliminate the agent the
internal defense mechanism will continue the defense mechanism
Isolation by fibrocytes
8-Clinical picture and complication
Differs from disease to another and from one case to another also.
This item will be discussed in details in Medicine.
Types of spread of communicable diseases:-
Sporadic cases infected cases have no common source of infection
. They spread all over far away areas not related to each other.
Outbreak spread of infection in confined place as school or
camp. Usually there is common source for infection, if controlled the
incidence of infection decreases.
Epidemic Widespread of infection, unexpected increase in number
of already present infection in certain area in short period. Or it is
introduction of new infection to the country never shown that disease
before as SARS, Avian flu.
Endemic :constant presence of disease within a given geographic
area or population group.
Pandemic : spread of infection all over the world or in many
countries e.g. avian flu, Aids.
Epizootic: Spread of Zoonotic disease in large scale among animals
e.g. cow mad disease.
• Common source epidemic
1- All individual are exposed to a common pathogen or noxious
2- The mode of transmission is indirect because
• The agent is vehicle borne (contact through fomites, food, air
• 2ry Host to host transmission (direct) is rare
3-By examining the epidemic curve:
• Fewest number of cases become apparent after minimum
• Largest number peak occur by the end of usual incubation
period (from the point of exposure to the midline of the
• The shape is typical unimodal shape of common source
• Point source epidemic
1- All susceptible individual are exposed to specific pathogen at
one point of time
2- Point source epidemic is a subcategory of common source
epidemic in which common exposure to the offending pathogen or
agent is both brief and simultaneous
3- By examining the curve
• Very explosive increase in the number of cases over a short
period of time after exposure to the agent
• One incubation period ,so the apex is much sharper and the
decline in the number of cases is more rapid than in typical
common source curve
• 2ry transmission is rarely seen in point source epidemic as with
common source epidemic
• Propagative source epidemic
1- Serial transmission as the pathogen is transmitted from
person to person .
2- Mode of transmission may be direct (direct human contact or
direct aerosolized respiratory droplets ) or may be indirect (
vector borne – airborne)
3- Individual immunogenicity and herd immunity play an
important role in propagative disease transmission
4- The curve shows :
• Initial rise in the number of cases that is less explosive than in
a point source epidemic
• Successive generations of secondary infection produce a poly-
modal distribution conforming to several generations of
Epidemic investigation is a set of procedures used to identify the cause
i.e. the infectious agent, responsible for the disease.
1. It is also used to identify the people affected, the circumstances
and mode of spread of the disease, and other relevant factors
involved in propagating the epidemic.
2. Epidemic investigation is a challenging task for health workers.
3. The main purpose of epidemic investigation is to control the spread
of the disease before it causes more deaths and illness.
Steps of epidemic investigation
1. Verify the diagnosis or causes:
-Careful analysis of the initial reports.
- Confirm diagnosis by performing clinical and laboratory studies.
-Putting the criteria for case definition.
2. Establish the existence of an epidemic:
By comparing the current level (incidence) with the past level of the
disease in that locality and population.
3. Description of the epidemic as regard time, place and person:
- By plotting the cases by time of onset (Epidemic curve).
- By plotting the cases by location (Spot map).
- Collect data on the age, sex, etc. of the cases.
4. Develop hypotheses to explain the occurrence of the epidemic.
5. Test the hypothesis
6. Identification of susceptible population.
7. Management of the epidemic.
8. Formulation of the report and communicate findings and
recommendation to higher levels in the health system,
community leaders and other local stakeholders
I-Primordial Prevention: health promotion
Prevention of emergence or development of Risk Factors.
Prevention from Risk Factors.
Discouraging harmful life styles.
Encouraging or promoting healthy eating habits (to prevent obesity
in childhood) .
Not focused to specific disease
Action taken prior to the onset of the disease
Pre-pathogenesis Phase of a certain disease.
Immunization - Use of specific Nutrients
Chemoprophylaxis - Protection against Occupational Hazards
Avoidance of Allergens - Control of specific hazards in general
environment - Control of Consumer Product Quality & Safety
III-Secondary Prevention: = disease control
Halt the progress of a disease at its incipient phase اولية .مرحلة
Early diagnosis & Adequate medical treatment.
DISEASE CONTROL: aimed at reducing:
The incidence of disease.
The duration of disease and the consequently the risk of transm
Physical and psychological complication.
The financial burden to the community.
CONCEPT OF CONTROL
1- ELIMINATION: Reduction of case transmission to
a predetermined very low level or interruption in transmission. E.g
. measles, polio, leprosy from the large geographic region or area
2- ERADICATION: Termination of all transmission of infection by
extermination of the infectious agent through surveillance and
containment. “All or none phenomenon”. E.g. Small pox
3- MONITORING: Defined as “the performance and analysis of
routine measurement aimed at detecting changes in the environment
or health status of population.” e.g. growth monitoring of child,
Monitoring of air pollution, monitoring of water quality……. etc.
4- SURVEILLANCE: Defined as “the continuous analysis of the
factors that determine the occurrence and distribution of disease and
other conditions of ill health.” e.g. Poliomyelitis surveillance
programme of WHO
Intervention in the late Pathogenesis Phase.
Reduce impairments, minimize disabilities & suffering.
The Objective is to prevent or halt the transition of the disease proc
ess from impairment to handicap.
Sequence of events leading to disability & handicap:
Disease → Impairment → Disability→ Handicap
Impairment: Loss or abnormality of psychological, physiological/
anatomical structure or function.
Disability: Any restriction or lack of ability to perform an activity
in a manner considered normal for one’s age, sex, etc.
Handicap: Any disadvantage that prevents one from fulfilling his
role considered normal.
Rehabilitation has been defined as the ‘combined and coordinated
use of medical, social, educational and vocational measures for training
and retraining the individual to the highest possible level of functional
Areas of concern in rehabilitation:
PREVENTION OF COMMUNICABLE
I- Primary prevention "Health promotion and specific protection".
The environment would be free of:
Vehicles of infection: polluted air, water, milk, food, soil
Vector of disease: infection transmitting arthropods
Rodents(including rats): potential reservoir of many infections
Infected animal reservoir (Stray dogs and cats)
Components of sanitary environment:
Proper town, village or district planning and design
Good housing with suitable ventilation
Sanitary collection and disposal of waste
Food and milk sanitation
Eradication or control of insects, rodents, stray dogs and cats
Health education of the public:
Proper knowledge, attitude and practice related to health, with special
consideration of life style, habits and behavior
Health promotion of the public:
Health promotion can be achieved by fulfilling requirements of health:
Physical, mental and social health
Prenatal, natal and post natal care
Specific prevention is specific protection of man against causative age
nts of infectious diseases by immunization (active and passive) and
Administration of antimicrobial drugs for specific protection of certain
infectious diseases to prevent development of disease and may be
Limitation of chemoprophylaxis:
a) Cost: extensive use of antimicrobial may be costly compared to expe
cted potential benefit
b) Adverse effects of drugs
c) Development of drug resistant strains
d) Provided protection is temporary, for short period.
Chemoprophylaxis may be the basic preventive measure of many disea
ses including: Rheumatic fever, Meningococcal meningitis, Cholera,
plague, Tuberculosis, Ophthalmia neonatorum
International preventive measures
1-International regulations are followed by different countries to
prevent transmission of certain infectious diseases called quarantinable
diseases in between countries. At present quarantine measures are taken
for cholera, yellow fever and plague.
2-Quarantine measures are taken for certain animals coming from
endemic or infected areas e.g Monkey for yellow fever, Cattle for rift
3- Imported goods:
For raw wool, shaving brushes. Authorized disinfection certificate is
4- Means of transportation: de rating certificate for ships in plague and
disinfection of planes coming from yellow fever endemic areas
II- Secondary prevention: "Early diagnosis and prompt treatment"
Control measures to be taken for existing infectious disease with the
Case finding: detection and diagnosis of cases
Management of cases and preventing complications and sequelae of
Measures for contacts and protecting susceptible
Preventing or minimizing spread of disease in involved community or
Control of human reservoir:
A- Control of cases:
1- Case finding.
Cases of definite or suspected diagnosis must be notified to local heal
Value of notification:
To take preventive and control measures
To help tracing sources and channels of infection in outbreaks
To collect significant statistical data
Cases of infectious diseases must be isolated either at home, hospital
or special place according to nature of disease
Value of isolation:
To stop activity and movement of case in the community
To protect the case from risk of secondary infection
Disinfection is the process of destroying pathogenic organisms outside
a) Concurrent disinfection is carried out during course of disease
b) Terminal disinfection
5- Treatment many communicable diseases have been treated by
effective drugs. The object of treatment is to kill the infectious agent
When it still in the reservoir, i.e. before it disseminated. Treatment
reduce the communicability of disease, cut short the duration of illness
and prevent the development of secondary cases.
6- Release Patient discharge or the formal ending of inpatient care
B- Control of carriers:
Carriers may be difficult to control. It is important to do pre-employment
and periodic medical examination of certain occupational groups
e.g food handlers, medical personnel and personnel serving children
C- Control measures for contacts:
Enlistment: a special list of contacts
Examination: for case finding
Not to be exposed to isolated case
Surveillance, segregation or isolation according to disease
Surveillance: contacts are put under supervision for incubation period of
disease meanwhile, they can perform their activities
Segregation: contacts are excluded from school or work but not isolated
e.g measles, enterica and diphtheria
Isolation: contacts of following diseases are isolated:
Cholera in non-endemic areas
Immunization or chemoprophylaxis
Eradication of animal reservoir if applicable.
Control of farm and pet animals to prevent or minimize animal-animal
or animal man transmission of infection through sanitary raising,
feeding and veterinary care.
Community control measures
Epidemiological study and investigation to trace sources and channels
Drastic control measures to be taken if necessary e.g closing schools
Surveillance is an ongoing systemic collection, analysis, interpretation
and dissemination of health data
Control of animal reservoir
Eradication of infectious disease: is getting rid of causative
organism and consequently of disease: no reported cases and no
reservoir of infection.
Elimination of disease: means that existing endemic infectious
disease is so controlled to reach the level of no reported cases
while causative agent is not necessarily eliminated.
IV- Tertiary Prevention "Disability
Limitation and Rehabilitation"
Their purpose is to reduce or eliminate long-term impairments and
disabilities, minimize suffering, optimize function, prevent further
deterioration of cases, to help complicated cases to cope with their
Vaccination VS Immunization
• Vaccination is the term used for getting a vaccine, that is,
actually getting the injection or taking an oral vaccine dose
• The US (CDC) defines a vaccine as "A product that stimulates a p
erson’s immune system to produce immunity to a specific diseas
e, protecting the person from that disease. Vaccines are usua
lly administered through needle injections, but can also be adminis
tered by mouth or sprayed into the nose.“
• Vaccination is the process of getting a vaccine into the body or "T
he act of introducing a vaccine into the body to produce immunity
to a specific disease." A vaccine is what initiates the immunizatio
• Immunization refers to the process of both getting the
vaccine and becoming immune to the disease following
• According to the (WHO), "Immunization is the process whereb
y a person is made immune or resistant to an infectious dis
ease, typically by the administration of a vaccine.
• Vaccines stimulate the body’s own immune system to protect t
he person against subsequent infection or disease.“
• A person becomes immune to a disease when the body has be
exposed to it either through illness or vaccination/immunization.
The immune system develops antibodies to the disease so that it
cannot make you sick again. Immunization, therefore, describes
the actual changes your body goes through after receiving
**Non communicable diseases are non-infectious and non-transmissible
between persons. Mostly they are chronic diseases of long duration and
slow progression which require chronic care management.
They represent about 63% of all deaths and one of the leading causes of
mortality according to World Health Organization (WHO) reports.
Nearly 80% of these NCD deaths (29 million) occurred in low- and
The leading causes of NCD deaths in 2008 were:
• cardiovascular diseases (17 million deaths representing 48% of NCD
• cancers (7.6 million, or 21% of NCD deaths);
• respiratory diseases, including asthma and chronic obstructive
pulmonary disease (COPD), (4.2 million).
• Diabetes caused an additional 1.3 million deaths.
Reasons of the increasing prevalence of NCDs:
(1) The demographic transition: The decrease in mortality resulted in
increase in the life expectancy with subsequent increase in the proportion
of the elderly populations. NCDs are usually associated with aging.
(2) The epidemiologic transition: There is shift from mortality from
communicable diseases (due to the use immunization and antibiotic use
etc.) to NCDs which have chronic nature due to specific genetic,
environmental and behavioral risk factors.
(3) Nutritional Transition: There has been shift from famines to
increased production and consumption of food. However, there is
another large shift in the pattern of nutrition to a diet high in total fat,
sugar and other refined carbohydrates and low in polyunsaturated fatty
acids and fibers.
At the same time there is increase in sedentary life . Such pattern resulted
in increasing the prevalence of obesity and subsequent degenerative
(4)The multi-factorial nature of the risk factors for the non-com
Compared to communicable diseases are difficult to identifying
the specific cause-effect relationship.
The multiplicity of the risk factors associated with specific NCDs
limit the opportunities to have specific intervention for
prevention and control.
The type of risk factors are difficult to be controlled by medical
technology (in communicable diseases , immunization and
antibiotics are effective in prevention and control of diseases)
The risk factors are related to genetic, environmental, culture
and behavior which represent a challenging issue to public health
Panel for demonstrating the demographic, epidemiologic and
(5) Migration of population across different cultures:
The individuals who migrate from low risk culture (e.g .rural areas) to
high risk culture (e.g. Urban areas ) follow the life style of the new
culture and demonstrate increased risk for NCDs.
(6) International communication:
International communication, multinational business and new food
technologies have resulted in introduction of new life-style and new
food products in the communities which have risks for NCDs.
Communication through the mass media∕ satellites∕ internet, overseas
travel, and international food marketing; facilitate the introduction of
different concepts and dietary pattern which predispose to exposure to
the risk factors of NCDs.
Adolescents and youth are population segments who are exposed to
such modernization in concepts and behavior. Consequently, the
exposure to the risk of NCDs early in the life cycle will result in
development of large cohort with health problems during adulthood and
(7) Environmental changes:
The increase in the level of physical and chemical air pollution is
associated with high prevalence of NCDs.
(8) Epidemiology of the NCDs differs across the countries:
Due to differences in the prevalence of the different risk factors for
NCDs (genetic, environmental, cultural and behavioral) across
countries, there are limitations to use the universal information in any
Public health specialists in each country should have specific
surveillance system for the different non communicable diseases (e.g.
countries in which people use spicy food have the problem of peptic
ulcers and stomach neoplasm).
(9) Epidemiology of NCDs is changing all the time:
Some countries succeeded in improving the pattern of some NCDs (i.e.
reduction in the incidence of coronary heart diseases through extensive
anti- smoking programs).
(10) Limited use of scientific progress in management of NCDs:
There are rapid and successful achievements in the science of risk
detection, use of medication and technologies to prevent and control
However, in the developing countries high cost of NCDs prevention
and control programs is challenging.
Almost all the non communicable diseases have unknown cause, but
they have some related risk factors.
They can be classified into: non modifiable and modifiable risk
A. Non modifiable risk factors: include genetics, age, sex, and race.
These risk factors cannot be prevented.
B. Modifiable risk factors: include smoking, alcoholism, unhealthy
diet, exposure to environmental pollution, physical inactivity and
stress. Other factors associated with higher risk of NCDs include
a person's economic and social conditions, also known as the "social
determinants of health."
The modification of these risk factors can prevent or delay the occurre
nce and complications of the chronic diseases.
Common risk factors of (NCDs)
Identified five important risk factors for non-communicable disease in
the top ten leading risks to health. These are :
1. raised blood pressure,
2. raised cholesterol level,
3. tobacco use,
4. alcohol consumption, and
5. overweight with insufficient physical activity.
World Health organization global status Report 2
Prevention of non communicable diseases
1- Primary prevention:
• health promotion
• health education
• adopting healthy life style (balanced diet and physical activity).
• Eating balanced diet; eating more fruits and vegetables, eating less
meat, fat, sugar and salt, and keeping weight within the normal
range are important preventive measures.
• practicing physical exercise as a routine fixed duty along with
getting sufficient time for rest and sleep can be very helpful for
preventing much NCDs.
• Social activity to relief stress;
• no smoking;
• avoiding drinking alcohol or taking drugs;
• living in a healthy environment free of pollutants have important
• Enhancing the role of laws and governance reform in preventing
NCDs and their risk factors, improving access to NCD treatments,
and addressing the social impacts of illness (e.g. Imposing and
increasing taxes on tobacco to reduce demand, Smoking bans in
public places, including workplaces, public transport and
restaurants, Improving food labeling to encourage healthier choices,
2- Secondary prevention:
Early detection of cases and proper management which give better
Screening tests can be used for at risk groups for early detection.
1. Blood pressure measurement for detection of hypertension (adults
aged 40 years or older )
2. Random blood sugar level for detection of diabetes (type 2
diabetes in adults 40 to 70 years of age who are overweight or
obese and repeating testing every three years if results are normal
3. Cervical smear for detection of cancer cervix( in women age 21
to 65 years with cytology (Pap smear) every 3 years)
3- Tertiary prevention:
To rehabilitate the complicated cases as in osteoporosis, osteoarthritis,
late cancer cases and complicated diabetes.
4. mammography or self examination of breast for detection of cancer
breast ( from the age of 40 years old)
5. Alfa fetoprotein for detection of cancer liver (For people at higher risk of
liver cancer due to cirrhosis OR chronic hepatitis B infection even without
cirrhosis) every 6 to 12 months
Egypt National Multi-sectoral Action Plan for
Prevention and Control of Non communicable Diseases 2018-2022
Egypt National STEPwise Survey for
Non-communicable Diseases Risk Factors Report 2017
Target population: National household survey on persons aged 15-69
Sample size : 6680 households participated in the survey out of 7200
HH (94.3% response rate)
Conducted by: Ministry of Health and population , control agency for
public mobilization and statistics, World Health organization