Epidemiology of Communicable and Non-communicable diseases

1. Communicable
and
Non-communicable
diseases

2. Epidemiology
“The study of the occurrence and distribution of health-related
events, states, and processes in specified populations, including
the study of determinants influencing such processes, and the
application of this knowledge to control relevant health problems”
(International Epidemiological Association, 2014)

3. Communicable
diseases

4. Epidemiological triad
Agent
Environment
Host

5. Selected definitions
• Infection: The entry and development or multiplication of an
infectious agent in an organism, including the body of man or
animals
»Colonization
»Subclinical or inapparent infection
»Latent infection
»Manifest or clinical infection

6. • Contamination: The presence of an infectious agent on a body
surface, on or in clothes, beddings, toys, surgical instruments or
dressings, or other inanimate articles or substances including
water, milk and food
• Infestation: The lodgement, development and reproduction of
arthropods on the surface of the body or in the clothing (e.g.,
lice, itch mite), also invasion of the gut by parasitic worms (e.g.,
ascariasis)

7. • Host: A person or other living animal, including birds and
arthropods, that affords subsistence or lodgement to an
infectious agent under natural conditions
»Obligate host means the only host
»Definitive hosts
»Secondary or intermediate hosts
»Transport host

8. • Communicable disease: An illness due to a specific infectious
agent or its toxic products that arises through transmission of
that agent or its products from an infected person, animal, or
reservoir to a susceptible host, either directly or indirectly
through an intermediate plant or animal host, vector, or the
inanimate environment

9. • Infectious disease: Disease due to an infectious agent
• Contagious disease: Disease that is transmitted through
contact (E.g., scabies, trachoma, STD, leprosy)
• Endemic: The constant presence of a disease or infectious
agent within a given geographic area or population group,
without importation from outside

10. • Hyperendemic: The disease is constantly present at a high
incidence and/or prevalence rate and affects all age groups
equally
• Holoendemic: A high level of infection beginning early in life
and affecting most of the child population
• Sporadic: (means scattered about) The cases occur irregularly,
haphazardly from time to time, and generally infrequently

11. • Epidemic: The occurrence in a community or region of cases of
an illness, specific health-related behaviour, or other health-
related events clearly in excess of normal expectancy
• Pandemic: An epidemic occurring over a very wide area,
crossing international boundaries, and usually affecting a large
number of people.

12. • Exotic: Diseases which are imported into a country in which
they do not otherwise occur
• Zoonoses: An infection or infectious disease transmissible
under natural conditions from vertebrate animals to man
»Anthropozoonoses
»Zooanthroponoses
»Amphixenoses

13. • Epizootic: An outbreak (epidemic) of disease in an animal
population (often with the implication that it may also affect
human populations)
• Epornithic: An outbreak (epidemic) of disease in a bird
population
• Enzootic: An endemic occurring in animals

14. • Nosocomial (hospital acquired) infection: An infection
originating in a patient while in a hospital or other health care
facility. It includes infections acquired in the hospital but
appearing after discharge, and also such infections among the
staff of the facility
• Opportunistic infection: Infection with organism(s) that are
normally innocuous but become pathogenic when the body’s
immunological defenses are compromised

15. • Iatrogenic disease: Literally, “doctor-generated”; adverse
effects of preventive, diagnostic, therapeutic, surgical, and other
medical, biotechnical, cosmetic, sanitary, and public health
products, services, procedures, interventions, or policies
• Surveillance: Continuous analysis, interpretation, and
feedback of systematically collected data, generally using
methods distinguished by their practicality, uniformity, and
rapidity rather than by accuracy or completeness

16. Dynamics of disease transmission
Source or
Reservoir
Modes of
transmissi
on
Susceptibl
e host

17. Sources and reservoir
• Source: The person, animal, object or substance from which an
infectious agent passes or is disseminated to the host
• Reservoir: Any person, animal, arthropod, plant, soil or
substance (or combination of these) in which an infectious
agent lives and multiplies, on which it depends primarily for
survival, and were it reproduces itself in such manner that it can
be transmitted to a susceptible host

18. • Homologous reservoir: when another member of the same
species is the victim, as for example man is the principal
reservoir for some enteric pathogens, e.g., vibrio cholerae
Types of reservoir
1. Human
2. Animal
3. Non-living things

19. Human reservoir
CASE: A person in the population or study group identified as
having the particular disease, health disorder or condition under
investigation
Clinical illness
Subclinical (inapparent/covert/missed/abortive) cases
Latent infection

20. • Primary case: the first case of a communicable disease
introduced into the population unit being studied
• Index case: the first case to come to the attention of the
investigator
• Secondary cases are those developing from contact with
primary case

21. • Suspect case(s): individual (or a group of individuals) who has
all of the signs and symptoms of a disease or condition, yet has
not been diagnosed as having the disease or had the cause of
the symptoms connected to the suspected pathogen

22. CARRIER: an infected person or animal that harbours a specific
infectious agent in the absence of discernible clinical disease and
serves as a potential source of infection for others
The elements in a carrier state are
a) the presence in the body of the disease agent
b) the absence of recognizable symptoms and signs of disease
c) the shedding of the disease agent in the discharges or
excretions

23. A. Type
a) Incubatory
b) Convalescent
c) Healthy
B. Duration
a) Temporary
b) Chronic
C. Portal of exit
a) Urinary
b) Intestinal
c) Respiratory
d) Others
Classification of carrier

24. A. Type
a) Incubatory: those who shed the infectious agent during
the incubation period of disease
b) Convalescent: those who continue to shed the disease
agent during the period of convalescence
c) Healthy: who have developed carrier state without
suffering from overt disease, but shedding disease agent

25. B. Duration
a) Temporary: those who shed the infectious agent for short
periods of time
b) Chronic: who excretes the infectious agent for indefinite
periods

26. C. Portal of exit
a) Urinary
b) Intestinal
c) Respiratory
d) Others (skin eruptions, open wounds, blood)

27. Animal reservoir
• Source of infection may sometimes be animals and birds
• These may be cases or carriers
• The best-known examples are rabies, yellow fever and
influenza
• The role of pigs and ducks in the spread of epidemic and
pandemic influenza both as reservoirs, carriers and “amplifying
hosts” is now well established

28. • Pigeons in cities can lead to infection with chlamydia; dust mites
from them can cause allergy in man
• Ornithosis and arboviruses can be transmitted to man from
various birds
• Wild birds are important hosts in the transmission cycles of
most of the mosquito-borne encephalitis and several mosquito-
borne undifferentiated febrile diseases
• Histoplasmosis is carried all over the world by birds

29. • As birds migrate from one locality to another, they may carry
ticks infected with viruses and rickettsiae that may cause
disease in humans
• Genetic recombination between animal and human viruses
might produce “new” strains of viruses

30. Reservoir in non-living things
Soil and inanimate matter can also act as reservoirs of infection
For example, soil may harbour agents that cause tetanus,
anthrax, coccidioidomycosis and mycetoma

31. Modes of transmission
Direct Indirect
1.Direct contact
2.Droplet infection
3.Contact with soil
4.Inoculation into skin or mucosa
5.Vertical
1.Vehicle-borne
2.Vector-borne
a)Mechanical
b)Biological
3.Air-borne
a)Droplet nuclei
b)Dust
4.Fomite-borne
5.Unclean hands and fingers

32. Direct transmission
• Direct contact : skin to skin, mucosa to mucosa, or mucosa to
skin of the same or another person. E.g., STD and AIDS,
leprosy, leptospirosis, skin and eye infections
• Droplet infection : direct projection of a spray of droplets of
saliva and nasopharyngeal secretions during coughing,
sneezing, or speaking and spitting, talking into the surrounding
atmosphere. E.g., common cold, diphtheria, whooping cough,
tuberculosis, COVID-19, meningococcal meningitis

33. • Contact with soil: direct exposure of susceptible tissue to the
disease agent in soil, compost or decaying vegetable matter in
which it normally leads a saprophytic existence. E.g., hookworm
larvae, tetanus, mycosis

34. Indirect transmission
Vehicle-borne: transmission of the infectious agent through the
agency of water, food (including raw vegetables, fruits, milk and
milk products), ice, blood, serum, plasma or other biological
products such as tissues and organs
 Food & water as vehicle: cholera, hepatitis A, typhoid
 Blood as vehicle: hepatitis B, CMV infection, malaria

35. Vector-borne:
• Vector is defined as an arthropod or any living carrier that
transports an infectious agent to a susceptible individual
• Transmission by a vector may be mechanical or biological
• Vector-borne diseases are classified into four types

36. Epidemiological classification of vector-borne diseases:
1) By vector
2) By transmission chain
3) By methods in which vectors transmit agent
4) By methods in which vectors are involved in the transmission
and propagation of parasites

37. 1) By vector
a) Invertebrate type
i. Diptera – flies & mosquitoes
ii. Siphonaptera – fleas
iii. Orthoptera – cockroaches
iv. Anoplura – sucking lice
v. Hemiptera – bugs, including kissing bugs
vi. Acarina – ticks & mites
vii. Copepoda – cyclops
1) By vector
a) Vertebrate type
Mice, rodents, bats

38. 2) By transmission chain
a) Man and a non-vertebrate host
i. Man-arthropod-man (malaria)
ii. Man-snail-man (schistosomiasis)
b) Man, another vertebrate host and a non-vertebrate host
i. Mammal-arthropod-man (plague)
ii. Bird-arthropod-man (encephalitis)

39. c) Man and 2 intermediate hosts
i. Man-cyclops-fish-man (fish tapeworm)
ii. Man-snail-fish-man (Chlonorchis sinensis)
iii. Man-snail-crab-man (Paragonomiasis)

40. 3) By methods in which vectors transmit agent
a) Biting
b) Regurgitation
c) Scratching-in of infective faeces
d) Contamination of host with body fluids of vectors

41. 4) By methods in which vectors are involved in the
transmission and propagation of parasites
a) Mechanical transmission: no multiplication or development of
agent
b) Biological transmission
i. Propagative (agent multiplies in vector, no change in form)
ii. Cyclo-propagative (agent changes form and number)
iii. Cyclo-developmental (only development, no multiplication)

42. 4) By methods in which vectors are involved in the
transmission and propagation of parasites
a) Mechanical transmission: no multiplication or development of
agent
b) Biological transmission
i. Propagative (agent multiplies in vector, no change in form)
ii. Cyclo-propagative (agent changes form and number)
iii. Cyclo-developmental (only development, no multiplication)
House fly: Transports bacteria that causes dysentery

43. 4) By methods in which vectors are involved in the
transmission and propagation of parasites
a) Mechanical transmission: no multiplication or development of
agent
b) Biological transmission
i. Propagative (agent multiplies in vector, no change in form)
ii. Cyclo-propagative (agent changes form and number)
iii. Cyclo-developmental (only development, no multiplication)
House fly: Transports bacteria that causes dysentery
Plague bacilli in rat flea

44. 4) By methods in which vectors are involved in the
transmission and propagation of parasites
a) Mechanical transmission: no multiplication or development of
agent
b) Biological transmission
i. Propagative (agent multiplies in vector, no change in form)
ii. Cyclo-propagative (agent changes form and number)
iii. Cyclo-developmental (only development, no multiplication)
House fly: Transports bacteria that causes dysentery
Plague bacilli in rat flea
Malaria parasites in mosquito

45. 4) By methods in which vectors are involved in the
transmission and propagation of parasites
a) Mechanical transmission: no multiplication or development of
agent
b) Biological transmission
i. Propagative (agent multiplies in vector, no change in form)
ii. Cyclo-propagative (agent changes form and number)
iii. Cyclo-developmental (only development, no multiplication)
House fly: Transports bacteria that causes dysentery
Plague bacilli in rat flea
Malaria parasites in mosquito
Microfilariae in mosquito

46. • Transovarial transmission: agent transmitted vertically from the
infected female to her progeny in the vector
• Transstadial transmission: transmission of disease agent from
one stage of the life cycle to another

47. • Transovarial transmission: agent transmitted vertically from the
infected female to her progeny in the vector
• Transstadial transmission: transmission of disease agent from
one stage of the life cycle to another
Rickettsiae (Rocky Mountain spotted
fever, scrub typhus) are transmitted from
infected ticks and mites to their offspring

48. • Transovarial transmission: agent transmitted vertically from the
infected female to her progeny in the vector
• Transstadial transmission: transmission of disease agent from
one stage of the life cycle to another
Rickettsiae (Rocky Mountain spotted
fever, scrub typhus) are transmitted from
infected ticks and mites to their offspring
Borrelia burgdorferi (Lyme disease)
infects a tick vector as a larva, and the
infection is maintained when it molts to a
nymph and later develops as an adult

49. Airborne:
1. Droplet nuclei
• Tiny particles (1-10 microns range) that represent the dried
residue of droplets
• Remain airborne for long periods of time, may be
disseminated by air currents from the
• Diseases spread by droplet nuclei include tuberculosis,
influenza, chickenpox, measles, COVID-19

50. 2. Dust
• Some of the larger droplets which are expelled settle down
objects in the immediate environment and become part of
the dust
• A variety of infectious agents (e.g., streptococci, other
pathogenic bacteria, viruses and fungal spores) and skin
squamae have been found in the dust of hospital wards and
living rooms

51. • Some (e.g.. Tubercle bacilli) may survive in the dust for
considerable periods under optimum conditions of
temperature and moisture
• During sweeping, dusting and bed-making, the dust is
release into the air and becomes once again airborne
• Airborne dust is primarily inhaled but may settle on
uncovered food and milk
• This transmission is most common in nosocomial infection

52. Fomite-borne
• Fomites (singular; fomes) are inanimate articles or substances
other than water or food capable of harbouring and transferring
the infectious agent
• Includes soiled clothes, towels, linen, handkerchiefs, cups,
spoons, pencils, books, toys, drinking glasses, door handles,
taps, lavatory chains, syringes, instruments and surgical
dressings

53. Fomite-borne
• Fomites (singular; fomes) are inanimate articles or substances
other than water or food capable of harbouring and transferring
the infectious agent
• Includes soiled clothes, towels, linen, handkerchiefs, cups,
spoons, pencils, books, toys, drinking glasses, door handles,
taps, lavatory chains, syringes, instruments and surgical
dressings
Diseases transmitted by fomites include
diphtheria, typhoid fever, bacillary dysentery,
hepatitis A, eye and skin infections

54. Unclean hands and fingers
• Most common medium by which pathogenic agents are
transferred to food
• Transmission takes place both directly and indirectly
• Unclean hands and fingers imply lack of personal hygiene
• Lack of personal hygiene coupled with poor sanitation favour
person-to-person transmission of infection

55. Unclean hands and fingers
• Most common medium by which pathogenic agents are
transferred to food
• Transmission takes place both directly and indirectly
• Unclean hands and fingers imply lack of personal hygiene
• Lack of personal hygiene coupled with poor sanitation favour
person-to-person transmission of infection
Diseases transmitted include staphylococcal and
streptococcal infections, typhoid fever, dysentery,
hepatitis A and intestinal parasites

56. Unclean hands and fingers
• Most common medium by which pathogenic agents are
transferred to food
• Transmission takes place both directly and indirectly
• Unclean hands and fingers imply lack of personal hygiene
• Lack of personal hygiene coupled with poor sanitation favour
person-to-person transmission of infection
Diseases transmitted include staphylococcal and
streptococcal infections, typhoid fever, dysentery,
hepatitis A and intestinal parasites
E.g., the 1984 dysentery epidemic in India

57. Susceptible Host
• Successful parasitism
• Incubation period
• Serial interval
• Generation time
• Communicable period
• Secondary attack rate

58. Successful parasitism
1. The infectious agent must find a PORTAL OF ENTRY
2. In the host, the organisms must reach SITE OF ELECTION
3. The disease agent must find a PORTAL OF EXIT
4. After leaving the host, organism must survive in the external
environment for sufficient period till new host is found

59. In addition, a successful disease agent should not cause the
death of the host but produce only a low-grade immunity so that
the host is vulnerable again and again to the same infection
Best example: common cold virus

60. Incubation period
• Time interval between invasion by an infectious agent and
appearance of the first sign or symptom of the disease
• It depends on the generation time of the particular pathogen,
infective dose, portal of entry and individual susceptibility

61. Importance of incubation period
• Tracing the source of infection and contacts
• Period of surveillance
• Immunization
• Identification of point source
• Prognosis

62. Serial interval
• Gap in time between the onset of the primary case and
the secondary case
• By collecting information about a whole series of such
onsets, we get a distribution of secondary cases from
which we can guess the incubation period of disease

63. Generation time
• The interval of time between receipt of infection by a host and
maximal infectivity of that host
• With person-to-person transmission of infection, the interval
between cases is determined by the generation time
• It refers to transmissions of infection, whether clinical or
subclinical

64. Communicable period
• The time during which an infectious agent may be transferred
directly or indirectly from an infected person to another person,
from an infected animal to man, or from an infected person to
an animal, including arthropods
• Communicability of some diseases can be reduced by early
diagnosis and treatment

65. Secondary attack rate
• The number of exposed persons developing the disease within
the range of the incubation period, following exposure to the
primary case
• Useful to determine whether a disease of unknown aetiology is
communicable or not; and in evaluating the effectiveness of
control measures such as isolation and immunization

66. Secondary attack rate
• The number of exposed persons developing the disease within
the range of the incubation period, following exposure to the
primary case
• Useful to determine whether a disease of unknown aetiology is
communicable or not; and in evaluating the effectiveness of
control measures such as isolation and immunization
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𝑤𝑖𝑡ℎ𝑖𝑛 𝑡ℎ𝑒 𝑟𝑎𝑛𝑔𝑒 𝑜𝑓 𝑡ℎ𝑒 𝑖𝑛𝑐𝑢𝑏𝑎𝑡𝑖𝑜𝑛 𝑝𝑒𝑟𝑖𝑜𝑑
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× 100

67. Prevention
and
Control
1. Controlling the reservoir
2. Interruption of transmission
3. The susceptible host

68. Controlling the reservoir 1. Early diagnosis
2. Notification
3. Epidemiological investigations
4. Isolation
5. Treatment
6. Quarantine

69. Controlling the reservoir 1. Early diagnosis
2. Notification
3. Epidemiological investigations
4. Isolation
5. Treatment
6. Quarantine
• For treatment of patients
• For epidemiological investigations
• To study the time, place and person distribution
• For the institution of prevention and control measures.

70. Controlling the reservoir 1. Early diagnosis
2. Notification
3. Epidemiological investigations
4. Isolation
5. Treatment
6. Quarantine
• Notify to the local health authority
• International Health Regulations (IHR)
• IDSP, IHIP

71. Controlling the reservoir 1. Early diagnosis
2. Notification
3. Epidemiological investigations
4. Isolation
5. Treatment
6. Quarantine
Identification of
• Source of infection
• Factors influencing its spread in the community
• Character of agent, reservoir, vectors and vehicles
• Susceptible host populations

72. Controlling the reservoir 1. Early diagnosis
2. Notification
3. Epidemiological investigations
4. Isolation
5. Treatment
6. Quarantine
“Separation, for the period of communicability of infected
persons or animals from others in such places and under such
conditions, as to prevent or limit the direct or indirect
transmission of the infectious agent from those infected to those
who are susceptible, or who may spread the agent to others”

73. Controlling the reservoir 1. Early diagnosis
2. Notification
3. Epidemiological investigations
4. Isolation
5. Treatment
6. Quarantine
• Main aim is to kill infectious agent before it spreads
• Reduce communicability, cut short duration of illness, prevent
development of secondary cases
• Individual treatment or mass treatment

74. Controlling the reservoir 1. Early diagnosis
2. Notification
3. Epidemiological investigations
4. Isolation
5. Treatment
6. Quarantine
• The limitation of freedom of movement of such well persons
or domestic animals exposed to communicable disease for a
period of time not longer than the longest usual incubation
period of the disease, in such manner as to prevent effective
contact with those not so exposed
• Types: absolute, modified, segregation,

75. Interruption of transmission
Examples:
• Provision of safe drinking water
• Improving food sanitation
• Adequate vector control

76. Susceptible host 1. Active immunization
2. Passive immunization
3. Combination of active and
passive immunization
4. Chemoprophylaxis
5. Non-specific measures

77. Susceptible host 1. Active immunization
2. Passive immunization
3. Combination of active and
passive immunization
4. Chemoprophylaxis
5. Non-specific measures
Vaccines

78. Susceptible host 1. Active immunization
2. Passive immunization
3. Combination of active and
passive immunization
4. Chemoprophylaxis
5. Non-specific measures
Vaccines
Immunoglobulins

79. Susceptible host 1. Active immunization
2. Passive immunization
3. Combination of active and
passive immunization
4. Chemoprophylaxis
5. Non-specific measures
Vaccines
Immunoglobulins
Mass drug administration

80. Susceptible host 1. Active immunization
2. Passive immunization
3. Combination of active and
passive immunization
4. Chemoprophylaxis
5. Non-specific measures
Vaccines
Immunoglobulins
Mass drug administration
• Better housing
• Sanitation
• Nutrition
• Education

81. National programmes
National Tuberculosis
Elimination
Programme (NTEP)
National Leprosy
Eradication
Programme (NLEP)
National Vector Borne
Disease Control
Programme
(NVBDCP)
National AIDS Control
Programme (NACP)

82. Non-communicable
diseases

83. • An impairment of bodily structure and/or function that
necessitates a modification of the patient’s normal life, and has
persisted over an extended period of time
(EURO symposium, 1957)
• Non-communicable diseases (NCDs), which are characterized
by long duration and slow progression (WHO)
• Duration of at least 3 months
(Wilson et al. Annual Review of Public Health, 1984)

84. Non-communicable diseases include
Cardiovascular
(hypertension,
CAD, stroke)
Mental diseases
(mania,
depression)
Musculoskeletal
(arthritis)
Respiratory
(asthma,
emphysema,
bronchitis)
Cancers Obesity
Blindness
Degenerative
disorders
Accidents

85. Non-communicable diseases risk factors
Non-modifiable Modifiable
Age Physical inactivity
Gender Unhealthy diet
Race Tobacco use
Genetics Alcohol consumption
High BP
Raised blood glucose
Raised blood cholesterol
Overweight, obesity

86. Risk factor approach for NCD (Causal chain)

87. Risk factor approach for NCD (Causal chain)
Risk factors
Tobacco Alcohol Physical inactivity Nutrition

88. Risk factor approach for NCD (Causal chain)
Physiological changes
BMI BP Blood glucose Cholesterol
Risk factors
Tobacco Alcohol Physical inactivity Nutrition

89. Risk factor approach for NCD (Causal chain)
Disease outcomes
Heart
disease
Stroke Diabetes Cancer
Respiratory
diseases
Physiological changes
BMI BP Blood glucose Cholesterol
Risk factors
Tobacco Alcohol Physical inactivity Nutrition

90. Gaps in the natural history
• Absence of a known agent
• Multifactorial causation
• Long latent period
• Indefinite onset

91. Gaps in the natural history
• Absence of a known agent
• Multifactorial causation
• Long latent period
• Indefinite onset
Whereas in some chronic diseases
the cause is known (e.g., silica in
silicosis, asbestos in mesothelioma),
for many chronic diseases the
causative agent is not known

92. Gaps in the natural history
• Absence of a known agent
• Multifactorial causation
• Long latent period
• Indefinite onset
Whereas in some chronic diseases
the cause is known (e.g., silica in
silicosis, asbestos in mesothelioma),
for many chronic diseases the
causative agent is not known
Most chronic diseases are the result
of multiple causes - rarely is there a
simple one-to-one cause-effect
relationship

93. Gaps in the natural history
• Absence of a known agent
• Multifactorial causation
• Long latent period
• Indefinite onset
Whereas in some chronic diseases
the cause is known (e.g., silica in
silicosis, asbestos in mesothelioma),
for many chronic diseases the
causative agent is not known
Most chronic diseases are the result
of multiple causes - rarely is there a
simple one-to-one cause-effect
relationship
Further obstacle to our understanding of the
natural history of chronic disease is the long
period between the first exposure to suspected
cause and the eventual development of disease

94. Gaps in the natural history
• Absence of a known agent
• Multifactorial causation
• Long latent period
• Indefinite onset
Whereas in some chronic diseases
the cause is known (e.g., silica in
silicosis, asbestos in mesothelioma),
for many chronic diseases the
causative agent is not known
Most chronic diseases are the result
of multiple causes - rarely is there a
simple one-to-one cause-effect
relationship
Further obstacle to our understanding of the
natural history of chronic disease is the long
period between the first exposure to suspected
cause and the eventual development of disease
Most chronic diseases are slow in onset and
development, and the distinction between diseased
and non-diseased states may be difficult to establish

95. Advanced model of the triangle of epidemiology
Causative factors
Environment,
behaviour, culture,
physiological factors,
ecological elements
Time
Groups or populations
and their
characteristics

96. Web of causation
Changes in lifestyle
Abundance
of food
Lack of
Physical
exercise
Smoking
Stress
Emotional
disturbances
Ageing and
other factors
Obesity
Hypertension
Hyperlipidemia
Coronary
atherosclerosis
Coronary occlusion
Myocardial ischemia
Myocardial infarction
Increased catecholamines
thrombotic tendency
Changes in walls of arteries

97. Prevention of Non-communicable diseases
• Primordial
• Primary
• Secondary
• Tertiary

98. Prevention of Non-communicable diseases
• Primordial
• Primary
• Secondary
• Tertiary
For healthy people

99. Prevention of Non-communicable diseases
• Primordial
• Primary
• Secondary
• Tertiary
For healthy people
For unhealthy people

100. Prevention of Non-communicable diseases
• Primordial
• Primary
• Secondary
• Tertiary
Prevention of the emergence or development of risk
factors, through individual and mass education

101. Prevention of Non-communicable diseases
• Primordial
• Primary
• Secondary
• Tertiary
Prevention of the emergence or development of risk
factors, through individual and mass education
• “Action taken prior to the onset of disease, which
removes the possibility that a disease will ever occur”
• Intervention in the pre-pathogenesis phase of a disease
or health problem or other departure from health
• Population (mass) strategy, high-risk strategy

102. Prevention of Non-communicable diseases
• Primordial
• Primary
• Secondary
• Tertiary
Prevention of the emergence or development of risk
factors, through individual and mass education
• “Action taken prior to the onset of disease, which
removes the possibility that a disease will ever occur”
• Intervention in the pre-pathogenesis phase of a disease
or health problem or other departure from health
• Population (mass) strategy, high-risk strategy
• “Action which halts the progress of a disease at its
incipient stage and prevents complications”
• Largely the domain of clinical medicine
• Early diagnosis and adequate treatment

103. Prevention of Non-communicable diseases
• Primordial
• Primary
• Secondary
• Tertiary
Prevention of the emergence or development of risk
factors, through individual and mass education
• “Action taken prior to the onset of disease, which
removes the possibility that a disease will ever occur”
• Intervention in the pre-pathogenesis phase of a disease
or health problem or other departure from health
• Population (mass) strategy, high-risk strategy
• “Action which halts the progress of a disease at its
incipient stage and prevents complications”
• Largely the domain of clinical medicine
• Early diagnosis and adequate treatment
• “All measures available to reduce or limit impairments
and disabilities, minimize suffering caused by existing
departures from good health and to promote the patient’s
adjustment to irremediable conditions”
• E.g., functional rehabilitation

104. National programmes
National Programme
for Prevention and
Control of Non-
communicable
diseases (NP-NCD)
National Iodine
Deficiency Disorders
Control Programme
(NIDDCP)
National Programme
for Control of
Blindness (NPCB)
National Programme
for Prevention and
Control of Deafness
(NPPCD)

105. To summarize
Communicable versus Non-communicable diseases
Sudden onset Gradual onset
Single cause Multiple causes
Short natural history Long natural history
Short treatment schedule Prolonged treatment
Cure is achieved Care predominates
Single discipline Multidisciplinary
Short follow-up Prolonged follow-up
Back to normalcy Quality of life after treatment

106. Questions?